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There is a very old theory called the "Tired Light Hypothesis" which supposes that for some unknown reason light loses energy as it travels over cosmological di

There is a very old theory called the "Tired Light Hypothesis" which supposes that for some unknown reason light loses energy as it travels over cosmological distances. This would reproduce the observed redshifts, but it has issues predicting pretty much every other cosmological observation. In particular it doesn't explain observed reductions in surface brightness (expansion has the effect of "defocusing" collimated light). And it doesn't explain observed time dilation effects.

rvnx 2y ago
I like your theory more than the current setup. I have an interesting addition to it: Time dilation could be that going very fast in the space makes you relatively faster in one direction. The thing is, atoms also have to travel; so the atoms (and matter in general) have a slightly longer distance to travel, to achieve the same chemical reaction. Which means interactions between atoms is slower, giving illusion of a slower time due to slower inter-atoms reactions.
- drdeca 2y ago
  I don’t think this would match the observations that can be made from earth of things on earth? Though the phrasing seems a bit ambiguous. Could you put some math behind those words?
- boxed 2y ago
  I think you just described relativity from the perspective of atoms. It's still the same old relativity though.
pdonis 2y ago
> This would reproduce the observed redshifts, but it has issues predicting pretty much every other cosmological observation. Not to mention contradicting the laws of conservation of energy and momentum.
- antognini 2y ago
  To be fair we do already know that energy is not globally conserved over cosmological timescales. (Energy conservation is a consequence of time invariance, but cosmological expansion breaks that symmetry.) Fritz Zwicky attempted to propose a mechanism of tired light that was caused by Compton scattering off of the intergalactic medium. But these kinds of scattering mechanisms produce far too much blurring in the expected images of distant galaxies and galaxy clusters.
  - pdonis 2y ago
    > To be fair we do already know that energy is not globally conserved over cosmological timescales. No, what we know is that there is no invariant global concept of "energy" at all except in a special class of spacetimes (the ones with a timelike Killing vector field), to which the spacetime that describes our universe as a whole does not belong. However, "tired light" (at least the versions of it that aren't ruled out the way the Zwicky model you describe was) violates local energy-momentum conservation, which is a valid conservation law in GR (the covariant divergence of the stress-energy tensor is zero).
    - antognini 2y ago
      That is a good clarification.
    - kaashif 2y ago
      Somehow I learnt about Riemannian manifolds and Killing vector fields in a geometry class that didn't mention physics at all. I am always entertained when some nonsense I learned actually has something to do with the real world.
mithametacs 2y ago
I've always wanted to play a game based on defunct theories. I'm a fan of luminiferous aether myself. What are the impacts on a spacefaring civilization? Sci-fi already grants alternative physics to enable FTL and other magic. What about hard sci-fi, but wrong-hard sci-fi? Extra credit: go back to Zeno and all motion is paradoxical, what would you even do in the game?
- matthewdgreen 2y ago
  If you haven’t read Greg Egan’s Orthogonal Trilogy, you might like it. https://en.m.wikipedia.org/wiki/The_Clockwork_Rocket https://en.m.wikipedia.org/wiki/The_Clockwork_Rocket
- macintux 2y ago
  It feels like all space combat games I've seen rely on Aristotle's theory that objects prefer to be at rest.
  - NovemberWhiskey 2y ago
    Try Frontier: Elite II if you want to try a "realistically modeled" view of space combat - things are pretty much strictly Newtonian.
    - vidarh 2y ago
      Terminus seemed to have pretty decent physics too, but it's been a long time.
    - voxic11 2y ago
      Children of a Dead Earth is my suggestion https://store.steampowered.com/app/476530/Children_of_a_Dead_Earth/ https://store.steampowered.com/app/476530/Children_of_a_Dead...
    - shagie 2y ago
      Not space combat ... Flight Of Nova > Flight of Nova is a simulator based on newtonian mechanics in which you control spacecraft in the Noren star system. You fly multiple types of spacecraft doing transport and search missions in an environment with realistic aerodynamics and orbital physics. https://www.youtube.com/@flightofnova5746 https://www.youtube.com/@flightofnova5746

rvnx 2y ago

I like your theory more than the current setup. I have an interesting addition to it: Time dilation could be that going very fast in the space makes you relatively faster in one direction. The thing is, atoms also have to travel; so the atoms (and matter in general) have a slightly longer distance to travel, to achieve the same chemical reaction. Which means interactions between atoms is slower, giving illusion of a slower time due to slower inter-atoms reactions.

drdeca 2y ago
I don’t think this would match the observations that can be made from earth of things on earth? Though the phrasing seems a bit ambiguous. Could you put some math behind those words?
boxed 2y ago
I think you just described relativity from the perspective of atoms. It's still the same old relativity though.

pdonis 2y ago

> This would reproduce the observed redshifts, but it has issues predicting pretty much every other cosmological observation. Not to mention contradicting the laws of conservation of energy and momentum.

antognini 2y ago
To be fair we do already know that energy is not globally conserved over cosmological timescales. (Energy conservation is a consequence of time invariance, but cosmological expansion breaks that symmetry.) Fritz Zwicky attempted to propose a mechanism of tired light that was caused by Compton scattering off of the intergalactic medium. But these kinds of scattering mechanisms produce far too much blurring in the expected images of distant galaxies and galaxy clusters.
- pdonis 2y ago
  > To be fair we do already know that energy is not globally conserved over cosmological timescales. No, what we know is that there is no invariant global concept of "energy" at all except in a special class of spacetimes (the ones with a timelike Killing vector field), to which the spacetime that describes our universe as a whole does not belong. However, "tired light" (at least the versions of it that aren't ruled out the way the Zwicky model you describe was) violates local energy-momentum conservation, which is a valid conservation law in GR (the covariant divergence of the stress-energy tensor is zero).
  - antognini 2y ago
    That is a good clarification.
  - kaashif 2y ago
    Somehow I learnt about Riemannian manifolds and Killing vector fields in a geometry class that didn't mention physics at all. I am always entertained when some nonsense I learned actually has something to do with the real world.

mithametacs 2y ago

I've always wanted to play a game based on defunct theories. I'm a fan of luminiferous aether myself. What are the impacts on a spacefaring civilization? Sci-fi already grants alternative physics to enable FTL and other magic. What about hard sci-fi, but wrong-hard sci-fi? Extra credit: go back to Zeno and all motion is paradoxical, what would you even do in the game?

matthewdgreen 2y ago
If you haven’t read Greg Egan’s Orthogonal Trilogy, you might like it. https://en.m.wikipedia.org/wiki/The_Clockwork_Rocket https://en.m.wikipedia.org/wiki/The_Clockwork_Rocket
macintux 2y ago
It feels like all space combat games I've seen rely on Aristotle's theory that objects prefer to be at rest.
- NovemberWhiskey 2y ago
  Try Frontier: Elite II if you want to try a "realistically modeled" view of space combat - things are pretty much strictly Newtonian.
  - vidarh 2y ago
    Terminus seemed to have pretty decent physics too, but it's been a long time.
  - voxic11 2y ago
    Children of a Dead Earth is my suggestion https://store.steampowered.com/app/476530/Children_of_a_Dead_Earth/ https://store.steampowered.com/app/476530/Children_of_a_Dead...
  - shagie 2y ago
    Not space combat ... Flight Of Nova > Flight of Nova is a simulator based on newtonian mechanics in which you control spacecraft in the Noren star system. You fly multiple types of spacecraft doing transport and search missions in an environment with realistic aerodynamics and orbital physics. https://www.youtube.com/@flightofnova5746 https://www.youtube.com/@flightofnova5746