Is the universe thermodynamically open or closed?

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Discussion Overview

The discussion centers around whether the universe is thermodynamically open or closed, exploring the implications of this classification and its relationship to thermodynamic laws. Participants consider the nature of the universe in terms of energy exchange, equilibrium, and the philosophical aspects of what lies beyond the observable universe.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Philosophical inquiry

Main Points Raised

  • One participant suggests that the universe must be closed, arguing that if it were open, there would be external entities to exchange energy with.
  • Another participant raises the question of whether an infinite universe with finite density would still adhere to thermodynamic laws.
  • A different viewpoint expresses uncertainty about applying thermodynamics to the universe, leading to a realization that it may be nonsensical to consider it open.
  • One participant introduces a philosophical angle, questioning what exists beyond the universe and suggesting that something flows beyond its boundaries.
  • Another participant reflects on the implications of the universe having existed for an infinite amount of time, noting the contradiction with the observed large-scale motions and the concept of equilibrium in classical statistical mechanics.
  • There is speculation that quantum effects in the early universe might have prevented the universe from reaching equilibrium as classical mechanics would suggest.

Areas of Agreement / Disagreement

Participants express differing views on whether the universe is thermodynamically open or closed, with no consensus reached. Some participants lean towards the idea of a closed universe, while others explore the implications of an infinite universe and its adherence to thermodynamic principles.

Contextual Notes

The discussion includes philosophical considerations and assumptions about the nature of the universe, energy conservation, and the application of thermodynamic laws, which remain unresolved.

µ³
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Googling reveals a bunch of information regarding to whether or not the universe is geometrically open or closed, but not thermodynmaically. Is it the same thing? So anyway, is the Universe open or closed thermodynamically speaking and what is the evidence behind it? Sorry if this has been answered before, I tried using the search feature and I couldn't find anything. Thanks in advance.
 
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It has to be closed. If there was anything else to exchange energy with it would be in the universe.
 
What if the universe was infinite (but with finite density)? Would it still obey the laws of thermodynamics then?
 
Let's see, it seems to obey the laws of thermo... Now just what is your question?
 
Nevermind, I got it, thanks. I was just wondering if thermodynamics could be strictly applied to the universe because I wasn't sure if it could be considered closed or not. But thanks to your explanation I realized it would be nonsensical to consider it "open".
 
I think, this is , almost a phylosophical question. What is behind of all the galazies, beyond the limits of everything?. The quantum vacuum?, The nothingness?, what crossess the boundaries of the universe? work?. heat,?, cosmic rays ?. Subtle radiations? what is it beyond?. Anyway. it looks to me that sometihng flows.
 
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[tex]\mu^3[/tex],
I once had the same question. Here's what I assume you're curious about. If the universe has existed for an infinite amount of time, then by the postulates of classical statistical mechanics, it should have already settled into an equilibrium situation (ie a maximum entropy state with as many degrees of freedom as possible). However, this is not what we see. There are still very large scale motions present in our universe with few "degrees of freedom" (the Earth's orbit around the Sun is an example). So then one is tempted to say that the universe has only "existed" for a finite time. So then what was here before it?? But if it really wasn't here, and then just "appeared", this would contradict conservation of mass (which is in relativity conservation of energy).
This has bothered me for a while. Well not really bothered--more like "intrigued". I suppose it's possible that quantum effects in the early universe prevented an approach to "equilibrium" as suggested by classical statistical mechanics. Let me know what you think about this.
 

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