if there is even just one blackhole, wouldnt it just keep on consuming matter and eventually consume everything?
In: Planetary Science
Black holes are not magic. They’re just a heavy thing.
Why doesn’t a planet destroy the universe?
Right now the universe is expanding, with no indication of it stopping any time soon. Black holes would have to travel impossible distances and tremendous time scales to pose any threat to the universe as we know it. It’s more likely the universe will experience “heat death” as the end.
There’s a theory called the “Big Crunch” that this expansion may stop, and all matter — including matter locked inside black holes — may eventually merge, and perhaps create another Big Bang.
Black holes have a finite range to the gravitational field they put out, same as the star they formed from. Stars don’t pull in the whole universe for the same reason black holes don’t.
>if there is even just one blackhole, wouldnt it just keep on consuming matter and eventually consume everything?
It might help to remember that the Earth is also a source of gravitation that attracts matter, but it doesn’t eat the solar system. Neither does Jupiter, which is far more massive. Neither does the sun, which is far more massive still. Black holes have great gravitational pull, but it’s not infinite, and over a long, long, long time they do radiate energy and equivalent mass away.
It is a myth that black holes are like a cosmic vacuum cleaner that just hoover everything up. The amount of gravity a black hole generates is still dependent on its mass, and the mass of a start doesn’t magically increase when it implodes and turns into a black hole.
I am pretty sure* that if the Sun were to implode into a black hole, and somehow that process itself wouldn’t destroy the planets, all the planets would just keep revolving around it. Sure, earth would become completely inhospitable for life due to the lack of solar energy, but the *orbit* of earth wouldn’t change.
* I am not an astronomer or physicist so I might be very mistaken though.
You and three of your friends each pick up a corner of a sheet and lift it so it is pulled tight. Get a fourth friend to through a 1kg bag of feathers into the middle of the sheet and watch it sag with the weight. Now take the bag out and do the same with a 4cm cube of osmium (the heaviest metal, which by my quick search is going to weigh about the same as the feathers). Other than the footprint of the object, there’s not going to be any difference in how the sheet behaves, or how far it sags.
Or to put it another way, if our sun turned into a Black Hole today, the Earth’s orbit would stay exactly the same.
There is a misconception that black holes are this super special dangerous thing that sucks and goes on to consume everything. In reality it’s just another body of mass that produces gravity, just like the sun or earth. The only difference between a star and a black hole of the same mass is that the star radiates light by nuclear fusion, and obviously that the black hole has an event horison.
So just like any other star or planet etc. stuff will orbit, fly by, miss, fall into it, and so on. And gravity falls of very quickly with distance.
(This is simplified to eli5, general relativity has weird consequences for black holes, we also have stuff like hawking radiation etc etc.)
a well in your backyard doesn’t consume the entire neighborhood. just don’t fall in and you’re fine.
Black holes function by extreme density/gravitational pull. The force of gravity is inversely proportional to the distance between them, ie the force between two objects 10 miles away is 1/100 the force between two objects 1 mile away. Space is REALLY big, so even though the gravitational force of a black hole is unfathomably strong, the distances between objects in the universe are so big it doesn’t have the ability to pull in objects that aren’t already close to it
A newly formed black hole has (almost) the same mass as the star it formed from. The thing that makes black holes powerful is that they’re so small.
If you try to get really close to a regular star’s center of mass, you hit the surface. When it becomes a black hole that star’s surface is gone so you can get much MUCH closer to its center of mass. Since the strength of gravity goes down by distance squared (one fourth as strong twice as far away) the black hole ”sucks” much harder than a star with the same mass once you get close enough.
Latest Answers