|
|
Joined: Jan 2001
Posts: 618
addict
|
addict
Joined: Jan 2001
Posts: 618 |
Sorry if this is too complex, boring or non-word-related.
Einstein was the first to propose the presence of black holes. The theory arose from his calculations around the relativity theories. "Objects" which act in the way Einstein described have since been "observed" in the universe. The support for the existence of black holes developed, in large part, due to the fact that Einstein was considered pretty smart, and was right most of the time. His calculations also suggested the "singularity" at the centre of a black hole. More on that later, maybe. It also pays to remember that much of this is still theory, despite its wide acceptance.
a) if the hole is just blackness how do they know that there is light in there that is not escaping? If there is no light seeping out maybe there is no light at all.
I think this was succinctly answered elsewhere. Basically it should be emitting radiation of some sort, but it appears not to be. Technically the event horizon is the point from which light can not as opposed to does not escape.
b) how do they know the laws of physics do not apply inside black holes? No one or no probe has ever been in there to send back info.
Again, this is Albert et al at work. And it depends which laws are being applied. Rather than laws not applying, it is more likely that laws and forces we are yet to decipher have such an overwhelming impact on the situation that the the laws we know can not explain what is happening. The concept of a singularity is a pretty damn confusing one, and I'll leave you to your own reading to make sense of it.
c) if there are places where the laws of physics do not apply can they really be called laws?
Short answer, yes. Long answer, see previous answer.
d) how do they know the inside of a black hole is infinitely dense - again, we've never been and it could be something else completely PLUS if something is infinitely dense doesn't it follow that nothing could be sucked into it since well, it's too dense and there is no place.
Ok, this one could be difficult. Infinitely dense is probably a simplification of the situation. Einstein's maths suggested that stuff just keeps going in and well, yeah. Your argument (or something similar) was the basis of the 'portals to somewhere else' theory. The stuff can't just stay there because it's too dense, hence it has to go somewhere else. Well, that associated with the whole space-time curvature thing. Does it help if you think of the universe as both infinitely big and infinitely small in the middle of a black hole? And infinite does not just mean really big, it means, well, infinite. And you'd be travelling at the speed of light, which means you'd be infinitely big.
I'm pretty sure that last paragraph wouldn't have helped much.
e) Portals into other universes???? It sounds exotic, and wouldn't it be nice, but how did they come up with that?
See previous answer.
I mean, why would they assume the far end of a black hole is not occupying same area of the universe as the near end? For example, if I cross the St Hypolite tunnel in Montreal Québec, I go from Montreal to Longueuil in Québec, Canada. I don't wind up in China.
I'm assuming the speed limit through the St Hypolite tunnel is not 300 000 000 m/s (1 080 000 000 km/h, 675 000 000 mph). And that your car is not infinitely massive. And that space is fairly undistorted and that time keeps ticking away at 1 second per second. And there's no 'far end' to a black hole. Just a middle. If you're in the middle of the St Hypolite tunnel, you could theoretically be anywhere.
Why is that assumption being championed by so many scientists? Is it wishful thinking? Or does it have as much validity as someone advancing the theory that when someone goes through a black hole they come out being born on the other side as a new baby.
It probably has a little more validity that the baby theory. Time would be distorted in much the same way as space, but distorting time only makes you age faster or slower, it doesn't reverse the ageing damn crossed thread process. I think I covered the reasons for it's popularity above.
How is it possible that a black hole appears to emit particles when we know that nothing can escape from within its event horizon?
When matter and anti-matter combine, they create well, nothing, basically. Similarly, nothing can spontaneously create matter and anti-matter particles. This happens continuously, although the particles don't last for very long and they pretty quickly combine to create nothing again. However, if this happens near the event horizon, and one particle enters the black hole, the other will (following the laws we know, which work well outside the event horizon) shoot off in the opposite direction. It is these particles which we can detect coming from where nothing should be able to come.
Any more questions?
|
|
|
|
|
Joined: Jun 2001
Posts: 2,636
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Jun 2001
Posts: 2,636 |
Yeah. Did you want fries with that?
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
Any more questions?
First, open-mouthed admiration, sir!
1.)Do you have a degree in physics, too?
2.)Isn't it possible that there is...something radiating from it, whether it is some form of light or not, that is either something we do not recognize or that we cannot measure?
3.)About that infinitely dense thing: stupid question: does pure energy take up actual, physical space? Is it possible that when the density is sufficient, that matter in a black hole simply becomes pure energy, and stays there, not going anywhere?
