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The Slow Mo Guys

WATCH: A CD Ripped Apart by Rotational Force at 170,000 Frames Per Second

FIONA MACDONALD
2 APR 2015

What happens when you take a perfectly good CD and spin it really, really fast? As you can see in the latest Slow Mo Guys video, the entire structure pretty quickly explodes into hundreds of tiny pieces. But if you think that's impressive, wait until you see the whole process slowed down to 170,000 frames per second and, holy crap, it really looks spectacular.

 

So what's going on here? The team explain that once a CD spins over 23,000 rotations per minute, its stability is compromised and it starts to fall apart. Very simply, that means that the rotational force at that point is stronger than the force that's holding the CD together.

Rhett Allain over at Wired has written up an amazingly detailed account of the physics going on to create the beautiful shatter patterns (complete with calculations), which you should definitely check out. But his summary?

"Before the CD breaks, the rest of the CD exerts a force on the CD piece causing it to move in a circular path. After the break, this force is no longer there. What do objects without forces on them do? The correct answer is that they don’t change their momentum (velocity would be acceptable). Moving in a straight line means the object has constant velocity."

While we don't recommend you try this at home (even if you did have the right fancy equipment), it's pretty spectacular to watch over and over again from behind the safety of your screen.

Sources: The Slow Mo Guys, Wired