From the brains behind brains on, this is the moment of um.

Moment of um comes to you from APM Studios. I'm Anna Goldfield.

You know what? to you from APM Studios. I'm Anna Goldfield. Um...

You know what's really fun to think about? Things that turn into other things.

I'm not talking about fairy tales or monster stories where magic transformations happen.

I'm talking about the amazing changes that happen in the real world.

Like how caterpillars totally change shape into their winged adult form,

or how tiny bits of minerals can gradually replace the cells of dead plants and animals to create fossils.

The biggest change I can think of, though, happens in outer space when a star becomes a black hole

just think about that a big shiny ball of light becomes the opposite of shiny a black hole

that absorbs light how does that even happen there's not some big light switch up in space, right?

Star, black hole. Star, black hole. No, that can't be it. Well, Ethan was curious about this, too,

so I think we should talk to someone who knows a lot more about stars than I do.

Thank you. a lot more about stars that I do. It takes a very specific type of star, a really, really massive star that's much more massive than our sun.

Hi, my name is Dakota Tyler, and I'm an astrophysicist at UCLA.

I study objects out on the universe, stars,

planets, black holes, and try to uncover the laws of physics that govern everything.

You could think of a star as really being held up by two different forces.

You have gravity that wants to push in,

and then you have this force from the radiation inside the star that pushes outwards.

So these two forces are, they're equal to each other.

So you've got one thing pushing in and one thing pushing out.

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