4.)Would you please elaborate on what combining matter and anti-matter create? It is more than nothing. Thank you.
|
|
|
|
|
Joined: Mar 2000
Posts: 1,981
Pooh-Bah
|
|
Pooh-Bah
Joined: Mar 2000
Posts: 1,981 |
4.)Would you please elaborate on what combining matter and anti-matter create? It is more than nothing. Thank you.
From what I remember of maths, the sums are fairly simple:
1 + (-1) = 0
|
|
|
|
|
Joined: Apr 2000
Posts: 3,065
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Apr 2000
Posts: 3,065 |
The words were Hawkings's, not mine. Possibly I cut off the quotation too soon, but the explanation went on for a couple of pages. To summarise as best I can:
In a normal situation particles and anti-particles are coming into being and destroying each other all the time. In the region just outside the event horizon it is possible for one of the particle/anti-particle pair to fall into the black hole across the event horizon (which would have to be a one-way trip) thus leaving the other particle floating about without anything to annihilate with. For reasons I didn't quite grasp, it is the anti-particle which tends to fall into the black hole leaving the particle to its own devices. The result is it looks as if the black hole is radiating particles, but that is not what is actually happening.
Bingley
Bingley
|
|
|
|
|
Joined: Sep 2000
Posts: 2,891
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Sep 2000
Posts: 2,891 |
I am trying to wrap my mind around your explanations doc but am having a bit of trouble To put it succinctly ...I don't get it.
It seems, from this layman’s point of view, that all these explanations would be perfect examples to cite when trying to explain the expression “begging the question.” They seem to rely on the end belief to prove that very same belief.
Take the tunnel example:
====================================================================
ME: I mean, why would they assume the far end of a black hole is not occupying same area of the universe as the near end? For example, if I cross the St Hypolite tunnel in Montreal Québec, I go from Montreal to Longueuil in Québec, Canada. I don't wind up in China.
DOC: I'm assuming the speed limit through the St Hypolite tunnel is not 300 000 000 m/s (1 080 000 000 km/h, 675 000 000 mph). And that your car is not infinitely massive. And that space is fairly undistorted and that time keeps ticking away at 1 second per second. And there's no 'far end' to a black hole. Just a middle. If you're in the middle of the St Hypolite tunnel, you could theoretically be anywhere.
====================================================================
You are using the un-proven and currently un-provable belief that the black hole is infinitely massive, that inside you move at a tremendous speed and that it only has a middle, to dispute my point. Nobody knows whether time is distorted in a black hole. It can be just as easily assumed that it ticks at 1 second per second like everywhere else in the universe.
If you’re in the middle of the St Hypolite tunnel you are most assuredly beneath the St. Lawrence river between Montreal and Longueuil, no ifs, ands, or buts about it. If you are from out of town, we blindfold you and bring you to the middle of the tunnel, you might not know where you are and you can conjecture all you want, but you’ll still be beneath the St. Lawrence.
I think people are making things up because they are from out of town and don’t know where they are. AND that the subsequent arguments are being based on these conjectures and the conjectures are being used as proofs that the arguments are right …lo and behold “begging the question.”
|
|
|
|
|
Joined: Mar 2000
Posts: 11,613
Carpal Tunnel
|
|
Carpal Tunnel
Joined: Mar 2000
Posts: 11,613 |
From what I remember of maths, the sums are fairly simple:
1 + (-1) = 0 Dear Jo: Pppbfffttt!  Nothing may be the end result in that space that was formerly occupied, but something happens that creates that nothing.
|
|
|
|
|
Joined: Mar 2000
Posts: 1,981
Pooh-Bah
|
|
Pooh-Bah
Joined: Mar 2000
Posts: 1,981 |
There is the other sum: E=MC2 (can't do superscript 2) Essentially, our everyday Newtonian concept of the universe falls apart at the extremes. When things get very small, we throw out Newtonian mechanics in favour of Quantum theory (Heisenberg etc, see this link: http://zebu.uoregon.edu/~imamura/122/feb9/hup.html). When things get very large we throw out Newtonian mechanics in favour of General Relativity (see this link http://archive.ncsa.uiuc.edu/Cyberia/NumRel/GenRelativity.html. As far as I remember, Hawking is in search of the big idea that unifies the theories. Because we don't live in a world where we are aware of E=MC2 applying in our everyday lives, it is hard to picture that particular relationship between mass and energy. We just have to remember to throw out the rules whereby apples fall out of trees (v=u+gt) and think in a completely different way, the amazing thing to me is how clear it all seemed to Einstein.
|
|
|
|
|
Joined: Jan 2001
Posts: 618
addict
|
|
addict
Joined: Jan 2001
Posts: 618 |
1.)Do you have a degree in physics, too?
