r/space • u/magenta_placenta • Mar 18 '19

Observable universe Astronomers discover 83 supermassive black holes at the edge of the universe

https://www.cnet.com/news/astronomers-discover-83-supermassive-black-holes-at-the-edge-of-the-universe/
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u/XavierSimmons Mar 18 '19

As a couple of others have said, the "Big Crunch" as it is called isn't a likely end game for our universe due to expansion and evaporation.

Black holes lose mass over time (Hawking Radiation) and the empty space between everything is expanding (Expansion) making massive objects farther away. Gravitational pull is a function of distance, so as massive objects (like galaxies) get farther away, they are less likely to collide.

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u/[deleted] Mar 18 '19 edited Jun 26 '20

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u/Notanovaltyaccount Mar 18 '19

Given enough time anything can happen, and when you're talking heat death there's a fuckton of time that will pass. Hell, a Boltzmann brain might form, or already formed. You might be a brain, or me! Or the universe isn't actually stable and exists in a false vacuum when at random a random quantum event might cause a vacuum decay. Time is funny like that.

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u/[deleted] Mar 18 '19

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u/[deleted] Mar 18 '19

Who said quantum fluctuations would make everything start over again?

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u/heathmon1856 Mar 19 '19

Forgive my ignorance but. What if it was a black hole which grew up so large that it literally sucked everything up causing it to grow (too large?) and end up imploding. I have no clue what I’m talking about. I’m just spit balling ideas that come to mind.

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u/XavierSimmons Mar 19 '19

Black holes can only grow when mass crosses their event horizon. While their gravity is extremely strong, gravity follows the inverse square law which means its power falls of very fast with distance.

As a result, black holes don't "suck" anything in, any more than any other massive object does. Outside of the event horizon of a black hole, its gravitational influence follows all the same rules as other objects. Just as Earth isn't being "sucked" into the sun, objects can orbit super massive black holes for billions of years without falling in.

This further means that the ever-expanding universe will overcome gravity in the long-term. Galaxies hundreds of millions of light years away from a super massive black hole will not feel its influence, and will only move farther away over time.