Comment on well?
Evilsandwichman@hexbear.net 1 month ago
I thought black holes aren’t actually holes at all, they’re literally gigantic physical objects because they’re dead suns with shockingly high gravity that prevents light from escaping; how could our universe be inside something like that?
fox@hexbear.net 1 month ago
Firstly, a black hole isn’t an object, really. If you manage to compress enough mass in one place, gravity becomes the dominant force and the mass collapses into itself, eternally compressing and densifying. This is the singularity at the center of a black hole, and we use the term singularity because it’s describing a single unmeasurable point in spacetime.
Next point: high gravity curves space. Light only travels in straight lines if it can get away with it, so when light bends in space it’s because the space being traversed is deformed by gravity. Like, the Earth is, as far as it cares, going in a straight line that happens to curve back to where it started. If gravity is strong enough in a region, all possible “paths” through space become bent inwards to higher gravity. Like, even a perfectly straight line away from the black hole will be forced inwards again. That’s the event horizon, the region in space around the singularity where nothing can escape anymore: all paths go deeper into the black hole.
Third point: weird shit happens inside the event horizon. We’re well into Math now because we can’t actually see inside these things, but we can use math to theorize and describe the inside of a black hole. Basically, time and space switch places inside the event horizon. Because every possible direction you can move in only takes you deeper, that means the future is the singularity, and as you move forward in time you move closer in space to it.
So in net: they’re not really holes and they’re not really physical objects: they’re regions where every path in space is forced into going towards the singularity, which is itself infinitely small and infinitely dense.