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## Negative Changes in Entropy??

Ok, but if you say the system and it's surroundings is the universe, then you can't have anything else outside of this, as the universe isn't believed to have a boundary.

 Quote by Drakkith Ok, but if you say the system and it's surroundings is the universe, then you can't have anything else outside of this, as the universe isn't believed to have a boundary.
It is not clear if you have something in mind and trying to drive at it.

Once you define your system then what all that you can imagine or want to have in the universe, can be included in the surroundings. the system and the surroundings now make the universe. You will then be left with nothing more to think of than the universe, which encompasses all that you could think of.

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 Quote by Radhakrishnam Once you define your system then what all that you can imagine or want to have in the universe, can be included in the surroundings. the system and the surroundings now make the universe.
I'm so confused lol. Ok, all I was saying was that if you have the system AND it's surroundings as the universe, you can't have another boundary somewhere that would be another system and it's surroundings. You could absolutely have part of the universe as the system and the rest as it's surroundings.

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 Quote by Radhakrishnam We define open system as one in which exchange of matter (besides energy in the form of heat and work) is allowed across the boundary that separates the system and surroundings. To distinguish it from a closed system, we define closed system as one in which exchange energy (in the form of heat and work) is allowed across the boundary that separates the system and surroundings.
You have failed to identify what 'boundary' you have in mind that applies to the universe.
 I think what he is trying to say is that the you need to define a system inside the universe, where the "universe" is the surroundings. It doesn't really matter if the universe is bounded or not so long as you define a system encompassed by we call the universe because thermodynamics only changes in a system. After-all, aren't all changes relative to something????
 An answer to your question lies in the fabric of the replies from your peers. While it can be assumed one could find negative entropy in areas of the universe, it is most obviously not so everywhere. Relativity teaches us that time can be warped by perspective, and as such there are an infinite number of perspectives from which to perceive negative entropy, as long as one understands that at energies/speeds approaching the speed of light that one becomes a source of negative entropy. Expansion is a huge source of negative entropy, happily subdividing the universe into contained areas.
 Very interesting. I really wish I studied physics in undergrad... Do you happen to know of any texts relating to stat-thermo as applied to the universe?

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 Quote by Aero51 Very interesting. I really wish I studied physics in undergrad... Do you happen to know of any texts relating to stat-thermo as applied to the universe?
Stat-Thermo?

 Quote by Drakkith Stat-Thermo?
statistical mechanics and thermodynamics?
 I was thinking something less broad as i already have Toleman and Hills book on statistical thermodynamics.