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Top 5 physics experiments you can do at home

October 17, 2022 By Emma Vanstone Leave a Comment

Physics is key to understanding the world around us. While some aspects may seem tricky to understand, many fundamental physics concepts can be broken down into simple concepts, some of which can be demonstrated using basic equipment at home.

This list of 5 physics experiments you can try at home is a great starting point for understanding physics and, hopefully a source of inspiration for little scientists everywhere!

Physics experiments you can do at home

1. archimedes and density.

The story behind Archimedes’ discovery of density is that he was asked by the King of Sicily to work out whether a goldsmith had replaced some gold from a crown with silver. Archimedes needed to determine if the goldsmith had cheated without damaging the crown.

The crown weighed the same as the gold the King had given the goldsmith, but gold is more dense than silver, so if there were silver in the crown its density would be less than if it were pure gold. Archimedes realised that if he could measure the crown’s volume, he could work out its density, but calculating the volume of a crown shape was a tough challenge. According to the story, Archimedes was having a bath one day when he realised the water level rose as he lowered himself into the bathtub. He realised that the volume of water displaced was equal to the volume of his body in the water.

Archimedes placed the crown in water to work out its density and realised the goldsmith had cheated the king!

Density Experiment

One fun way to demonstrate density is to make a density column. Choose a selection of liquids and place them in density order, from the most dense to the least dense. Carefully pour a small amount of each into a tall jar or glass, starting with the most dense. You should end up with a colourful stack of liquids!

2. Split light into the colours of the rainbow

Isaac Newton experimented with prisms and realised that light is made up of different colours ( the colours of the rainbow ). Newton made this discovery in the 1660s. It wasn’t until the 1900s that physicists discovered the electromagnetic spectrum , which includes light waves we can’t see, such as microwaves, x-ray waves, infrared and gamma rays.

How to split light

Splitting white light into the colours of the rainbow sounds tricky, but all you need is a prism. A prism is a transparent block shaped so light bends ( refracts ) as it passes through. Some colours bend more than others, so the whole spectrum of colours can be seen.

If you don’t have a prism, you can also use a garden hose! Stand with your back to the sun, and you’ll see a rainbow in the water! This is because drops of water act like a prism.

3. Speed of Falling Objects

Galileo’s falling objects.

Aristotle thought that heavy objects fell faster than lighter objects, a theory later disproved by Galileo .

It is said that Galileo dropped two cannonballs with different weights from the leaning tower of Pisa, which hit the ground at the same time. All objects accelerate at the same rate as they fall.

If you drop a feather and a hammer from the same height, the hammer will hit the ground first, but this is because of air resistance!

If a hammer and feather are dropped somewhere with no air resistance, they hit the ground simultaneously. Commander David Scott proved this was true on the Apollo 15 moonwalk!

Hammer and Feather Experiment on the Moon

Brian Cox also proved Galileo’s theory to be correct by doing the same experiment in a vacuum!

While you won’t be able to replicate a hammer or heavy ball and feather falling, you can investigate with two objects of the same size but different weights. This means the air resistance is the same for both objects, so the only difference is the weight.

Take two empty water bottles of the same size. Fill one to the top with water and leave the other empty. Drop them from the same height. Both will hit the ground at the same time!

4. Newton’s Laws of Motion

Sir Isaac Newton pops up a lot in any physics book as he came up with many of the laws that describe our universe and is undoubtedly one of the most famous scientists of all time. Newton’s Laws of Motion describe how things move and the relationship between a moving object and the forces acting on it.

Making and launching a mini rocket is a great way to learn about Newton’s Laws of Motion .

The rocket remains motionless unless a force acts on it ( Newton’s First Law ).

The acceleration of the rocket is affected by its mass. If you increase the mass of the rocket, its acceleration will be less than if it had less mass ( Newton’s Second Law ).

The equal and opposite reaction from the gas forcing the cork downwards propels the rocket upwards ( Newton’s Third Law ).

4. Pressure

Pressure is the force per unit area.

Imagine standing on a Lego brick. If you stand on a large brick, it will probably hurt. If you stand on a smaller brick with the same force it will hurt more as the pressure is greater!

Snowshoes are usually very wide. This is to reduce the pressure on the snow so it sinks less as people walk on it.

Pressure and Eggs

If you stand on one egg, it will most likely break. If you stand on lots of eggs with the same force, you increase the area the force is applied over and, therefore, reduce the pressure on each individual egg.

That’s five easy physics experiments you can do at home! Can you think of any more?

Last Updated on June 14, 2024 by Emma Vanstone

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Babble Dabble Do

80 of the Best Physics Projects for Clever Kids

February 21, 2020 by Ana Dziengel Leave a Comment

Physics projects are some of the most memorable science projects your kids will ever try. There, I said it even if you don’t believe it!

You see, physics is the branch of science that studies flying, launching, moving, and floating, as well as magnets, motors and electrical circuits, heat, light, and sound. Physics is fun! After you look over some of the projects in this collection I hope you’ll agree.

Now before we begin I want to address a common notion a lot of folks have about this branch of science: Physics is really hard! I completely understand this thought.

In fact the only class I ever almost failed in my entire academic career was physics. And I know why. Physics was presented to me as formulas about force, equilibrium, and momentum with not one single demonstration. Then I walked into a structural engineering class where we discussed the forces at work in designing buildings and my teacher told us he didn’t want us to open a book all quarter. Instead he told us to build models. He wanted us to experiment with how forces really interact in a structure by testing them in hands-on experiments. It was a profound experience for me and suddenly all the book learning “clicked.”

My goal with this collection of projects is to make physics more accessible and inviting to parents, teachers, and kids alike! But before we dive into the physics projects let’s get a bird’s eye view of what physics is all about!

What is the study of physics?

Physics is the branch of science that studies matter, how it moves and how it interacts. It is a HUGE topic and there is a lot of overlap with chemistry and biology. It’s really easy to hear the word physics and have your eyes glaze over, but in simple words physics is the study of how things move and interact with each other.

How do you explain physics to a child?

The best way to explain physics to kids is to skip an explanation and do a demonstration . Since physics encompasses the study of motion, light, electricity, magnetism, and aerodynamics, instead of trying to explain these concepts demonstrate them! I am a big believer in hands-on projects that give kids a chance to experience and experiment with a scientific concept rather than just hear or read about it. We all know an amazing project is memorable while a wordy explanation is forgettable. Kids are great visual learners so give them the chance to get excited about physics through projects!

What are main branches of Physics?

While I was assembling this post I realized scientists define the branches of physics in many different ways. The following is a list of the most commonly cited branches of physics compiled from both online and offline resources:

• Mechanics This includes force, motion, fluid and aerodynamics, and is the branch most people think of when they hear the word physics.
• Electromagnetism Electricity is physics!

Thermodynamics

• Sound and Waves
• Quantum Mechanics This is for the very serious! It’s the branch that studies atomic particles.

80+ Physics Projects for Kids

How to use this guide.

The physics projects for kids featured here are sorted by branches of physics and subcategories as follows (click on the topic to skip to that section) :

• Mechanics and Motion: Work & Energy, Newton’s Law’s of Motion, Radial Forces, Gravity, and Balance
• Electromagnetism & Electricity: Magnetism, Electricity

Optics & Sound

• Heat, Liquids, and Air: Thermodynamics, Hydrodynamics, & Aerodynamics

Some topics and categories were really easy to find great projects for (work and energy) some were more challenging (thermodynamics) and at least one impossible (Quantum mechanics, but that’s okay!). We tried to assemble as many as we could on this list!

Please note that many of these projects could fit in two or more categories as they demonstrate various principles and forces. I only classified them once on this list.

Mechanics and Motion

When most people think of physics they think about mechanics and motion. Mechanics refers to the motion of objects and motion is the position change of an object over time. Everything around us is constantly in motion. Even when we consider ourselves to be sitting still, the earth is rotating on its axis and moving around the sun.

Scientists have studied motion over the centuries and determined there are laws that can explain the motion of objects. These laws revolve around the idea of forces .

A force is something that pushes or pulls on an object to make it move. A force can make an object speed up (like kicking a ball) or or slow down (like friction) or hold an object in place (like gravity). Momentum is the force an object has based on its weight and motion. For a deeper look into forces go here .

In this section we’ll cover projects that focus on motion including 3 of the most famous laws of motion as outlined by Sir Isaac Newton.

Work and Energy Projects

Energy is defined as the ability to do work. Work refers to the amount of energy needed to move something over a distance using a force. The Law of Conservation of Energy states that energy is never created or destroyed it is simply changed from one state to another.

Potential Energy vs. Kinetic Energy

Two types of energy frequently disucssed in phyiscs are kinetic energy and potential energy. Kinetic energy is energy in motion. Potential energy is energy that is stored. An example of potential enrgy is a rubber band twisted up and held in place. Once the rubber band is released it unwinds quickly as kinetic energy.

Here are some projects that demonstrate work and energy:

Physics Project Idea: Rollback Can

Steam activity: stixplosions, how to build a catapult, transfer of energy science experiment, catapult stem project – diy catapult for kids, how to make a windmill model with a printable pattern, simple machines for kids: lego pulleys stem building challenge, power up your planes with a paper airplane launcher, featured work & energy videos:, newton's laws of motion.

Sir Isaac Newton was a mathematician and scientist who studied motion in the 1600's. He is credited with discovering the force of gravity as well as developing three laws of motion to describe how objects move. We'll look at each law of motion and some projects that highlight them below.

Newton's First Law of Motion is called the Law of Interia and states: An object at rest tends to stay as rest and an object in motion tends to stay in motion unless acted upon by an external force.

Newton's Second Law of Motio n states that the acceleration of an object depends on the force applied to the object and the object's mass. The relationship can be described with the following formula: F=ma

Force= Mass x Acceleration

Newton's Third Law of Motion states: For every action there is an equal and opposite reaction.

Here are some projects that focus on the laws of motion:

How To Make A Simple Newton's Cradle

Easy inertia science experiments with pennies, inertia zoom ball: super fun s.t.e.a.m. project, make a balloon pinwheel science demonstration, physics activities that explore newton's laws of motion, radial forces.

Kids love things that spin! There are several types of forces and movement that act upon objects as they spin:

Angular Momentum The momentum of an object rotating around a point.

Centripetal Force A force that pulls an object towards the center point, causing it to move in a circular path. The force is always orthogonal to the fixed center.

Centrifugal Force A force that pushes away from the center as an object is spinning. It's not a REAL force but an apparent force.

Friction is a force that slows down objects sliding against each other. It's the reason that spinning tops eventually slow down. If there was no friction on between the point on which a top spins and the surface on which it is spinning, it would spin forever!

Action Art: Spin Art Using a Bike

Diy spin art: art spinners from steam play & learn, simple paper toys: paper tops, homemade toy idea: diy skip-it, diy toys: spinning tops (+ magical disappearing colors), diy toy idea: spin-finite tops, gorgeous spin art hearts painting activity for kids, easy fidget spinner diy (free template) - science fair project idea, halloween science for kids: pumpkin spinning tops, stem toy: penny spinners, featured radial forces videos:.

Gravity is a force that attracts two bodies together. It's also the natural force that pulls everything towards the earth. The greater the mass of an object the more garvitational pull it has.

Scientists measure the acceration of gravity at the Earth's surface at 32 feet per second squared! That means the longer an object is free falling the more it's speed increases (not accounting for air resistance).

Here are some phyics projects for kids that explore the force of gravity and speed:

Recycled DIY Marble Run

Playground sized diy marble run, science & art for kids: salt pendulum.

Substitute paint for the sand to make a painting pendulum!

Drippy Gravity Painting | TinkerLab

Gravity beads experiment, the lincoln high dive, egg drop project with printable recording sheets, preschool science: weight, featured gravity videos:.

In phyiscs we use the word balance to describe a situation in which two forces are equal in magnitude and extered in opposite directions.

See saws and scales are two easy wasy to illustrate the concept of balance to kids. Here are some additonal project ideas:

How to Make a Balance Toy: Balance Hearts STEAM Activity

Diy balance toy & game, awesome earth day activity: make an earth balancer, how to make balance scales for toddlers and preschoolers, easy kid's craft: straw mobile, engineering for kids: twirling twig mobile, featured balance project videos, electromagnetism & electricity.

Did you know that electricity and magnetism are physics topics? Both of these “invisible” forces are some of kids’ favorites to explore through hands-on projects!

Magnetism describes a force that attracts or repels objects that are made of magnetic material.

A magnet is a type of material that attracts iron and produces it's own magnetic field. Magnets have a north and a south pole. If you hold two magnets close to each other and place like poles together the magnets will repel each other. If you place the opposite poles together they will quickly attract each other.

Science and Art for Kids: Magnetic Sculptures

The creepiest slime ever: how to make magnetic slime, 4 easy magnet experiments that will amaze your kids, science for kids: bouncing magnets, steam camp: how to make a magnetic field sensory bottle, how to make a compass - magnetic science experiment for kids, five minute craft: magnet painting, make an aladdin magic flying carpet, traveling magnets, easy science experiments for kids: gravity activity with paperclips, featured magnetism videos, electricity.

Electrical force is a force that causes electically charged bodies to either repel or attract. It's the force that carries electrical current through a wire. There are two types of electrical charges: positive and negative.

Similar to magentism like charges REPEL each other and opposite charges ATTRACT each other.

Here are some fun ways to explore elctriclty with kids.

