Explore Gravity Bouncing Ball

Bouncing Ball: What If Gravity Suddenly Changed?

We interact with gravity every single day, yet rarely pay close attention to it.

Let go of a ball in your hand, and it falls downward; toss a ball into the air, and it eventually drops back to the ground; slap it down hard, and it bounces back up, getting a little lower with each bounce.

These seemingly ordinary motions are, in fact, physical laws at work.

Now, imagine tweaking this familiar world just a bit. What if gravity became weaker? What if gravity suddenly vanished?

Or even: what would happen if a ball had elasticity that barely decayed at all?

In this Physics Wonder Box, you can directly observe these changes for yourself.

Different Gravity, Completely Different Worlds

First, try the Classic mode. Here, the ball experiences downward gravitational pull and continually falls toward the ground. With each collision, it rebounds upward, but due to energy loss, each bounce gradually weakens. This is the world we are most familiar with.

However, if you lower the gravity, things begin to get intriguing.

Moon

The surface gravity on the Moon is only about one-sixth of Earth's. In the simulation, the downward gravitational force acting on the ball is noticeably reduced, causing it to fall much more slowly and linger longer in midair with each bounce. The very same ball suddenly feels remarkably 'light' here.

Mars

Gravity on Mars is roughly 38% of Earth's, sitting right between Earth and the Moon. You will observe a distinct change in the ball's tempo: it still falls, collides, and rebounds, but the entire process unfolds much more gently and leisurely than on Earth.

Thus, on different celestial bodies, the exact same action creates completely different experiences.

What If There Were No Gravity at All?

Next, give Zero Gravity a try. This is where the most fascinating thing occurs: the ball no longer 'falls down'.

In this simulation, gravity is set to zero while balls are granted initial velocities, sending them continuously drifting and colliding throughout space.

Here, you'll discover an easily overlooked truth: 'things fall downward' is not an inherent law of motion itself, but rather the consequence of gravity's existence.

Without gravity, 'downward' loses its special meaning. Balls can glide freely in any direction, and collisions with walls and other balls continually alter their states of motion.

Why Do Some Balls Bounce So Dramatically?

In addition to modifying gravity, this wonder box allows you to adjust another crucial physical parameter: elasticity. Simply put, it describes how much bounce a body retains after a collision.

In normal mode, the coefficient of restitution is set to 0.78, whereas in High Elasticity mode, it increases to 0.97. The numbers may seem close, but across consecutive collisions, the difference is striking. Balls in High Elasticity mode barely slow down from each bounce and can keep bouncing for an extended period.

This reveals an essential concept: a collision is not merely 'hitting and bouncing away', but a continuous transfer and loss of energy.

In real life, balls can never bounce endlessly because air resistance, deformation, friction, and internal dissipation continually consume energy.

What If a Ball Were Extremely Heavy?

Finally, test out the 'Heavy Ball' mode. Here, gravity is increased alongside higher friction and a reduced coefficient of restitution.

The outcome is clear: the ball plunges downward much faster and scarcely bounces back after hitting the floor. It looks as if it has abruptly adopted a completely different 'personality'.

Yet underneath, there is no mysterious magic at play—only a few physical parameters were altered.

This is one of the most delightful aspects of physics: seemingly complex motions can emerge naturally from a handful of very simple rules.

You Can Also 'Create' Collisions Yourself

This wonder box isn't just for passive watching. You can click on the upper area of the canvas to drop a new ball, or drag an active ball with your mouse and fling it across the screen.

When you drag a ball, you are actively changing its state of motion; the moment you release the mouse, the ball continues moving at that new velocity.

Here are a few things to try: drop a ball from up high and count how many times it bounces; fling a ball sideways with force and watch it ricochet off the walls; impart an initial velocity in zero gravity and follow its endless path; switch between Moon and Mars modes to compare trajectories under the same action; activate High Elasticity mode to see how long it takes for a ball to truly come to rest; or even generate a flurry of balls and watch them bounce into each other.

The system continuously generates new balls while keeping the total count on screen neatly within a reasonable limit.

The Simple Physics Behind the Scenes

The two core concepts powering this experiment are gravity and collisions.

Gravity dictates the direction in which an object's velocity changes. In this simulation, gravity can be simply understood as: F = m · g, where m represents the object's mass and g is the gravitational acceleration.

How high a ball can rebound after a collision depends on the coefficient of restitution, which can be thought of as: e = v' / v, the ratio of velocity after collision to velocity before collision. A higher coefficient preserves more motion post-collision, while a lower coefficient makes the ball quickly lose momentum.

Of course, collisions in the real world are far more intricate than this model. Balls deform, air introduces drag, materials absorb energy internally, and the ground is rarely perfectly rigid. What this wonder box does is distill several of the most fundamental factors so you can directly see what happens when they change.

Physics Is Right in Front of Your Eyes

Physics can sometimes feel rather abstract—formulas, symbols, and units often seem disconnected from our daily routines.

Yet in truth, the world we observe every day is itself a massive physics experiment: a ball dropping, a collision occurring, a rebound, and an object gradually coming to a stop.

Change just one parameter, and the entire world feels brand new.

There is no need to memorize equations first. Simply toss a ball, watch how it moves, and gradually discover for yourself—so this is what physics is all about.