[math-fun] Does entropy increase because the universe is expanding?
Will someone who holds an affirmative view on this question answer the following. A chemist constructs two vessels separated by a closed stopcock. One vessel is filled with gas, the other is evacuated. The stopcock is opened. In our expanding universe, the gas expands into the empty vessel until the pressures are equalized. Entropy has increased. What would be observed in a contracting universe? -- Gene
On 7/29/2013 9:50 AM, Eugene Salamin wrote:
Will someone who holds an affirmative view on this question answer the following.
A chemist constructs two vessels separated by a closed stopcock. One vessel is filled with gas, the other is evacuated. The stopcock is opened. In our expanding universe, the gas expands into the empty vessel until the pressures are equalized. Entropy has increased. What would be observed in a contracting universe?
If a chemist can exist he'll see the gas expand into the empty vessel AND he'll see the universe as expanding. Brent P.S. If a chemist constructs a vessel it'll probably leak. That's what technicians are for.
And if a chemist from a locally exapnding region shakes hands with a chemist from a contracting region ... ? (If they can't manage to organise that, send technicians instead.) WFL On 7/29/13, meekerdb <meekerdb@verizon.net> wrote:
On 7/29/2013 9:50 AM, Eugene Salamin wrote:
Will someone who holds an affirmative view on this question answer the following.
A chemist constructs two vessels separated by a closed stopcock. One vessel is filled with gas, the other is evacuated. The stopcock is opened. In our expanding universe, the gas expands into the empty vessel until the pressures are equalized. Entropy has increased. What would be observed in a contracting universe?
If a chemist can exist he'll see the gas expand into the empty vessel AND he'll see the universe as expanding.
Brent P.S. If a chemist constructs a vessel it'll probably leak. That's what technicians are for.
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From: meekerdb <meekerdb@verizon.net> To: Eugene Salamin <gene_salamin@yahoo.com>; math-fun <math-fun@mailman.xmission.com> Sent: Monday, July 29, 2013 10:37 AM Subject: Re: [math-fun] Does entropy increase because the universe is expanding?
On 7/29/2013 9:50 AM, Eugene Salamin wrote:
Will someone who holds an affirmative view on this question answer the following.
A chemist constructs two vessels separated by a closed stopcock. One vessel is filled with gas, the other is evacuated. The stopcock is opened. In our expanding universe, the gas expands into the empty vessel until the pressures are equalized. Entropy has increased. What would be observed in a contracting universe?
If a chemist can exist he'll see the gas expand into the empty vessel AND he'll see the universe as expanding.
Brent P.S. If a chemist constructs a vessel it'll probably leak. That's what technicians are for.
So you are saying that the universe cannot be observed to be contracting. How do you reconcile that with general relativity, which does admit as a solution a contracting universe? -- Gene
On 7/29/2013 12:03 PM, Eugene Salamin wrote:
From: meekerdb <meekerdb@verizon.net> To: Eugene Salamin <gene_salamin@yahoo.com>; math-fun <math-fun@mailman.xmission.com> Sent: Monday, July 29, 2013 10:37 AM Subject: Re: [math-fun] Does entropy increase because the universe is expanding?
On 7/29/2013 9:50 AM, Eugene Salamin wrote:
Will someone who holds an affirmative view on this question answer the following.
A chemist constructs two vessels separated by a closed stopcock. One vessel is filled with gas, the other is evacuated. The stopcock is opened. In our expanding universe, the gas expands into the empty vessel until the pressures are equalized. Entropy has increased. What would be observed in a contracting universe? If a chemist can exist he'll see the gas expand into the empty vessel AND he'll see the universe as expanding.
Brent P.S. If a chemist constructs a vessel it'll probably leak. That's what technicians are for.
So you are saying that the universe cannot be observed to be contracting. How do you reconcile that with general relativity, which does admit as a solution a contracting universe?
In that contracting model, t is just a coordinate parameter. I collapses to a big crunch which is just a time-reversed big bang. Physical time has to correspond, at least locally, to increasing entropy so that one can form memories, etc. I think that for life to have evolved it has to have been in an expanding universe for a long time. Brent
From: meekerdb <meekerdb@verizon.net> To: Eugene Salamin <gene_salamin@yahoo.com>; math-fun <math-fun@mailman.xmission.com> Sent: Monday, July 29, 2013 12:53 PM Subject: Re: [math-fun] Does entropy increase because the universe is expanding?
On 7/29/2013 12:03 PM, Eugene Salamin wrote:
From: meekerdb <meekerdb@verizon.net> To: Eugene Salamin <gene_salamin@yahoo.com>; math-fun <math-fun@mailman.xmission.com> Sent: Monday, July 29, 2013 10:37 AM Subject: Re: [math-fun] Does entropy increase because the universe is expanding?
On 7/29/2013 9:50 AM, Eugene Salamin wrote:
Will someone who holds an affirmative view on this question answer the following.
A chemist constructs two vessels separated by a closed stopcock. One vessel is filled with gas, the other is evacuated. The stopcock is opened. In our expanding universe, the gas expands into the empty vessel until the pressures are equalized. Entropy has increased. What would be observed in a contracting universe? If a chemist can exist he'll see the gas expand into the empty vessel AND he'll see the universe as expanding.
Brent P.S. If a chemist constructs a vessel it'll probably leak. That's what technicians are for.
So you are saying that the universe cannot be observed to be contracting. How do you reconcile that with general relativity, which does admit as a solution a contracting universe?
In that contracting model, t is just a coordinate parameter. I collapses to a big crunch which is just a time-reversed big bang. Physical time has to correspond, at least locally, to increasing entropy so that one can form memories, etc. I think that for life to have evolved it has to have been in an expanding universe for a long time.
Brent
In general relativity the direction of time is not arbitrary. The future is the direction in which black holes form. To continue the saga of this chemist in the contracting universe who observes the gas filling both vessels and the universe expanding, does he observe black holes or white holes? -- Gene
participants (3)
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Eugene Salamin -
Fred Lunnon -
meekerdb