gravitational force experiments

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Gravity Experiments for Kids

July 5, 2021 By Emma Vanstone Leave a Comment

These gravity experiments are all fantastic demonstrations of gravity and a great way to learn about Isaac Newton and Galileo ‘s famous discoveries. If you enjoy them, do check our my book This IS Rocket Science which is full of exciting space activities demonstrating how rockets overcome gravity and other forces to launch into space followed by a tour of the solar system with an activity for each planet.

What is Gravity?

Gravity is the force that pulls objects towards the Earth. It’s the reason we walk on the ground rather than float around.

Gravity also holds Earth and the other planets in their orbits around the Sun.

Did you know – gravity exists on the Moon but it is not as strong as on Earth, which is why astronauts can jump higher on the Moon than on Earth. This article from ScienceAlert tells you how high you could jump on each planet in the Solar System compared to Earth.

Great Gravity Experiments for Kids

Galileo and gravity.

Galileo was a famous scientist in the 16th and 17th Century. His most famous observation was that two objects of the same size but slightly different mass (how much “stuff” it is made of) hit the ground at the same time, as far as he could tell, if they are dropped from the same height. This happens because the acceleration due to gravity is the same for both objects and that actually this acceleration has nothing to do with the mass of an object. This fact has been demonstrated many times, even on the moon with a feather and a hammer.

Back on our air-filled planet, if a feather and a ball are dropped from the same height they clearly do fall at different rates. This is because gravity is not the only force acting on the falling object, air resistance is also a factor and that does depend on quite a few properties of the object and the fluid it is falling in. This does include its mass, the surface area and how fast it is moving. The feather suffers a lot here being so light and having a much greater surface area.

Galileo dropped two balls of different weights but the same size off the Leaning Tower of Pisa, giving a hint that the mass of an object doesn’t affect how fast it falls.

However if a ball and feather are dropped in a vacuum , where there is no air resistance as there’s no air, the ball and feather will fall together and hit the ground at the same time.

Bottle Drop Experiment

Following on from the ball and feather experiment another great example of Galileo’s discovery is to half fill one plastic bottle and leave another ( the same size ) empty. If dropped from the same height they will hit the ground at the same time!

Issac Newton and Gravity

According to legend Issac Newton was sitting under an apple tree when an apple fell on his head, which made him wonder why if fell to the ground.

Newton published the Theory of Universal Gravitation in the 1680s, setting out the idea that gravity was a force acting on all matter. His theory of gravity and laws of motion are some of the most important discoveries in science and have shaped modern physics.

Film Canister Rocket

A film canister rocket is a fantastic demonstration of all three of Newton’s Laws of Motion , but it falls back to the ground thanks to gravity.

Water powered bottle rockets are another great fun example of gravity and lots of other forces too!

Defy gravity with a magnet

Did you know you can defy gravity using magnets. We love this activity as you can theme it however you want. Your floating object could be a spaceship in space, a flower growing towards the sun or even a plane in the sky.

The magnet holds the paperclip in the air as if it’s floating!

Straw Rockets – Gravity Experiment

Create your own straw rockets and launch at different angles to investigate how the trajectory changes. Of course these don’t have to be rockets, they could be anything you want, so get creative!

Parachutes are another great gravity experiment and perfect for learning about air resistance too!

Marble Runs

A DIY marble run is another hands on way to demonstrate gravity. Can you build one where the ball has enough energy to move uphill?

DIY Sling Shot

Finally, a simple slingshot is a brilliant and simple STEM project and perfect for learning about gravity as a shower of pom poms fall to the ground!

Last Updated on May 25, 2022 by Emma Vanstone

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Science Sparks ( Wild Sparks Enterprises Ltd ) are not liable for the actions of activity of any person who uses the information in this resource or in any of the suggested further resources. Science Sparks assume no liability with regard to injuries or damage to property that may occur as a result of using the information and carrying out the practical activities contained in this resource or in any of the suggested further resources.

These activities are designed to be carried out by children working with a parent, guardian or other appropriate adult. The adult involved is fully responsible for ensuring that the activities are carried out safely.

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Simple Gravity Experiments

The Physical Factors Affecting Parachutes

Gravity is a fundamental part of nature that keeps our feet planted firmly on the ground. This unseen force is responsible for tides, keeping Earth from careening into the darkness of space, and for causing food to hit the kitchen floor when it slips from your hand. Though invisible, gravity's effects can be observed by performing simple and easy-to-do experiments.

Galileo's Experiment

Named after the scientist who is popularly believed (though not verified) to have performed this experiment, it involves taking two objects of different sizes and weights and dropping them to see which one hits the ground first. As the Earth's gravity affects objects at the same rate regardless of their weight, without air resistance the objects should hit the ground at the same time. Try this with different objects with varying weights and air resistance and observe its effects.

The Spinning Bucket

Showing the relation between motion and gravity, for this experiment you need a bucket with water and someone with a strong arm to spin it. In theory, when the bucket turns upside down the water should come spilling out as gravity pulls it downwards. Spinning it fast enough, the water tends to keep going in a straight line, counteracting the pull of gravity and thus wedging it to the end of the bucket, preventing the natural pull of gravity from spilling the water. This is why this effect, called “centrifugal force” is often referred to as artificial gravity.

The Hole in the Cup

For this experiment you need a paper cup and some water. Poke a hole in the cup and cover it with a finger; fill the cup with water. Take your finger from the hole and notice the water spills out. Though gravity pulls down both objects, only water moves freely (because you're holding the cup); thus, gravity forces the water out. Fill the cup again and drop it to the ground. Now that both objects are free to move, they drop at the same speed so the water isn't forced out of the hole.

Center of Gravity

A center of gravity experiment can be done quite easily; all that is required is a pencil or pen and your finger. Try to balance the pen at different positions on your finger until you reach the point where it doesn't fall off. This is the center of gravity of the pen, the point in which its weight averages out and, if it were in a weightless environment, the point at which it can freely rotate. Put on the cap and try to balance it again. As the weight of an object changes, so does its center of gravity.

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• Kids Science Experiments: Spinning Bucket of Water
• Discovery Channel: Gravity Gets You Down
• NASA: Center of Gravity

About the Author

Steve Johnson is an avid and passionate writer with more than five years of experience. He's written for several industries, including health, dating and Internet marketing, as well as for various websites. He holds a bachelor's degree from the University of Texas.

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Top 10 Gravity Experiments: Fun & Easy

Blow your mind with these easy and amazing gravity experiments!

Do you need a creative and engaging way to introduce students to the idea of gravity? Look not more than this collection of gravity experiments that students and teachers can perform in the classroom.

We’ve assembled a variety of experiments suitable for different age groups, covering concepts such as gravitational force, mass, weight, and free-fall motion. These hands-on, enlightening activities will not only help you grasp the fundamental principles of gravity but also ignite a lifelong fascination with physics.

1. Gravity-Defying Water Experiment

Students can learn more about the concepts of surface tension and the effects of gravity on liquids while having fun and being creative by trying out the gravity-defying water experiment.

2. Finding the Center of Gravity

The finding of the center of gravity experiment is an excellent way to introduce kids to the concept of balance and gravitational laws. These experiments also provide students with practical experience in learning the significance of the center of gravity in determining an object’s stability.

3. Anti-Gravity Galaxy in a Bottle

The anti-gravity galaxy in a bottle experiment is an engaging and innovative way to introduce children to the concepts of density and liquid characteristics.

Students can create a container that appears to defy gravity and gives the appearance of a galaxy by filling it with a vibrant mixture of glitter, oil, and water.

Learn more: Anti-Gravity Galaxy in a Bottle

4. Pool Noodle Marble Run

The pool noodle marble run gravity experiment is a fun and engaging way to teach students about the properties of gravity and motion.

In this experiment, students will create a track made from pool noodles and other materials to guide a marble as it travels from the top of the track to the bottom.

Learn more: Make a Pool Noodle Marble Run for Kids

5. Gravity Water Cup Drop

The water cup drop experiment teaches students about the laws of gravity and the effects of air resistance on falling items in a simple yet entertaining way. Students will perform this experiment by dropping a cup of water from a height and watching it fall.

6. Balloon Gravity Experiments

A creative and entertaining way to teach students about the force of gravity and its effects on objects is through the balloon gravity experiment.

By trying out these experiments, students can improve their problem-solving and critical-thinking skills while also learning more about the fundamentals of science.

7. DIY Balance Scales

Making your own balancing scales is a creative and engaging approach to introduce pupils to the ideas of stability and balance. Students can improve their sense of balance and coordination by carefully arranging the objects in this activity and adjusting their position and orientation.

Learn more: DIY Balance Scales

8. How to Make a Bottle Rocket

Making a bottle rocket for a gravity experiment is a fun and educational approach to teach students about the laws of physics and how gravity affects moving things. Students will use a plastic bottle, water, and pressured air to design and build a rocket during this project.

Learn more: How to Make a Bottle Rocket

9. Parachute Egg Drop Experiment

A fun and instructive technique to teach students about the fundamentals of physics and the science of aerodynamics is to try the parachute egg drop experiment. Students will design and build a parachute for this project.

This activity is a great bonus to any scientific curriculum because it is suited to different age groups and ability levels.

Learn more: Parachute Egg Drop Experiment

10. Putting Together the Gravity 

Putting together the gravity experiment is an exciting and educational way to teach students about the fundamental principles of physics and gravity.

