# Black Holes

Discussion in 'Physics & Math' started by JimmyJames, May 23, 2001.

1. ### JimmyJamesMaster JediRegistered Senior Member

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Think of space as a giant bag and in this giant bag are lots of fire crackers (representing stars). lets say a fire cracker goes off (supernova) ...if it is close to a side then it most likely will break a hole in the bag (the bag is representing space or the universe)...the universe would be exposed to the outside. Lets say it was not near a side, but in the middle...then the bag would be unharmed...right? Anyway what I am trying to say is that if a black hole doesn't occur at the farthest points of our universe then how can they supposably lead to other places???

3. ### discord5Registered Senior Member

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when you take a bath and let the water out it manages to get to the ocean eventually , you dont see the pipes and the pipes are not in your way at all. so what you see is the drain the outlet for that drain is somewhere unknown to you but the water manages to get there

5. ### mirrorRegistered Senior Member

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I have difficulty thinking in terms of the universe as being bounded, like a bag. To me, if an area of space can be thought of as a bag which has boundaries, with something "outside" of the bag, then that which is outside of the bag is also part of the universe. Therefore, the bounded area (the bag) cannot be the universe, but only a part of the universe.

I understand that some people refer to those things which have been observed as "the universe", and speak in terms of "parallel universes", however, in my mind, these are misnomers.

7. ### discord5Registered Senior Member

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good point
hence the use of uni at the begining of the word , and since the universe would have to include everything then other-universe would be an oxymoron

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Well said!

9. ### Kram006Registered Member

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It depends on how you look at it

My personal opinion is the actual "universe" does go on forever, even past the "bag." However, if there isn't anything outside of the "bag," I would consider that nothingness... and when they originally created a word to mean everything in every direction, they probably thought that the stars kept on going on forever. However we now perceive that this isnt the case. The question is, "Is the universe what we originally perceived it to be?"

Whether it be all the stars in the "bag"
or
Everything that exists... whether it be star systems or empty space.

10. ### papa_smirfRegistered Senior Member

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A black hole doesn't have to lead anywheres. The matter sucked in can just stay there in a super compacted state which abides by the law of conservation of matter.

11. ### RamblerSenior MemberRegistered Senior Member

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pap smirf

Isn't a balck hole a "singularity" I would think that the most compacted state would be that of a neutron star, i.e. the electrons combine with protons and all matter is turned into neutrons. I beieve these kind of dead stars exist but are not actually considered as black holes because they are just a super dense mass. I think the amount of matter needed to turn a neutron star into a blackhole is much greater...i.e. the size of the star matters, if its greater then some threashold it will be a neutron star if its greater again the gravity will colapse it further into a singularity...where all that mass is pushed into a single infentesemially small point. Hence the exotic properties being theorised about black holes.

P.s. forgive my spelling errors...I'm a hopeless speller.

12. ### rich68Registered Senior Member

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rambler

good points,but before the singularity,what accurs?could the blackhole explode?as we now,that sooner or later the blackhole will shrink,caused by some particles escaping,while others are pulled in,then they cant reunite,this causing a drain on the blackholes mass,then what?

13. ### Science GeekRegistered Member

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Blk holes are all different

I think the example you've given of the universe is somewhat of a small scale version, though it is an interesting analogy. I think that the reason all black holes don't, or may not lead anywhere because they are all different. Some, like the one in the center of our galaxie probable lead somewhere. Others like perhaps a small primordial black hole were formed at the begining of the universe, and therefor had nowhere to go.

14. ### Kram006Registered Member

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Kinda weird how this thread started out... had nothing to do with black holes... but anyways...

I agree somewhat with Rambler... although I don't think that it's all condensed infinitely into one single point. I'd guess that it would have like the diameter of Washington DC or so... about 10-15 mile diameter. The thing that I find interesting is that its force of gravity is much stronger than the speed of light. So I wonder what color a black hole really is if it were to somehow reflect any light off of it and it escaped

15. ### RamblerSenior MemberRegistered Senior Member

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Kram006,

I think it would be more correct to say that the gravity of a black hole will not allow light to escape. I.e. the gravity is so huge that it bends space in on itself, and hence once light enters this space (beyond the event horizon) it is forever trapped inside the blackhole. That is why they are refered to as black...they cannot emit light because light can not escape them so they cannot have colour since colour requires light to escape.

As far as how big the hole is well, I'm not sure but from what I have read the singularity is infact a single point which has no dimensions (infentesinally small), infact (and this could be way off so take it with a grain of salt) all that remains is gravity all matter is destroyed.

One thing to consider with colour etc:
The way that these things have been found and observered is when they a close enough to another star (say in a binary system where one of the stars has colapsed into a black hole) they will suck matter from its neighbour star and illuminate the event horizon by super heating the matter and releasing x-rays. So don't confuse that with light being emitted from the hole, the light seen in this respect is at the event horizon or just outside the hole.

16. ### ogsterRegistered Member

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since a black whole was a gaint star that copapst, and whos denstiy is that more than anything else.its gravtey would b so great that it would bend not only light, but space and time.

as 4 its colour, since it 'sucks' or 'does not give out light' and it is black, means that must have all the coulers, making it black.which means that it could b any colour. it could b red as a red gaint that has colaped?

just a lil thought

17. ### rich68Registered Senior Member

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Mmm

with the problems of gravity,and gravity is the basis of the black holes mighty power,there can be no colors as we no nothing can escape its irresistible gravitational pull,so it is the ultimate hole where rays of light are trapped inside,rendering the hole blacker than night.so the only thing is that a black hole is invisible,and that the only thing to be seen would be bending of light,giving it a glowing halo from the event horizon.

18. ### ogsterRegistered Member

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yeah but the thought i had, is that b4 its denstiy was so great that it bent light and became invisbul, would it not have been the colour of say a red gaint that was about 2 calapse?

19. ### rich68Registered Senior Member

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ogster

are u saying something b4 a true black hole,i would say yes that your statement of red giant would accour,but then again theres many stars that would give different patterns,what about a hypernova,a hypernova is probably the death of the most massive star where its life perhaps a hundred times heavier than the sun.
the core of this star doesnt just collapes to become a neutron star,the shrinking inexorably under the force of its own gravity would turn into a black hole,its an exquisite cosmic paradox that a black hole THE DARKEST OBJECT THAT CAN EXSIST can power the most brilliant explosions in the universe.

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yeah

21. ### XerxesasdfghjklValued Senior Member

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my personal belief is that because there is so much mass in one small area, a black hole would work like a time machine and transport you into different times in the universe

22. ### AnkitThe AngelRegistered Senior Member

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Vital words...

Y'all seemed to have ostensibly evaded the admittedly perilous subject of space-time continuum, the pith of Einstein's opus...the theory of relativity. This 'bag', as you glib ones call it, is actually space-time and vice versa. When we talk of a ball distorting (yep, there's another good word), we mean 'frame-dragging'; the whole system is being dragged along with it.

A black hole can be anything...but since it emits X-rays, radiactivity is a must, so the novel possibility of wormholes and whatnot is very plausible. If a black hole is a tear in the fabric of the space time continuum, then almost anything is possible. However, the thought of alternate/parallel universes is the invention of creative minds and science fiction writers (not unlike like myself). Sure the 'time-travel' theory achives scientific basis, and, ergo, is plausible, but other universes...no. Besides, to quote discord5:

'hence the use of uni at the begining of the word , and since the universe would have to include everything then other-universe would be an oxymoron'