Re: Energy - the "hot potato"?

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Sujet : Re: Energy - the "hot potato"?
De : ram (at) *nospam* zedat.fu-berlin.de (Stefan Ram)
Groupes : sci.physics.research
Date : 20. Jun 2024, 14:39:40
Autres entêtes
Organisation : Stefan Ram
Message-ID : <thermodynamics-20240620102320@ram.dialup.fu-berlin.de>
References : 1 2
Mikko <mikko.levanto@iki.fi> wrote or quoted:
On 2024-06-18 18:25:10 +0000, Stefan Ram said:
. Here's a quotation from "Quora":
. . .
|It turns out that it is a general law of nature that physical
|systems always "want" to be in the state of lowest possible
|energy.
. . .
Not exactly. The law is that entropy always increases, which means
that energy becomes more evenly distributed.

  The heat death (the conversion of all forms of energy into
  heat energy) is rather something long-term, but one can also
  be interested in the dynamics within shorter periods of time.

  At the system boundaries, the flow of extensive quantities
  is determined by the difference of the intensive quantities
  (potentials).

  Thus, (positive) electric charge (extensive quantity)
  flows, for example, from the system with the higher
  electric potential (intensive quantity) to the system
  with the smaller electric potential.

  Yes, and in doing so, the total energy in the two systems would
  become smaller. But since energy must not be destroyed, it must
  be converted into another form. If the systems cannot exchange any
  other forms of energy, then only the generation of entropy remains.
  And it then flows rather to the colder of the two systems.

  So you were right insofar as one must take entropy into account.

  Here is the formulation with potential differences, once without
  and once with "want":

  Without "want": When two systems come into contact, an extensive
  quantity flows to the system with the smaller associated potential.

  With "want": Every system wants to give off its extensive
  quantities (which reduces its energy), but this is only
  possible if the system finds another system in which the
  potential associated with the extensive quantity is smaller.

  If we regard a system with a small potential as "weak"
  and a system with a large potential as "strong", we can say
  that every system wants to impose its energy in the form of
  extensive quantities on other systems, but it only succeeds
  in doing so if it finds a weaker system.

  The concept of the thermodynamic potential, which determines
  the direction of the flow of extensive quantities, was still
  missing from your explanations.

  (I'm not particularly interested in the Higgs field itself, as
  I wrote, but if I imagine the Higgs field and another field, and
  each wants to give away its energy, then I can't find suitable
  forms of energy with their associated extensive and intensive
  quantities that would help me predict the temporal evolution.)

Date Sujet#  Auteur
18 Jun 24 * Energy - the "hot potato"?3Stefan Ram
19 Jun 24 `* Re: Energy - the "hot potato"?2Mikko
20 Jun 24  `- Re: Energy - the "hot potato"?1Stefan Ram

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