In this experiment, students will design and create a setup that demonstrates the effects of gravity on different objects.

Learn more: Putting Together the Gravity

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Easy Gravity Experiments For Kids

Why do things fall to the ground when you let go of them? It’s all to do with gravity! Learn about what gravity is with a simple definition and everyday examples of gravity. Explore simple physics with easy, hands-on experiments kids will love. From falling objects, balancing apples, and even an egg drop challenge, enjoy these fun gravity  science projects  for kids!

Everyday Examples of Gravity

Here are 15 everyday examples of gravity that are easy for kids to understand:

• Falling Objects: When you drop a ball, it falls to the ground because of gravity.
• Jumping: When you jump up, gravity pulls you back down to the Earth.
• Walking: Gravity helps you stay on the ground while you walk.
• Sitting: You stay in your chair because gravity keeps you down.
• Climbing: Climbing a ladder or a tree is harder because gravity pulls you down.
• Bouncing: When you bounce on a trampoline, gravity brings you back down.
• Swinging: Swinging on a swing set is possible because gravity pulls you back towards the Earth.
• Driving: Your car stays on the road because of gravity.
• Eating: Because of gravity, your food stays on your plate and in your mouth.
• Pouring Drinks: Gravity helps the liquid flow from a cup when you tip it.
• Throwing a Ball: Gravity makes the ball come back down after you throw it in the air.
• Rolling a Ball: A rolling ball eventually stops because of friction, but gravity helps it move downhill.
• Riding a Bike: You can stay balanced on a bike because gravity helps keep the tires on the ground.
• Water Flow: Water flows downhill because of gravity, which is why rivers and streams exist.
• Kite Flying: Gravity keeps the kite from flying too high, and the tension in the string is balanced by gravity pulling it downward.

Can you think of any more examples of gravity?

Free Gravity Information and Activity Printable

Get up and test gravity for yourself with a free gravity activity pack ! Share this information guide, quick activity, and gravity coloring sheet with your kids!

12 Gravity Experiments To Try

Here are 12 gravity science experiments that are great for elementary school kids. Learn about gravity and its effects in a fun and hands-on way.

You may also want to explore: Air Resistance Projects

Dropping Objects

Gather various objects of different weights and sizes (e.g., a feather, a paperclip, a small ball). Have kids predict which object will hit the ground first when dropped simultaneously and then test their predictions.

Paper Airplane Challenge

Have kids create paper airplanes of different sizes and shapes. Let them fly the planes and observe how gravity affects their flight paths differently based on their designs. See how to make a paper airplane launcher.

Falling Rates

Use a ruler or a measuring tape to drop different objects from the same height and measure the time it takes for them to reach the ground. Compare the falling rates of various objects.

Balloon Rocket

Attach a string to a balloon and tape the other end to a straw. Inflate the balloon and then release it. Observe how the air escaping from the balloon propels the straw in the opposite direction due to Newton’s Third Law of Motion.

Coin and Card Drop

Place a playing card on the edge of a table and let half of it hang over the edge. Hold a coin over the card’s hanging part and let it go. The card will fall due to gravity, but the coin’s rapid descent might surprise the kids as they learn about mass and air resistance .

Build A Pipeline

Make your own pipeline below that will transport water from the main tank to a smaller tank using an incline. Observe how the moves because of gravity.

Water Upward

Fill a glass with water and place a piece of cardboard on top. Hold the cardboard and glass firmly together, then quickly turn the glass upside down. The water will stay inside the glass due to air pressure, demonstrating the balance between gravity and air pressure.

Rolling Race

Set up a ramp using books or a board. Have kids release different objects (marbles, toy cars) from the top of the ramp and see which one reaches the bottom first. Discuss how gravity affects the speed of rolling objects. See how to set it up with toy cars , pumpkins , apples and plastic Easter eggs .

Gravity-Powered Pendulum Painting

Attach a small container with paint to the bottom of a pendulum (a string with a weight at the end). Set the pendulum in motion and observe how it creates unique patterns on a piece of paper beneath it.

Crumpled Paper Drop

Crumple two pieces of paper into balls, one larger and one smaller. Drop them both at the same time and discuss how their sizes and air resistance affect their falling speed.

Balancing Act

Have kids experiment with balancing different objects on their fingertips. Discuss how the weight and shape of objects affect their balance due to the force of gravity. Have fun balancing animal puppets , mobile of paper shapes , pumpkins , and paper apples .

Egg Drop Challenge

Provide kids with materials like straws, rubber bands, tape, and newspapers. Challenge them to design a structure that will protect a raw egg when dropped from a certain height, demonstrating how objects experience less impact force when they have more time to slow down (larger parachutes or cushioning). See our egg drop ideas for younger and older students.

Water Wheel

Build a simple water wheel using a plastic container, a stick, and a paper cup. Place the water wheel under a steady stream of water and observe how gravity causes the wheel to turn. See how to build a simple water wheel here.

What Is Gravity?

Earth’s gravity is the force that keeps everything on the planet’s surface and makes things fall to the ground. Good thing!

Imagine you are standing on the ground, and there’s an invisible force pulling you down toward the Earth. That force is called gravity. It’s like a giant magnet that attracts everything with mass toward the center of the Earth.

The Earth is super big and has a lot of mass, which means it has a strong pull. That’s why we don’t float away into space like astronauts do when they’re far from Earth. Instead, gravity keeps us firmly planted on the ground.

Have you ever watched a NASA video of an astronaut floating around inside his/her ship?

The Moon also has gravity, but its pull is not as strong because it’s much smaller than Earth. That’s why astronauts can jump higher on the Moon than on Earth! Even if you can jump really high, you’ll still come back down!

Now, the Earth’s gravity doesn’t just work on you; it also works on everything around you, living and nonliving! It pulls down the trees, the buildings, and even the air you breathe.

That’s why things always fall when you drop them. The Earth’s gravity is pulling them like the glass of milk that my son knocked off the table this morning! When you throw a ball up in the air, it comes back down because of gravity!

Gravity is a fantastic force that keeps our feet on the ground, helps things stay where they are, and makes the world work together. Without gravity, everything would be floating around in space. So, we can thank Earth’s gravity for making our planet such a fantastic place to live!

Have younger kiddos? Check out these fun gravity activities for preschool and kindergarten.

Gravity Defined

For older kids, a more in-depth understanding of how gravity affects objects involves exploring the concepts of gravitational force, mass, distance, and the universal law of gravitation proposed by Isaac Newton. You can find more science terms explained here.

Gravitational Force

Gravity is the force of attraction between all objects with mass. The greater the mass of an object, the stronger its gravitational pull. This force keeps planets in orbit around the Sun and objects on Earth grounded.

Mass is the amount of matter in an object. The more massive a thing is, the more gravitational force it exerts and experiences. The relationship between mass and gravitational force is directly proportional: if you double the mass of an object, its gravitational force doubles as well.

The distance between two objects also affects the gravitational force between them. The greater the distance, the weaker the gravitational force. This relationship follows the inverse square law, which means that if you double the distance between two objects, the gravitational force becomes one-fourth as strong.

Universal Law of Gravitation

Isaac Newton formulated a law that describes how gravitational force works universally. It states that every object with mass attracts every other object with mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Read about Isaac Newton’s famous experiment below.

When an object falls under the influence of gravity alone, it is said to be in free fall. Without air resistance, all objects fall at the same rate regardless of their masses. This is known as the principle of equivalence, demonstrated famously by Galileo dropping objects from the Leaning Tower of Pisa.

Weight is the force of gravity acting on an object’s mass. It is different from mass, as it depends on both mass and acceleration due to gravity. Weight is often measured in newtons (N) or pounds (lb) and is calculated using the equation:

Weight = mass x acceleration due to gravity

Understanding these concepts helps kids comprehend gravity’s role in the universe and how it influences the behavior of objects of different masses and distances.

The Most Famous Gravity Experiment

Sir Isaac Newton is famous for many contributions to physics, and his experiments with gravity are among his most renowned works. One of the key experiments associated with Newton’s study of gravity is often called the “Newton’s Falling Apple,” which is a story rather than a controlled experiment.

According to the legend, Newton was sitting under an apple tree in his garden when he saw an apple fall to the ground. This event got him thinking about the force that caused the apple to fall. Newton realized that the same force, gravity, was responsible for the apple’s fall and the motion of bodies in space like the Moon and planets.

While this story is well-known, it’s important to note that it wasn’t a formal experiment. However, Newton conducted a series of experiments and observations to develop his laws of motion and the law of universal gravitation. These experiments and observations included:

• Prism Experiments: Newton’s experiments with prisms and light led to his groundbreaking work on optics, which is separate from gravity but an important part of his overall scientific contributions. See Newton’s color wheel spinner.
• Mathematical Calculations: Newton used mathematics to formulate his laws of motion and universal gravitation. He developed the mathematics of calculus to help describe and predict the behavior of objects under the influence of gravity.
• Kepler’s Laws: Newton built upon Johannes Kepler’s laws of planetary motion to develop his laws of universal gravitation. Kepler’s work was based on extensive astronomical observations.

So, while there isn’t a specific experiment directly related to the falling apple, Newton’s contributions to our understanding of gravity are based on a combination of observations, mathematical calculations, and experiments.