How to Make Electric Play Dough with Kids

Steam project: tiny dancers (a homopolar motor), simple electronics: how to make a magic wand, how to make dance bots an electronics project for kids, how to make salty circuits: a simple circuit project for kids, how to make a lemon battery and a lime light, how to make a lightning bug paper circuit card, make an electromagnet, science for kids: diy magnetic led lights, static electricity balloon and salt and pepper experiment, steam camp: how to make a modern art steady hand game, origami firefly paper circuits, featured electricity videos.

What we see and hear is determined by physics! This includes the behavior of light waves and sounds waves, those that we can perceive and those we cannot.

Light is a type of energy made up of photons. Our eyes can perceive some of it and some forms we cannot perceive at all. Light travels in both wave form and particle form.

Photons are particles which can transmit light.

Optics is the study of light's behavior as well as tools we use to study and understand it, including how our eyes perceive it.

For a further study of light head over here .

Magic Mirrors: How To Make Reflection Art

Optical illusion toy: decotropes, how to make a teleidoscope (a type of diy kaleidoscope), how to make a microscope with water, magic happens when you pour water into a jar, steam project ideas - zoetrope and benham disk, rainbow science: creating light patterns with a cd, light box - a great tool for exploring the museum, spiral illusion, featured optics videos.

Sound is a vibration that travels in waves and can be detected by the ear. Sound can be transmitted through air, water, and solids.

Here are some projects that make use of sound and vibrations:

Simple Engineering Project: DIY Voicepipe

Explore the science of sound with a diy spinner, how to do the dancing oobleck experiment, sound sandwich, water-bottle membranophone, vibrating snake, how to make a rainstick instrument, rainbow water xylophone - mama.papa.bubba., featured sound videos, heat, liquids, and air.

Physics also covers the study of heat and fluid dynamics which includes aerodynamics (the study of movement in air and gases) and hydrodynamics (the study of movement in liquids) .

Thermodynamics is the branch of physics that studies heat and heat transfer. When two obejcts of different temperatures come in contact, energy will transfer between them until they reach the same temperature and are in a state of equilibrium. Heat always transfers from the higher temperature to a lower temperature. You can read more about heat here.

Heat Sensitive Color Changing Slime

Kids science: flying tea bag hot air balloon, magic jumping coin trick, convection detection, inverted bottles, convection currents, featured thermodynamics videos, hydrodynamics.

Hydrodynamics is the study of how fluids move and behave and the forces they exert. And let's be honest, kids love playing with water so use it an an entree to science!

Magic Potions Density Tower

Make a freestanding diy water wall, science for kids: scupley ships, stem project- build a hydraulic elevator, buoyancy for kids: will it sink or float, science experiments for kids: siphon water coaster, anti-gravity water - sick science, simple machines science lesson: lift water with an archimedes' screw, simple rain gauge, density science for kids : create fireworks in water & oil, featured hydrodynamics videos, aerodynamics.

After playing with water I'd say thay making things fly ranks very high on kids' must try list! Aerodynamics focuses on air movement and the forces at work as objects move through the air. It's the physics branch that let's kids explore building planes, helicopters, and rockets!

How To Make A Paper Helicopter

Diy toy: zappy zoomers, awesome science experiments with hot wheels cars, whirly twirly flying birds, stem for kids: straw rockets (with free rocket template), make an indoor paper boomerang with the kids, straws circle paper planes - s.t.e.m. for kids, how to make awesome paper airplanes 4 designs, more physics for kids resources.

The following websites are terrific resources for more information on the wonderful world of physics! These all offer in depth explanations about the phenomena we touched on above and some of them also offer additional physics projects to try.

• NASA and Newton’s Laws
• Exploratorium
• Physics 4 Kids
• Science 4 Fun

More Science on Babble Dabble Do

There’s lots more science on Babble Dabble Do! Here are some additional projects collections for you to check out:

50+ Chemistry Projects for Kids

30+ science fair projects that will wow the crowd, leave a reply cancel reply.

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Science News

Quantum experiments with entangled photons win the 2022 nobel prize in physics.

Physicists Alain Aspect, John Clauser and Anton Zeilinger laid the groundwork for quantum technology

Experiments on a bizarre feature of quantum physics known as entanglement (illustrated here as two objects entangled into one) have netted the 2022 Nobel Prize in physics. When two particles are entangled, what happens to one determines what happens to the other — even if the particles are far apart.

Nicolle R. Fuller/NSF

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By James R. Riordon

October 4, 2022 at 10:47 am

Tests of quantum weirdness and its potential real-world applications have been recognized with the 2022 Nobel Prize in physics. 

At some level we are all subject to quantum rules that even Albert Einstein struggled to come to terms with. For the most part, these rules play out behind the scenes in transistors that make up computer chips, lasers and even in the chemistry of atoms and molecules in materials all around us. Applications that stem from this year’s Nobel Prize take advantage of quantum features at larger scales. They include absolutely secure communications and quantum computers that may eventually solve problems that no conceivable conventional computer could complete in the lifetime of the universe.

This year’s prize is shared among three physicists. Alain Aspect and John Clauser confirmed that the rules of quantum mechanics, as weird and difficult to believe as they are, really do rule the world, while Anton Zeilinger has taken advantage of strange quantum behavior to develop rudimentary applications that no conventional technology can match. Each laureate will take home a third of the prize money, which totals 10 million Swedish kronor, worth roughly $915,000 as of October 4.

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“Today, we honor three physicists whose pioneering experiments showed us that the strange world of entanglement … is not just the micro-world of atoms, and certainly not the virtual world of science fiction or mysticism, but it’s the real world that we all live in,” said Thors Hans Hansson, a member of the Nobel Committee for Physics, at a press conference announcing the award on October 4 at the Royal Swedish Academy of Sciences ( SN: 11/5/10 ). 

“It was certainly very exciting to learn about the three laureates,” says physicist Jerry Chow of IBM Quantum in Yorktown Heights, N.Y. “Aspect, Zeilinger and Clauser — they’re all very, very well known in our quantum community, and their work is something that’s really been a big part of many people’s research efforts over many years.”

Aspect, of the Université Paris-Saclay and École Polytechnique in France, and Clauser, who now runs a company in California, showed that there are no secret back channels of communication that explain how two particles can exist as a single entity, even though they are far apart ( SN: 12/29/14 ). 

The experiments of Zeilinger, of the University of Vienna, that rely on that quantum behavior include demonstrations of communications, absolutely secure encryption and components crucial for quantum computers. He pioneered another, widely misunderstood, application — quantum teleportation. Unlike the teleportation of people and objects in science fiction, the effect involves the perfect transmission of information about a quantum object from one place to another. 

“I was always interested in quantum mechanics from the very first moments when I read about it,” Zeilinger said via phone at the news conference announcing the award. “I was actually struck by some of the theoretical predictions, because they did not fit the usual intuitions which one might have.”

The discovery of quantum behavior that rules the world at small scales, like the motion of an electron around an atom, revolutionized physics at the beginning of the 20th century. Many leading scientists, most famously including Einstein, acknowledged that quantum theories worked, but argued that they couldn’t be the true description of the world because they involved, at best, calculating the probabilities that something would happen ( SN: 1/12/22 ). To Einstein, this meant that there was some hidden information that experiments were too crude to uncover.

Others believed that quantum behavior, derogatively called weirdness, though difficult to understand, had no secret ways of transmitting information. It was largely a matter of opinion and debate until physicist John Bell proposed a test in the 1960s to prove that there were no hidden channels of communication among quantum objects ( SN: 12/29/14 ). At the time it wasn’t clear that an experiment to perform the test was possible.

Clauser was the first to develop a practical experiment to confirm Bell’s test, although there remained loopholes his experiment couldn’t check that left room for doubt. (His interest in science developed early. In 1959 and 1960, Clauser competed in the National Science Fair , now known as the International Science and Engineering Fair ( SN: 5/23/59 ). The fair is run by the Society for Science, which publishes Science News .) 

Aspect took the idea further to eliminate any chance that quantum mechanics had some hidden underpinnings of classical physics ( SN: 1/11/86 ). The experiments of Clauser and Aspect involved creating pairs of photons that were entangled, meaning that they were essentially a single object. As the photons moved in different directions, they remained entangled. That is, they continue to exist as a single, extended object. Measuring the characteristics of one instantly reveals characteristics of the other, no matter how far apart they may be. 

Entanglement is a delicate state of affairs and is difficult to maintain, but the results of the experiments of Clauser and Aspect show that quantum effects cannot be explained with any hidden variables that would be signs of non-quantum underpinnings.

To Chow, the significance of this research is twofold. “There’s really an element of showing, from a philosophical point, that quantum mechanics is real,” he says. “But then, from the more practical standpoint … this same beautiful theory of quantum mechanics gives a different set of rules by which information is processed.” That, in turn, opens up new avenues for next-generation technologies like quantum computers and communications ( SN: 12/3/20 ). 

Zeilinger’s experiments take advantage of entanglement to achieve feats that would not be possible without the effects that Clauser and Aspect confirmed. He has extended the experiments from the lab to intercontinental distances , opening up the possibility that entanglement can be put to practical use ( SN: 5/31/12 ). Because interacting with one of a pair of entangled particles affects the other, they can become key components in secure communications and encryption. An outsider trying to listen in on a quantum communique would be revealed because they would break the entanglement as they snooped.

Quantum computers that rely on entangled particles have also become a topic of active research. Instead of the ones and zeros of conventional computers, quantum computers encode information and perform calculations that are blends of both one and zero. In theory, they can perform some calculations that no digital computer could ever match. Zeilinger’s quantum teleportation experiments offer a route to transfer the information that such quantum computers rely on ( SN: 1/17/98 ). 

“This [award] is a very nice and positive surprise to me,” says Nicolas Gisin, a physicist at the University of Geneva in Switzerland. “This prize is very well-deserved, but comes a bit late. Most of that work was done in the [1970s and 1980s], but the Nobel Committee was very slow, and now is rushing after the boom of quantum technologies.” 

That boom is happening on a global scale, Gisin says. “In the U.S. and in Europe and in China, billions — literally billions of dollars are poured into this field. So, it’s changing completely,” he says. “Instead of having a few individuals pioneering the field, now we have really huge crowds of physicists and engineers that work together.”

Although some of the most esoteric quantum applications are in their infancy, the experiments of Clauser, Aspect and Zeilinger bring quantum mechanics, and its strange implications, to the macroscopic world. Their contributions validate some of the key, once controversial ideas of quantum mechanics and promise novel applications that may someday be commonplace in daily life, in ways that even Einstein couldn’t deny.

Maria Temming contributed reporting to this story.

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October 6, 2022

11 min read

The Universe Is Not Locally Real, and the Physics Nobel Prize Winners Proved It

Elegant experiments with entangled light have laid bare a profound mystery at the heart of reality

By Daniel Garisto

Athul Satheesh/500px/Getty Images

One of the more unsettling discoveries in the past half a century is that the universe is not locally real. In this context, “real” means that objects have definite properties independent of observation—an apple can be red even when no one is looking. “Local” means that objects can be influenced only by their surroundings and that any influence cannot travel faster than light. Investigations at the frontiers of quantum physics have found that these things cannot both be true. Instead the evidence shows that objects are not influenced solely by their surroundings, and they may also lack definite properties prior to measurement.

This is, of course, deeply contrary to our everyday experiences. As Albert Einstein once bemoaned to a friend, “Do you really believe the moon is not there when you are not looking at it?” To adapt a phrase from author Douglas Adams, the demise of local realism has made a lot of people very angry and has been widely regarded as a bad move.

Blame for this achievement has been laid squarely on the shoulders of three physicists: John Clauser, Alain Aspect and Anton Zeilinger. They equally split the 2022 Nobel Prize in Physics “for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science.” (“Bell inequalities” refers to the trailblazing work of physicist John Stewart Bell of Northern Ireland, who laid the foundations for the 2022 Physics Nobel in the early 1960s.) Colleagues agreed that the trio had it coming, deserving this reckoning for overthrowing reality as we know it. “It was long overdue,” says Sandu Popescu, a quantum physicist at the University of Bristol in England. “Without any doubt, the prize is well deserved.”

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“The experiments beginning with the earliest one of Clauser and continuing along show that this stuff isn’t just philosophical, it’s real—and like other real things, potentially useful,” says Charles Bennett, an eminent quantum researcher at IBM. “Each year I thought, ‘Oh, maybe this is the year,’” says David Kaiser, a physicist and historian at the Massachusetts Institute of Technology. “[In 2022] it really was. It was very emotional—and very thrilling.”

The journey from fringe to favor was a long one. From about 1940 until as late as 1990, studies of so-called quantum foundations were often treated as philosophy at best and crackpottery at worst. Many scientific journals refused to publish papers on the topic, and academic positions indulging such investigations were nearly impossible to come by. In 1985 Popescu’s adviser warned him against a Ph.D. in the subject. “He said, ‘Look, if you do that, you will have fun for five years, and then you will be jobless,’” Popescu says.

Today quantum information science is among the most vibrant subfields in all of physics. It links Einstein’s general theory of relativity with quantum mechanics via the still mysterious behavior of black holes. It dictates the design and function of quantum sensors, which are increasingly being used to study everything from earthquakes to dark matter. And it clarifies the often confusing nature of quantum entanglement, a phenomenon that is pivotal to modern ma­­ter­i­als science and that lies at the heart of quantum computing. “What even makes a quantum computer ‘quantum?’” Nicole Yunger Halpern, a physicist at the National Institute of Standards and Technology, asks rhetorically. “One of the most popular answers is en­­tanglement, and the main reason why we understand entanglement is the grand work participated in by Bell and these Nobel Prize winners. Without that understanding of entanglement, we probably wouldn’t be able to realize quantum computers.”

