Black Holes: They Matter
Learn about black holes and how they might lead to time travel.
Black holes are anything but big empty holes in space. In fact, they have so much matter (stuff) packed inside that nothing can escape, not even light! And the only way we know they exist is because we can see them sucking in the light around them.
So what exactly is a black hole? They start out as stars, much like our sun, but then they burn out and collapse in on themselves. They are still the same stuff they were, but they have different properties. Properties are how something behaves or acts.
Do a little experiment: grab a sheet of aluminum foil. Now crumple it into a loose ball. Tap that against a counter or wall. That is your star. Now take that ball and crush it as small as you can make it. Stand on it, maybe hammer it. Now take that ball and tap it on the counter. Sounds totally different even though it is the same amount of foil.
That is sort of how a black hole works: it is the same amount of matter as the star, but the properties have changed! Instead of giving off light, they pull light in.
- Black holes don’t last forever. They slowly evaporate, giving all their energy back to the universe.
- Albert Einstein predicted black holes existed before anyone ever discovered one.
- Some are the size of one white star, others are millions of times larger!
- There is a supermassive black hole at the center of the milky way, our very own galaxy!
There is a theory that if you were sitting close enough to a black hole and looked at your watch, the hands would move at a normal speed. However, anyone further away would see the hands on your watch moving really slowly. So if you could get close enough to a black hole, you could travel days, months, and maybe thousands of years in time!
Right now the idea of traveling anywhere near a black hole is just science fiction. They are hundreds and thousands of light years away. We don’t have materials strong enough to withstand the gravitational pull of a black hole. That could all change though, and you could be the one to do it!