Have fun with physics! Check out our complete list of easy physics experiments.

Tips For Teaching Kids About Gravity

1. keep it hands-on.

Kids learn best through hands-on experiences, especially when it comes to abstract concepts like gravity. These gravity experiments below allow them to directly interact with materials and observe concrete examples of gravity in action, making scientific concepts more tangible and understandable.

2. Predict-Observation-Explanation Cycle

Use the scientific method ‘s basic cycle of predicting outcomes, making observations, and explaining results. This helps kids develop critical thinking skills, and an understanding of how science works. Learn more about the scientific method for kids.

3. Variety of Learning Styles

These activities cater to various learning styles. Some children learn best by seeing, others by doing, and some by discussing. These experiments encompass all these styles, ensuring that different types of learners can benefit.

4. Use Real Life Applications

Many of these experiments represent everyday situations, such as dropping objects or rolling things down ramps. This connection to real life helps children see the relevance of science in their world and apply concepts of gravity when they are not in the classroom.

You Might Also Like Real World STEM Project Template

5. Encourage Curiosity

Encourage curiosity and exploration in kids by giving them opportunities to ask questions and seek answers. This is how they develop a natural sense of wonder about the world around them, fostering a lifelong interest in learning.

Grab your FREE printable science worksheets!

Helpful Science Resources To Get You Started

Here are a few resources that will help you introduce science more effectively to your kiddos or students and feel confident yourself when presenting materials. You’ll find helpful free printables throughout.

• Best Science Practices (as it relates to the scientific method)
• Science Vocabulary
• 8 Science Books for Kids
• All About Scientists
• Science Supplies List
• Science Tools for Kids
• Join us in the Club

Printable Science Projects For Kids

If you’re looking to grab all of our printable science projects in one convenient place plus exclusive worksheets and bonuses like a STEAM Project pack, our Science Project Pack is what you need! Over 300+ Pages!

• 90+ classic science activities  with journal pages, supply lists, set up and process, and science information.  NEW! Activity-specific observation pages!
• Best science practices posters  and our original science method process folders for extra alternatives!
• Be a Collector activities pack  introduces kids to the world of making collections through the eyes of a scientist. What will they collect first?
• Know the Words Science vocabulary pack  includes flashcards, crosswords, and word searches that illuminate keywords in the experiments!
• My science journal writing prompts  explore what it means to be a scientist!!
• Bonus STEAM Project Pack:  Art meets science with doable projects!
• Bonus Quick Grab Packs for Biology, Earth Science, Chemistry, and Physics.

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Science Experiments for Kids: Learning About Gravity

Up, up, and away: fun and easy gravity experiments for kids.

Table of Contents

Amaze your friends and family with a science show. Ask your audience to predict the outcome of each of these easy science experiments about gravity .

All objects on Earth are pulled toward the planet’s center by the force of gravity. Gravity is the force that makes a basketball swish through a hoop. Gravity is the force that makes your glass of juice crash to the floor when it slips out of your hand. Gravity is the force that keeps your feet on the ground when you go for a walk. As Judy Breckenridge points out in Simple Physics Experiments with Everyday Materials, “Without gravity we would all float off into outer space.” Hooray for gravity!

In this post, we will share some of the best gravity experiments that you can do with your kids, using everyday materials that you can find at home. From balloon rockets to pendulum painting, these experiments will keep your kids entertained and educated all at once. Get ready to inspire your little ones with the wonder of science!

Quick Introduction to Gravity

Gravity is the force by which a planet or other body draws objects toward its center. The force of gravity keeps all of the planets in orbit around the sun . Earth’s gravity is what keeps you on the ground and what makes things fall. It’s what holds the atmosphere in place so we can breathe and it’s what allows us to use rockets to launch into space.

Gravity is a fundamental force of nature that is present everywhere in the universe. It is what gives objects weight and is responsible for the motion of planets, stars, and galaxies. Without gravity, the universe as we know it would not exist.

Understanding the basics of gravity is important for many areas of science, including physics, astronomy, and engineering. By conducting simple gravity experiments, kids can learn about this fascinating force of nature in a fun and engaging way. From exploring how gravity affects different objects to create their own mini-gravity wells, there are many exciting experiments that kids can do to learn more about this fundamental force.

Science Experiment: Dropping objects of different weights

Experiment 1: Dropping objects of different weights is a classic gravity experiment that teaches kids about mass and gravity. All you need for this experiment are a few objects of different weights, like a feather, a rock, and a rubber ball, and a place to drop them from, like a balcony or a staircase.

Start by asking your child what they think will happen when they drop each object. Will the heavier object fall faster or slower than the lighter object? Then, drop each object one by one and observe what happens.

You’ll find that all objects fall at the same rate, regardless of their weight. This is because gravity pulls all objects towards the earth at the same acceleration rate , which is 9.8 meters per second squared. You can explain this to your child by saying that the earth’s gravity pulls all objects towards it with the same force, so they all fall at the same rate.

You can also ask your child to try dropping the objects from different heights and see if that affects the way they fall. This will give them a better understanding of how gravity works and how it affects objects. This experiment is a great way to introduce your child to science and to help them understand the world around them.

Science Experiment: Making a gravity well

A gravity well is a concept that is used to represent the way gravity affects the path of objects in space. In this experiment, your child will learn how gravity works by creating a visual representation of a gravity well.

Materials needed:

• A large, flat container (such as a baking tray)
• A small ball (such as a marble)
• Food coloring (optional)

Instructions:

• Pour a thin layer of flour into the flat container, making sure it covers the entire surface.
• Place the small ball in the center of the container.
• If desired, add a few drops of food coloring to the flour around the ball.
• Use your fingers to gently press down on the flour around the ball, creating a depression in the flour. The depression should be deepest around the ball and gradually become shallower as you move away from the ball.
• Observe how the ball remains in the center of the depression you created in the flour. This is because the flour represents the fabric of space-time and the ball is pulled towards the center by the force of gravity.

To take the experiment further, you can try adding more balls to the container and observe how they behave differently depending on their mass and distance from the center of gravity well. This experiment is a great way to introduce your child to the fascinating concept of gravity and spark their curiosity about the world around them.

Science Experiment: Magnets to simulate gravity

Using magnets to simulate gravitational pull can be a fun and interactive way to teach kids about gravity. In this experiment, you’ll need a few simple materials such as a magnet, paper clips, and a thin piece of string.

First, tie the string to the magnet and then attach a few paper clips to the other end of the string. Next, hold the magnet above one of the paper clips and release it. You’ll notice that the paper clip is attracted to the magnet and will follow it as it falls. This is similar to how gravity works, as objects with more mass are attracted to each other.

You can also use this experiment to show how different objects with varying masses will be affected by gravity. Try attaching different objects to the string, such as a feather, a coin, and a small toy car. You’ll notice that the magnet has a stronger pull on the coin and car due to their greater mass, while the feather will not be affected as much because it has less mass.

This experiment is a great way to introduce kids to the concept of gravity in a fun and interactive way. It can also be a starting point for further discussions about the laws of physics and the universe around us.

Science Experiment: Making a simple pendulum

Making a simple pendulum is a fun and easy way to learn about gravity and motion. For this experiment, you will need a few simple materials:

• A piece of string or thread
• A small weight, such as a paperclip or washer
• A sturdy surface to attach the string

To make your pendulum, tie the string around your weight and attach the other end to your sturdy surface. You can use a table, a chair, or any other surface that won’t move around too much.

Once your pendulum is set up, give it a gentle push to set it swinging. Watch how it moves back and forth, and notice how the speed and direction of the pendulum change.

To make your experiment even more fun, try changing the length of the string or the weight of the pendulum. How does this affect the way the pendulum moves? Can you predict how the pendulum will behave based on these changes?

Making a simple pendulum is a great way to introduce kids to the concept of gravity and motion. Plus, it’s a fun and easy experiment that can be done with materials you probably already have at home.

Science Experiment: Gravity and Air Resistance

Before performing this experiment, show your audience a shoe and a flat piece of notebook or copy paper. Explain that you will be dropping both objects from the same height. Then ask your audience these questions:

• Who thinks the shoe will hit the floor first?
• Who thinks the paper will hit the floor first?
• Who thinks both objects will hit the floor at the same time?

Experiment:

• Hold the shoe in one hand and the paper in the other.
• Hold both objects high in front of you at equal heights.
• Release both objects at the same time.

Observation: The shoe hits the floor first.

Explanation: Because of the paper’s shape, its fall is slowed by air pushing up against its under-surface – this slowing effect is called air resistance.

Science Experiment: Effect of Gravity on Plant Growth

One of the most interesting aspects of gravity is its effect on living organisms. In this experiment, we’ll be looking at how gravity affects plant growth.

To start, you’ll need to gather some materials. You’ll need:

• 2 identical plants
• 2 identical pots
• Begin by filling both pots with soil and planting one of your plants in each pot.
• Water them both thoroughly and place them side by side in a sunny location.
• Now comes the fun part. Take one of the pots and place it on its side. This will cause the plant inside to be growing at a 90-degree angle to the ground. Leave the other pot standing upright.
• Over the next few weeks, observe the growth of both plants. Measure their height using the ruler and take note of any other differences you can see.

What you should find is that the plant growing at a 90-degree angle to the ground will grow differently than the plant growing upright. This is because gravity plays an important role in how plants grow. The plant growing on its side will have to work harder to grow against the pull of gravity, resulting in a different growth pattern than the one growing normally.