No, 'fraid not. Just an unhealthy interest in astrophysics.
2.)Isn't it possible that there is...something radiating from it, whether it is some form of light or not, that is either something we do not recognize or that we cannot measure?
Based on Einstein's premise that nothing can travel faster than the speed of light, we must assume that nothing can be radiating from it. But we don't know anything.
3.)About that infinitely dense thing: stupid question: does pure energy take up actual, physical space? Is it possible that when the density is sufficient, that matter in a black hole simply becomes pure energy, and stays there, not going anywhere?
Energy doesn't so much take up space, as exist in space and have an effect on space. In a black hole it is more likely that the energy becomes pure matter - the large "forces" providing the energy needed for the transformation. Having said that, the matter and energy aren't really there, the singularity is.
4.)Would you please elaborate on what combining matter and anti-matter create? It is more than nothing. Thank you.
I'm going to struggle on this one, I think. All (isolated) reactions must conserve momentum, mass-energy, charge and probably other stuff. When nothing becomes matter and anti-matter, energy is produced as well. Hence when matter and anti-matter combine, the process requires energy. If external energy is unavailable, there will be a resultant negative energy afterwards. However, there can be no such thing as anti-energy, so the universe pulls some weird stunt whereby a photon-like particle is created with whatever qualities it needs to ensure conservation of whatever needs conserving.
Or something like that.
|
|
|
|
|
Joined: Jan 2001
Posts: 618
addict
|
|
addict
Joined: Jan 2001
Posts: 618 |
Some of these answers may seem flippant, and I apologise if they do. Many of the concepts I do not even pretend to understand. I do not comment, I merely report...
You are using the un-proven and currently un-provable belief that the black hole is infinitely massive, that inside you move at a tremendous speed and that it only has a middle, to dispute my point. Nobody knows whether time is distorted in a black hole. It can be just as easily assumed that it ticks at 1 second per second like everywhere else in the universe.
You are absolutely correct. None of this can be proved. It is simply the best current explanation we have, However, working on the assumption that Einstein was right...
Nothing can travel faster than the speed of light.
As things travel faster, they become more massive.
If light can not escape a black hole, which is what the maths suggests and what we appear to be observing in the universe, then even something which is not moving at the even horizon, will be moving at the speed of light when it gets to the middle.
Anything moving at the speed of light is infinitely massive.
However, the black hole itself is not infinitely massive because...
Space and time are distorted by the black hole (and indeed by any object)
At the singularity, space-time is infinitely small, and stuff is infinitely big, hence there is infinite density.
Because of this, although there is another side to the black hole, there is not necessarily another end. All we can say is there is a big happy oneness in the middle, through which nothing passes.
Although space-time are distorted, if you exist in that space-time, time will continue to tick away at 1s/s. Only to an external observer will time appear different.
If you’re in the middle of the St Hypolite tunnel you are most assuredly beneath the St. Lawrence river between Montreal and Longueuil, no ifs, ands, or buts about it. If you are from out of town, we blindfold you and bring you to the middle of the tunnel, you might not know where you are and you can conjecture all you want, but you’ll still be beneath the St. Lawrence.
You are only beneath the St Lawrence if you are observed beneath the St Lawrence, which is a different argument altogether. Otherwise you are only probably there.
A black hole is not like a hole in the ground with an opening at one end and a closed bit at the other, nor even like a tunnel, with two openings and some space in between. It would only appear as a 2-dimensional black circle on a simple 2D image of space. It is actually a 3-dimensional entity, into which things enter and never leave. We hypothesise that these things reach the middle and then do their mystic singularity thing. If the St Hypolite tunnel became progressively smaller, such that it was impossible to pass the half-way point, then as traffic approached the middle, there would be progressively more cars, and they would be moving slower. Where the tunnel analogy falls down is that the cars would be able to keep coming forever, yet none would ever get through, and there would be no road rage.
|
|
|
|
Forums16
Topics13,913
Posts229,322
Members9,182
| |
Most Online3,341
Dec 9th, 2011
|
|
|
0 members (),
585
guests, and
2
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
