View Full Version : Black holes
01-16-2003, 10:14 AM
Why does everybody call a Black Hole a hole? It isn't.
People hear this and postulate ideas about traveling through it as if it were a portal.
A black hole is really a star. It exists in 3 dimensions it is round and just because it absorbs everything we know about does not mean you can pass into or through it. Just like a White Dwarf or a any other high gravity object it adds any material that comes near enough into its mass. The Earth absorbs tons of space debris every year in the same way a black hole takes in material.
Nothing will ever pass into a black hole or out of one.
If you know better, bring it............. Please :)
01-16-2003, 01:18 PM
aHA! A Black hole isn't really a star, it USED to be a star, but then after the star burned itself out etc. etc. it ceased to be a star and became a black hole. :D
01-16-2003, 02:47 PM
That is what was tought in school. But in truth, I have read this in a book writen by a scientist, A black hole does not exist. Scientists only assume it does, they think that if a star implodes(or whatever) it would cause a gravitational hole(or whatever).
But no one can prove a black hole acctually exists.
01-16-2003, 02:52 PM
Sci-Fi thinks of them as many things.
In Sphere, it was a portal for time.
In some other things it is like "wormholes" from DS9.... (are wormholes real, or not?)
01-16-2003, 04:05 PM
From me, a physicist, in simple terms:
A black hole has once been a Red Giant Star. When a star is in this stage it can take one of either two courses depending on the proportion of energy compared with mass. It can either go supernova, or move in totally the opposite direction (but with just as much force) and be crushed inwards under its own gravity until only the size of an egg. Its density will be unimaginable high. From this point all is known is that the gravitational force is so high that not even light can escape its reach for a distance which is proportional to its density. Without light there is nothing to see, i.e. it appears black. From this point anything else is just speculation. From Einstein's Theories it is stated that the black hole has formed a tear in space, and subsiquently time. And from this point onwards you wouldnt understand, and from that point onwards is sci-fi.
As for wormholes, NO. None have ever been found or seen...those have been made up enitirly for science fiction.
01-16-2003, 04:22 PM
I never knew you had it in you, RAVE :D
Posted by Katarn07
(are wormholes real, or not?)They're thought to be :) (Although not all scientists agree, as per usual :D)
Here's a link (http://www.dd.chalmers.se/~f93jojo/sidan2.htm) to a page I happened across that has some stuff about wormholes... It's an interesting read if you can make sense of it :)
01-16-2003, 04:31 PM
Yea, Biology and Physics are my main subjects, and i HATE chemistry.
Thanks for that link. If you understand it, its pretty cool, although alot of it shouldnt be too bad even if you dont understand much science :).
01-16-2003, 04:46 PM
I like Biology and Earth Science.
I hate Physical Science (even though I'm gettin a 98% in the class :D).
Wasn't sure about wormholes. Thanks.
01-16-2003, 04:59 PM
Posted by CaptainRAVE
Yea, Biology and Physics are my main subjects, and i HATE chemistry.Same here :D (Well, they're my favourites, at least - I'm not actually doing biology :()
Valencies and balancing chemical equations were what did it for me - give me quantum theory any day over that rubbish! :p :D
Thanks for that link.No probs :)
*goes off to find ever more info to assimilate on the subject :D*
If you understand it, its pretty cool, although alot of it shouldnt be too bad even if you dont understand much science :).True and true :D
01-16-2003, 05:18 PM
Biology and Medical Science are my favorites (Going to be a Radiologist :D) But I've read that a star "runs" on nuclear fuel, it will lose heat and contract. The warping of spacetime will become so great that a black hole will be created from which light cannot escape. Inside the black hole time will come to an end. Yeah, add this with what Rave said at you have a better discription of black holes. Interesting subjects on these forums though, I love it. :)
01-16-2003, 05:27 PM
We know very little about black holes, so I guess it's impossible to state anything for sure at all.
I believe (note the italics) that a new universe is created and exists in every black hole. But this is only because it sounds hella cool and would be yet another way to explain the origin of our universe. I like the theory because I feel like it. You can all go ahead and kick me now.
An interesting take on black holes, is that if we could place them where we wanted, we could have a very effective shield to protect ourselves with once the universe starts contracting again and implodes.
01-16-2003, 05:34 PM
Earlier on in a post I said Red Giant, and of course it is a Gas giant. It can be any colour. Its just generalized as being red in most text books.
Originally posted by Wacky_Baccy
Same here :D (Well, they're my favourites, at least - I'm not actually doing biology
Valencies and balancing chemical equations were what did it for me - give me quantum theory any day over that rubbish!
*goes off to find ever more info to assimilate on the subject *
True and true :D
Balacing chemical equestions is what did it for me to. I could just never get the hang of those for some reason. But at least I never did badly in chemistry.
Originally posted by Xylan
Biology and Medical Science are my favorites (Going to be a Radiologist ) But I've read that a star "runs" on nuclear fuel, it will lose heat and contract. The warping of spacetime will become so great that a black hole will be created from which light cannot escape. Inside the black hole time will come to an end. Yeah, add this with what Rave said at you have a better discription of black holes. Interesting subjects on these forums though, I love it.[/B]
Well its not really a nuclear reaction. A nuclear reaction is defined as being self sustaining from the other products (the neutrons), where as the sun's internal reaction is kept going by the heat produced, and the constant supply of hydrogen 1. Technically there is no inside the black hole. Actually, I cant explain it any other way either. But, noone actually knows if it should be in or on. Theoretical Physics, you've just gotta love it :p
01-16-2003, 05:59 PM
Originally posted by Cjais
we could have a very effective shield to protect ourselves with once the universe starts contracting again and implodes.