This experiment is a great way to teach kids about the effects of gravity on living organisms and can lead to further discussions about how gravity affects everything from trees to humans. Have fun experimenting!

Science Experiment: Gravity and Weight

Before performing this experiment, show your audience the shoe and the piece of paper crumpled into a ball. Explain that you will be dropping both objects from the same height. Then ask your audience these questions:

• Who thinks the paper ball will hit the floor first?
• Hold the shoe in one hand and the paper ball in the other.

Observation: The shoe and the paper ball hit the floor at the same time.

Explanation: Even though the earth exerts more pull on a heavier object, a lighter object experiences a greater degree of acceleration, meaning that it moves at a greater speed. Consequently, objects of different weights fall at the same rate when other forces such as air resistance are not a factor.

Science Experiment: Center of Gravity

Now it’s time for audience participation in your science show. Ask for volunteers for each of these exercises involving the center of gravity:

Pick up a penny

Ask a volunteer to stand against a wall with his feet together, heels pressed against the wall. Place a penny about one foot away on the floor in front of him. Ask him to pick up the penny without moving his feet or bending his knees. Can he do it?

Lift your left foot

Ask a volunteer to stand with her right side against a wall, pressing her right foot and cheek against it. Instruct her to lift her left foot off the floor. Can she do it?

Jump forward

Ask a volunteer to bend forward and grab his toes, keeping his knees slightly bent. Tell him to jump forward without letting go of his toes. Can he do it?

Ask a volunteer to sit in a straight-backed chair. Tell her to keep her back straight, her feet flat on the floor, and her arms folded across her chest. Then ask her to stand up. Can she do it?

Observation: Because all of these tasks restrict the center of gravity, it’s almost impossible for a person to perform any of them.

Explanation: As far as gravity is concerned, the weight of an object is concentrated at a single center point. The center of gravity for an object with a regular shape – the Earth, for example – is located at its geometric center. However, in irregularly shaped objects – the human body , for instance – the center of gravity moves around. If you try to shift too far away from your center of gravity, you’ll lose your balance.

Share Fun Science Experiments With Family and Friends

Learning new things about the world around you is fun and exciting. It’s even more fun when you share your discoveries with your family and friends. Gravity is just one of the interesting forces of nature – there are many more to explore and share.

Final thoughts on teaching kids about gravity

Gravity is a fascinating concept that has been studied and explored by scientists for centuries. Teaching kids about gravity can be a fun and engaging way to introduce them to the wonders of science and the natural world around them.

By conducting simple experiments and activities, kids can learn about the basic principles of gravity and how it affects the world around us. From dropping objects of different weights to observing how objects fall at the same rate, there are endless ways to explore this fascinating force.

Not only can teaching kids about gravity be fun, but it can also help to develop their critical thinking skills, problem-solving abilities, and scientific knowledge. By encouraging kids to ask questions and explore the world around them, we can inspire a love of learning and an appreciation for science that can last a lifetime.

Teaching kids about gravity can be a fun and rewarding experience for both children and adults alike. By providing opportunities for hands-on exploration and discovery, we can help kids develop a lifelong love of science and learning. So, let’s get started and see where the wonders of gravity take us!

• Bardhan-Quallen, Sudipta. Championship Science Fair Projects . NY: Sterling Publishing, 2004.
• Breckenridge, Judy. Simple Physics Experiments with Everyday Materials . NY: Sterling Publishing, 1993.
• Cobb, Vicki. Bet You Can’t! NY: Lothrop, Lee & Shepard Books, 1980.

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Six Ideas For Gravity Science Projects - From Beginner to Advanced

• Dawn Marcotte
• Categories : Great ideas for science fair projects
• Tags : Homework help & study guides

Gravity Science Experiments

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Every time you fall down you’re experiencing the pull of gravity. Gravity is defined as the force that pulls everything on earth toward the center of the earth. Sir Isaac Newton, rumored to have discovered gravity when he saw an apple fall from a tree, wrote mathematical formulas that proved the truth of experiments previously performed by Galileo centuries earlier. Some of these experiments can be replicated by students to learn about the force of gravity and how it relates to the motion of objects on earth.

Early Grade Gravity Science Projects

Observation Grade school students are just beginning to explore the world of science. Simple experiments to test gravity and how it affects the balance of objects will provide experience with observation. Students can observe gravity by balancing a pencil on their finger. Gravity is pulling the ends down toward the center of the earth, and if the pencil is not properly balanced it will fall off the finger. Expand the experiment by tying small objects to one end of the pencil to determine how this changes the point of balance. Marble Dropping Students can explore how gravity affects objects as they impact the Earth in a simple experiment using flour, a baking tray and a marble. Pour enough flour into the baking pan to create a layer one-inch deep. Spread newspaper under the pan of flour to make clean-up easier. Drop the marble onto the pan of flour. Carefully remove the marble from the pan and observe the crater in the flour. Drop the marble from different heights to test if the size of the crater will change. This experiment can also be done outside with rocks and a large area of mud. This experiment will allow students to better understand what happens when a meteor hits the earth. How Weight Affects Gravity Use a ping-pong ball and a piece of clay to test how the weight of objects affects gravity. Cut a ping-pong ball in half. Press a small piece of clay into the bottom of the first half ball. Insert a straw vertically into the clay. Pull the straw down toward the table and then release. The straw should flip back into a vertical position. Repeat the experiment with various sizes of clay balls attached to the top of the straw and observe the results.

Middle School Projects

Create a Gravity Measuring Device Middle school students can perform more advanced experiments. Students can explore the concept of how gravity affects balance and create their own gravity device with a candle, a needle, two glasses and two saucers. Cut off the bottom half-inch of a long candle to expose the wick. Push a needle through the center of the candle along its horizontal axis. Use the needle to balance the candle on the lip of two glasses. Place the saucers under each end of the candle so they catch the wax as it melts. Light both ends of the candle. Gravity will pull the heavy end down and cause it to drip more wax, thus making the other end heavier and causing the candle to oscillate between the two ends as the weight changes. Inclined Planes Another experiment is to use an inclined plane to test how gravity effects the movement of objects. Students can time how long a ball or car takes to roll down planes of different heights. A simple ramp made with a piece of plywood and a stack of books will provide an inclined plane that can be changed easily.

High School Experiments

Galileo’s Original Experiment High school students can mimic Galileo’s research: They can measure the speed of falling objects relating the time of the fall to the objects’ weight and size. Use marbles made of various sizes but of the same material and drop them from the same height. They should reach the floor at the same time. Use a marble and a ball the same size, but of different material, to identify the impact of air resistance on falling objects. Inclined Planes - Advanced Repeat the inclined plane experiment with model cars of various sizes. Test the importance of friction by laying a piece of fabric on the inclined plane and comparing the speed of the cars as they roll down the inclined plane. Modify the wheels of the cars to be larger or smaller to test the affect. Sources for additional experiments: Science Buddies https://www.juliantrubin.com/bigten/galileofallingbodies.html Isaac Newton Portrait Other science experiments - baking soda and vinegar Other science experiments - water and oil

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01 gravit y/.

Observations

How do celestial bodies warp the fabric of space-time and interact with each other?

ABOUT THIS EXPERIMENT

We tend think of gravity as a force of attraction, but it’s also been described as a curvature of space-time in the presence of mass. This National Science and Technology Medals Foundation interactive invites you to bend the fabric of space-time and observe the resulting gravitational forces. By adjusting the variables of mass, distance, and velocity, you can trigger orbits, collisions, and escape velocities in space.

The National Science and Technology Medals Foundation celebrates the amazing individuals who have won the highest science, technology, engineering, and mathematics award in the United States.

Jeremiah P. Ostriker

Studied the gravitational effects of dark matter.

John A. Wheeler

Popularized Einstein’s theory of relativity after WWII.

Edward Witten

Charted the topology of space-time.

Robert H. Dicke

Predicted the discovery of the Big Bang echo.

Allan R. Sandage

Discovered the first quasar.

See All Laureates in Theory & Foundations

Your universe has reached critical mass and collapsed. Fascinating!

Learn more about the pioneering scientists and thinkers behind this experiment at nationalmedals.org

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The inverse square law

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• Table Of Contents

The essence of Newton’s theory of gravitation is that the force between two bodies is proportional to the product of their masses and the inverse square of their separation and that the force depends on nothing else. With a small modification, the same is true in general relativity. Newton himself tested his assumptions by experiment and observation. He made pendulum experiments to confirm the principle of equivalence and checked the inverse square law as applied to the periods and diameters of the orbits of the satellites of Jupiter and Saturn.

Recent News

During the latter part of the 19th century, many experiments showed the force of gravity to be independent of temperature , electromagnetic fields, shielding by other matter, orientation of crystal axes, and other factors. The revival of such experiments during the 1970s was the result of theoretical attempts to relate gravitation to other forces of nature by showing that general relativity was an incomplete description of gravity. New experiments on the equivalence principle were performed, and experimental tests of the inverse square law were made both in the laboratory and in the field.

