Re: Any Christian Electronic Designers Here?

On Sun, 26 Apr 2009 09:29:34 +0100, Martin Brown
<|||newspam|||@nezumi.demon.co.uk> wrote:

Rich Grise wrote:
On Fri, 24 Apr 2009 07:02:30 -0700, John Larkin wrote:
On Fri, 24 Apr 2009 18:37:05 +1000, Bob Larter <bobbylarter@xxxxxxxxx>
John Larkin wrote:
On Tue, 21 Apr 2009 09:00:48 +0100, John Devereux <john@xxxxxxxxxxxxxx>

believe the whole document to be literally true, that it should be the
basis of of our laws.

It is these people I would ridicule.
Now you're talking about fundamentalist Islamists. Fine, please
ridicule them. In the USA, schools can't even mention creationist
theories, some of which are worth mentioning.
Don't be ridiculous. Creationist "theories" are complete mumbo-jumbo.
Panspermia isn't. I give it a 50:50 chance of explaining life on Earth.

The problem I have with panspermia is it's based on the premise that life
was created somewhere else and transported here. That sounds like a handy
way of evading the question, "So how did it get started in the first
place?"

Clays and iron rich sulphurous springs look like the most promising
starting points for life. Plenty of easy inorganic foods waiting for
something to find a way of utilising them. And clays are just about the
right scale to help things fit together.

I wonder, "so what made all these atoms decide to get together and reverse
entropy?"

You only wonder this because you don't understand entropy. Global
entropy must always increase, but local entropy can decrease massively
by losing energy and dumping entropy into the surrounding environment.

Don't forget Sol, either, as part of the 'box' under consideration.

Consider as a simple example how salt crystals form from brine. The
solid is very highly ordered and can form easily from saturated brine.
Magic is not required.

By the way, just reading "atoms getting together and reverse entropy"
makes me cringe and tells me instantly that the questioner has NO CLUE
whatsoever and has no business even asking. Chances are, they won't
understand ANY good answer.

Jon

P.S.
Entropy is a macro-scale concept that arrives as a result of large
number statistics and the likelihoods of states the measurement system
can distinguish.

If anyone thinks it is an easy matter to master and apply, they should
keep in mind that Hawking initially got it wrong when Bekenstein first
proposed his interpretation of black hole event horizon areas as
entropy. (And besides black hole entropy, there is at least Boltzmann
entropy, Shannon entropy, Gibbs entropy, and Galois entropy that I
know about. Probably more.) A short story illustrates:

Bekenstein, in 1970 or so, as a grad student of Princton's Wheeler,
suggested the idea that black holes might have entropy - a lot of
entropy, in fact. He was motivated by the idea that the entropy of a
closed system always increases and reasoned that if you drop a bunch
of disorganized matter into a black hole, it just 'disappears' leaving
a highly ordered vacuum, so to speak. The entropy of the black hole
would certainly have to increase in order to account for the lost
entropy elsewhere. He then drew on Hawking's demonstration that the
area of the event horizon of a black hole always increases in any
physical interaction. Bekenstein felt this suggested a link; that the
total area of the event horizon of a black hole should be directly
proportional to the entropy of that black hole -- in other words, that
the area would be a precise measure of its entropy.

At that time, though, black holes were thought to be among the most
ordered objects in the universe. With only mass, charge, and spin to
account for, a black hole just didn't seem to have enough defining
characteristics to account for a lot of entropy (or much of any, at
all.) More, Hawking felt that Bekenstein's proposal was nothing more
than coincidence -- Hawking pointed out that if one takes the law of
thermodynamics seriously in this case, then assigning entropy to the
area of the event horizon would require a temperature to be assigned,
as well. Which would require that black holes radiate! Hawking felt
simply that when matter carrying entropy fell into a black hole, the
entropy was simply lost. (So much for the 2nd law of thermodynamics,
but Hawking was okay with that in the case of black holes... for a
time.)

In 1974 I think, Hawking considered the idea of the frantic mess of
virtual particles in empty space, with particles and their
antiparticles errupting and annihilating one another. Near the black
hole, it's possible that one of these pairs falls into the event
horizon, never to be seen again. The other actually gets a boost of
energy from the gravitational energy of the black hole and gets shot
outward. Black holes actually radiate!

Hawking calculated the temperature that a far-off observer would
associate with the emitted radiation, thus produced, and discovered
that it is given simply by the strength of the graviational field at
the event horizon and in exactly the amount that prosaic
thermodynamics would suggest from Berkenstein's entropy proposal.

A black hole thus has entropy and temperature. And the gravitational
laws of black holes are little other that just another way of
rewriting the law of thermodynamics, even if in a highly exotic
gravitational context. (Just another story of those confirming arches
one finds in physics, linking strongly different domains.)

Anyway, there was still the problem of disorder to consider. Black
holes appear to be very simple objects. So what's the source of the
disorder they must have? On this, Hawking was silent. Hawking was
able to finesse a partial union of quantum mechanics and general
relativity to yield his limited results, that black holes *do*
radiate. But he wasn't able to go further. This lack of a
_microscopic_ insight became the Bekenstein-Hawking entropy problem of
black holes.

An interesting side story how M-Theory can intrude as a viable theory
came by way of Strominger and Vafa in 1996, building on Susskind and
Sen. They put out a paper called 'Microscopic Origin of the
Beckenstein-Hawking Entropy.' They were able to use string theory to
precisely calculate the associated entropy of certain kinds of black
holes. They meticulously wove a precise combination of branes into
these black holes and were able to exactly predict the characteristics
from that process. They could sum and thus demonstrate the various
observable properties, from the ground up so to speak. And they could
compare these with the entropy predicted by Bekenstein and Hawking.
Perfect agreement!

So perhaps there's one modest success in M-Theory. (An insight _may
be_ that black holes and elementary particles are just different
phases of fundamental vibrational string patterns, configured only by
their initial Calabi-Yau shape.)

The point here is that entropy isn't something one can just bandy
about, in ignorance, as though they are capable of applying it as
evidence for or against some conclusion. Even those who masters the
domain's material well may miss some important insight that others
will find later.

Rich first needs to get some detailed clues before he starts making
arguments.

Jon
.

Relevant Pages

  • Re: black hole entropy
    ... >> Old Man A BH has a temperature so it has to have entropy. ... >> thinking about BH with a temperature and not radiating it outward. ... >> thinking.You are right going with the event horizon area. ... >> that goes under the surface of a black hole is sci-fiction. ...
    (sci.physics)
  • Re: Do results from black hole thermodynamics actually suggest or support
    ... We have the result that the entropy of a hole (and ... black hole of the same horizon area. ... any other sphere including the moon. ... since it's surface (the event horizon) is not ...
    (sci.physics.research)
  • Re: Entropy and the "big bang"
    ... We could even say the total entropy inside a black hole is continually going up. ... This guy Bekenstein since the area of the event horizon gets bigger as stuff falls in he could use this increasing horizon size to measure the entropy of a black hole. ...
    (sci.physics)
  • Re: The Answer to Life... the Universe... and Everything...
    ... > The stronger the vacuum the greater the entropy, ... > so, from a human's frame of reference, black holes have the most entropy ... > as they have the strongest vacuum... ... > Sagittarius A* at the center of our Milky Way is a supermassive black hole. ...
    (sci.physics)