Comments on: Negative Heat Capacity http://oklo.org/2006/05/16/negative-heat-capacity/ characterizing planetary systems Fri, 18 Nov 2011 22:27:52 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Aristotle Pagaltzis http://oklo.org/2006/05/16/negative-heat-capacity/comment-page-1/#comment-4899 Aristotle Pagaltzis Thu, 01 May 2008 16:40:26 +0000 http://oklo.org/?p=88#comment-4899 But the system also gets smaller. Isn’t it therefore the case that the increased heat is an expression of energy density increasing at the expense of the volume of the system, which shrinks so much that the total energy content of the system is still smaller than it started out, even though the density has increased? So to make the analogy with the open front door correct, in a house where leaving the front door open caused it to heat up, doing so would primarily cause the house to deflate. And it would shrink fast enough that even though heat was draining from it, it would still heat up. Ah, I guess that is what motivated your remark on the spendthrift principle of nature. But the system also gets smaller. Isn’t it therefore the case that the increased heat is an expression of energy density increasing at the expense of the volume of the system, which shrinks so much that the total energy content of the system is still smaller than it started out, even though the density has increased?

So to make the analogy with the open front door correct, in a house where leaving the front door open caused it to heat up, doing so would primarily cause the house to deflate. And it would shrink fast enough that even though heat was draining from it, it would still heat up.

Ah, I guess that is what motivated your remark on the spendthrift principle of nature.

]]> By: systemic - Good Librations http://oklo.org/2006/05/16/negative-heat-capacity/comment-page-1/#comment-157 systemic - Good Librations Mon, 29 May 2006 00:53:32 +0000 http://oklo.org/?p=88#comment-157 [...] Last week, I wrote a post about the negative heat capacity of self-gravitating systems. I never cease to find it remarkable that if you drain energy out of a system that is held together by its own gravity (such as a giant planet, or a cluster of stars), then that system gets hotter. There really is such a thing as a free lunch (brought to you courtesy of the attractive gravitational force.) [...] [...] Last week, I wrote a post about the negative heat capacity of self-gravitating systems. I never cease to find it remarkable that if you drain energy out of a system that is held together by its own gravity (such as a giant planet, or a cluster of stars), then that system gets hotter. There really is such a thing as a free lunch (brought to you courtesy of the attractive gravitational force.) [...]

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