There also has been a continuing interest in the determination of the constant of gravitation, although it must be pointed out that G occupies a rather anomalous position among the other constants of physics . In the first place, the mass M of any celestial object cannot be determined independently of the gravitational attraction that it exerts. Thus, the combination G M , not the separate value of M , is the only meaningful property of a star , planet , or galaxy . Second, according to general relativity and the principle of equivalence, G does not depend on material properties but is in a sense a geometric factor. Hence, the determination of the constant of gravitation does not seem as essential as the measurement of quantities like the electronic charge or Planck’s constant . It is also much less well determined experimentally than any of the other constants of physics.

Experiments on gravitation are in fact very difficult, as a comparison of experiments on the inverse square law of electrostatics with those on gravitation will show. The electrostatic law has been established to within one part in 10 16 by using the fact that the field inside a closed conductor is zero when the inverse square law holds. Experiments with very sensitive electronic devices have failed to detect any residual fields in such a closed cavity. Gravitational forces have to be detected by mechanical means, most often the torsion balance , and, although the sensitivities of mechanical devices have been greatly improved, they are still far below those of electronic detectors. Mechanical arrangements also preclude the use of a complete gravitational enclosure. Last, extraneous disturbances are relatively large because gravitational forces are very small (something that Newton first pointed out). Thus, the inverse square law is established over laboratory distances to no better than one part in 10 4 .

Recent interest in the inverse square law arose from two suggestions. First, the gravitational field itself might have a mass, in which case the constant of gravitation would change in an exponential manner from one value for small distances to a different one for large distances over a characteristic distance related to the mass of the field. Second, the observed field might be the superposition of two or more fields of different origin and different strengths, one of which might depend on chemical or nuclear constitution. Deviations from the inverse square law have been sought in three ways:

• The law has been checked in the laboratory over distances up to about 1 metre.
• The effective value of G for distances between 100 metres and 1 km has been estimated from geophysical studies.
• There have been careful comparisons of the value of the attraction of Earth as measured on the surface and as experienced by artificial satellites.

Early in the 1970s an experiment by the American physicist Daniel R. Long seemed to show a deviation from the inverse square law at a range of about 0.1 metre. Long compared the maximum attractions of two rings upon a test mass hung from the arm of a torsion balance. The maximum attraction of a ring occurs at a particular point on the axis and is determined by the mass and dimensions of the ring. If the ring is moved until the force on the test mass is greatest, the distance between the test mass and the ring is not needed. Two later experiments over the same range showed no deviation from the inverse square law. In one, conducted by the American physicist Riley Newman and his colleagues, a test mass hung on a torsion balance was moved around in a long hollow cylinder. The cylinder approximates a complete gravitational enclosure and, allowing for a small correction because it is open at the ends, the force on the test mass should not depend on its location within the cylinder. No deviation from the inverse square law was found. In the other experiment, performed in Cambridge, Eng., by Y.T. Chen and associates, the attractions of two solid cylinders of different mass were balanced against a third cylinder so that only the separations of the cylinders had to be known; it was not necessary to know the distances of any from a test mass. Again no deviation of more than one part in 10 4 from the inverse square law was found. Other, somewhat less-sensitive experiments at ranges up to one metre or so also have failed to establish any greater deviation.

The geophysical tests go back to a method for the determination of the constant of gravitation that had been used in the 19th century, especially by the British astronomer Sir George Airy . Suppose the value of gravity g is measured at the top and bottom of a horizontal slab of rock of thickness t and density d . The values for the top and bottom will be different for two reasons. First, the top of the slab is t farther from the centre of Earth, and so the measured value of gravity will be less by 2( t / R ) g , where R is the radius of Earth. Second, the slab itself attracts objects above and below it toward its centre; the difference between the downward and upward attractions of the slab is 4π G t d . Thus, a value of G may be estimated. Frank D. Stacey and his colleagues in Australia made such measurements at the top and bottom of deep mine shafts and claimed that there may be a real difference between their value of G and the best value from laboratory experiments. The difficulties lie in obtaining reliable samples of the density and in taking account of varying densities at greater depths. Similar uncertainties appear to have afflicted measurements in a deep bore hole in the Greenland ice sheet .

New measurements have failed to detect any deviation from the inverse square law. The most thorough investigation was carried out from a high tower in Colorado. Measurements were made with a gravimeter at different heights and coupled with an extensive survey of gravity around the base of the tower. Any variations of gravity over the surface that would give rise to variations up the height of the tower were estimated with great care. Allowance was also made for deflections of the tower and for the accelerations of its motions. The final result was that no deviation from the inverse square law could be found.

A further test of the inverse square law depends on the theorem that the divergence of the gravity vector should vanish in a space that is free of additional gravitational sources. An experiment to test this was performed by M.V. Moody and H.J. Paik in California with a three-axis superconducting gravity gradiometer that measured the gradients of gravity in three perpendicular directions. The sum of the three gradients was zero within the accuracy of the measurements, about one part in 10 4 .

The absolute measurements of gravity described earlier, together with the comprehensive gravity surveys made over the surface of Earth, allow the mean value of gravity over Earth to be estimated to about one part in 10 6 . The techniques of space research also have given the mean value of the radius of Earth and the distances of artificial satellites to the same precision. Thus, it has been possible to compare the value of gravity on Earth with that acting on an artificial satellite. Agreement to about one part in 10 6 shows that, over distances from the surface of Earth to close satellite orbits, the inverse square law is followed.

Thus far, all of the most reliable experiments and observations reveal no deviation from the inverse square law.

Experiments with ordinary pendulums test the principle of equivalence to no better than about one part in 10 5 . Eötvös obtained much better discrimination with a torsion balance. His tests depended on comparing gravitational forces with inertial forces for masses of different composition . Eötvös set up a torsion balance to compare, for each of two masses, the gravitational attraction of Earth with the inertial forces due to the rotation of Earth about its polar axis. His arrangement of the masses was not optimal, and he did not have the sensitive electronic means of control and reading that are now available. Nonetheless, Eötvös found that the weak equivalence principle ( see above Gravitational fields and the theory of general relativity ) was satisfied to within one part in 10 9 for a number of very different chemicals, some of which were quite exotic. His results were later confirmed by the Hungarian physicist János Renner. Renner’s work has been analyzed recently in great detail because of the suggestion that it could provide evidence for a new force. It seems that the uncertainties of the experiments hardly allow such analyses.

Eötvös also suggested that the attraction of the Sun upon test masses could be compared with the inertial forces of Earth’s orbital motion about the Sun. He performed some experiments, verifying equivalence with an accuracy similar to that which he had obtained with his terrestrial experiments. The solar scheme has substantial experimental advantages, and the American physicist Robert H. Dicke and his colleagues, in a careful series of observations in the 1960s (employing up-to-date methods of servo control and observation), found that the weak equivalence principle held to about one part in 10 11 for the attraction of the Sun on gold and aluminum. A later experiment by the Russian researcher Vladimir Braginski , with very different experimental arrangements, gave a limit of about one part in 10 12 for platinum and aluminum.

Galileo’s supposed experiment of dropping objects from the Leaning Tower of Pisa has been reproduced in the laboratory with apparatuses used to determine the absolute value of gravity by timing a falling body. Two objects, one of uranium, the other of copper, were timed as they fell. No difference was detected.

Laser-ranging observations of the Moon in the LAGEOS ( la ser geo dynamic s atellites) experiment have also failed to detect deviations from the principle of equivalence. Earth and the Moon have different compositions , the Moon lacking the iron found in Earth’s core. Thus, if the principle of equivalence were not valid, the accelerations of Earth and the Moon toward the Sun might be different. The very precise measurements of the motion of the Moon relative to Earth could detect no such difference.

By the start of the 21st century, all observations and experiments on gravitation had detected that there are no deviations from the deductions of general relativity, that the weak principle of equivalence is valid, and that the inverse square law holds over distances from a few centimetres to thousands of kilometres. Coupled with observations of electromagnetic signals passing close to the Sun and of images formed by gravitational lenses, those observations and experiments make it very clear that general relativity provides the only acceptable description of gravitation at the present time.

The constant of gravitation has been measured in three ways:

• The comparison of the pull of a large natural mass with that of Earth
• The measurement with a laboratory balance of the attraction of Earth upon a test mass
• The direct measurement of the force between two masses in the laboratory

The first approach was suggested by Newton; the earliest observations were made in 1774 by the British astronomer Nevil Maskelyne on the mountain of Schiehallion in Scotland. The subsequent work of Airy and more-recent developments are noted above. The laboratory balance method was developed in large part by the British physicist John Henry Poynting during the late 1800s, but all the most recent work has involved the use of the torsion balance in some form or other for the direct laboratory measurement of the force between two bodies. The torsion balance was devised by Michell, who died before he could use it to measure G . Cavendish adapted Michell’s design to make the first reliable measurement of G in 1798; only in comparatively recent times have clearly better results been obtained. Cavendish measured the change in deflection of the balance when attracting masses were moved from one side to the other of the torsion beam. The method of deflection was analyzed most thoroughly in the late 1800s by Sir Charles Vernon Boys , an English physicist, who carried it to its highest development, using a delicate suspension fibre of fused silica for the pendulum. In a variant of that method, the deflection of the balance is maintained constant by a servo control.

The second scheme involves the changes in the period of oscillation of a torsion balance when attracting masses are placed close to it such that the period is shortened in one position and lengthened in another. Measurements of period can be made much more precisely than those of deflection, and the method, introduced by Carl Braun of Austria in 1897, has been used in many subsequent determinations. In a third scheme the acceleration of the suspended masses is measured as they are moved relative to the large attracting masses.

