MigL

I don't think so Imatfaal. Even in the very distant future there will be objects transiting out of the observable universe due to expansion. Unless that expansion stops. This means that there will always be objects which aren't gravitationally bound and measurements can be made to determine the rate of expansion. Maybe once we get a grip on vacuum energy, we may even be able to deduce the rate of expansion of flat ( non gravitational ) space without measuring recession rates.

My two cents... Saying 'Time is Change' seems to be circular reasoning, as we define the passage of time by change. It would be akin to saying distance is metres. At a point in time so far in the future that all other galaxies have disappeared from our observable universe, recall that the galaxies aren't moving away, rather spatial separation between them is increasing. This will happen for all other objects in the observable universe ( vast size ), not just galaxies, and I'm sure any surviving intelligent civilization will be able to measure the rate of expansion, and 're-wind' the expansion back to the big bang.

I live 15 min away from the American border at Niagara Falls and have spent many fine nights in the bars and clubs of Western New York over the past 30 yrs. I find no inherent difference in thinking and morals between Americans and Canadians, but, as has been pointed out, countries like Switzerland require adult males to have military weapons in their homes as they may all be called upon to defend their country. Obviously gun ownership is not the problem, and the only possible explanation is that all Americans are nuts. Just kidding, actually the only North American city to have had three school multi-shootings in the last 20 yrs is Canada's own Montreal. But then again, we know that Quebecers are definitely nuts.

The Pauli exclusion principle only comes into play when all lowest orbitals are filled. And this only happens at extremely high densities.

I realise all that John ( and swansont ). The point I was trying to make is that there are no EM emissions from electron level hopping as no electrons are captive in atoms. A plasma is a bunch of free electrons and bare nucleii and of course they will collide and react to external fields and so emit radiation. However, a source of energy had to have been initially applied to strip the electrons from their respective nucleii, and it is greater than any emissions generated by collisions and accelerations. As in the sun !

I believe most of the make-up of the sun is nucleii stripped of all electrons. The early universe before it became transparent was composed of electronless nucleii. I think the critical temp is about 4000 deg. Ok swansont, does a single nucleus of a plasma, if isolated, have a mechanism for emitting EM radiation. And I'm not considering radioactive nucleii, ridiculously high temps or annihilation.

Agreed swansont, but plasma being devoid of electrons, does not itself radiate unless accelerated ( as I originally posted ).

Sorry studiot, I now understand your question. It would be a lot clearer to say a portion of the energy involved in any process becomes unuseable and is lost to the universe. It moves the universe one step closet to a final temperature equilibrium.

Usually plasma does not radiate ( unless accelerated as John has explained ), but there is a source of radiative energy which causes the ionization of the resulting plasma. A good example would be the Sun.

Endercreeper01, you are getting the same malady as Decraig, but you can still be saved. "An object will never actually reach the event horizon," ??? The mathematics is all well and good but you have to consider the physicality of the results. Sometimes they don't make sense. Consider sending a probe towards the event horizon of a black hole. The probe sends a signal back to us ( at a safe distance ), using pulses of light. It is not just the interval between pulses which dilates as the EH is approached, the timebase of the EM wave also dilates so that the frequency approaches zero and the wavelength approaches infinity as the EH is approached. In effect there is no more signal reaching us, not even reflected light from the probe. To us, distant observers, the probe does not stop at the EH, rather it disappears and sends no more information to us. Now if an astronaut was riding the probe, he would certainly see himself crossing the EH and proceeding to the ( possible ) singularity. Now other than the fact that the astronaut is an idiot, I would say his point of view is the more physical, since we will never detect ( by any means you can possibly imagine ), anything 'frozen' at the event horizon.

Any process involves an exchange or transformation of energy. In a two particle collision you can account for all energies and they are conserved. When you start dealing with statistically large systems of particles, processes become irreversible. Energy is still conserved but a small amount is no longer available to the system. Consider a divided box with gas at high temp on one side and lo temp on the other. you can extract work out of this system by taking advantage of this temperature difference. when you remove the partition the gases mingle and the temperature reaches an equilibrium at medium temp. All the energy can still be accounted for ( theoretically ) but it is not available to do work anymore. The entropy of the system has increased. I did mention in my first post that this was a simplistic explanation so I didn't think I should mention increases or decreases in degrees of freedom.

The use of a suitable operator with the wave function will provide a probability distribution of the observable ( energy levels, momentum, spin, position, etc. ) related to said operator. See the previously posted electron orbital probability distributions.