Work by John Stewart Bell in the 1960s sparked a quiet revolution in quantum physics.

Peter Menzel/Science Source

FOR WHOM THE BELL TOLLS

The trouble with quantum mechanics was never that it made the wrong predictions—in fact, the theory described the microscopic world splendidly right from the start when physicists devised it in the opening decades of the 20th century. What Einstein, Boris Podolsky and Nathan Rosen took issue with, as they explained in their iconic 1935 paper, was the theory’s uncomfortable implications for reality. Their analysis, known by their initials EPR, centered on a thought ex­­periment meant to illustrate the absurdity of quantum mechanics. The goal was to show how under certain conditions the theory can break—or at least de­­­liver nonsensical results that conflict with our deepest assumptions about reality.

A simplified and modernized version of EPR goes something like this: Pairs of particles are sent off in different directions from a common source, targeted for two observers, Alice and Bob, each stationed at opposite ends of the solar system. Quantum mechanics dictates that it is impossible to know the spin, a quantum property of individual particles, prior to measurement. Once Alice measures one of her particles, she finds its spin to be either “up” or “down.” Her results are random, and yet when she measures up, she instantly knows that Bob’s corresponding particle—which had a random, indefinite spin—must now be down. At first glance, this is not so odd. Maybe the particles are like a pair of socks—if Alice gets the right sock, Bob must have the left.

But under quantum mechanics, particles are not like socks, and only when measured do they settle on a spin of up or down. This is EPR’s key conundrum: If Alice’s particles lack a spin until measurement, then how (as they whiz past Neptune) do they know what Bob’s particles will do as they fly out of the solar system in the other direction? Each time Alice measures, she quizzes her particle on what Bob will get if he flips a coin: up or down? The odds of correctly predicting this even 200 times in a row are one in 10 60 —a number greater than all the atoms in the solar system. Yet despite the billions of kilometers that separate the particle pairs, quantum mechanics says Alice’s particles can keep correctly predicting, as though they were telepathically connected to Bob’s particles.

Designed to reveal the incompleteness of quantum mechanics, EPR eventually led to experimental results that instead reinforce the theory’s most mind-boggling tenets. Under quantum mechanics, nature is not locally real: particles may lack properties such as spin up or spin down prior to measurement, and they seem to talk to one another no matter the distance. (Be­­cause the outcomes of measurements are random, these correlations cannot be used for faster-than-light communication.)

Physicists skeptical of quantum mechanics proposed that this puzzle could be explained by hidden variables, factors that existed in some imperceptible level of reality, under the subatomic realm, that contained information about a particle’s future state. They hoped that in hidden variable theories, nature could recover the local realism denied it by quantum mechanics. “One would have thought that the arguments of Einstein, Podolsky and Rosen would produce a revolution at that moment, and everybody would have started working on hidden variables,” Popescu says.

Einstein’s “attack” on quantum mechanics, however, did not catch on among physicists, who by and large accepted quantum mechanics as is. This was less a thoughtful embrace of nonlocal reality than a desire not to think too hard—a head-in-the-sand sentiment later summarized by American physicist N. David Mermin as a demand to “shut up and calculate.” The lack of interest was driven in part because John von Neumann, a highly regarded scientist, had in 1932 published a mathematical proof ruling out hidden variable theories. Von Neumann’s proof, it must be said, was refuted just three years later by a young female mathematician, Grete Hermann, but at the time no one seemed to notice.

The problem of nonlocal realism would languish for another three decades before being shattered by Bell. From the start of his career, Bell was bothered by quantum orthodoxy and sympathetic toward hidden variable theories. Inspiration struck him in 1952, when he learned that American physicist David Bohm had formulated a viable nonlocal hidden variable interpretation of quantum mechanics—something von Neumann had claimed was impossible.

Bell mulled the ideas for years, as a side project to his job working as a particle physicist at CERN near Geneva. In 1964 he rediscovered the same flaws in von Neumann’s argument that Hermann had. And then, in a triumph of rigorous thinking, Bell concocted a theorem that dragged the question of local hidden variables from its metaphysical quagmire onto the concrete ground of experiment.

Typically local hidden variable theories and quantum mechanics predict indistinguishable experimental outcomes. What Bell realized is that under precise circumstances, an empirical discrepancy between the two can emerge. In the eponymous Bell test (an evolution of the EPR thought experiment), Alice and Bob receive the same paired particles, but now they each have two different detector settings—A and a, B and b. These detector settings are an additional trick to throw off Alice and Bob’s apparent telepathy. In local hidden variable theories, one particle cannot know which question the other is asked. Their correlation is secretly set ahead of time and is not sensitive to up­­dated detector settings. But according to quantum mechanics, when Alice and Bob use the same settings (both uppercase or both lowercase), each particle is aware of the question the other is posed, and the two will correlate perfectly—in sync in a way no local theory can account for. They are, in a word, entangled.

Measuring the correlation multiple times for many particle pairs, therefore, could prove which theory was correct. If the correlation remained below a limit derived from Bell’s theorem, this would suggest hidden variables were real; if it exceeded Bell’s limit, then the mind-boggling tenets of quantum mechanics would reign supreme. And yet, in spite of its potential to help determine the nature of reality, Bell’s theorem languished unnoticed in a relatively obscure journal for years.

THE BELL TOLLS FOR THEE

In 1967 a graduate student at Columbia University named John Clauser accidentally stumbled across a library copy of Bell’s paper and became enthralled by the possibility of proving hidden variable theories correct. When Clauser wrote to Bell two years later, asking if anyone had performed the test, it was among the first feedback Bell had received.

Three years after that, with Bell’s encouragement, Clauser and his graduate student Stuart Freedman performed the first Bell test. Clauser had secured permission from his supervisors but little in the way of funds, so he became, as he said in a later interview, adept at “dumpster diving” to obtain equipment—some of which he and Freedman then duct-taped together. In Clauser’s setup—a kayak-size apparatus requiring careful tuning by hand—pairs of photons were sent in opposite directions toward detectors that could measure their state, or polarization.

Unfortunately for Clauser and his infatuation with hidden variables, once he and Freedman completed their analysis, they had to conclude that they had found strong evidence against them. Still, the result was hardly conclusive because of various “loopholes” in the experiment that conceivably could allow the influence of hidden variables to slip through undetected. The most concerning of these was the locality loophole: if either the photon source or the detectors could have somehow shared information (which was plausible within an object the size of a kayak), the resulting measured correlations could still emerge from hidden variables. As M.I.T.’s Kaiser explained, if Alice tweets at Bob to tell him her detector setting, that interference makes ruling out hidden variables impossible.

Closing the locality loophole is easier said than done. The detector setting must be quickly changed while photons are on the fly—“quickly” meaning in a matter of mere nanoseconds. In 1976 a young French ex­­pert in optics, Alain Aspect, proposed a way to carry out this ultraspeedy switch. His group’s experimental re­­sults, published in 1982, only bolstered Clauser’s re­­sults: local hidden variables looked extremely un­­likely. “Perhaps Nature is not so queer as quantum mechanics,” Bell wrote in response to Aspect’s test. “But the experimental situation is not very encouraging from this point of view.”

Other loopholes remained, however, and Bell died in 1990 without witnessing their closure. Even As­­pect’s experiment had not fully ruled out local ef­­fects, because it took place over too small a distance. Similarly, as Clauser and others had realized, if Alice and Bob detected an unrepresentative sample of particles—like a survey that contacted only right-handed people—their experiments could reach the wrong conclusions.

No one pounced to close these loopholes with more gusto than Anton Zeilinger, an ambitious, gregarious Austrian physicist. In 1997 he and his team improved on Aspect’s earlier work by conducting a Bell test over a then unprecedented distance of nearly half a kilometer. The era of divining reality’s nonlocality from kayak-size experiments had drawn to a close. Finally, in 2013, Zeilinger’s group took the next logical step, tackling multiple loopholes at the same time.

“Before quantum mechanics, I actually was interested in engineering. I like building things with my hands,” says Marissa Giustina, a quantum researcher at Google who worked with Zeilinger. “In retrospect, a loophole-free Bell experiment is a giant systems-engineering project.” One requirement for creating an experiment closing multiple loopholes was finding a perfectly straight, unoccupied 60-meter tunnel with access to fiber-optic cables. As it turned out, the dungeon of Vienna’s Hofburg palace was an almost ideal setting—aside from being caked with a century’s worth of dust. Their results, published in 2015, coincided with similar tests from two other groups that also found quantum mechanics as flawless as ever.

BELL’S TEST REACHES THE STARS

One great final loophole remained to be closed—or at least narrowed. Any prior physical connection between components, no matter how distant in the past, has the potential to interfere with the validity of a Bell test’s results. If Alice shakes Bob’s hand prior to departing on a spaceship, they share a past. It is seemingly im­­­plausible that a local hidden variable theory would exploit these kinds of loopholes, but it was still possible.

Today quantum information science is among the most vibrant subfields in all of physics.

In 2016 a team that included Kaiser and Zeilinger performed a cosmic Bell test. Using telescopes in the Canary Islands, the researchers sourced random decisions for detector settings from stars sufficiently far apart in the sky that light from one would not reach the other for hundreds of years, ensuring a centuries-spanning gap in their shared cosmic past. Yet even then, quantum mechanics again proved triumphant.

One of the principal difficulties in explaining the importance of Bell tests to the public—as well as to skeptical physicists—is the perception that the veracity of quantum mechanics was a foregone conclusion. After all, researchers have measured many key aspects of quantum mechanics to a precision of greater than 10 parts in a billion. “I actually didn’t want to work on it,” Giustina says. “I thought, like, ‘Come on, this is old physics. We all know what’s going to happen.’” But the accuracy of quantum mechanics could not rule out the possibility of local hidden variables; only Bell tests could do that.

“What drew each of these Nobel recipients to the topic, and what drew John Bell himself to the topic, was indeed [the question], ‘Can the world work that way?’” Kaiser says. “And how do we really know with confidence?” What Bell tests allow physicists to do is remove the bias of anthropocentric aesthetic judgments from the equation. They purge from their work the parts of human cognition that recoil at the possibility of eerily inexplicable entanglement or that scoff at hidden variable theories as just more debates over how many angels may dance on the head of a pin.

The 2022 award honors Clauser, Aspect and Zeilinger, but it is testament to all the researchers who were unsatisfied with superficial explanations about quantum mechanics and who asked their questions even when doing so was unpopular. “Bell tests,” Giustina concludes, “are a very useful way of looking at reality.”

Daniel Garisto is a freelance science journalist covering advances in physics and other natural sciences. He is based in New York.

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60 Physics Science Experiments For Middle School: Crafts, Investigations, Model Building, And DIYs

January 11, 2024 //  by  Carly Gerson

Physics is a subject that can be difficult for students to understand, so hands-on experiences like experiments are excellent to give your students a better understanding of tricky concepts and theories! Not only do experiments and activities help your kiddos’ understanding but they also create an interactive way to engage them in the learning. Read on to discover 60 phenomenal physics science experiments to try out with your middle school students!

1. Newton’s Cradle

Newton’s Cradle is a classic physics experiment that uses basic materials to demonstrate kinetic energy and potential energy . Your students will love creating their very own version using some string and straws! This is a great way to demonstrate the basic concept of energy transfer in an engaging way.

Learn More: 123 Homeschool 4 Me

2. Simple Bernoulli Experiment

The Bernoulli experiment is an excellent way to teach your kids about air pressure. Show your learners how to use construction paper, tape, a bendy straw, a ping pong ball, scissors, and a pencil to create a fun experiment that they can have a go at! This is a simple way to demonstrate to them how large vehicles like planes can stay high in the air. This abstract concept will be brought to life quickly!

3. Car Science Experiment for Air Resistance and Mass

A physics concept that is sure to be fun to teach your kiddies is the impact of mass on motion! They’ll feel like modern physicists as they place cars with different masses on their race track and time them on their journey! While this may seem like a pretty simple experiment, you can challenge your kids to complete lots of different trials to find out how a range of different factors affects the speed of their cars.

Learn More: Frugal Fun 4 Boys

4. Archimedes’ Screw Simple Machine

Can water flow up? Your kids will be able to answer this question after completing this fun experiment! The Archimedes’ Screw is a commonly known invention that moves water upward and transfers it from one place to another. Help your learners construct their own using a piece of plastic pipe and some clear plastic tubing, then let them experiment and see if they can make it work!

5. Layering Liquids Density Experiment

Children will love participating in this colorful activity. Have your students use different colored liquids to test out the density of each one by creating a density tower! Everyone will watch in amazement as the different colored liquids separate and float to different places in the jar!

Learn More: Green Kid Crafts

6. Launching Easter Eggs Experiment

This activity would make for an incredibly fun science fair project or a great science activity during the Easter season. Using a mini catapult and plastic eggs, your kiddies will have great fun testing how mass impacts the distance traveled by the egg. This experiment will definitely make you smile!

Learn More: STL Motherhood

7. Balloon in a Bottle Properties of Air Experiment

Challenge your learners to put a balloon inside a plastic bottle and blow it up; sounds easy enough, right? They’ll find this one to be a little trickier than they initially thought! As they work to try to blow up their balloons discuss the properties of air which makes this seemingly simple task almost impossible!