In another arrangement a balance with heavy attracting masses is set up near a free test balance and adjusted so that it oscillates with the same period as the test balance. The latter is then driven into resonant oscillations with an amplitude that is a measure of the constant of gravitation. The technique was first employed by J. Zahradnicek of Czechoslovakia during the 1930s and was effectively used again by C. Pontikis of France some 40 years later.

Suspensions for two-arm balances for the comparison of masses and for torsion balances have been studied intensively by T.J. Quinn and his colleagues at the International Bureau of Weights and Measures , near Paris, and they have found that suspensions with thin ribbons of metal rather than wires provide the most stable systems. They have used balances with such suspensions to look for deviations from the predictions of general relativity and have most recently used a torsion balance with ribbon suspension in two new determinations of the constant of gravitation.

Many new determinations of G were made in the five years from 1996 to 2001 and are summarized in the table. However, despite the great attention given to systematic errors in those experiments, it is clear from the range of the results that serious discrepancies, much greater than the apparent random errors, still afflict determinations of G . In 2001 the best estimate of G was taken to be 6.67553 × 10 −11 m 3 s −2 kg −1 . Results before 1982 indicate a lower value, perhaps 6.670, but those from 1996 onward suggest a higher value.

The 20th-century English physicist P.A.M. Dirac , among others, suggested that the value of the constant of gravitation might be proportional to the age of the universe; other rates of change over time also have been proposed. The rates of change would be extremely small, one part in 10 11 per year if the age of the universe is taken to be 10 11 years; such a rate is entirely beyond experimental capabilities at present. There is, however, the possibility of looking for the effects of any variation upon the orbit of a celestial body, in particular the Moon. It has been claimed from time to time that such effects may have been detected. As yet, there is no certainty.

The constant of gravitation is plainly a fundamental quantity, since it appears to determine the large-scale structure of the entire universe. Gravity is a fundamental quantity whether it is an essentially geometric parameter , as in general relativity, or the strength of a field , as in one aspect of a more-general field of unified forces. The fact that, so far as is known, gravitation depends on no other physical factors makes it likely that the value of G reflects a basic restriction on the possibilities of physical measurement, just as special relativity is a consequence of the fact that, beyond the shortest distances, it is impossible to make separate measurements of length and time.

Falling for Gravity

Calculate the acceleration of gravity using simple materials, a cell phone, and a computer to record, watch, and analyze the motion of a dropped object.

• Two-meter measuring tape or two meter sticks
• Masking tape
• Small, cheap, rugged flashlight
• Towel, carpeting, or other soft material for the dropped flashlight to land on
• Digital camera with video capability (the HD camera on a phone should work fine)
• Computer with a program that lets you play videos frame by frame (not shown)
• Pencil and paper to record data (not shown)

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27 Gravity Activities For Elementary Students: Experiments And Resources

December 28, 2023 //  by  Alison Vrana

The concept of gravity is one of the core concepts that are taught in elementary science classes. Students also need to be able to understand how gravity works in order to move on to upper-level science classes like physics. The lessons, activities, and gravity science experiments below teach kids how gravity and motion work in tandem. These lessons are aimed at creating life-long science interests so check out our 27 amazing activities that’ll help you do just that! 

1. Watch “How Gravity Works For Kids”

This animated video is perfect to start a unit. The video explains gravity in simple science vocabulary that students can understand. As an added bonus, this video can be shared with absent students so they don’t get behind.

Learn More: YouTube

2. DIY Balance Scales

This science activity can be used to teach motion and gravity at any age. Using hangars, cups, and other household items, students will have to determine which items balance and which items are heavier than others. Teachers can then talk about the relationship between weight and gravity.

Learn More: Go Science Kids

3. Egg Drop Experiment

The egg drop experiment is a student-friendly science activity for elementary students. There are different ways to complete the experiment which include building a paper cradle or using a balloon drop to protect the egg. Kids will love trying to protect their eggs as they’re dropped from a high vantage point.

Learn More: Science Sparks

4. Gravity Drop

This gravity drop activity is super simple and requires very little prep from the teacher. Students will drop different items and test how each item falls. 

Learn More: Stay At Home Educator

5. Marble Maze

The marble maze is a hands-on science investigation task that will teach kids about gravity and motion. Kids will build different mazes and observe how the marble travels through the maze based on different ramp heights.

Learn More: Investors Of Tomorrow

6. DIY Gravity Well

The DIY gravity well is a quick demonstration that students can complete at a learning center or as a group in class. Using a strainer, students can observe how an object travels from the top to the bottom. This great lesson also doubles as an opportunity to teach about speed.

7. Superhero Gravity Experiment

Kids will love combining their favorite superheroes with learning. In this experiment, children work in partners to experiment with how to make their superhero “fly”. They learn about different heights and textures to see how gravity helps the superhero move through the air.

Learn More: Teaching Ideas

8. Anti-Gravity Galaxy in a Bottle

This activity demonstrates how gravity and water work. Teachers can also connect this demonstration to the idea of friction. Students will make an “anti-gravity” galaxy in a bottle to see how glitter floats in the water.

Learn More: One Little Project

9. Gravity Book Read-aloud

Reading aloud is a great way to start the day or start a new unit with your elementary learners. There are several helpful books about gravity that kids will love. These books also explore science concepts like friction, motion, and other core ideas.

Learn More: CBC Public Library

10. Balancing Stick Sidekick Activity

This is a super simple activity that helps introduce kids to the concepts of balance and gravity. Teachers will give each student a popsicle stick, or a similar item, and have them try to balance the stick on their fingers. As students experiment, they will learn how to balance the sticks.

Learn More: Hands-On As We Grow

11. G is for Gravity Experiment

This is another good activity to introduce the concept of gravity in your primary classroom. Give your students a bunch of different objects of varying weights and sizes. The students will then drop them from a designated height whilst timing the drop with a stopwatch. What a fun way to learn how gravity relates to mass!

Learn More: PBS

12. Large Tube Gravity Experiment

This activity is a fun idea to introduce students to friction, motion, and gravity. Kids will experiment with how to get a car to travel faster down the tube. As students try different tube heights they will record real-time student data for their experiment.

13. Splat! Painting

This art lesson is a simple way to incorporate a cross-curricular lesson that teaches gravity. Students will use paint and different objects to see how the paint creates different shapes with the help of gravity.

Learn More: Fun A Day

14. Gravity Defying Beads

In this activity, students will use beads to demonstrate the concepts of inertia, momentum, and gravity. The beads are a fun tactile resource for this experiment, and as an added bonus, they make noise which adds to the appeal of a visual and auditory lesson.

Learn More: The Chaos And The Clutter

15. The Great Gravity Escape

This lesson is good for upper elementary students or advanced students who need more enrichment. The activity uses a water balloon and string to see how gravity can create an orbit. Teachers can then apply this concept to space crafts and planets.

Learn More: Teach Engineering

16. Center of Gravity

This lesson requires only a few resources and little preparation. Students will experiment with gravity and balance to discover different items’ centers of gravity. This hands-on experiment is super simple but teaches kids a lot about core gravity concepts.

Learn More: Teacher Source Blog

17. Gravity Spinner Craft

This gravity craft is a great lesson to wrap up your science unit. Kids will use common classroom resources to make a spinner that is controlled by gravity. This a fun way to bring science concepts to life for young learners.

Learn More: Teach Beside Me

18. The Spinning Bucket

This lesson shows the relationship between gravity and motion. A strong person will spin a bucket full of water and students will see how the motion of the bucket affects the trajectory of the water.

Learn More: Sciencing

19. Hole in the Cup

This activity demonstrates how objects in motion together stay in motion together. Teachers will use a cup with a hole at the bottom filled with water to demonstrate how the water will come out of the cup when the teacher is holding it because of gravity. If the teacher drops the cup, the water won’t spill out of the hole because the water and the cup are dropping together.

20. Water Defying Gravity

This is a cool experiment that seemingly defies gravity. All you need is a glass filled with water, an index card, and a bucket. The lesson will demonstrate how gravity affects objects differently to create the illusion of anti-gravity.

Learn More: Kidz Search

21. Gravity Painting

This crafty activity is another great way to incorporate gravity into a cross-curricular activity. Students will use paint and straws to create their very own gravity painting. This is perfect for 3rd- 4th-grade science class.

Learn More: Curiodyssey

22. Bottle Blast Off!

Kids will love building their own rockets using just air to launch them. Teachers can help students understand how rockets are able to travel into the sky despite gravity. This lesson requires a lot of student direction, but they will remember what they learn for a lifetime!

Learn More: Exploratorium

23. Falling Feather

5th-grade science teachers will love this experiment. Students will observe how objects fall at different accelerations if resistance in the air is present versus falling at the same acceleration if there is no resistance.

24. A Pencil, Fork, and Apple Experiment

This experiment uses just three objects to demonstrate how weight and gravity interact. Students will be able to visualize how the objects are able to balance because of gravity. This experiment is best conducted if the teacher demonstrates it at the front of the class for all to see.

Learn More: Kid Minds

25. Watch 360 Degree Zero Gravity

This video is great to incorporate into a gravity unit. Students will love seeing how zero gravity affects people and what astronauts look like in space.

