🚀 go-pugleaf

On Jan 23, 8:03 pm, dwhig...@peoplepc.com wrote:
> On Jan 21, 5:32 am, Pentcho Valev <pva...@yahoo.com> wrote:
>
>
>
> > On Jan 21, 11:59 am, "rayoha...@yahoo.com.ar" <juanp...@gmail.com>
> > wrote:
>
> > > On Jan 21, 3:52 am, Pentcho Valev <pva...@yahoo.com> wrote:
>
> > > > On Jan 21, 4:46 am, "rayoha...@yahoo.com.ar" <juanp...@gmail.com>
> > > > wrote in sci.physics:
>
> > > > > On Jan 20, 10:21 am, Pentcho Valev <pva...@yahoo.com> wrote:
>
> > > > > > On Jan 18, 2:58 pm, blackboab <blackb...@gmail.com> wrote in
> > > > > > sci.physics:
>
> > > > > > > The second law of thermodynics says that the direction of time is
> > > > > > > dictated by the increase of entropy,.
>
> > > > > > Does it? Why don't you read Jos Uffink's paper:
>
> > > > > >http://philsci-archive.pitt.edu/archive/00000313/
> > > > > > Jos Uffink: "This summary leads to the question whether it is fruitful
> > > > > > to see irreversibility or time-asymmetry as the essence of the second
> > > > > > law. Is it not more straightforward, in view of the unargued
> > > > > > statements of Kelvin, the bold claims of Clausius and the strained
> > > > > > attempts of Planck, to give up this idea? I believe that Ehrenfest-
> > > > > > Afanassjewa was right in her verdict that the discussion about the
> > > > > > arrow of time as expressed in the second law of the thermodynamics is
> > > > > > actually a RED HERRING."
>
> > > > > > Jos Uffink:http://www.phys.uu.nl/igg/jos/
>
> > > > > > Pentcho Valev
> > > > > > pva...@yahoo.com
>
> > > > > i had looked that article. it is interesting, but any consideration of
> > > > > thermodynamics that not relate this to statistical mechanics seems to
> > > > > me out of target. and it get lost in mathematical considerations about
> > > > > things as for example
> > > > > when a process is irreversible or not. it get lost, because if you not
> > > > > look at the microscopic level, then you cannot look for a basis from
> > > > > which assume good sense. take a look to the article and u will see
> > > > > that.
>
> > > > You mean there is no "good sense" in classical thermodynamics?
> > > > Ironically, the alleged STRENGTH of that science was that it was
> > > > PHENOMENOLOGICAL, that is, it did not have to deal with the
> > > > microscopic level and yet it could give, through rigorous deduction,
> > > > valuable results. But you can verify this. Take a look at Clausius
> > > > 1850 deduction of the original version of the second law of
> > > > thermodynamics: "It is this maximum of work which must be compared
> > > > with the heat transferred. When this is done it appears that there is
> > > > in fact ground for asserting, with Carnot, that it depends only on the
> > > > quantity of the heat transferred and on the temperatures t and tau of
> > > > the two bodies A and B, but not on the nature of the substance by
> > > > means of which the work is done.":
>
> > > >http://web.lemoyne.edu/~giunta/Clausius.html
> > > > "Ueber die bewegende Kraft der Warme" 1850 Clausius: "It is this
> > > > maximum of work which must be compared with the heat transferred. When
> > > > this is done it appears that there is in fact ground for asserting,
> > > > with Carnot, that it depends only on the quantity of the heat
> > > > transferred and on the temperatures t and tau of the two bodies A and
> > > > B, but not on the nature of the substance by means of which the work
> > > > is done.....If we now suppose that there are two substances of which
> > > > the one can produce more work than the other by the transfer of a
> > > > given amount of heat, or, what comes to the same thing, needs to
> > > > transfer less heat from A to B to produce a given quantity of work, we
> > > > may use these two substances alternately by producing work with one of
> > > > them in the above process. At the end of the operations both bodies
> > > > are in their original condition; further, the work produced will have
> > > > exactly counterbalanced the work done, and therefore, by our former
> > > > principle, the quantity of heat can have neither increased nor
> > > > diminished. The only change will occur in the distribution of the
> > > > heat, since more heat will be transferred from B to A than from A to
> > > > B, and so on the whole heat will be transferred from B to A. By
> > > > repeating these two processes alternately it would be possible,
> > > > without any expenditure of force or any other change, to transfer as
> > > > much heat as we please from a cold to a hot body, and this is not in
> > > > accord with the other relations of heat, since it always shows a
> > > > tendency to equalize temperature differences and therefore to pass
> > > > from hotter to colder bodies."
>
> > > > If Clausius deduction is invalid (try to discover why it IS invalid),
> > > > then you are right: there is no "good sense" in classical
> > > > thermodynamics.
>
> > > > Pentcho Valev
> > > > pva...@yahoo.com
>
> > > no, classical thermodynamics has sense, it is a very good theory, but
> > > it has no sense when u try to link it with arrow time, that is another
> > > story, I had expressed wrong (the word this sings to a preferred arrow
> > > time direction, sorry for that), and u then had a bad interpretation,
> > > it is my fault, read entirely what i´d writed.
>
> > Let me translate yout statement that classical thermodynamics "is a
> > very good theory, but it has no sense when u try to link it with arrow
> > time" in the following way: The version of second law saying perpetuum
> > mobile of the second kind is impossible is correct; the version of the
> > second law saying the entropy always increases is nonsense. I disagree
> > with the first part (perpetuum mobile of the second kind IS POSSIBLE)
> > but this disagreement of mine is irrelevant for the moment.
>
> I responded 4 hours earlier to let you know I had already been there
> 18 years ago. Please let us hear your version. DWH
>
>  If the
>
> > principle of entropy increase is really nonsense, the devastation
> > suffered by science and caused by this particular nonsense is much
> > greater than the devastation caused by Einstein's 1905 false light
> > postulate. Just remember this:
>
> >http://web.mit.edu/keenansymposium/overview/background/index.html
> > "The law that entropy always increases, holds, I think, the supreme
> > position among the laws of Nature. If someone points out to you that
> > your pet theory of the universe is in disagreement with Maxwell's
> > equations--then so much the worse for Maxwell's equations. If it is
> > found to be contradicted by observation--well, these experimentalists
> > do bungle things sometimes. But if your theory is found to be against
> > the second law of thermodynamics, I can give you no hope; there is
> > nothing for it but to collapse in deepest humiliation." Sir Arthur
> > Eddington (The Nature of the Physical World, 1915)
>
> > Pentcho Valev
> > pva...@yahoo.com- Hide quoted text -
>
> > - Show quoted text -