Are you planning to be around for that?
But back to what I first said guys, it's not a hole, there is no opening, no cavity, there is no gap, aperture or space inside.
It is a solid object, a VERY solid object, no room for a universe Cjais. Sorry.
01-16-2003, 07:34 PM
Posted by Cjais
I believe (note the italics) that a new universe is created and exists in every black hole. But this is only because it sounds hella cool and would be yet another way to explain the origin of our universe. I like the theory because I feel like it. You can all go ahead and kick me now.We won't kick you for believing something :p :)
Ridicule you, taunt you, prove you wrong, perhaps... But kick you? Never. :D
...Or we could just start quizzing you on certain things you posted once upon a time :)
An interesting take on black holes, is that if we could place them where we wanted, we could have a very effective shield to protect ourselves with once the universe starts contracting again and implodes.But surely the imploding universe would simply destabilise any black hole 'shield' we could create, only serving to hasten our demise? :D
Posted by griff38
Are you planning to be around for that?He's weird like that ;)
But back to what I first said guys, it's not a hole, there is no opening, no cavity, there is no gap, aperture or space inside.I don't think that was the point he was trying to make - if black holes create a tear in spacetime, then that would result in a holf of sorts... I'm not really sure where any of us is going with this though, so I'll leave it there before I confuse myself :D
01-16-2003, 08:31 PM
Originally posted by CaptainRAVE
As for wormholes, NO. None have ever been found or seen...those have been made up enitirly for science fiction.
Well.....not completely, most quantum physicists DO believe in wormholes, because they believe that space is much like the ocean, look at the ocean from an airplane and it looks nice and smooth, but down in a boat you see it is very choppy and rough. They think the universe is all bumpy and rough, and makes foamy bubbles of sorts, known as quantum foam. They think that wormholes exist between these bubbles.
01-17-2003, 03:20 PM
Well there are particles in the universe which make physicists postulate that a wormhole COULD exist. However, after this theories meet science fiction and it becomes a blur. I cant remember the name of the particles....beginning with M I think....
01-17-2003, 06:06 PM
I recomend the book 'when science fails'. It'll tell you all about how black holes can not be proven to exist.
02-02-2003, 02:01 PM
:rolleyes: Cjais, cjais, cjais...
And you laugh at creationists. Well, black holes are far more absurd than our theory - so no more making fun of it. Besides, if each universe were contained in a black whole, think about the paracox - we would be living inside of a black whole inside our own universe, which is inside of our own universe...
The whole thing is with singularities is that they are so singular - as far as we can tell, a true singularity is the classical point of geometry - zero length, width or volume - but in this case, what amounts to infinite mass. I don't think the use of black holes for wormholes is possible. The gravity would simply compress anything that passed into it to a mass point, infinitely small. But, the idea of manipulating the curvature of spacetime has some interesting possibilities.
The biggest problem with black holes is that we don't know that they exist. We think they do, but in reality, it's just a guess, and not a very educated one at that. Until we fly the Entreprise through one and pop out in a different quadrant, I don't think we will know.
02-02-2003, 02:13 PM
Originally posted by Master_Keralys
Until we fly the Entreprise through one and pop out in a different quadrant, I don't think we will know.
Errrr...how can you fly through a black hole? It's not a hole, it's an object. Perhaps you are thinking about wormholes?
02-02-2003, 02:45 PM
That was sort of my point; I just didn't get it across very well.
02-04-2003, 12:38 PM
Ahh - black holes!! my favourite subject!! :D
I think agreement about whether black holes actually exist has been almost universally reached by the 'credible' scientific community around the world. And the agreement is that black holes do indeed exist.
Well - at least what we know as 'black holes' anyway. There are many theories about the specifics of black holes which - in my opinion - may or may not be true. But the basic idea is almost conclusively proven.
For those who argue that black holes can never be proven to exist - there isn't actually a hell of a lot of things in this universe you can prove 100% - depending on what you define as 'proof'. Take molecules for example. No-one's ever seen one, but we know damn well they exist...
It's the same for black holes. No-one has (or ever will) see one directly. But TONS and TONS of evidence exist for them.
One form of evidence are other bodies in space which are near 'black holes'. From their movements, we know they are being affected by some kind of other body with a known gravitational force. Yet NOTHING can be seen in that space. Until someone else comes up with a theory to explain how something that large can not be visible (i.e. not a star), then the black hole theory is the only one which makes any sense.
Also, current black hole theory indicates that the surface of black holes can emmit a certain kind of radiation. And by detecting that radiation, you can - in effect - SEE a black hole. This kind of radiation emmitions have correlated with where black holes are expected to be - throught the observations I just mentioned.
(I believe the emmitions are caused by the fact that anti-particles effectively 'escape' from just under the surface of balck-holes. I'd have to double-check on this though, I can't exactly remember how that works!!)
As far as black holes being some kind of portal, that is true in a way. They are certainly not like wormholes or any of that sci-fi stuff. I think it's VERY VERY unlikely humans would / will ever find a way to get anywhere near a black hole without getting strung out like sphigetti (sorry about the spelling!!).
BUT - a black hole does represent a boundry which - as far as I'm aware - is unique to black holes. Once you pass the 'event horizon' (the distance from the centre of a black hole from which light iself cannot escape), the known laws of physics cease to have effect. In other words, we cannot possibly determine what happens beyond the event horizon.
You can describe - then - a black hole as a boundry between our known universe and another universe - another universe being an 'area' which does not comply to our known laws of physics. But using the word 'portal' is a bit misleading methinks!! :)
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