Learn More: Steve Spangler Science

8. How to Make a Pendulum Wave

This physics science project is both fun to make and incredible to look at! Using washers and a few other simple materials like string, your students will be captivated by their experiment for hours on end. Besides being completely mesmerized, they’ll also learn about waves and motion.

Learn More: YouTube

9. Creating Catapults

A homemade catapult is a great way to use cheap materials in a STEM project. Have your kiddos use simple household and craft materials to determine which combination makes for the best catapult. You can launch anything from scrunched-up paper to marshmallows! Encourage your middle schoolers to consider how they can scientifically measure which catapult is best!

Learn More: Science Gal

10. Inertia Tower Activity

Raise the stakes with this amazingly fun inertia activity. This creative activity uses sheets of paper or index cards to separate a tower of cups or blocks, which your students then need to pull out quickly without disturbing the tower. Can they remove all the pieces of paper?

Learn More: Perkin’s E-Learning

11. Rice Friction Experiment

Friction can be a challenging concept to teach middle school students. Thankfully this experiment makes it a little bit easier! Give your kids a better understanding of this tricky concept by using a plastic bottle, funnel, chopstick, and rice. They’ll learn how to increase and decrease friction and will be amazed when this amazing force lets them lift a bottle up with just a single chopstick!

Learn More: Carrots Are Orange

12. Balancing Robot

Combine arts and crafts and physics with this adorable activity! Use the printable template and have your kids customize their robots, decorating them however they like before cutting them out. Next, you’ll use some putty to stick a penny to the end of each of the robot’s arms. All that’s left is to let them find out where they can get their robots balancing! 

Learn More: Buggy and Buddy

13. Make Your Own Ice Cream in a Bag

You had us at ice cream! Your kiddies will be so excited to have a go at making their own ice cream using just a few Ziplock bags. Have them start by measuring cream, sugar, and vanilla flavoring into one bag, making sure it’s sealed up. Then, get them to place this bag inside another bag that also has ice and salt inside and shake! Once they’re done learning, make sure you set aside time for some taste testing!

Learn More: Delish

14. Skittles Density Rainbow

Build the rainbow with this fun density experiment. Start by having your kiddies dissolve Skittles in water, using a different quantity of each color of Skittles in each liquid. They’ll then gently use a pipette to layer their liquids while you discuss how the solids have impacted the density of each liquid!

Learn More: Gift Of Curiosity

15. Dancing Raisins Science Experiment

Did you know that you can make raisins dance? Ok, well maybe they’re not actually dancing, but they’re definitely doing something! Your learners will love this fun science experiment where they’ll watch as they watch the carbonation and bubbles of the soda water lift the raisins and “make them dance”.

16. Learning With Dry Ice

Dry ice is so exciting for your little learners! It has almost magical properties that give it a mysterious element that kids are completely captivated by. Using dry ice is a great way to teach students about how clouds are formed and how they eventually evaporate by capturing a dry ice cloud in a bag! You’ll be inspiring future meteorologists with this visually appealing experiment!

Learn More: Penguin Dry Ice

17. Learning About Arches

Arches are surprisingly impressive feats of architecture. Their unique shape actually makes them surprisingly strong! Teach your kiddos about how heavy-weight objects such as cars on a bridge are supported as they test out different types of arches to see which one holds the most weight!

Learn More: Imagine Childhood

18. Heat Changing Colored Slime

This unique experiment requires very specific materials, but we promise it’s worth it! Blow your kids’ minds as they learn about thermodynamics and how heat can change the color of certain materials as they make some heat-sensitive color-changing slime! 

Learn More: Left Brain Craft Brain

19. Homemade Marble Run

Let your kiddies get creative with any materials they can get their hands on with this next activity! Challenge them to create a track for marbles, testing out different course layouts to see how these impact the time it takes the marble to complete it. Encourage them to record their results and share their findings!

Learn More: Buggy And Buddy

20. Ice Hockey Puck Friction Experiment

The ice hockey fans in your class will love this next one! In this activity, your kids will use different flat circular items like bottle caps and coins to determine which materials make the best ice hockey puck! This is a great experiment to take outside on an icy winter day to let them learn about and see friction in action!

Learn More: Science Sparks

21. Transfer of Momentum Basketball Activity

Here’s a quick physics experiment your kiddos can do during recess or on a sunny day! Grab some basketballs and racquetballs and instruct your kids to hold the smaller ball on top of the basketball. Next, have them let go and watch in amazement as the basketball bounces up into the racquetball, transferring momentum as it makes contact! 

Learn more: Frugal Fun 4 Boys

22. Pumpkin Boats

Wondering what to do with all those leftover pumpkins after Halloween? Look no further! Get your learners to make them into boats as they investigate the link between density and buoyancy. Support them to make differently-sized pumpkin boats and then make predictions about whether or not their pumpkin boat will sink or float.

Learn More: The Preschool Toolbox

23. How to Make a Hovercraft

Hovercrafts were once something that only appeared in sci-fi stories, but now your kids will be making them in your classroom! Using simple household materials, they’ll learn how to harness the power of air resistance in this unique craft. Neat!

24. St. Patrick’s Day Balloon Rockets

This holiday-themed activity is a great way to teach students about air resistance and acceleration! Your kids will craft their balloon rockets with a balloon, some tape, and a straw to keep it attached to the line. All that’s left is to let go to watch their balloon rockets blast off down the track! Why not make it competitive with a prize for the winning balloon of each race?

Learn More: Housing A Forest

25. Marshmallow Shooter

Your learners will love this silly activity that incorporates a favorite sweet treat and a unique contraption! As they launch their marshmallows through the air, you can discuss how the force of the pull impacts the motion of the marshmallows.

Learn More: Teky Teach

26. Use The Force

Star Wars fans will have fun with this one as they use “the force” to magically pick up paper clips! This exciting activity will have your kiddos wanting to learn more about magnetism and how it works! Simply have them place a large magnet on the back of their hand, reach toward a pile of paper clips, and watch as the paper clips magically fly into their hands!

Learn More: Rookie Parenting

27. Magic Toothpick Star Experiment

You’ll have a tough time convincing your kids that this experiment shows physics at work and not magic! Have your kids take five toothpicks and snap them in half. Let them arrange them as shown, and then drip water in the middle of the sticks. They’ll be amazed as the water moves the sticks, seemingly mending them and creating a star!

Learn More: Living Life And Learning

28. Water Powered Bottle Rocket

Bottle rockets are a fun science experiment to bring the science classroom outdoors . Your students will love learning about pressure and how it impacts the velocity of an item using just a recycled plastic bottle, a cork, some water, and a pump with a needle adaptor. To add even more excitement to this activity, let your kiddos decorate their own rockets!

29. Magnetic Levitation Activity

With all these seemingly magical experiments, your kids are really going to wonder if you attended Hogwarts instead of a teacher-training college! Use the power of magnets to make a pencil float! Show your kids how to position their magnets so that they repel each other enough to suspend a pencil in mid-air! 

Learn More: Arvin D. Gupta Toys

30. Rubber Band Powered Car

This adorable craft will teach your kiddos about force and motion! Let them spend some time going through a trial and error process to make a working car that’s powered by applying force to a  rubber band! Once they’ve got their models working, let them race to see whose creation goes the fastest and the farthest!

Learn More: Stem Inventions

31. Making a Water Wheel

Waterwheels have been around since Roman times, over 2000 years ago! Historically they were used in mills to grind grains into flour but nowadays they can be used as a source of renewable energy. Task your pupils with making a working waterwheel out of some simple household items like plastic cups, straws, and tape- are they up to the challenge? 

Learn More: Deceptively Educational

32. DIY Pulley Physics

This pulley system will show your students that simple machines aren’t always so simple! Using whatever materials they can find and some string, they’ll need to create a fully functional, intricate pulley system along your classroom walls! This would make a great display for the entire school year!

Learn More: The Homeschool Scientist

33. How to Make an Orange Sink or Swim

What is more likely to float, a peeled or unpeeled orange? Let your kids vote on this seemingly straightforward question then reveal the answer with a simple demonstration. Your students will watch in awe as they learn that they can change the density and buoyancy of an object by slightly altering it. In the case of the orange, however, the results might not be what they were expecting!

Learn More: Woo Jr.

34. Paper Airplane Test

There’s nothing kids love more than making and throwing paper airplanes. If they’re usually banned in your classroom, then you might want to consider lifting that ban for one day! Turn this simple activity into an engineering investigation where your students will test out different designs to see which shape of the paper airplane will fly the furthest and which shape will stay in the air the longest! Physics made fun!

Learn More: Feels Like Home

35. Rising Water Experiment

Water experiments in the classroom can be so much fun! This activity will teach your students how temperature and oxygen levels can affect the density of the air! All you’ll need are some matches, a cork, a plate of water, and a glass! They’ll love watching what seems like magic!

Learn More: Teach Beside Me

36. Physics Mystery Bag Challenge

This unique physics activity will have your kiddos work in groups to solve a physics mystery. Each group will receive identical bags of mystery items and will be told what type of machine they need to create. The challenge is that there are no instructions! Using only the items in front of them and their ingenuity, your students will compete to see which group creates the best of the designated machine!

Learn More: Teaching Highschool Math

37. Solar Oven S’mores

Fun science experiments are even better when combined with food! This solar oven teaches your students about how transmission, absorption, and reflection are used in a solar cooker to cook food. Your middle schoolers will be amazed at how easy it is to make yummy smores using an array of simple supplies, such as plastic boxes, aluminum foil, cotton, and glass.

Learn More: PBS

38. Laser Jello

Here’s another edible science project for your class! In this fun project, your kiddos will put the concepts of reflection and refraction into practice in a hands-on experiment. Give them some red and blue Jello to investigate how differently colored lasers project through it; they’ll be amazed as the Jello changes the lasers’ color and sometimes blocks out the light altogether! 

Learn More: Exploratorium

39. The Electric Butterfly

Elevate the basic static-electricity balloon experiment by adding a paper butterfly! Teach your learners about positive and negative electrons by charging up the balloon with static electricity and using it to move the paper butterfly’s wings. This hands-on activity is a super way for them to see what can be a very abstract concept in action!

Learn More: CACC Kids

40. Homemade Thermometer

This classic science experiment is great for showing how heat affects certain liquids by making them expand. Using the simple supplies of a bottle, cold water, rubbing alcohol, food coloring, a straw, and some modeling clay, have your students build their very own thermometer. As they heat or cool the surroundings, your kiddos will observe the liquid rising and falling in the straw!

41. DIY Electromagnet

Creating an electromagnet is a cool way of combining middle-grade physics and engineering! This fun activity uses screws, some wire, and batteries to demonstrate how an electric current flows through metal to create a magnetic field. After this simple experiment, you can challenge your kids to take this activity to the next level and create bigger versions like their own electromagnetic cranes!

Learn More: Teach Engineering

42. Optical Illusion Fun

Experiments don’t get much cooler than optical illusions! You can use these amazing visual activities to teach your middle graders about how our eyes process light and send signals to our brains. Simply print out the template and let your kids add some color before they cut them out and attach them to a pencil. As they spin, they won’t believe their eyes! What a fun way to make this lesson about our eyes memorable!

43. Water Cycle in a Bag

This cute little experiment is a great way to give your kids their very own visual of the water cycle! Print off the template and let your kids trace it onto their own Ziploc bag. All that’s left is to add water and tape it to a window where it’ll catch the sun! These little experiments are really quick to make and set up, but your kids will spend days analyzing them!

Learn More: Kiwi Co

44. Homemade Barometer

Your students might have already made a DIY thermometer, but what about a barometer? You can help them learn about atmospheric pressure by crafting barometers using a jar or can, a balloon, a wooden stick, rubber bands, and some tape! As the weather changes over the next few days, so will the air pressure which will move the wooden stick of their barometers! Cool, right?!

Learn More: Easy Science For Kids

45. Basic Motor Mechanics

It is amazing what you can do with some modeling clay, a magnet, a battery, and wire! This cool project showcases how electric energy works, demonstrating the interaction between the current and a magnetic field. This nifty little experiment will definitely get your students’ physics motors running! 

Learn More: Education

46. Xylophone fun

Sound waves are much easier to teach and learn about when your kiddies can make visual connections. Have your learners fill empty jars with varying amounts of cold water (and a few drops of food coloring in each to make it look even more interesting) and then let them test the different pitches by hitting each one! 

Learn More: Sugar, Spice And Glitter

47. Build a Paper Bridge

This fantastic activity uses some really simple materials to challenge your kiddies to ‘build a bridge’. What seems like a pretty basic activity actually teaches them all about the scientific method and physics concepts behind building a bridge. They’ll learn about concepts like compression and tension to explain how bridges stay in place even under pressure! This is one your future engineers will love! 

48. Magnet Maze

Art and physics are combined in this clever classroom experiment! Task your students first of all, with drawing a colorful maze on the outside of the bottle. Next, have them put in different items like coins, marbles, paperclips, and buttons to explore which ones they can attach the magnet to from the outside and navigate through their maze. A -maze- ing, right?!

Learn More: Science Museum Group

49. Super Sundial

If you feel like taking your teaching outdoors, this sundial construction lesson is ideal! Bring some paper plates, bendy straws, and a pencil, and you’re good to go! Your learners won’t need a lot of background knowledge before the activity, but they’re sure to learn a lot about the Earth’s orbit and rotation in the process!

