Bill Nye The Science Guy - Motion

Season 05

Episode 20

Duration 23:26

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Sit still on the sofa. Are you moving? You are, faster than you think. In this episode of Bill Nye the Science Guy, Bill shows how everything in the universe is in motion, and how three simple rules written down by Isaac Newton explain almost all of it.

In this episode you will discover:

Why nothing moves unless it is pushed or pulled
What Isaac Newton meant by his three laws of motion
What inertia is and why a bowling ball has more of it than a golf ball
Why mass and weight are not the same thing
How your frame of reference changes what you see moving
How fast the Earth, the Sun and the whole galaxy are already carrying you along

Newton’s three laws

Bill uses an air track full of little scooters to show the first law: at rest they stay at rest, moving they keep moving, until something pushes them. He hangs an anvil from a chain to show that inertia takes real force to overcome, and slams cars together to show the third law: for every action there is an equal and opposite reaction.

Key concept
Inertia
The tendency of anything with mass to keep doing what it is doing, whether sitting still or coasting along.

Key concept
Force
A push or a pull, measured in newtons, that starts, stops or changes the direction of a moving object.

Key concept
Action and reaction
Every push comes in a pair, so when one thing pushes another, the other pushes back with equal force.

Bill Nye’s demonstrations

Bill floats scooters on an air track to show that things in motion stay in motion. He drops an anvil to prove how much force it takes to overcome inertia. He weighs an apple on a plane during a dive to show that mass stays the same while weight can vanish in free fall. And a farmyard scene explains how the Earth, the Sun and the entire solar system are hurtling through the galaxy at hundreds of kilometres per second.

Try this at home

The playing card and coin. Balance a playing card on top of a glass and place a coin in the middle of the card. Flick the edge of the card sharply with your finger. The card zips away sideways but the coin drops straight into the glass, because the card slides too fast to drag the coin with it, and the coin’s inertia keeps it in place until gravity takes over.

Cool facts

The Earth is spinning on its axis at about 1600 kilometres an hour at the equator.
The Earth orbits the Sun at roughly 30 kilometres every second.
The whole solar system is racing around the Milky Way at around 220 kilometres a second.
A bowling ball has more inertia than a golf ball, which is why it is harder to start rolling.

Science update: since this episode aired

Astronomers using the European Space Agency’s Gaia mission mapped the speed of millions of stars orbiting the Milky Way and found the rotation curve gently falling off at the edges, which means our galaxy weighs about four to five times less than previous estimates suggested. European Space Agency Gaia mission, Madrid, 2023
Europe’s Atomic Clock Ensemble in Space was launched to the International Space Station on 21 April 2025 to test whether time really runs faster in weaker gravity, one of the ways Einstein extended Newton’s laws of motion to the whole universe. European Space Agency, Paris, 2025
The LIGO, Virgo and KAGRA collaboration released its latest catalogue in May 2026 listing 390 confirmed detections of gravitational waves, actual ripples in space itself caused by pairs of black holes and neutron stars orbiting and crashing together far from Earth. European Gravitational Observatory, Cascina, 2026

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Curriculum focus

Built on NGSS MS-PS2-1 (Newton’s third law and collisions), MS-PS2-2 (change in motion depends on force and mass) and MS-PS2-4 (gravity as a force). Complementing that, it is pitched at KS3 physics (forces, motion and Newton’s laws) and works as an introduction or revision aid for GCSE and IGCSE physics and combined science on force, mass, acceleration and momentum, across boards such as AQA, Edexcel, OCR and Cambridge IGCSE. The worksheet and critical thinking questions take these ideas further than the episode alone.

NGSS MS-PS2
KS3 physics
GCSE revision
IGCSE revision
Newton’s laws
Inertia