Can black holes grow?

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Kasuha
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Re: Can black holes grow?

Post by Kasuha » Tue Feb 23, 2010 4:19 pm

March_Hare wrote:1. Not according to what I have read about it (don't remember where): for an outside observer (at a safe distance etc.) the object never reaches the horizon, but for an observer falling into a black hole the ride down is swift and very short.
Yes, it's swift and very short. No problem with it. But during this swift and very short fall you can still continue observing the black hole and I believe you will see the event horizon shrinking away from you towards the center of the black hole so you will never see yourself pass through it. At least it will do that on your eye level - but I believe it will be sooner.

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March_Hare
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Re: Can black holes grow?

Post by March_Hare » Wed Feb 24, 2010 5:31 pm

Ah I see!
Thanx for the explanation.
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Kasuha
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Re: Can black holes grow?

Post by Kasuha » Fri Feb 26, 2010 12:16 pm

I have found this nice page about how falling to a black hole looks like (from the falling observer point of view). It's quite impressive I think.

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March_Hare
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Re: Can black holes grow?

Post by March_Hare » Fri Feb 26, 2010 6:43 pm

Nice one, Thx!
Also the other illustrations and moves are very interesting.

BTW - His site links to an earlier site here he made, with more primitive animations but also describing in text what happens during a trip into a black hole (scroll a little down to the Index).


Strange... why do I have this urge for spaghetti all of a sudden? :happy-jumpyellow:
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Thein
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Re: Can black holes grow?

Post by Thein » Mon May 10, 2010 1:22 am

Sorry if this is a huge bump.
I am new to this forum and decided to join due to this discussion.

I'm merely a researching student as of now; however, I will express my idea on this topic.
I think that there is far too little information on black holes to really claim anything. We have mathematics, but just because we can put things into an equation doesn't mean they are concrete. We have theorized wormholes and white holes based off the formula for a black hole, yet logically both are unstable and do not work.
It wasn't until (insert scientist's name here!... Probably someone like Humason, or Huggins... One of the scientist who measured the materials found in stars due to the light they emit) discovered a "proof" for black holes (They found two stars with the exact same composition, which is logically impossible; that's when Einstein theorized it was actually a black hole bending the light of one star, creating a symmetric twin) As explained before, we really cannot see one, therefore, it is incredibly hard to argue anything about one.
That's why we would look for Quasars; the most active black holes (And the most "visible")
I noticed a bunch of people so far have made the association that "singularity" is an actual object... Just to clarify before I explain my thought, singularity is simply a fancy word for scientists to say "We have no idea about this area,"
Black holes ruin almost all rules of physics and even logic. Time and space is frozen at a black hole's event horizon, hence it is an extremely flexible subject. Black holes even ruin the law of conservation of energy. (Space itself can ruin that law, and this has been proven due to Vacuum fluctuation in space.)
I typed that novel in order to sum up one simple thing before I go on to my thought: This is all speculative in many ways.

So a black hole breaks all these rules, shatters the fabric of space, and completely destroys our minds when thought of... Well, does one grow? Logically, yes, but you can argue both sides. Hawkings claimed that this is not true; however, that debate was resolved and he claimed he was wrong-- on stage, in fact, which shocked everybody.
I will explain how logically this makes sense.

Think about it in terms of our laws. Conservation of energy would be ruined (I had claimed earlier, note, that a black hole does indeed ruin the law of conservation of energy, but I said let's think about this in terms of our laws, for it seems the most LOGICAL.) If a black hole fades away, then the energy it contains does too, which means that energy simply goes away... This makes no sense. If light cannot escape a black hole, surely energy cannot.
Think about all of this like a giant crushing trash disposal machine (or something along those lines.) If you drop a large load of trash into the trash disposal, logically, the trash that is crushed and compacted builds up, right? If it just disappears, that ruins the law of conservation of energy. So yes, in terms of mass, a black hole would increase; but again, everything about a black hole is flexible... We don't know, and we will never know until we send a probe in one to study the few seconds of its survival.

I feel as though that makes sense, does it not? The outside observer, though, would not see a black hole gain mass, for light cannot escape a black hole, therefore everything around a black hole tends to look like nothingness or simply freeze. In the aspect of what an outside observer can see, it is all optical illusions, due to the bizarre effects black holes have on light. Even if Black holes can grow in mass, it would be an (close to) infinitely small (just a way for saying REALLY REALLY *REALLY* small because of how heavy the central point is)

This is my first time posting. Hope it seems sufficient.
~Thein
"We had a Galactic Clash"

davidarheault
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Re: Can black holes grow?

Post by davidarheault » Thu Feb 23, 2012 11:42 am

despite any unproven theory on the subject and considering that it has been confirmed by measurement in mature galaxies that the mass of a central super massive black hole equals one half of one percent of the mass of the surrounding galaxy, if black holes grow, wouldn't we, shouldn't we observe incredibly huge mega super colossal sized galaxies? We don't. we do find larger and smaller ones, but none large enough to indicate they continually grow. if it were the case, wouldn't one of these extra large galaxies simply be swallowing up the universe?

If hawking radiation theory were correct, then the larger the black hole the faster the galaxy would grow, exponentially even. theory only, never observed.

Conversely, couldn't we, shouldn't we observe tiny galaxies as well. we don't.

There is no hard evidence to show that black holes ever change their size except for when they combine with other black holes.

It takes the largest release of energy in the universe to create the material which comprises a black hole. what reasoning is there that by it's very existence alone that more would be created? or destroyed? or released? No logic, no reasoning, no evidence, just a theory. Sounds more like God worship to me.

Kasuha
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Re: Can black holes grow?

Post by Kasuha » Fri Feb 24, 2012 9:30 am

davidarheault wrote:despite any unproven theory on the subject and considering that it has been confirmed by measurement in mature galaxies that the mass of a central super massive black hole equals one half of one percent of the mass of the surrounding galaxy, if black holes grow, wouldn't we, shouldn't we observe incredibly huge mega super colossal sized galaxies? We don't. we do find larger and smaller ones, but none large enough to indicate they continually grow. if it were the case, wouldn't one of these extra large galaxies simply be swallowing up the universe?
Correlation does not mean causality. And the universe is only this much old, it takes time to create larger galaxies. There are known observed galaxies way bigger than ours and the observations suggest the galaxies are continuing to merge.
davidarheault wrote:If hawking radiation theory were correct, then the larger the black hole the faster the galaxy would grow, exponentially even. theory only, never observed.
I don't see why Hawking radiation should have any relation to black hole growth. Hawking radiation is a minute effect, compensated for even smallest star-originated black holes just by effect of background radiation "falling" on the black hole.
davidarheault wrote:Conversely, couldn't we, shouldn't we observe tiny galaxies as well. we don't.
Of course we do.
davidarheault wrote:There is no hard evidence to show that black holes ever change their size except for when they combine with other black holes.
Except for radiation from known black holes created by material falling into them.
davidarheault wrote:It takes the largest release of energy in the universe to create the material which comprises a black hole. what reasoning is there that by it's very existence alone that more would be created? or destroyed? or released? No logic, no reasoning, no evidence, just a theory. Sounds more like God worship to me.
It just takes one decent supernova.

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