Learn More: Generation Genius

50. Sound Sandwich

Your kiddies might initially be confused when you announce that they’ll be making sound sandwiches! Their confusion will soon turn to fascination at how such simple materials can make really interesting sounds! In this activity, they’ll be learning how to make music with sticks, straws, and rubber bands. See if they can figure out that it is the rubber band vibrating that makes the differently-pitched sounds!

51. Optical Lens Experiment

Did you know that you can actually bend light? Your students will be surprised to learn this for sure! Through this investigation, you’ll teach them how when light goes from one medium to another (e.g. from air to glass), it usually bends. This series of simple activities covers the effects of convex and concave lenses on light, and thus how refraction works.

Learn More: Discover Primary Science And Maths

52. Density Tower floating experiment

Combine the previously mentioned density tower and floating experiments in this cool activity! Using just a few simple ingredients that can be found around most homes, you can instruct your learners to combine cornstarch, vegetable oil, and rubbing alcohol. This will create the colored layers in this cool activity! Then they’ll add small items of their choosing to see which ones float in the various liquids, and at what density!

53. Walking Water experiment

Capillary action isn’t a term that most of your kiddies will be familiar with but after doing this experiment they won’t forget it! Help your learners set up a row of cups with water and different colors of food dye. Next, they’ll add some strips of paper towels dipping each end into a different up and let them watch in amazement as the colored water seems to defy gravity and ‘walk’ up the paper and into the next cup!

Learn More: Made In A Pinch

54.  Build a Solar Still

This easy experiment is the perfect way to demonstrate the water cycle and how sunlight can purify water. Start by letting your kiddos have a bit of fun to make ‘dirty’ water using assorted safe and edible kitchen ingredients. Then you’ll challenge them to make their own solar stills from plastic glasses, cling wrap, and, a bowl. Finally, they’ll set their glass of ‘dirty’ water inside the bowl, cover it with cling wrap, and then sit it out in the sun. And voila – clean water!

55. Slinky Sound Waves

A metal slinky is a super simple but really effective source of demonstrating sound waves for your kids. Get two volunteers to hold the ends of the slinky and encourage your other students to take note of the different wave patterns when one or both of them shake it. This is a super way to make this abstract concept a little more visual for your class.

Learn More: Fizzics Education

56. Bike Wheel Gyroscope 

Momentum is an important concept that your little physicists will cover in middle school science. A bike wheel gyroscope activity will amaze and enthrall your students as you use it to show off how the wheel’s mass and rotation obey the laws of angular momentum! The best part is that you’ll only need a bike wheel and some willing participants! 

Learn More: NASA

57. DIY Kaleidoscope

Teach your kids all about the law of multiple reflections with this super fun, customizable activity! Using a cardboard tube, some mirrors, and small colorful items like confetti or sequins, these kaleidoscopes will be something they’ll always remember making. If you don’t have mirrors, why not try using aluminum foil instead? 

Learn More: Home Science Tools

58. Mapping Magnetic Field Lines

Teaching theoretical, intangible ideas is one of the hardest parts of teaching a subject like physics. Thankfully this short but practical activity makes this a whole lot easier by showcasing how the magnetic field lines of a bar magnet do not ever cross, are continuous, and go from north to south! All your kiddies will need is a magnet, a compass, and a marker!

59. Buzz Wire game

Electrical circuits can be really interesting to make, and this activity makes it fun too! Get your students to create their own ‘Buzz Wire’ game which will teach them about the loop system needed for electricity to work. Once they’ve made their loops, let them have a go at completing each others’ games! Can they get to the end without setting the buzzer off?

60. Galileo’s Gravity Experiment

As the story goes, Galileo dropped two items from the Leaning Tower of Pisa to see which hit the ground first. Though we can’t be sure he actually did this, you can be sure that your students will have fun trying out this similar activity to learn about the effects of mass and air resistance on falling objects! Simply have them pick out two different objects, drop them from a height, and record which lands first!

Learn More: Science-Sparks

Cool Physics Experiments to Do at Home

Cool Physics experiments will not only fascinate and amaze your kids but will teach them about important scientific principles.

Some coolest physics experiments include Newton’s cradle, the simple Bernoulli experiment, the balloon rocket experiment, and the density tower experiment. Learn about atmospheric pressure with the egg in the bottle and the rising water experiments.

In this blog post, I will share the details of these and more cool physics experiments that are perfect for young kids and teenagers. These experiments are not only educational but also fun. I hope you enjoy them.

Table of Contents

7 Cool Physics Experiments to Do at Home

Here are the 7 most fun Physics experiments you can do at home.

1. Newton’s Cradle Experiment

Newton’s cradle experiment demonstrates the conservation of momentum and energy.

How to do it

You will need the following items:

• A set of Newton’s Cradle balls (or any type of metal balls that are identical in size and weight)
• A table or other flat surface
• Strings that are the same length

Attach one end of each string to a different ball. Suspend the balls from a frame so that they are touching each other. You can easily achieve this by making sure the strings are the same length and attaching them to a board at the same height.

Pull back one ball and release it so that it hits the middle ball. The released ball will swing up and hit the ball at the opposite end. That ball will then swing up and hit the ball next to it and so on. The last ball will swing up and hit the first ball, starting the process all over again.

The results explained

What is happening is that the balls are colliding in such a way that the momentum of each ball is conserved. In other words, the combined momentum of all the balls before the collision is equal to the combined momentum of all the balls after the collision.

The energy is also conserved in this experiment. The energy is converted from kinetic energy (the energy of motion) to potential energy (the energy stored in the balls as they are raised up) and back to kinetic energy again.

This is a simple but elegant demonstration of some very important scientific principles. Try it yourself and see.

2. The Simple Bernoulli Experiment

The Bernoulli principle is one of the most important principles of fluid dynamics. It explains how wings generate lift and how airfoils work. When the speed of a fluid increases, the pressure decreases. This principle is what makes flight possible.

Here’s how to do it

• A piece of paper
• A pair of scissors

Cut a rectangular piece of paper that is about twice as wide as the straw. Fold the paper in half lengthwise and tape it together.

Cut a slit in the center of the paper, being careful not to cut all the way through. Insert the straw into the slit and tape it in place. Now blow gently across the top of the paper. What happens?

When you blow across the top of the paper, the airspeed above the paper increases. An increase in airspeed means a decrease in pressure. The decrease in pressure on the top of the paper is greater than the increase in pressure on the bottom of the paper. This creates a force that lifts the paper up into the air.

This is how airplanes generate lift. The wings are shaped so that the air travels faster over the top of the wing than the bottom. This decreases the pressure on the top of the wing and creates lift.

Try this experiment with different shapes of paper and see how it affects the results.

3. The Egg in the Bottle Experiment

This experiment demonstrates how atmospheric pressure and temperature can affect the shape of an object.

• A hard-boiled egg
• A glass bottle with a narrow neck

Remove the shell from the hard-boiled egg. Place it in the mouth of the glass bottle. The mouth should be just smaller than the egg in diameter so the egg doesn’t fall through.

Roll the piece of paper into a cone shape and hold it over the neck of the bottle. Light the paper on fire, remove the egg and drop the burning paper into the bottle. Quickly place the egg back in the mouth of the bottle. What happens?

The fire goes out almost immediately because the oxygen in the bottle is quickly used up. After some time, the egg drops into the bottle.

Before we placed the burning paper into the bottle, the atmospheric pressure inside the bottle was the same as the atmospheric pressure outside. So there was no pressure pushing the egg into the bottle.

When we placed the burning paper in the bottle, it heated up the air inside the bottle. The air inside the bottle expanded. When we sealed the bottle with the egg, the fire went out and the air inside the bottle contracted. This created a vacuum.

The atmospheric pressure outside the bottle became greater than the atmospheric pressure inside the bottle, so the egg was forced into the bottle.

4. The Balloon Rocket Experiment

The Balloon Rocket is a classic physics experiment that demonstrates Newton’s Third Law of Motion: for every action, there is an equal and opposite reaction. In simple terms, it is all about thrust.

• Two chairs or a table
• A plastic clip or peg

Place two chairs a few feet apart or use a table. Cut a length of string and tie one end to the back of one chair. Thread the other end through the straw and tie it to the back of the other chair. The string should be taut but not too tight.

Cut two small pieces of tape and affix them on the top part of the straw, about an inch apart. These will be used to hold the balloon in place.

Blow up the balloon, twist the neck, and use the peg to make sure the air doesn’t escape. Now attach the balloon to the straw using the two pieces of tape.

Remove the peg and release the balloon and watch it fly!

Once you remove the peg and release the balloon, the air will rush out of the balloon in one direction with great force. The straw will be forced in the opposite direction with an equal force. This is because of Newton’s Third Law of Motion. The faster the air rushes out of the balloon, the greater the force will be.

5. The Candle in the Jar Experiment

This experiment is a great way to learn about the relationship between air and combustion.

• A glass jar
• A wooden board or a ceramic plate
• A lighter or matches

Light the candle and place it on a wooden board or ceramic plate. Quickly put the glass jar upside down on top of the candle. After some time, the flame will go out.

The flame will keep burning for some time before it eventually goes out. Combustion requires oxygen. When you put the jar on top of the candle, you create a sealed environment. The oxygen inside the jar is quickly used up and the flame goes out.

If you want to see the flame burning for longer, try using a bigger jar. The bigger jar will trap more oxygen than the smaller jar and the flame will burn for a longer period of time.

6. Density Tower Experiment

This is another fun Physics experiment that you can do at home. It’s a great way to learn about density and how some liquids are heavier or denser than others.

• A clear plastic bottle with a screw-on lid
• Vegetable oil
• Food coloring
• Turkey baster
• You may also need other liquids such as rubbing alcohol, milk, dish soap, etc.

Mix some drops of food coloring into your water and mix well. Add equal parts of all the liquids into the bottle. Start with one liquid before going to the next. Each time you add a liquid, make sure it doesn’t touch the sides of the bottle.

You can start by ranking all the liquids based on how dense you think they are and then add them starting with the densest. After adding all the liquids, close the bottle and let it sit for some time.

The liquids will form layers based on their density. The densest liquid will be at the bottom and the lightest liquid will be at the top. This experiment tells us that some liquids are heavier than others.

The lighter liquid will float on top of the denser liquid because it is less dense.

7. Rising Water Experiment

The rising water experiment is a great way to learn about air pressure, heat, expansion, and contraction.

• A votive candle
• A clear glass jar
• A shallow dish
• Lighter or Matches
• Food coloring (Optional)

Pour some water into a shallow dish. You will only need just enough to cover the bottom part of the dish. You can add food coloring to the water for better visibility. Place the votive candle in the center of the jar and light it using a lighter or matches.

Immediately you light the candle, place the clear glass jar upside down on top of the shallow dish. Observe what happens to the water inside the jar.

When you light the candle, the heat from the flame will start to heat up the air inside the jar. The air inside the jar expands, but soon, the oxygen inside is depleted and the candle goes out.

The heated air inside the jar starts to cool and contracts. As the air inside the jar cools, it creates a vacuum. The atmospheric pressure outside is greater than the pressure inside the jar and this causes water to be forced up the jar.

Why Physics Experiments Are Great for Kids

Here’s why you might want to start helping your kids perform fun Physics experiments at home:

They Foster Curiosity

Kids are fascinated by the world around them, and there is no better way to foster that curiosity than through hands-on learning. Physics experiments are a great way to introduce your kids to the basic concepts of science while also providing them with some fun and engaging activities.

Physics Experiments Encourage Observation and Exploration

You will appreciate the value of good observation skills when your kids are constantly asking you how things work. Physics experiments provide a perfect opportunity for kids to practice their observational skills while also exploring the world around them.

They Help Kids Develop Problem-Solving Skills

Nothing is more satisfying than watching your child figure out how to solve a problem on their own. Physics experiments can help kids develop their problem-solving skills as they learn how to apply the concepts they are observing.

Physics Experiments Are a Great Opportunity for Family Bonding

There is no better way to spend some quality time with your kids than by helping them with their physics experiments. Not only will you get to bond with your kids, but you will also get to share in their excitement as they learn about the world around them.

Evaluation and Critical Thinking

Another great benefit of physics experiments is that they help kids develop their evaluation and critical thinking skills. As your kids experiment, they will learn how to identify the variables that are affecting their results. This will help them develop their ability to think critically about the world around them.

So, what are you waiting for? Get started on some cool physics experiments with your kids today. The ones listed here are among the most fun that you can do at home. Not only are they fun, but they’re also a great way to learn about the world around us.

Do you have any other cool Physics experiments that you like to do at home? Share them with us in the comments below.

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99+ Unique Physics Project Ideas for College Students

Are you a college student who loves science? Get ready for some exciting physics projects! These ideas are not just ordinary school work – they’re like tickets to an amazing journey of exploration and learning.

Whether you’re already crazy about physics or just starting to get interested, there’s something here for you. These projects will make you go, “Wow, physics is cool!”

We’re not going to confuse you with difficult stuff. Our goal is to make physics easy to understand and fun to learn. So, if you’re ready for a hands-on adventure full of scientific discoveries, put on your lab goggles (real or imaginary) and let’s get started!

What are Physics Projects?

Table of Contents

Physics projects are activities or experiments that let you explore different ideas and concepts in physics by doing things yourself.

They can be simple or more complicated and cover topics like how things move, electricity, light, heat, and more.

These projects help you understand what you’ve learned in class by putting it into practice. You might design experiments, collect data, and figure out what it all means.

By doing physics projects, you learn by doing and get a better understanding of how science works.

