bounce-- the basketball, the super bouncy ball, and the golf

ball.

Now, I'm going to try the golf ball on top

of the bouncy ball on top of the basketball,

and then I'm going to explain how

it's related to a supernova.

Did you see that?

Probably not, so here it is again.

The golf ball bounced to 28 feet.

We dropped it from about 3 and 1/2 feet, so it went up 800%

of its dropped height.

In fact, if you consider that by itself-- the golf ball bounces

about 70% of it's dropped height--

it went as high as if it had fallen from 40 feet up.

That is awesome.

So how can we get the golf ball to bounce up

with that much energy?

Let's simplify it to these two balls.

When you drop them individually, each ball

starts out with some potential energy

from the height of the drop.

As the balls hit the ground, some energy

goes into heating up the ground, and some

goes into heating the ball.

Because that energy left the ball system,

you can't get back up to the same height.

But when you combine them, the tennis ball

goes higher than its dropped height, way higher.

Where does it get the extra energy?

As the basketball bounces, it compresses, storing

elastic potential energy.

As it releases, it springboards the tennis ball upward

just at the right moment.

This is like the double bounce on a trampoline

when you jump right before someone else.

You prepare the elastic of the trampoline

by stretching it and storing energy, which can then

bounce the jumper even higher.

In the same way, the basketball stores energy

in its compression and is able to push the tennis ball,

but just like the double bounce preparer,

the basketball can't go as high.

You can see that here.

It bounces even less when three balls are dropped together.

Also during that transfer of energy,

some momentum transfers from the basketball to the tennis ball,

and since the basketball starts with way

more momentum because of its larger mass, the tennis ball's

velocity increases by a lot.

And it flies up, up, and away.

Now, back to the triple super ball bounce.

Now, do you get the energy from the basketball's bounce being

transferred into the bounce of the super bouncy

ball, which is then transferred to the golf ball's bounce.

You put the same amount of energy or momentum

from two more massive objects into a smaller object,

and it will go much faster, epic,

just like the explosions of a supernova, which

may seem unrelated.

But what we just did is analogous to the process

that occurs during the explosion of a supernova.

Just like our more massive basketball transfers momentum

to the smaller balls, energy from the dense core

of the supernova is transferred in a shockwave that

moves through the star to the less dense layers

and accelerates them outward at a super high velocity.

More massive or denser layers in the core of the supernova

begin to collapse when fusion stops there.

The collapse is halted when the neutrons in the core

actually touch, sort of.

This causes the implosion to rebound and bounce outward.

You end up with a dense core left behind

and these wild outer shells of star exploding outward, pretty

cool.

And, of course, if you try this at home, which you should,

you have to make sure the balls are perfectly vertically

aligned because any off centeredness gets amplified

by the two points of contact, which

is why we sadly couldn't get the quadruple tower of balls

to work.

But if you put a little ring of hot glue or something

similar on the balls, it helps to balance them.

Happy physicsing.

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