- #1
Bolhuso
- 6
- 1
I just finished rereading the great "A Brief History of Time". To me, what stands out the most in this book, is its ability to keep raising questions while you read it. This thought came up. It's been stuck in my mind for days, so I will humbly post it here to get some feedback. Please forgive my poor (technical) English and the assumptions and simplifications I made. The hypothesis is as follows:
Hypothesis:
Predominant galaxy redshift is not just a consequence of an expanding universe. It is in fact required to comply with the Laws of Thermodynamics. In other words, as long as thermodynamics laws hold and entropy can only grow, the universe can only expand.
Reasoning:
(Especially here, please forbid my poor technical English, I just hope that the idea comes through though).
- When light redshifts, it loses part of its capacity to do work due to that light losing temperature. In other words, if that light was to be used after redshifting in a Carnot Cycle, its temperature would be lower, the temperature gradient would be lower, and less work could be extracted.
- On the other hand when light blueshifts it increases its capacity to do work due to that light gaining temperature.
If, on a macro scale, there was more blueshifting than redshifting in the Universe, light would be on average increasing its capacity to do work, which seems a violation of the Laws of Thermodynamics.
Therefore, to avoid an overall increase in the capacity of light to do work, there has to be more redshift than blueshift, and the Universe can do nothing but expand for as long as the laws of thermodynamics hold.
Self assessment of this reasoning:
I'm well aware that this reasoning assumes a simplified Universe and that it doesn't take into account a lot of aspects and interactions, but so far I haven't found a strong reasoning against.
For example, light doesn't increase its capacity to do work while travelling, as my wording might suggest, since the redshift of blueshift happens due to the different velocities of source and observation point. Hence I have considered that my reasoning could be moot and easily explainable through looking at the problem from the point of view of different frames of reference. But I don't think that it renders my hypothesis moot since it's not about a pair of frames of reference, but as the Universe as a whole (supposedly thermodynamically) closed system with all the frames of reference in it.
Also, I would like to point out that my feeling is that the hypothesis and reasoning would be better expressed in terms of entropy gradients, yet I don't have the academic skill to do so.
Possible consequences
The above is as far as I would go making a logical statement. The following are just ideas that could be (or not) consequences of the above. Don't take them very seriously.
1. Should the above hold true, it doesn't by itself prove that the Universe will keep expanding forever. But it ties Thermodynamic Laws to universe expansion and it would hint that, should the universe start contracting (and blueshift become predominant), thermodynamic laws would need to be reversed.
2. It would at the same time hint to there being a relationship between Universe size and entropy (a relationship that already appears to be there when looking at the Universe through the lens of the holographic principle). It would hint that the Big Bang would be the moment with the lowest entropy and that as size grows entropy grows. Similarly, should the universe start contracting, entropy would start to decrease down to the lowest amount which would be at the Big Crunch.
I would really appreciate if you came back with your ideas. It may well be that this, or equivalent perspectives, have already been analyzed by the scientific community. As said, I would appreciate your comments, especially if you could include links or references to materials that I could use to increase my knowledge in this area.
Many humble thanks in advance.
Hypothesis:
Predominant galaxy redshift is not just a consequence of an expanding universe. It is in fact required to comply with the Laws of Thermodynamics. In other words, as long as thermodynamics laws hold and entropy can only grow, the universe can only expand.
Reasoning:
(Especially here, please forbid my poor technical English, I just hope that the idea comes through though).
- When light redshifts, it loses part of its capacity to do work due to that light losing temperature. In other words, if that light was to be used after redshifting in a Carnot Cycle, its temperature would be lower, the temperature gradient would be lower, and less work could be extracted.
- On the other hand when light blueshifts it increases its capacity to do work due to that light gaining temperature.
If, on a macro scale, there was more blueshifting than redshifting in the Universe, light would be on average increasing its capacity to do work, which seems a violation of the Laws of Thermodynamics.
Therefore, to avoid an overall increase in the capacity of light to do work, there has to be more redshift than blueshift, and the Universe can do nothing but expand for as long as the laws of thermodynamics hold.
Self assessment of this reasoning:
I'm well aware that this reasoning assumes a simplified Universe and that it doesn't take into account a lot of aspects and interactions, but so far I haven't found a strong reasoning against.
For example, light doesn't increase its capacity to do work while travelling, as my wording might suggest, since the redshift of blueshift happens due to the different velocities of source and observation point. Hence I have considered that my reasoning could be moot and easily explainable through looking at the problem from the point of view of different frames of reference. But I don't think that it renders my hypothesis moot since it's not about a pair of frames of reference, but as the Universe as a whole (supposedly thermodynamically) closed system with all the frames of reference in it.
Also, I would like to point out that my feeling is that the hypothesis and reasoning would be better expressed in terms of entropy gradients, yet I don't have the academic skill to do so.
Possible consequences
The above is as far as I would go making a logical statement. The following are just ideas that could be (or not) consequences of the above. Don't take them very seriously.
1. Should the above hold true, it doesn't by itself prove that the Universe will keep expanding forever. But it ties Thermodynamic Laws to universe expansion and it would hint that, should the universe start contracting (and blueshift become predominant), thermodynamic laws would need to be reversed.
2. It would at the same time hint to there being a relationship between Universe size and entropy (a relationship that already appears to be there when looking at the Universe through the lens of the holographic principle). It would hint that the Big Bang would be the moment with the lowest entropy and that as size grows entropy grows. Similarly, should the universe start contracting, entropy would start to decrease down to the lowest amount which would be at the Big Crunch.
I would really appreciate if you came back with your ideas. It may well be that this, or equivalent perspectives, have already been analyzed by the scientific community. As said, I would appreciate your comments, especially if you could include links or references to materials that I could use to increase my knowledge in this area.
Many humble thanks in advance.