How To Find Great Physics Topics

Finding good physics project ideas can be tough, but there are ways to make it easier. Here are some practical tips to help you:

• Check out reliable science websites for inspiration.
• Look for physics books in your school library.
• Talk to your teacher or supervisor for guidance.
• Brainstorm with your classmates to come up with ideas together.

If those methods don’t work, you can always ask for help from professional writers. Don’t risk missing out on graduation just because of a project!

Here are some sample physics project ideas to get you started.

Physics Project Ideas for College Students

Have a close look at the physics project ideas for college students:-

Classical Mechanics

• Experiment with different materials to create an efficient trebuchet.
• Build a simple hovercraft and study its motion.
• Investigate the physics of a boomerang’s return flight.
• Analyze the forces involved in a roller coaster loop.
• Study the effects of air resistance on falling objects.
• Build a functional model of a steam engine.
• Investigate the physics of a yo-yo’s motion.
• Explore the principles behind a Newton’s cradle.
• Analyze the mechanics of a trampoline’s bounce.
• Build and test a paper airplane launcher for maximum distance.

Electromagnetism

• Create an electromagnetic levitation system.
• Study the behavior of magnetic fluids (ferrofluids).
• Investigate the physics of electromagnetic radiation using a radio telescope.
• Build a Gauss rifle to demonstrate magnetic acceleration.
• Explore the concept of electromagnetic induction with a homemade generator.
• Analyze the properties of superconducting materials at low temperatures.
• Create a simple electric motor using household materials.
• Study the behavior of electromagnetic waves in different mediums.
• Build a magnetic levitation (maglev) train model.
• Investigate the principles behind wireless power transmission.

Thermodynamics

• Build a solar water heater and measure its efficiency.
• Investigate the physics of heat exchangers.
• Analyze the cooling rates of various beverages in different containers.
• Study the efficiency of a homemade wind turbine generator.
• Investigate the heat transfer properties of different materials.
• Build a DIY thermoelectric generator powered by a temperature gradient.
• Study the principles of a Stirling engine and build a functional model.
• Analyze the thermodynamics of a cryogenic freezing process.
• Investigate the physics of a simple steam turbine.
• Build a solar-powered car and test its efficiency.

Quantum Mechanics

• Conduct a double-slit experiment with particles of your choice.
• Investigate quantum entanglement using a pair of entangled photons.
• Study the behavior of particles in a quantum well.
• Build a basic quantum computer simulator.
• Investigate the properties of quantum dots and their applications.
• Analyze the principles behind quantum teleportation.
• Study quantum cryptography methods and perform secure communication experiments.
• Investigate the physics of Bose-Einstein condensates in a lab setting.
• Explore the concept of quantum superposition with a simple experiment.
• Analyze the behavior of particles in a magnetic field using a cloud chamber.
• Build a model to demonstrate time dilation and the twin paradox.
• Study the effects of gravity on the flow of time using a simple experiment.
• Investigate the physics of gravitational lensing using a lens and light source.
• Analyze the principles of relativistic jets in astrophysics with a simulation.
• Build a simple wormhole or black hole analog and study its properties.
• Investigate the physics of warp drives and their feasibility in theoretical physics.
• Study the consequences of a closed, time-like curve and its implications for time travel.
• Analyze the behavior of light in a strong gravitational field (gravitational redshift).
• Build a model illustrating frame-dragging effects in general relativity.
• Investigate the principles behind gravitational wave detection and measurement.
• Create a holographic display using a laser and holographic plate.
• Investigate the physics of total internal reflection using optical fibers.
• Study the properties of different types of lenses and their applications.
• Build a simple spectrometer to analyze the spectra of different light sources.
• Analyze the dispersion of light in a prism and its effects on a spectrum.
• Study the interference patterns of laser light with a double-slit experiment.
• Investigate the physics of polarized light and its applications in 3D glasses.
• Build a simple optical microscope and explore its magnification capabilities.
• Analyze the properties of diffraction gratings and their use in spectrometry.
• Study the physics of color perception and optical illusions with visual experiments.

Nuclear Physics

• Investigate the properties of different types of radioactive decay.
• Study the behavior of radioactive isotopes and their half-life.
• Build a cloud chamber to detect and visualize cosmic rays.
• Investigate the principles of nuclear fusion reactions and their energy production.
• Analyze the characteristics of a Geiger-Muller counter and its applications.
• Study the behavior of particles in a cyclotron and their acceleration.
• Investigate the physics of nuclear reactors and their operation.
• Analyze the concept of nuclear magnetic resonance (NMR) in medical imaging.
• Study the behavior of neutrinos and their detection methods.
• Investigate the principles of radioactive dating methods in geology and archaeology.

Astrophysics

• Build a simple telescope and observe celestial objects.
• Investigate the physics of different types of stars and their life cycles.
• Study the behavior of galaxies in a cosmic web with a simulation.
• Analyze the effects of dark matter on galaxy dynamics in a computational model.
• Investigate the physics of supernova explosions and their remnants.
• Study the behavior of black holes and event horizons with simulations.
• Analyze the expansion of the universe and its evidence, such as redshift.
• Investigate the properties of exoplanets and their potential habitability.
• Study the cosmic microwave background radiation and its significance.
• Analyze the effects of gravitational waves on the fabric of space-time.
• Investigate the physics of DNA’s double helix structure.
• Study the mechanics of muscle contraction and its role in human movement.
• Analyze the physics of the human circulatory system and blood flow.
• Investigate the behavior of sound waves in human hearing and speech.
• Study the physics of vision and visual perception.
• Analyze the biomechanics of animal locomotion and flight.
• Investigate the physics of neural transmission in the brain.
• Study the principles of medical imaging techniques, such as MRI and CT scans.
• Analyze the physics of bioluminescence in marine organisms.
• Investigate the effects of physical forces on cellular structures and tissues.
• Build a seismometer to detect and analyze earthquake vibrations.
• Investigate the physics of plate tectonics using models and simulations.
• Study the behavior of magnetic fields in Earth’s geodynamo.
• Analyze the principles behind geophysical survey methods, such as ground-penetrating radar.
• Investigate the physics of ocean currents and their impact on climate.
• Study the Earth’s magnetic field and its variations over time.
• Analyze the effects of gravitational forces on Earth’s surface and tides.
• Investigate the properties of geological materials, such as rocks and minerals.
• Study the physics of volcanoes and volcanic eruptions.
• Analyze the Earth’s geothermal energy potential and its utilization for power generation.

These project ideas span the various branches of physics, providing college students with a wide range of topics to explore, experiment with, and investigate in their studies and research endeavors.

How to Choose Physics Ideas for College Students?

Choosing the perfect physics project for college students is like picking the right adventure – it should be exciting, tailored to their abilities, and align with their interests. Here’s a more engaging and natural approach to selecting physics ideas:

Gauge Their Level

To kick things off, take a look at where your students stand academically. Are they just starting their physics journey as freshmen, or are they seasoned seniors? The project’s complexity should match their experience.

Tap into Passion

Find out what lights a fire in your students’ physics-loving hearts. Are they into the mind-bending mysteries of quantum mechanics, the celestial wonders of astrophysics, or perhaps the elegant dance of classical mechanics?

Peek at the Syllabus

Sneak a peek at your college’s physics curriculum. What topics are they currently tackling in the classroom? A project that complements their coursework can make learning more cohesive.

Inventory Resources

Take stock of what you’ve got in your physics toolkit. Do you have a well-equipped lab, specific materials, or faculty support? The project should be doable with the resources at hand.

Unleash Creativity

Encourage your students to dream big! Explore intriguing and cutting-edge topics that spark their curiosity. After all, physics is about uncovering the unknown.

Mix Theory and Hands-On Fun

Balance the scales between theory and experimentation. Projects that involve real hands-on work can turn learning into an adventure.

Career Compatibility

Think about your students’ career ambitions. If they’re aspiring researchers, aim for a project that aligns with their future path.

Team Up for Success

Promote collaboration. Group projects can foster a sense of camaraderie and help students learn from each other.

Ask the Experts

Reach out to your fellow physics pros. Consult with faculty members who can lend their wisdom in selecting the perfect project.

Match Timeframes

Ensure the project fits within the allotted time. Some are quick and snappy, while others are more of a marathon . Choose wisely.

Real-World Relevance

Look for projects with real-world applications. Connecting physics to practical life can be incredibly motivating.

Flexibility Matters

Pick a project that allows for twists and turns. Unexpected discoveries and challenges are all part of the thrilling physics adventure.

Historical Hits

Dive into the archives of past student projects. Success stories from the past can inspire the next generation.

Student Input is Key

Lastly, let your students have their say. After all, they’re the ones embarking on this physics journey. Their enthusiasm and ideas can make the adventure even more exciting.

With this approach, you’ll embark on a physics journey that’s not just educational but also an absolute blast!

And that brings us to the end of our tour through these awesome physics projects for college students. But hold on, this isn’t a farewell; it’s just the start of your scientific adventure!

Think of these projects as your keys to unlocking the mysteries of the universe, but without the complicated jargon. They’re like your backstage pass to the world of physics, where you get to see the magic happen up close and personal.

These projects aren’t just about acing assignments; they’re about having fun, being curious, and understanding the world in a whole new way. You’re not just learning facts; you’re becoming a scientist – someone who asks questions, runs experiments, and discovers cool stuff.

So, whether you’re launching things into the air, creating rainbows of light, or using the sun’s power, remember that science is an adventure, and you’re the fearless explorer. The universe has endless secrets waiting for you to uncover.

In the end, physics is like a treasure hunt, and these projects are your map. They lead you to discoveries, aha moments, and a deeper appreciation for the world around you. So, grab your lab coat, put on your explorer’s hat, and let’s keep this physics party going!

Frequently Asked Questions

How can i choose the right physics project for me.

Consider your interests and the subfield of physics that intrigues you the most. Choose a project that aligns with your passion.

Are these projects suitable for beginners in physics?

Yes, some of the projects are designed with beginners in mind, while others may require more advanced knowledge. Choose one that matches your skill level.

Do I need expensive equipment for these projects?

The complexity of the project determines the equipment required. Many projects can be done with basic materials, while others may need specialized tools.

Can these projects be done as group assignments?

Absolutely! Collaborating with fellow students can enhance the learning experience and make complex projects more manageable.

How can I ensure the safety of my experiments?

Always prioritize safety by following proper procedures, wearing protective gear, and seeking guidance from professors or mentors when needed.

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35 IB Physics IA Ideas: Simple and Score High Marks

• Use different lengths of string and record the period of the pendulum swings for each
• A good technique for this would be to record the time for 5 periods then divide it by 5

Looking at how the intensity of a light source varies with distance

• You need a light source of constant power, a photometer or similar device, and a long bench
• Take measurements of the intensity of the light source at various distances away from it
• Graphing  I against r^-2  should give the gradient P/4π  where  is the power of the light source

How does the concentration of sucrose in a water solution affect the refractive index of the water?

• Fill a container with water in a bright room and shine a weak laser at it such that you can determine the angle of deflection due to the body of water
• Gradually fill the water container with sucrose, calculating the concentration each time, and measure how the deflection changes
• Plot these variables against each other to see if there is a relationship

Investigating how the frequency of a simple pendulum varies with string length

• Record the frequency of a simple pendulum, for example by counting how many oscillations it completes in 10 seconds
• Do this for pendulums of different string length
• Plot frequency against string length to see if there is a relationship

How does the frequency of oscillation of an object on a spring depend on the mass of the object?

• Attach a block of known mass to a spring and extend it on a slippery horizontal surface such that it starts oscillating
• Record the frequency, for example by counting how many oscillations it completes in 10 seconds
• Repeat this for blocks of different mass

Investigating how the refractive index of a liquid varies with temperature

• Fill a container with a given liquid, e.g. water
• Use a weak laser in a dark room to see how the angle of the light path changes as it passes through the liquid
• Hence use Snell’s law to calculate the refractive index
• Now use an electric heater to increase the temperature of the liquid – record this and repeat the measurement for different temperatures
• Plot the refractive index against the temperature to see if there is a relationship

How does the fundamental frequency of a standing wave on a string vary with string length?

• An example of this would be a guitar string, where “plucking” the string gives the fundamental frequency
• Use equipment such as a slow-motion camera to record the period of the string oscillation, and hence find the frequency
• Do this for strings of different lengths (always fixed at either end), and plot a graph to see if there is a relationship between frequency and length

Investigating the relation between temperature and speed of sound in a material (you choose the material!)

• Choose a material where sound can travel through, and which you a large enough sample of that sound diffracting around it will be negligible
• It also needs to be long enough for sound to take a measurable time to travel through it
• Use an oscilloscope or computer software that allows you to find the time taken for sound from a given source to travel between two microphones
• Put the microphones on either side of the material, measure the separation and hence find the sound speed
• Heat up the material, record its temperature and repeat the experiment
• Plot speed against temperature to see if there is a relationship

Investigating Snell’s law for more than one refraction at a time

• Put samples of two or more transparent materials (e.g. glass and water) next to each other and shine a weak laser through both
• Use Snell’s law for multiple refractions to determine the expected relationship between the entering and exiting angles of the light beam
• Repeat the experiment for a variety of angles and plot the result to see if the relationship holds

What is the relationship between the width of interference maxima and the number of slits illuminated in a diffraction grating?

