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Invisible because sudden Stelling1 #115216 If the jump to low entropy takes place all at once, rather than in steps, it would not be observed. The usual presumption is that such fluctuations will take this form. The paper cited below disputes this (see sibling node).

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The Arrow of Time »The Arrow of Time The Arrow of Time ☜A map exploring some issues concerning the nature of time that lie at the boundary of physics and philosophy. The map follows up a talk to the Blackheath Philosophy Forum on 2 April 2011 by Huw Price, Professor of Philosophy and director of the Center for Time at Sydney University.☜F1CEB7

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The thermodynamic arrow »The thermodynamic arrowThe thermodynamic arrow☜The Second Law of Thermodynamics implies an arrow of time in the sense that the entropy (or disorder) of an isolated system such as the whole universe never decreases - it either increases or remains constant.☜59C6EF

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Can observers see low entropy? »Can observers see low entropy?Can observers see low entropy?☜How will downward entropy fluctuations appear to observers in them? If the thermodynamic arrow determines the psychological arrow they will be indistinguishable from upward fluctuations. If not, their appearance will depend on whether they are sudden or gradual. Which is likely to be true?☜FFB597

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Invisible because suddenInvisible because sudden☜If the jump to low entropy takes place all at once, rather than in steps, it would not be observed. The usual presumption is that such fluctuations will take this form. The paper cited below disputes this (see sibling node).☜59C6EF

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Link[1] Out of equilibrium: understanding cosmological evolution to lower-entropy states

Citerend uit: Aguire, Anthony and Carroll, Sean and Johnson, Mathew
Geciteerd door: Peter Baldwin 3:21 AM 11 August 2011 GMT
Citerank: (2) 113880Updated Boltzmann-SchuetzThere have been some recent attempts to combine the basic Boltzmann-Schuetz idea with modern cosmology - especially theories that envisage a multiverse. This overcomes a key defect of Boltzmann-Schuetz - the fact that our observable universe is not old or large enough to provide the fluctuations.959C6EF, 115218Observed by Boltzmann brainOne response to the original Boltzmann-Schuetz hypothesis is that the most probable form in which observers could arise from a low-entropy fluctuation would be as a fully formed brain with a minimal environment. If formed gradually, rather than in one step, it would observe declining entropy.959C6EF
URL:

http://arxiv.org/PS_cache/arxiv/pdf/1108/1108.0417v1.pdf

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It would therefore be useful to better understand the precise nature of these excursions, which are acknowledged but vaguely described in the cosmological literature. It is often imagined that these fluctuations are sudden and dramatic transitions, or that they do not admit any classical description. We will argue that cosmological fluctuations o lower-entropy states should be thought of as the time reverse of a - generally smooth, or at least gradual - natural evolution from a low-entropy state into equilibrium.

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Gemaakt door: Peter Baldwin
NodeID: #115216
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Gemaakt op (GMT): 8/11/2011 3:20:00 AM
Laatste bewerking (GMT): 8/11/2011 3:25:00 AM
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