26. Magnetism and Defying Gravity

This science experiment uses paper clips and magnets to help students determine if magnetism or gravity is stronger. Students will use their observation skills to determine which force is stronger before stating why.  

Learn More: Education

27. Textured Ramps

In this cool science activity, students will use different ramp heights and the variable of ramp texture to see how gravity and friction affect speed. This is another experiment that’s great for science centers or as a whole class demonstration.

Learn More: Teach Junkie

3 Unique Gravity Experiments to Try with Your Kids

Simply put, gravity is the force of the earth that pulls objects towards its core, preventing them from floating off into space. For many adults, explaining the concept of gravity to a child can seem daunting. However, through the use of the following gravity experiments for kids, children will gain a better grasp of gravity’s role in our everyday lives while also having some fun!

Paperclip Gravity Experiment

Most gravity experiments don’t require many materials. For this experiment you’ll use:

• Paper clips

First, tie one end of a piece of string to a paperclip and tie the other end around the stick. Repeat twice more so that the stick has three paper clips attached. Hold the stick up in the air, allowing the paperclips hang freely. Tilt the stick back and forth.

As is demonstrated, Earth’s gravity is continuously pulling our bodies and the objects around us to its core. Even when the stick is tilted, Earth’s gravitational pull exerts its force on the paper clips pulling them straight down toward the Earth.

Gravity Water Drop

This next experiment requires just three items:

• A paper cup

On the outside of the cup near the bottom, poke a hole using a pencil. Placing a finger over the hole, fill the cup with water. Remove your finger from the hole. You should find that the water flows out of the cup in an even, steady stream (if the water is not quite flowing smoothly, try poking a new hole and refill the cup with water). Next, holding your finger over the hole, fill the cup once again with water. Drop the cup, removing your finger from the hole at the same time. You’ll find that as the cup falls, no water flows out of the hole.

When you first held the cup in the air and removed your finger, gravity pulled the water down towards the ground and water pressure forced it out of the hole. However, when the cup and water fell at the same speed, there is no water pressure. Without this force, the water remains inside the cup as gravity pulls both to the ground.

Galileo’s Experiment

• A sturdy chair
• Various household items

Gather items of differing weights and sizes, such as a ball, action figure or doll, and a balloon. Have your child stand on top of the chair while holding the items. One at a time, have your child drop each item from the same height. Keep track of how long it takes each item to reach the ground.

Though many believe that larger, heavier items will hit the ground first, this is not true. The rate of Earth’s gravitational pull on all objects is the same regardless of weight. Given the absence of air resistance, each object should reach the floor at the same time. Do your finding support this?

Testing the laws of gravity (or defying them !) can be done in a variety of hands-on, entertaining ways around the house and at school. Experiments for kids like those above are a great way to get kids learning and asking important questions about the world around them.

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Science News

Galileo’s famous gravity experiment holds up, even with individual atoms.

Different types of atoms fall with the same acceleration due to gravity

Individual atoms fall at the same rate due to gravity, scientists report, reaffirming a concept called the equivalence principle.

vchal/iStock/Getty Images Plus

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By Emily Conover

October 28, 2020 at 6:00 am

According to legend, Galileo dropped weights off of the Leaning Tower of Pisa, showing that gravity causes objects of different masses to fall with the same acceleration. In recent years, researchers have taken to replicating this test in a way that the Italian scientist probably never envisioned — by dropping atoms.

A new study describes the most sensitive atom-drop test so far and shows that Galileo’s gravity experiment still holds up — even for individual atoms. Two different types of atoms had the same acceleration within about a part per trillion, or 0.0000000001 percent, physicists report in a paper in press in Physical Review Letters .

Compared with a previous atom-drop test, the new research is a thousand times as sensitive. “It represents a leap forward,” says physicist Guglielmo Tino of the University of Florence, who was not involved with the new study.

Researchers compared rubidium atoms of two different isotopes, atoms that contain different numbers of neutrons in their nuclei. The team launched clouds of these atoms about 8.6 meters high in a tube under vacuum. As the atoms rose and fell, both varieties accelerated at essentially the same rate, the researchers found.

In confirming Galileo’s gravity experiment yet again, the result upholds the equivalence principle, a foundation of Albert Einstein’s theory of gravity, general relativity. That principle states that an object’s inertial mass, which determines how much it accelerates when force is applied, is equivalent to its gravitational mass, which determines how strong a gravitational force it feels. The upshot: An object’s acceleration under gravity doesn’t depend on its mass or composition.

So far, the equivalence principle has withstood all tests. But atoms, which are subject to the strange laws of quantum mechanics, could reveal its weak points. “When you do the test with atoms … you’re testing the equivalence principle and stressing it in new ways,” says physicist Mark Kasevich of Stanford University.

Kasevich and colleagues studied the tiny particles using atom interferometry, which takes advantage of quantum mechanics to make extremely precise measurements. During the atoms’ flight, the scientists put the atoms in a state called a quantum superposition, in which particles don’t have one definite location. Instead, each atom existed in a superposition of two locations, separated by up to seven centimeters. When the atoms’ two locations were brought back together, the atoms interfered with themselves in a way that precisely revealed their relative acceleration.

Many scientists think that the equivalence principle will eventually falter. “We have reasonable expectations that our current theories … are not the end of the story,” says physicist Magdalena Zych of the University of Queensland in Brisbane, Australia, who was not involved with the research. That’s because quantum mechanics — the branch of physics that describes the counterintuitive physics of the very small — doesn’t mesh well with general relativity, leading scientists on a hunt for a theory of quantum gravity that could unite these ideas. Many scientists suspect that the new theory will violate the equivalence principle by an amount too small to have been detected with tests performed thus far.

But physicists hope to improve such atom-based tests in the future, for example by performing them in space, where objects can free-fall for extended periods of time. An equivalence principle test in space has already been performed with metal cylinders , but not yet with atoms ( SN: 12/4/17 ).

So there’s still a chance to prove Galileo wrong.

More Stories from Science News on Quantum Physics

Physicists measured Earth’s rotation using quantum entanglement

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Two real-world tests of quantum memories bring a quantum internet closer to reality

The neutrino’s quantum fuzziness is beginning to come into focus

A maverick physicist is building a case for scrapping quantum gravity

The development of quantum dots wins the 2023 Nobel prize in chemistry

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Quantum computers could break the internet. Here’s how to save it

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March 10, 2021

Physicists Measure the Gravitational Force between the Smallest Masses Yet

A laboratory experiment captured the pull between two minuscule gold spheres, paving the way for experiments that probe the quantum nature of gravity

By Ben Brubaker

Gravity is measured between two gold masses (one-millimeter radius each) that are brought close to each other.

  Tobias Westphal University of Vienna

Physicist Markus Aspelmeyer vividly remembers the day, nearly a decade ago, that a visitor to his lab declared the gravitational pull of his office chair too weak to measure. Measurable or not, this force certainly ought to exist. Ever since the work of Isaac Newton in 1687, physicists have understood gravity to be universal: every object exerts a gravitational force proportional to its mass on everything around it. The visitor’s comment was intended to bring an increasingly fanciful conversation back down to Earth, but Aspelmeyer, a professor at the University of Vienna, took it as a challenge. “My resolution was ‘Okay, I am going to not only measure the gravitational field of this chair, but we are going to go small, small, small!’” he recalls.

The research effort born on that day has now produced its first result: a measurement of the gravitational force between two tiny gold spheres, each about the size of a sesame seed and weighing as much as four grains of rice—the smallest masses whose gravity has been measured to date. The results, published in Nature today, bring physicists one step closer to the distant goal of reconciling gravity with quantum mechanics , the theory underlying all of nongravitational physics.

Precision Gravity

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It is hard to fathom just how extraordinarily weak gravity is for such small masses. The gravitational pull of one sphere (the “source mass”) on the other (the “test mass”) a few millimeters away is more than 10 million times smaller than the force of a falling snowflake. The central challenge facing Aspelmeyer’s team was to design a detector exquisitely sensitive to this gravitational force yet totally insensitive to much larger background forces pushing and pulling on the test mass from all sides.

The researchers achieved this sensitivity using a detector called a torsion pendulum, which looks like a miniature version of a mobile hanging above a child’s crib. The test-mass sphere is fixed to one end of a thin rod that is suspended at its midpoint by a four-micron-thick quartz fiber. An identical sphere on the other end of the rod acts as a counterweight. A force on the test mass causes the torsion pendulum to rotate until it is balanced by a restoring force from the twisting of the fiber. Such a thin fiber is extremely compliant, so even a very weak force yields a relatively large rotation. Critically, the torsion pendulum is very insensitive to forces from distant objects, which tug on the test mass and counterbalance together and thus do not induce rotation.

Gravity can be understood as originating from a warping of spacetime, which is shown in this artist’s impression. Credit: Arkitek Scientific

But even this clever torsion pendulum design did not totally isolate the test mass from the busy urban environment of daytime Vienna. “The sweet spots are always between midnight and 5 A.M., when no people are on the street,” Aspelmeyer explains. “[But] this was not true of Friday or Saturday.”