quote:
{In 1990 an early version of my theory stated: " The universe is a
pure
system and inasmuch as it is the only system, cannot react with any
other system adiabatically or otherwise.  Net entropy in such a system
is zero and therefore the universe must recycle, and is the only
perpetual motion machine of the second kind." This was copyrighted by
me,of course. Regards, Dwain W. Higginbotham }

i think that this is a better look than before.  agree with the fact
that ¨universe must recycle, and is the only perpetual motion machine
of the second kind.¨  not sure with
recycle, no one knows what happens if big bang its true, and big
crunch also. but main theories are consistent with the assumption that
entire universe corresponds to microcanonical ensemble, that is,
universes do not interact with another thing because by definition
there is not another thing.

but I disagree with ¨Net entropy in such a system is zero¨. I think
that the reason for this mistake comes from a misconception of how to
relate entrophy with the system in this case, that is, universe. for a
good uses of entrophy, u must think in the main basis of it, that is,
entrophy is a measure of ignorance (see c. shannon famous paper).
I think that resume some basic of this point of view related to
mechanical statistics will be a good exercise. suppose that at the
micro level description the vector x=(x1,...,xN) in R^N, describes the
state of the system at time t, so the phase space of the system is
some subset of R^N,  say Q is the phase space. then an order parameter
O_f, is just a number that can be calculated from the average of some
function f(p) over some distribution probability {p} over Q.
now, the value of Q_f depends on how trayectories behaves on Q. and
that depends on some parameters that may affect the hamiltonian (think
in some kind of thermodynamical variables as for example could be a
magnetic field B).
now, entrophy is such an order parameter, a praticular one that we
denotate S. now for things has sense it is important that {p} where
well defined on Q, in principle that is by mean of avergaing over all
available trayectories on Q from time zero to infinity (birkhoff´s
theorem).
so in essence, what measures entrophy ?? think that we can measure
over the system some set of order parameters O_f1,O_f2,...,O_fr, now
assume that we know  how to calculate this order parameters from {p}.
and that order parameters are all that we can measure from the system.
then S(O_f1,..,O_fr) is the amount of information that we need to
establish the particular trajectory that the system follows, our
ignorance comes, by averaging over all initial conditions and then by
mean of {p} looking how much ¨consistent¨ is each initial condition
with the values of O_f1,..,O_fr. in other words, if we choose a
suitable set O_f1,...,O_fr the we restrict the system to only one
trajectory possible consistent with that set, that is S=0. if it is
not the case, the S measures how much the set O_f1,...,O_fr fail to
¨restrict¨ the choose of a trajectory. if the set O_f1,...,O_fr is
measured, then S measures the fail to restrict the choose of the real
trajectory, because O_f1,...,O_fr can´ t be inconsistent with the real
trajectory.

now all this has sense for system where {p} is defined (system at
equilibrium, or system where {p} admits definition by means of
averaging all trajectories from t=-infinity to t=infinity), what
happens when this is not the case ?? the universe is one of this
cases. well here a more complicated considerations are needed, and in
particular the considerations can be system dependent in order to at
least admit some simplifications. but in general one can define a set
O_f1(t),...,O_fr(t) and S(t)
, then S(t) is the ignorance about the initial condition at time t.

so, in practice, we measure some things as voume of universe, and
temperature, etc, all variables that approximates some set
O_f1(t),...,O_fr(t). and from it speculate about if S(t) grows or
decreases or remain constant.

if big bang is true, then those considerations says that S(t) grows
with time. so entrophy can´ t be zero in that case.

best regards
rayohauno