No, I'm implying that any change in energy ( from one form to another ) involves a release of unuseable energy into the universe. This is for example seen as heat in a generator ( from friction of the bearings ) or in an internal combustion engine. The fact that total entropy of the system ( or universe as we can' t really have an isolated system ) must always increase is a valid argument for the non-existence of perpetual motion machines. This is of course not valid for systems composed of a few particles as processes are then reversible, but it applies to any system ofstatistically significant number of particles ( irreversible ). This is part of the three laws of thermodynamics that are in gambling terms... You can't win You can't break even You can't get out of the game

The asymmetrical collapse of various interacting masses to form a symmetrical black hole was addressed in the 60s by people like Wheeler , Thorne and Zel'dovich ( who called them 'frozen stars' as Wheeler's term , black hole, has vulgar connotations in Russian ). And no I can't quote references, do a search If you're interested. But you won't, your mind is made up, no sense peeking around the blinders! Is your intent to re-do the past 50 yrs of high energy gravitational physics and cosmology ( as these theories apply to the very early universe as well )? If so, you should give it a rest as I really don't think you're at the same level as the three named gentlemen, plus Oppenheimer, Novikov, Penrose and Hawking. You may well have been drunk when you started this thread.

To put it extremely simple, if you released any heat during the manufacture of this car, you may have decreased the entropy of the car by making it more ordered, but you increased the entropy of the 'surroundings' by an amount much greater than the car's decreased entropy. This increased entropy of the 'surroundings' is proportional to the heat lost to the surroundings which can no longer be used to do work.

Don't put words in my mouth decraig. I did not mention Newton and I understand the math of GR quite well. I also like to believe I understand some Physics. All Relativity does is tell us how the same event 'looks' to different observers or frames. The fact that gravitational collapse 'seems' to not happen in a non-local frame does not mean it doesn't happen in a local frame. The local observer does pass through the mathematical point of no return ( event horizon ) and on to the singularity. Now I would claim that this singularity is non-physical but you having faith in the math of GR, must consider it real.

The event horizon, no matter what co-oedinate system is used, is a strictly mathematical construct. THERE IS NOTHING ACTUALLY THERE ! Decraig, you need to consider the physicality of the situation not just the mathematics. You say you have 30 yrs experience with the mathematics describing the situation and I say that there is no force or mechanism that can stop the collapse of a massive star once gravity overcomes nuclear radiation pressure and electron and neutron degeneracy. So again I ask you, not for mathematical proof, which may or may not be valid ( we have estabilished that GR is only valid within certain limits, have we not ? ), but for physical options.

Well decraig, we can agree that neutron degeneracy prevents the further collapse of spent stars up to a certain size limit. As you don't believe black holes are a physical possibility, tell us your mechanism for for preventing the collapse of spent stars of mass higher than said limit. And since you brought up Star Trek, as Spock says, 'once you've eliminated all possibilities, you must consider the impossible'.

Not to be picky Jdaniel343, but if you were on a planet 2 million years away you wouldn't see dinosaurs. You'd have to be at least 65 million years away to see them.

The event horizon, the point where not even light can escape, is only 18 km.

Electromagnetic and strong force have been quantized in the last 50 yrs through QED and QCD, where a somewhat dubious process called re-normalization disposes of the infinities caused by virtual particles. Any attempt at quantising gravity so far, has proved to be infested with infinities and not re-normalizable. Re-normalization is apparently related to spin of carrier bosons and higher spin bosons , like gravitons of spin 2, are extremely hard, if not impossible to re-normalize. AJB would probably be able to explain better as I am out of my depth here.

Sorry Strange. I'm guilty of the same mistake that I've accused Alan of.

The data that Sir Arthur Eddington collected during the eclipse of 1919 ( I believe ) did not actually support the conclusions he drew from it. The data did not conclusively show that light bends the required amount around the sun; it was much too scattered. Whether he chose to publish because of his strong belief in relativity or other reasons is unknown. He may have been brilliant but I've disliked him since reading about his treatment of Sebrahim Chandrasekhar.

The name of the brilliant but pompous physicist/astronomer was Eddington, not Ellington, Alan. Space-time and its various non-Euclidian geometries are a mathematical model which does a damn good job of describing reality. It is very simple to describe a real kitchen table mathematically on a computer, and perform all sorts of operations on it such as rotations and translations, using Cartesian co-ordinates. This does not mean, in any way, that the geometric , cubic construct of X, Y and Z co-ordinates is real also. This is all GR and any other theory is doing, nothing more, nothing less.

What do you mean by 'gravity getting out of the black hole' or event horizon ? Why do you assume gravity has to 'travel' to a location to affect said location ? Gravity is the condition assumed by space-time in response to the presence of energy-momentum. The fact that a black hole is there means space-time in its vicinity is distorted from flat into a curvature which we call gravity. It certainly does not radiate from the centre or the event horizon outwards. And yes, from the definition, even gravity would gravitate. Are you proposing that there is another stable state at the Planck or string level so that we can avoid the singular state currently indicated by GR to be the final state of a collapsing large star ? In effect, there is no singularity at the centre of the event horizon, just extremely dense 'stringonium" ?