Quantised Inertia: A Solution to Dark Matter and Galaxy Rotations

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  • Thread starter wolram
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In summary: This is tangential to the subject matter, but isn't the present-epoch event horizon farther than the Hubble radius? Shouldn't they...Yes, the present-epoch event horizon is farther than the Hubble radius.
  • #36
timmdeeg said:
Correct? Otherwise it seems that Wikipedia is wrong.

It's not wrong but it's a bit ambiguous. What is meant by "where an inertial observer would observe none" is merely "vacuum state". They don't attempt to reconcile the detection events on the accelerated detector with the vacuum state measured by the first. This is done, as was said, by realizing that according to the inertial observer the detector emits radiation and Unruh radiation makes sense. You can think of it as a quantum mechanical analogue of centrifugal force, which is something you have to include for consistency when writing Newton's laws in a noninertial frame.

That said, any phenomenon that you explain in a noninertial frame has to have a corresponding explanation in the inertial one, for consistency. There is no Rindler horizon for the inertial observer, so it can't impose any boundary conditions on the radiation (even if it made sense that horizons did this, and it doesn't). This is a serious problem.
 
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  • #37
kimbyd said:
I added to that that the proper acceleration for an object in free-fall is identically zero. Which means that the proper acceleration of all stars and galaxies is so close to zero that it can be considered negligible, thus there should be no noticeable Unruh radiation with which to cause the rotation curve effect suggested by McCulloch.
Yes. As a layman I was confused by this approach. The observer dependence of Unruh radiation is a bit subtle as I realized here, but that it is due to proper acceleration isn't.
 
  • #38
LeandroMdO said:
It's not wrong but it's a bit ambiguous. What is meant by "where an inertial observer would observe none" is merely "vacuum state". They don't attempt to reconcile the detection events on the accelerated detector with the vacuum state measured by the first. This is done, as was said, by realizing that according to the inertial observer the detector emits radiation and Unruh radiation makes sense.
They should have mentioned the latter at least shortly. They didn't and I'm the best example what kind of misunderstanding it creates. :frown:
 

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