• Use a diffraction grating and a stationary flashlight
• Move the flashlight closer or further away from the grating such that different numbers of slits are illuminated – calculate the number by measuring the fraction of the grating that is covered by light
• Use a piece of paper or a white wall to see the interference maxima, and measure their width using a ruler
• Plot maximum width against number of slits illuminated to see the relationship

ELECTRICITY AND MAGNETISM IB Physics IA ideas

Testing Ohm’s law for different electrical components

• Use components such as resistors, filament lamps, thermistors, and others that you would like to test
• Build a circuit containing a voltmeter and ammeter, and where you can toggle the voltage
• Record how the current changes as you change the voltage
• Plot the results for each component; if the V-I curve is linear, the component follows Ohms law and the gradient is R
• For the components that don’t follow Ohm’s law, try to fit other relationships

Finding the resistivity of a metal (you choose the material!)

• Choose a metal where you have access to several samples of similar shape but different lengths and/or cross-sectional areas
• Place one sample in the circuit at a time and record how the current changes with voltage – when you plot these against each other the resistance is the gradient of the graph
• After having done this for every sample, plot their resistances as a function of length and/or cross-sectional area (one at a time, keeping the other one constant) and use the relationship  R=ρL/A  to find the resistivity

How does the efficiency of an electric motor depend on temperature?

• Use a small electric motor for a task where you can calculate the energy output, e.g. lifting something up
• Feed the motor with electric power and calculate the efficiency it has with completing the task
• If you repeat this many times the motor will heat up due to energy lost to inefficiencies
• Record its temperature and see how its efficiency changes for a range of temperatures

How does the emf produced by rotating coils depend on the rotational speed of the coils?

• Do this only if your school has access to a permanent magnet large enough to create a constant and uniform magnetic field
• Connect a conducting coil to a voltmeter and a mechanism where you can rotate the coil at a desired speed (either by hand or electronically)
• Record how the peak readings of the voltmeter changes with rotational speed of the coils
• Predict the relationship theoretically using Faraday’s law, then plot your data to see if you get the same result

Finding the work function of metals

• You need a thin metal plate connected to an ammeter and EM wave sources/lasers with a wide range of available frequencies
• Record the maximal current produced when light of different frequencies is shone onto the plate, and relate this to the kinetic energy of the electrons
• On a graph of E against f, the y-intercept should be the negative of the metal’s work function

Investigating the relation between temperature and the efficiency of a transformer

• Calculate the efficiency of a small transformer by feeding it with current and measuring the output current using an ammeter
• If you repeat this many times the transformer will heat up due to energy lost to inefficiencies

How does the power output of a solar cell vary with thickness of cellophane laid over it?

• Choose a sunny day and bring a small solar cell out in the open
• Record the current or power output of the cell, and re-do the recordings while you continuously put thin layers of cellophane on top of the cell
• Plot the power output against thickness after you are done to see if there is a relationship

Finding out how the current magnetically induced in a solenoid depends on the number of coils

• Move solenoids with different numbers of coils through the magnetic field at the same speed and record the current produced in them using an ammeter
• Plot peak current against number of coils to see if there is a relationship

Investigating the efficiency of a diode rectifier as a function of temperature

• Build a diode rectifier circuit and investigate its efficiency by measuring the current ahead of and beyond the diode using ammeters
• If you leave the circuit for a while the diode will heat up due to energy lost to inefficiencies

Finding the internal resistance of a battery

• Construct a simple circuit containing a battery and a variable resistor
• Use an ammeter to measure the current and a voltmeter to measure the terminal potential difference for different values of resistance
• According to the relationship  V=ε-Ir , if you plot  V against I the gradient should be  -r where  r is the internal resistance

Finding the time constant of a capacitor

• Fully charge a capacitor by connecting it to a cell or battery, then disconnect the cell or battery and let the capacitor discharge through a resistor
• Measure either how the voltage changes with time using a voltmeter or how the current changes with time using an ammeter

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Physicists Create a Holographic Wormhole Using a Quantum Computer

November 30, 2022

Researchers were able to send a signal through the open wormhole, though it’s not clear in what sense the wormhole can be said to exist.

Kim Taylor for Quanta Magazine

Introduction

Editor’s note: In February 2023, a team of physicists led by Norman Yao of Harvard University published a  comment  about the holographic wormhole experiment described in this article. After analyzing the mathematical properties of the model used to simulate the wormhole in a quantum computer, the group concluded that the teleportation demonstration should not be thought of as a holographic wormhole. They argue that the model underlying the experiment was too simple to capture key properties of gravitational systems such as black holes and wormholes. The comment has not yet been peer reviewed, but independent experts contacted by  Quanta find the arguments compelling. Our ongoing coverage is available here: https://www.quantamagazine.org/wormhole-experiment-called-into-question-20230323/

Physicists have purportedly created the first-ever wormhole, a kind of tunnel theorized in 1935 by Albert Einstein and Nathan Rosen that leads from one place to another by passing into an extra dimension of space.

The wormhole emerged like a hologram out of quantum bits of information, or “qubits,” stored in tiny superconducting circuits. By manipulating the qubits, the physicists then sent information through the wormhole, they reported today in the journal Nature .

The team, led by Maria Spiropulu of the California Institute of Technology, implemented the novel “wormhole teleportation protocol” using Google’s quantum computer, a device called Sycamore housed at Google Quantum AI in Santa Barbara, California. With this first-of-its-kind “quantum gravity experiment on a chip,” as Spiropulu described it, she and her team beat a competing group of physicists who aim to do wormhole teleportation with IBM and Quantinuum’s quantum computers.

When Spiropulu saw the key signature indicating that qubits were passing through the wormhole, she said, “I was shaken.”

The experiment can be seen as evidence for the holographic principle, a sweeping hypothesis about how the two pillars of fundamental physics, quantum mechanics and general relativity, fit together. Physicists have strived since the 1930s to reconcile these disjointed theories — one, a rulebook for atoms and subatomic particles, the other, Einstein’s description of how matter and energy warp the space-time fabric, generating gravity. The holographic principle, ascendant since the 1990s, posits a mathematical equivalence or “duality” between the two frameworks. It says the bendy space-time continuum described by general relativity is really a quantum system of particles in disguise. Space-time and gravity emerge from quantum effects much as a 3D hologram projects out of a 2D pattern.

Video : Wormholes were first envisioned almost a century ago, but it would take a number of theoretical leaps and a “crazy” team of experimentalists to build one on a quantum computer.

Emily Buder, Bongani Mlambo, Ibrahim Rayintakath, Rui Braz and Kim Taylor for Quanta Magazine; Kristina Armitage/Quanta Magazine

Indeed, the new experiment confirms that quantum effects, of the type that we can control in a quantum computer, can give rise to a phenomenon that we expect to see in relativity — a wormhole. The evolving system of qubits in the Sycamore chip “has this really cool alternative description,” said John Preskill , a theoretical physicist at Caltech who was not involved in the experiment. “You can think of the system in a very different language as being gravitational.”

To be clear, unlike an ordinary hologram, the wormhole isn’t something we can see. While it can be considered “a filament of real space-time,” according to co-author Daniel Jafferis of Harvard University, lead developer of the wormhole teleportation protocol, it’s not part of the same reality that we and the Sycamore computer inhabit. The holographic principle says that the two realities — the one with the wormhole and the one with the qubits — are alternate versions of the same physics, but how to conceptualize this kind of duality remains mysterious.

Opinions will differ about the fundamental implications of the result. Crucially, the holographic wormhole in the experiment consists of a different kind of space-time than the space-time of our own universe. It’s debatable whether the experiment furthers the hypothesis that the space-time we inhabit is also holographic, patterned by quantum bits.

“I think it is true that gravity in our universe is emergent from some quantum [bits] in the same way that this little baby one-dimensional wormhole is emergent” from the Sycamore chip, Jafferis said. “Of course we don’t know that for sure. We’re trying to understand it.”

Into the Wormhole

The story of the holographic wormhole traces back to two seemingly unrelated papers published in 1935: one by Einstein and Rosen, known as ER, the other by the two of them and Boris Podolsky, known as EPR. Both the ER and EPR papers were initially judged as marginal works of the great E. That has changed.

In the ER paper, Einstein and his young assistant, Rosen, stumbled upon the possibility of wormholes while attempting to extend general relativity into a unified theory of everything — a description not only of space-time, but of the subatomic particles suspended in it. They had homed in on snags in the space-time fabric that the German physicist-soldier Karl Schwarzschild had found among the folds of general relativity in 1916, mere months after Einstein published the theory. Schwarzschild showed that mass can gravitationally attract itself so much that it becomes infinitely concentrated at a point, curving space-time so sharply there that variables turn infinite and Einstein’s equations malfunction. We now know that these “singularities” exist throughout the universe. They are points we can neither describe nor see, each one hidden at the center of a black hole that gravitationally traps all nearby light. Singularities are where a quantum theory of gravity is most needed.

Albert Einstein, pictured on the top in 1920, and Nathan Rosen, pictured around 1955, stumbled across the possibility of wormholes in a 1935 paper.

The Scientific Monthly (top); AIP Emilio Segrè Visual Archives, Physics Today Collection

Albert Einstein, pictured on the left in 1920, and Nathan Rosen, pictured around 1955, stumbled across the possibility of wormholes in a 1935 paper.

The Scientific Monthly (left); AIP Emilio Segrè Visual Archives, Physics Today Collection

Einstein and Rosen speculated that Schwarzschild’s math might be a way to plug elementary particles into general relativity. To make the picture work, they snipped the singularity out of his equations, swapping in new variables that replaced the sharp point with an extra-dimensional tube sliding to another part of space-time. Einstein and Rosen argued, wrongly but presciently, that these “bridges” (or wormholes) might represent particles.

Ironically, in striving to link wormholes and particles, the duo did not consider the strange particle phenomenon they had identified two months earlier with Podolsky, in the EPR paper: quantum entanglement.

Entanglement arises when two particles interact. According to quantum rules, particles can have multiple possible states at once. This means an interaction between particles has multiple possible outcomes, depending on which state each particle is in to begin with. Always, though, their resulting states will be linked — how particle A ends up depends on how particle B turns out. After such an interaction, the particles have a shared formula that specifies the various combined states they might be in.

The shocking consequence, which caused the EPR authors to doubt quantum theory, is “spooky action at a distance,” as Einstein put it: Measuring particle A (which picks out one reality from among its possibilities) instantly decides the corresponding state of B, no matter how far away B is.

Entanglement has shot up in perceived importance since physicists discovered in the 1990s that it allows new kinds of computations. Entangling two qubits — quantum objects like particles that exist in two possible states, 0 and 1 — yields four possible states with different likelihoods (0 and 0, 0 and 1, 1 and 0, and 1 and 1). Three qubits make eight simultaneous possibilities, and so on; the power of a “quantum computer” grows exponentially with each additional entangled qubit. Cleverly orchestrate the entanglement, and you can cancel out all combinations of 0s and 1s except the sequence that gives the answer to a calculation. Prototype quantum computers made of a few dozen qubits have materialized in the last couple of years, led by Google’s 54-qubit Sycamore machine.

Meanwhile, quantum gravity researchers have fixated on quantum entanglement for another reason: as the possible source code of the space-time hologram.

Talk of emergent space-time and holography started in the late 1980s, after the black hole theorist John Wheeler promulgated the view that space-time and everything in it might spring from information. Soon, other researchers, including the Dutch physicist Gerard ’t Hooft, wondered whether this emergence might resemble the projection of a hologram. Examples had cropped up in black hole studies and in string theory, where one description of a physical scenario could be translated into an equally valid view of it with one extra spatial dimension. In a 1994 paper titled “ The World as a Hologram ,” Leonard Susskind , a quantum gravity theorist at Stanford University, fleshed out ’t Hooft’s holographic principle, arguing that a volume of bendy space-time described by general relativity is equivalent, or “dual,” to a system of quantum particles on the region’s lower-dimensional boundary.

A momentous example of holography arrived three years later. Juan Maldacena , a quantum gravity theorist now at the Institute for Advanced Study in Princeton, New Jersey, discovered that a kind of space called anti-de Sitter (AdS) space is, indeed, a hologram.

Juan Maldacena (top) and Leonard Susskind are leaders of the approach to quantum gravity known as holography. In 2013, they proposed that wormholes in space-time are equivalent to quantum entanglement, a conjecture known as ER = EPR.

Sasha Maslov for Quanta Magazine (top); Linda A. Cicero/Stanford News Service

Juan Maldacena (left) and Leonard Susskind are leaders of the approach to quantum gravity known as holography. In 2013, they proposed that wormholes in space-time are equivalent to quantum entanglement, a conjecture known as ER = EPR.

Sasha Maslov for Quanta Magazine (left); Linda A. Cicero/Stanford News Service

The actual universe is de Sitter space, an ever-growing sphere driven outward by its own positive energy. By contrast, AdS space is infused with negative energy — resulting from a difference in the sign of one constant in the equations of general relativity — giving the space a “hyperbolic” geometry: Objects shrink as they move outward from the center of the space, becoming infinitesimal at an outer boundary. Maldacena showed that space-time and gravity inside an AdS universe exactly correspond to properties of a quantum system on the boundary (specifically a system called a conformal field theory, or CFT).

Maldacena’s bombshell 1997 paper describing this “AdS/CFT correspondence” has been cited by subsequent studies 22,000 times — more than twice a day on average. “Trying to exploit ideas based on AdS/CFT has been the main goal of thousands of the best theorists for decades,” said Peter Woit , a mathematical physicist at Columbia University.

