What does this new twist in astrophysics reveal?

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Discussion Overview

The discussion revolves around the concept of Observer Dependent Entropic States in astrophysics, particularly in relation to black holes and cosmological horizons. Participants explore theoretical implications, references to existing literature, and the potential for new insights into entropy measurements based on the observer's position.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants propose that the Hubble far-wide deep field images may require re-gauging of parameters due to an entropic "observable" function that influences what is received from distant horizons.
  • There is confusion regarding the Covariant entropy bound, which some participants identify as Bousso's bound, and express interest in its potential proof.
  • Participants discuss the idea that entropy measurements differ based on the observer, referencing Marolf's work on how observers crossing a horizon measure different entropy flux compared to those outside.
  • Questions are raised about whether entropy calculations for black holes apply to the cosmological horizon, particularly regarding the implications of accelerated mass becoming invisible.
  • One participant reflects on the differences in entropy measurements between inertial and Rindler observers in Minkowski space, expressing a desire to understand the Unruh effect better.
  • Concerns are voiced about how to ascertain the amount of matter that has fallen behind the cosmological horizon and the apparent contradiction of the horizon size in relation to falling mass.
  • Another participant references a previous discussion on the variability of physical laws and observations, particularly in quantum mechanics versus relativity, and how local measurements may differ from those made at a distance.
  • Several links to relevant papers are shared, indicating ongoing research and cross-referencing within the entropic domain.

Areas of Agreement / Disagreement

Participants express a range of views on the implications of observer-dependent entropy, with no clear consensus on how these concepts apply to black holes and cosmological horizons. The discussion remains unresolved with multiple competing perspectives presented.

Contextual Notes

Some limitations include the dependence on specific definitions of entropy, the unresolved nature of mathematical steps in the theories discussed, and the varying interpretations of observer effects in different contexts.

Wave's_Hand_Particle
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From the Eire conference:http://arxiv.org/abs/hep-th/0410168

Interesting concept for Observer Dependent Entropic States.
 
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Some obvious consequence paramiters must be re-gauged for say..the Hubble far-wide deep field images?

Are we 'instrumental', in dictating what images are received from far away (b-h) Horizons, by an Entropic "OBSERVABLE", Function?
 
The text mentions the Covariant entropy bound; it got me confused as i never heard of such a bound, but then looking the references i realized that is an alternative name for Bousso's bound, that I've found always interesting. Would be nice if Bousso's conjecture can be proven
 
Wave's_Hand_Particle said:
Interesting concept for Observer Dependent Entropic States.

for explicitness, this exerpt
---quote from Marolf abstract---
...a new sense [3] in which the entropy of an “object” depends on the observer making the measurement, so that observers crossing the horizon measure a different entropy flux across the horizon than do observers remaining outside.
---end quote---

and he cites a 2003 paper by him and two others about this
3. D. Marolf, D. Minic and S. F. Ross, arXiv:hep-th/0310022.
so if one wanted to follow up on the observer-dependence of entropy one might check out
http://arxiv.org/hep-th/0310022

for some people here it may be obvious that entropy is going to depend majorly on the observer---if someone does have a good grasp of this it would be great to have some explanation/clarification. meteor? sA? anybody?
 
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marcus said:
for explicitness, this exerpt
---quote from Marolf abstract---
...a new sense [3] in which the entropy of an “object” depends on the observer making the measurement, so that observers crossing the horizon measure a different entropy flux across the horizon than do observers remaining outside.
Do you suppose all those entropy calculations for black holes applies equally to the cosmological horizon which is also has accelerated mass that becomes invisible?
 
meteor said:
Would be nice if Bousso's conjecture can be proven.
You may find this of interest
http://arxiv.org/abs/hep-th/9908070
This paper has 79 citations, so it apparently has been well received.
 
marcus, I read the link you gave and Marolf proposes there also the idea of observer dependent entropy. He says that in a Minkowski space, had you some localized matter in some part of it, and being the space completely void apart of the matter and two observers, the inertial observer will measure a different entropy for the matter than the Rindler observer (a Rindler observer is an observer in Minkowski space undergoing constant acceleration)
I cannot give many much insight about it, as the math is a bit beyond me, i think I'm going to try to improve my knowledge of the Unruh effect, that always has seemed me somewhat misterious
 
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Mike2 said:
Do you suppose all those entropy calculations for black holes applies equally to the cosmological horizon which is also has accelerated mass that becomes invisible?
It does seem that they are indeed applying the entropy of area calculations to the cosmological horizon. What I have to wonder is how would they know how much matter has already disappeared behind the horizon? And how is this consistent with the horizon getting smaller as more matter falls behind the cosmologcial horizon? Shouldn't the horizon be getting larger as more mass falls behind it?
 
Me and Self A discussed this on another forum 2yrs ago, this is his reply:

http://www.superstringtheory.com/forum/timeboard/messages8/25.html

there were mitigating circumstances to my reasoning then, as still is the case today, the Laws of Physics and the Law of Observation vary, QM has a differing viewpoint from SR/GR, if one measures 'something' locally, then an observer measuring the same something further away will have to contend that there are differing laws regarding information recieved.

A simple example is a local measurement of a specific single Photon, this cannot be correlated by a measurer that is not local, in the paper I linked by Marolf, this equates to a Far away observer registering an Electron Positron emission, in response to a single photon crossing the Event(local) horizon near a Blackhole, 2 for 1 !
 
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