To measure the gravitational force of the source mass, the researchers did not simply place it near the test mass. Instead they moved it continuously back and forth around an average separation of a few millimeters. This technique, called modulation, is implicit in the design of turn signals and blinking bike lights: regular, periodic signals are much more visible against ever-present background noise than constant ones. Sure enough, the scientists observed an oscillating force at precisely the right frequency. They then repeated this process many times, changing the average separation between the masses, and measured forces as small as 10 femtonewtons at separations between 2.5 and 5.5 millimeters. The team compared these measurements to Newton’s famous inverse square law of gravity, which describes how the gravitational force between two objects depends on their separation: the data were consistent with Newton’s law to within 10 percent.

“[That] you can measure these really, really, really tiny forces—I think that is pretty amazing,” says Stephan Schlamminger, a physicist at the National Institute of Standards and Technology, who studies gravity but was not involved in the work.

But Aspelmeyer and his colleagues could not declare victory quite yet: they still had to rule out the possibility that the source mass modulation was generating other forces on the test mass that would oscillate at precisely the same frequency. Periodic rocking of the table supporting the experimental apparatus, caused by recoil from the barely visible motion of the source mass, was just one of a host of confounders the researchers had to carefully quantify. In the end, they found that all known nongravitational forces would be at least 10 times smaller than the gravitational interaction.

Reaching toward Quantum Scales

Aspelmeyer believes that an improved torsion pendulum will be sensitive to gravity from masses 5,000 times smaller still—lighter than a single eyelash. His ultimate goal is to experimentally test the quantum nature of gravity, a question that has perplexed physicists for nearly a century. Quantum mechanics is one of the most successful and precisely tested theories in all of science: it describes everything from the behavior of subatomic particles to the semiconductor physics that makes modern computing possible. But attempts to develop a quantum theory of gravity have repeatedly been stymied by contradictory and nonsensical predictions.

Particles described by quantum mechanics behave in remarkably counterintuitive ways. One of the strangest kinds of quantum behavior is a special form of correlation called entanglement : when two particles become entangled, their fates become inextricably linked, and they cannot be described separately. Entanglement and other quantum effects are most prominent in very small and well-isolated systems such as atoms and molecules, and they become increasingly fragile on larger scales where gravity is relevant. Until recently, tests of quantum gravity have seemed far beyond the reach of laboratory-scale experiments.

But the past few years have seen remarkable experimental progress toward discerning subtle quantum effects in ever larger systems. In late 2017 two groups of theoretical physicists independently proposed an ambitious but possibly realizable experiment that could make a definitive statement about the quantum nature of gravity. The effort would measure whether gravity can entangle two quantum particles. If so, “there’s no escape from the fact that it has to be, in some sense, nonclassical,” says Chiara Marletto, a theoretical physicist at the University of Oxford, who co-authored one of the proposals with her Oxford colleague Vlatko Vedral.

The observation of gravitationally induced entanglement would be groundbreaking. But a conclusive demonstration that gravity is quantum mechanical would require proving that the two particles interacted only through gravity. Aspelmeyer’s efforts to isolate gravitational forces between progressively smaller masses are a critical step toward such a definitive test. “Since quantum is going from small to big, there’s a chance for gravity and quantum to meet somewhere in the middle,” says Sougato Bose, a theoretical physicist at University College London, who co-wrote the other proposal with nine collaborators.

“The question of whether gravity fundamentally behaves quantum is an experimental question,” Aspelmeyer says. “We can’t wait to go the whole nine yards and see how things turn out.”

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Short Wave: Space Camp

In our wildest dreams, we’re able to warp across the universe to witness its mysteries and discover its quirks up close. In this series, we do exactly that: Regina and Emily blast off into space and travel to the most distant, weirdest parts of our universe — from stars to black holes.

• About Short Wave
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From the physics of g-force to weightlessness: How it feels to launch into space

Regina G. Barber

Emily Kwong

Berly McCoy

Rebecca Ramirez

Astronaut Wendy B. Lawrence was aboard the the Space Shuttle Endeavour for the STS-67/ASTRO-2 mission when it launched March 2nd, 1995. NASA hide caption

Astronaut Wendy B. Lawrence was aboard the the Space Shuttle Endeavour for the STS-67/ASTRO-2 mission when it launched March 2nd, 1995.

This story is part of Short Wave's series Space Camp about all the weird, wonderful things happening in the universe. Check out the  rest of the series .

What does it take to launch into space?

Other than money, hard work and many moving parts, the answer is science ! This summer, NPR science podcast Short Wave is launching Space Camp, a series about all the weird and wonderful things in our universe. We start with how to get to outer space in the first place.

Rockets and Isaac Newton

It mostly goes without saying, but for a person to get to outer space, they need to be in some sort of spacecraft attached to a rocket.

That rocket shoots out exhaust when it leaves the launch pad. That exhaust is shooting towards the launchpad. This is where Isaac Newton's third law of motion comes into action. This law says that "for every action there is an equal and opposite reaction." So, as the exhaust pushes downward, it creates an upward force, letting the rocket shoot skyward.

Here, Walter Lewin, formerly a professor of MIT, completes a common demonstration of Newton's third law of motion, as part of his farewell lecture.

A good example on a smaller scale is a common physics demonstration where someone holds a fire extinguisher while sitting on something with wheels. Like in this video, as the extinguisher fires, the person goes the opposite direction.

The exhaust from a rocket launching into space does the same thing.

The rocket has to go really fast because it needs to overcome the curvature of spacetime itself. The fabric of our universe, called spacetime, can be thought of as a bendable sheet. The mass of Earth makes the flat fabric of spacetime curve inward in a funnel-like shape. Moving up the funnel — thereby escaping Earth's gravity — is more difficult than moving down.

This illustration explains gravitational force, also known as "g-force." It is one of the four fundamental forces in the universe, and is seen bending spacetime amid the mass of Earth. NASA hide caption

This illustration explains gravitational force, also known as "g-force." It is one of the four fundamental forces in the universe, and is seen bending spacetime amid the mass of Earth.

G-forces and why floating is falling

When those rockets blast off, astronauts experience intense g-forces.

G-forces come from when your body experiences acceleration. When you're just sitting or walking around on Earth, you're probably not noticing them — even though there's always the regular pull of Earth's gravity, which is 1 G.

You're more likely to notice them when you're doing something like going up in an elevator pretty fast. Then, you feel heavier.

Explore the full series: Space Camp

But the heaviness of being in a fast elevator is nothing compared to what astronauts experience during a launch. Retired Navy Captain and former NASA astronaut Wendy Lawrence recalled the feeling of intense g-forces to NPR in a recent interview.

"I remember on my first flight thinking, 'Oh, my gosh, somebody just sat down on my chest,'" she says. "I tried to see if I could put my arm out in front of me ... and like, 'Wow, I cannot hold it out there against this tremendous power and acceleration being produced by this amazing space vehicle.'"

Astronaut Wendy B. Lawrence, flight engineer and mission specialist for STS-67, scribbles notes on the margin of a checklist while monitoring an experiment on the Space Shuttle Endeavour's mid-deck. MSFC/NASA hide caption

Astronaut Wendy B. Lawrence, flight engineer and mission specialist for STS-67, scribbles notes on the margin of a checklist while monitoring an experiment on the Space Shuttle Endeavour's mid-deck.

Pretty quickly, that experience changes. Once rockets detach from the spaceship, that force pushing the astronauts into their seats is gone. They start to float under their seatbelts.

They feel what is commonly called weightlessness.

But gravity isn't gone. Even on the International Space Station, astronauts experience microgravity.

You can get a small taste of this feeling on Earth. There are amusement park rides that shoot up — causing riders to feel heavy — and then drop riders. During that drop, the riders feel weightless even though they're actually falling. In physics this is called freefall. All the astronauts in the International Space Station are technically falling very slowly, which is why they feel weightless.

Captain Lawrence says it's an amazing experience. "You just relax," she recalls. "You're suspended right there in the middle of the air, and you want park yourself in front of a window and float in front of it and watch the world go by."

To orbit is to fall and miss Earth

It turns out that orbiting, as astronauts aboard the International Space Station do, is falling. Specifically, it's towards Earth.

Newton had a series of thought experiments to explain this idea.

Scenario 1: Imagine you're standing on flat ground. Now imagine that you shoot a cannonball horizontally from your spot on the ground. In this scenario, the cannon ball will travel horizontally for a while before it starts to fall along a curved path. This is projectile motion.

Scenario 2: You shoot this same cannonball horizontally — from the top of a very tall mountain. In this case, the ball would hit the ground even farther away because it had farther to fall and would have been in the air longer. If you shoot the cannonball out at a higher velocity, it would travel even farther . That curved path is getting more and more stretched.

Scenario 3: With a high enough launch speed you can get the cannonball to fall at a curved path that matches the curvature of Earth. Since the curvatures match, the cannon ball keeps missing Earth. This is what it means to have something in orbit. The cannonball falls but never reaches the ground.

Next up: Short Wave Space Camp: Pluto

Now if we get out of Earth's orbit and to the end of our solar system, we will pass the beloved once-planet Pluto. Why are there only eight planets in our solar system? What does it mean that Pluto was downgraded to a dwarf planet all those years ago? We also explain why Pluto's geology surprised scientists.

More from Short Wave

Have other space stories you want us to cover? Email us at [email protected] .

Listen to Short Wave on Spotify , Apple Podcasts and Google Podcasts .

Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave .

This episode was produced by Berly McCoy, edited by Rebecca Ramirez and fact checked by Regina Barber, Emily Kwong and Rebecca. Gilly Moon was the audio engineer.

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