As Maldacena himself explored his AdS/CFT map between dynamical space-times and quantum systems, he made a new discovery about wormholes. He was studying a particular entanglement pattern involving two sets of particles, where each particle in one set is entangled with a particle in the other. Maldacena showed that this state is mathematically dual to a rather dramatic hologram: a pair of black holes in AdS space whose interiors connect via a wormhole.

A decade had to pass before Maldacena, in 2013 (under circumstances that “to be frank, I do not remember,” he says),  realized that his discovery might signify a more general correspondence between quantum entanglement and connection via wormhole. He coined a cryptic little equation — ER = EPR — in an email to Susskind, who understood immediately. The two quickly developed the conjecture together, writing, “We argue that the Einstein Rosen bridge between two black holes is created by EPR-like correlations between the microstates of the two black holes,” and that the duality might be more general than that: “It is very tempting to think that any EPR correlated system is connected by some sort of ER bridge.”

Maybe a wormhole links every entangled pair of particles in the universe, forging a spatial connection that records their shared histories. Maybe Einstein’s hunch that wormholes have to do with particles was right.

A Sturdy Bridge

When Jafferis heard Maldacena lecture about ER = EPR at a conference in 2013, he realized that the conjectured duality should allow you to design bespoke wormholes by tailoring the entanglement pattern.

Standard Einstein-Rosen bridges are a disappointment to sci-fi fans everywhere: Were one to form, it would quickly collapse under its own gravity and pinch off long before a spaceship or anything else could get through. But Jafferis imagined stringing a wire or any other physical connection between the two sets of entangled particles that encode a wormhole’s two mouths. With this kind of coupling, operating on the particles on one side would induce changes to the particles on the other, perhaps propping open the wormhole between them. “Could it be that that makes the wormhole traversable?” Jafferis recalls wondering. Having been fascinated by wormholes since childhood — a physics prodigy, he started at Yale University at 14 — Jafferis pursued the question “almost for fun.”

Back at Harvard, he and Ping Gao , his graduate student at the time, and Aron Wall , then a visiting researcher, eventually calculated that, indeed, by coupling two sets of entangled particles, you can perform an operation on the left-hand set that, in the dual, higher-dimensional space-time picture, holds open the wormhole leading to the right-hand mouth and pushes a qubit through.

Jafferis, Gao and Wall’s 2016 discovery of this holographic, traversable wormhole gave researchers a new window into the mechanics of holography. “The fact that if you do the right things from the outside you can end up getting through, it also means you can see inside” the wormhole, Jafferis said. “It means that it’s possible to probe this fact that two entangled systems get described by some connected geometry.”

Within months, Maldacena and two colleagues had built on the scheme by showing that the traversable wormhole could be realized in a simple setting — “a quantum system that’s simple enough that we can imagine making it,” Jafferis said.

The SYK model, as it’s called, is a system of matter particles that interact in groups, rather than the usual pairs. First described by Subir Sachdev and Jinwu Ye in 1993, the model suddenly mattered much more starting in 2015 when the theoretical physicist Alexei Kitaev discovered that it is holographic. At a lecture that year in Santa Barbara, California, Kitaev (who became the K in SYK) filled several chalkboards with evidence that the particular version of the model in which matter particles interact in groups of four is mathematically mappable to a one-dimensional black hole in AdS space, with identical symmetries and other properties. “Some answers are the same in the two cases,” he told a rapt audience. Maldacena was sitting in the front row.

Merrill Sherman/Quanta Magazine

Connecting the dots, Maldacena and co-authors proposed that two SYK models linked together could encode the two mouths of Jafferis, Gao and Wall’s traversable wormhole. Jafferis and Gao ran with the approach. By 2019, they found their way to a concrete prescription for teleporting a qubit of information from one system of four-way-interacting particles to another. Rotating all the particles’ spin directions translates, in the dual space-time picture, into a negative-energy shock wave that sweeps through the wormhole, kicking the qubit forward and, at a predictable time, out of the mouth.

“Jafferis’ wormhole is the first concrete realization of ER = EPR, where he shows the relation holds exactly for a particular system,” said Alex Zlokapa , a graduate student at the Massachusetts Institute of Technology and a co-author on the new experiment.

Wormhole in the Lab

As the theoretical work was developing, Maria Spiropulu, an accomplished experimental particle physicist who was involved in the 2012 discovery of the Higgs boson, was thinking about how to use nascent quantum computers to do holographic quantum gravity experiments. In 2018 she persuaded Jafferis to join her growing team, along with researchers at Google Quantum AI — keepers of the Sycamore device.

To run Jafferis and Gao’s wormhole teleportation protocol on the state-of-the-art but still small and error-prone quantum computer, Spiropulu’s team had to greatly simplify the protocol. A full SYK model consists of practically infinitely many particles coupled to one another with random strengths as four-way interactions occur throughout. This is not feasible to calculate; even using all 50-odd available qubits would have required hundreds of thousands of circuit operations. The researchers set out to create a holographic wormhole with just seven qubits and hundreds of operations. To do this, they had to “sparsify” the seven-particle SYK model, encoding only the strongest four-way interactions and eliding the rest, while retaining the model’s holographic properties. “That took a couple of years to figure out a clever way to do it,” Spiropulu said.

Maria Spiropulu, a physicist at the California Institute of Technology, led the team behind the new wormhole experiment.

Bongani Mlambo for Quanta Magazine

One secret to success was Zlokapa, a waifish orchestra kid who joined Spiropulu’s research group as a Caltech undergrad. A gifted programmer, Zlokapa mapped the particle interactions of the SYK model onto the connections between neurons of a neural network, and trained the system to delete as many network connections as possible while preserving a key wormhole signature. The procedure reduced the number of four-way interactions from hundreds down to five.

With that, the team started programming Sycamore’s qubits. Seven qubits encode 14 matter particles — seven each in the left and right SYK systems, where every particle on the left is entangled with one on the right. An eighth qubit, in some probabilistic combination of states 0 and 1, is then swapped with one of the particles from the left SYK model. That qubit’s possible states quickly get tangled up with the states of the other particles on the left, spreading its information evenly among them like a drop of ink in water. This is holographically dual to the qubit entering the left mouth of a one-dimensional wormhole in AdS space.

Then comes the big rotation of all the qubits, dual to a pulse of negative energy coursing through the wormhole. The rotation causes the injected qubit to transfer to the particles of the right-hand SYK model. Then the information un-spreads, Preskill said, “like chaos run backward,” and refocuses at the site of a single particle on the right — the entangled partner of the left-hand particle that was swapped out. Then the qubits’ states are all measured. Tallying 0s and 1s over many experimental runs and comparing these statistics to the prepared state of the injected qubits reveals whether qubits are teleporting over.

Alex Zlokapa, a graduate student at the Massachusetts Institute of Technology who joined the wormhole project as an undergrad, found a way to simplify the wormhole protocol enough to run it on Google’s quantum computer.

The researchers look for a peak in the data that represents a difference between two cases: If they see the peak, it means qubit rotations that are dual to negative-energy pulses are allowing qubits to teleport, whereas rotations in the opposite direction, which are dual to pulses of normal, positive energy, don’t let qubits through. (Instead, they cause the wormhole to close.)

Late one night in January, after two years of gradual improvements and noise-reduction efforts, Zlokapa ran the finished protocol on Sycamore remotely from his childhood bedroom in the San Francisco Bay Area, where he was spending winter break after his first semester of grad school.

The peak appeared on his computer screen.

“It kept getting sharper and sharper,” he said. “I was sending screenshots of the peak to Maria and getting very excited, writing, ‘I think we see a wormhole now.’” The peak was “the first sign that you could see gravity on a quantum computer.”

Spiropulu says she could hardly believe the clean, pronounced peak she was seeing. “It was very similar to when I saw the first data for the Higgs discovery,” she said. “Not because I didn’t expect it, but it came too much in my face.”

Surprisingly, despite the skeletal simplicity of their wormhole, the researchers detected a second signature of wormhole dynamics, a delicate pattern in the way information spread and un-spread among the qubits known as “size-winding.” They hadn’t trained their neural network to preserve this signal as it sparsified the SYK model, so the fact that size-winding shows up anyway is an experimental discovery about holography.

“We didn’t demand anything about this size-winding property, but we found that it just popped out,” Jafferis said. This “confirmed the robustness” of the holographic duality, he said. “Make one [property] appear, then you get all the rest, which is a kind of evidence that this gravitational picture is the correct one.”

The Meaning of the Wormhole

Jafferis, who never expected to be part of a wormhole experiment (or any other), thinks one of the most important takeaways is what the experiment says about quantum mechanics. Quantum phenomena like entanglement are normally opaque and abstract; we don’t know, for instance, how a measurement of particle A determines B’s state from afar. But in the new experiment, an ineffable quantum phenomenon — information teleporting between particles — has a tangible interpretation as a particle receiving a kick of energy and moving at a calculable speed from A to B. “There seems to be this nice story from the point of view of the qubit; it moves causally,” said Jafferis. Maybe a quantum process like teleportation “always feels gravitational to that qubit. If something like that could come out of this experiment and other related experiments, that will definitely tell us something deep about our universe.”

Maria Spiropulu on the campus of the California Institute of Technology.

Susskind, who got an early look at today’s results, said he hopes that future wormhole experiments involving many more qubits can be used to explore the wormhole’s interior as a way of investigating the quantum properties of gravity. “By doing measurements on what went through, you interrogate it and see what was in the inside,” he said. “That seems to me like an interesting way to go.”

Some physicists will say the experiment tells us nothing about our universe, since it realizes a duality between quantum mechanics and anti-de Sitter space, which our universe is not.

In the 25 years since Maldacena’s discovery of the AdS/CFT correspondence, physicists have sought a similar holographic duality for de Sitter space — a map going from a quantum system to the positively energized, expanding de Sitter universe we live in. But progress has been far slower than for AdS, leading some to doubt whether de Sitter space is holographic at all. “Questions like ‘What about getting this to work in the more physical case of dS?’ are not new but very old and have been the subject of tens of thousands of person-years of unsuccessful effort,” said Woit, a critic of AdS/CFT research. “What’s needed are some quite different ideas.”

Critics argue that the two kinds of space differ categorically: AdS has an outer boundary and dS space does not, so there’s no smooth mathematical transition that can morph one into the other. And AdS space’s hard boundary is the very thing that makes holography easy in that setting, providing the quantum surface from which to project the space. By comparison, in our de Sitter universe, the only boundaries are the farthest we can see and the infinite future. These are hazy surfaces from which to try projecting a space-time hologram.

Renate Loll , a noted quantum gravity theorist at Radboud University in the Netherlands, also emphasized that the wormhole experiment concerns 2D space-time — the wormhole is a filament, with one spatial dimension plus the time dimension — whereas gravity is more complicated in the 4D space-time that we actually live in. “It is rather tempting to get entangled in the intricacies of the 2D toy models,” she said by email, “while losing sight of the different and bigger challenges that await us in 4D quantum gravity. For that theory, I cannot see how quantum computers with their current capabilities can be of much help … but I will happily stand corrected.”

Most quantum gravity researchers believe these are all difficult but solvable problems — that the entanglement pattern that weaves 4D de Sitter space is more complicated than for 2D AdS, but we can nevertheless extract general lessons by studying holography in simpler settings. This camp tends to see the two types of space, dS and AdS, as more similar than different. Both are solutions to Einstein’s relativity theory, differing only by a minus sign. Both dS and AdS universes contain black holes that are stricken with the same paradoxes. And when you’re deep in AdS space, far from its outer wall, you can hardly distinguish your surroundings from de Sitter.

Still, Susskind agrees that it’s time to get real. “I think it’s about time we got out from under the protective layer of AdS space and open up into the world that might have more to do with cosmology,” he said. “De Sitter space is another beast.”

To that end, Susskind has a new idea. In a preprint posted online in September, he proposed that de Sitter space might be a hologram of a different version of the SYK model — not the one with four-way particle interactions, but one in which the number of particles involved in each interaction grows as the square root of the total number of particles. This “double-scaled limit” of the SYK model is “behaving more like de Sitter than AdS,” he said. “There’s far from a proof, but there is circumstantial evidence.”

Such a quantum system is more complex than the one programmed so far, and “whether that limit is something that will be realized in the lab I don’t know,” Susskind said. What seems certain is that, now that there’s one holographic wormhole, more will open up.

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Title: forecasts on anisotropic cosmic birefringence constraints for cmb experiment in the northern hemisphere.

Abstract: The study of cosmic birefringence through Cosmic Microwave Background (CMB) experiments is a key research area in cosmology and particle physics, providing a critical test for Lorentz and CPT symmetries. This paper focuses on an upcoming CMB experiment in the mid-latitude of the Northern Hemisphere, and investigates the potential to detect anisotropies in cosmic birefringence. Applying a quadratic estimator on simulated polarization data, we reconstruct the power spectrum of anisotropic cosmic birefringence successfully and estimate constraints on the amplitude of the spectrum, $A_{\mathrm{CB}}$, assuming scale invariance. The forecast is based on a wide-scan observation strategy during winter, yielding an effective sky coverage of approximately 23.6%. We consider two noise scenarios corresponding to the short-term and long-term phases of the experiment. Our results show that with a small aperture telescope operating at 95/150GHz, the $2\sigma$ upper bound for $A_{\mathrm{CB}}$ can reach 0.017 under the low noise scenario when adopting the method of merging multi-frequency data in map domain, and merging multi-frequency data in spectrum domain tightens the limit by about 10%.A large-aperture telescope with the same bands is found to be more effective, tightening the $2\sigma$ upper limit to 0.0062.

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