Re: The Laws of Intelligence Examined


Zoe wrote:
On Wed, 22 Mar 2006 21:39:10 +0000 (UTC),
carlip-nospam@xxxxxxxxxxxxxxxxxxx wrote:

Zoe <muze10@xxxxxxx> wrote:

[...]
gravity is fascinating, from what I've been reading. The fact that
two stars appear to exert an instantaneous effect on each other, even
though they are millions of miles apart, would seem to indicate that
there is some force that is faster than light.

There is as yet no direct measurement of the "speed of gravity." But
all observations so far are consistent with general relativity, our
best current theory of gravity. If general relativity is correct,
gravity propagates at the speed of light, not instantaneously.

well, isn't general relativity correct only in its sphere, but when
checked against quantum mechanics, it appears to be not correct? And
vice versa, when quantum mechanics is studied in the context of
general relativity, it, too, encounters problems? Separate, they work
in their fields, but together, both theories cannot be correct?

The word scientists would use is "regime" rather than "sphere".
General relativity describes the large-scale structure of matter
and motion. Quantum mechanics describes the small scale behavior
(atoms, molecules.) The theories don't mix well because general
relativity is a classical theory based on continuous quantities.
Quantum theory deals with quantities that are discrete in their
behavior (states come in descrete values).

Now, this is all fine as long as gravity can be ignored in the small.
However, there are such problems as the big bang singularity or the
the case of black holes, where interactions in the small encounter
large gravitational influence. In these types of calculations general
relativity collides with quantum theory.

So, there are fields of theoretical physics where a "quantum theory of
gravity" is sought to remedy problems encountered in these special
cases.




That would leave the door open for gravity to not necessarily
propagate at the speed of light, but to propagate faster than c,
wouldn't it?

The reason that gravity is believed to propagate at the speed of light
is that it is easy to take Einstein's general relativity equation and
turn it into a wave equation that just happens to have the speed of
light
as its wavespeed. The Einstein equation is useful for a lot of
calculations,
and seems to hold up against the challenges put against it, so the
"speed of gravity" is another test of the Einstein equation. If the
speed is
not the speed of light, then something is very weird.






What about superstrings? I've read a little about them and the
question could be asked: What if the entire universe consists of and
is connected by a fabric of superstrings so that what we consider to
be empty space that needs to be traversed by gravitational
attractions, is, in fact, one continuous fabric with hills (i.e.,
stars and planets) and valleys (i.e., space) so that any change in the
positions of the stars would automatically and instantaneously be felt
by the others, without need to wait for gravity to travel from one
point to the next?

Einstein's theory of general relativity is a geometric theory. It is
the shape of space-time,
particularly the curvature of space time that is supposed to make
gravity. Superstrings
are an attempt to make something that appears on grosser lengthscales
to be a
continuous medium theory, like general relativity, but which has
discrete aspects
(natural resonant frequencies of the strings) so it would actually *be*
general relativity
in the regime where GR is valid, and it would actually *be* quantum
theory in the
range where quantum theory is valid, with the added feature that all
the elementary
particles seen in particle accelerator experiments, and described via
something called
"group theory" fall out as special cases of characteristic vibrations
of the strings.




(If you want a technical discussion of this -- you probably don't --
see my paper at http://arxiv.org/abs/gr-qc/9909087.)

I printed your paper to read in spare moments during my day. Frankly,
I don't understand the math, but I trust that it proves your point,
which is that the absence of gravitational aberration can be explained
by the fact that the aberration has been canceled by
velocity-dependent interactions.

It certainly is not for me to argue with someone as learned as you
are, but please allow me ask a few befuddled questions.

Van Flandern proposes that gravity propagates at a speed much greater
than c. What if the aberration that you say is canceled by
velocity-dependent interactions really doesn't exist after all? Would
that mean that the lack of aberration makes both you and Van Flandern
potentially correct? It makes you correct via your mathematical proof
and it makes Van Flandern correct via the possible reality that there
really is no aberration after all. If so, how can it be determined
who is really correct?

Van Flandern has posed an interesting question. If the speed of gravity
is infinite,
then there is something wrong with the Einstein equation that is very
weird.
Now the question that Dr. Carlip has addressed is the one of whether or
not it is
easy to measure gravitational aberration, and has found that it is not
so easy
to measure.




The cancellation that you prove through your mathematical equations is
one that is based on such precise conditions that it makes me wonder
about the chances of this kind of precision happening by chance. But
then, that is the forte of evolutionary theory. The lottery is won on
a consistent basis by the same person.

We don't need exact cancellation to make it significantly more
difficult to see
gravitational aberration. It is a tough quantity to measure from the
get go.


Also, back to the idea of travel being faster than light, is it
possible that at speeds nearing the speed of c, that the atoms,
quarks, charms, or whatever the particles are in the speeding mass,
will bounce around so violently, they would behave the way particles
do in a particle smasher, getting to a point where matter and
antimatter would annihilate each other, producing pure energy? And
could this energy then be pushed faster than the speed of light?

A particle traveling near the speed of light becomes increasingly more
massive
as it approaches the speed of light. It takes correspondingly more
energy to
to raise the velocity. These are predictions from special relativity
that have been
shown to hold in particle accelerator experiments. Annihilating
particles would produce
other particles, as well as radiant energy in the form of photons which
travel at
the speed of light.



As to your statement that a cloud of hydrogen gas in space is subject
to its own gravity, are you saying that the more atoms or molecules
there are in a gas, the higher the chance is that the gas will become
dense and not spread out?

Yes, definitely.

is this based on Jeans mass, as some posters have mentioned? And if
so, what do you have to say about what some astrophysicists have
pointed out, that Jean's analysis was flawed? Do you agree that Jeans
was incorrect to assume that the area around the collapsing cloud was
surrounded by a static medium, which would mean that such a medium
would also collapse, leading to a slower growth rate than predicted by
Jeans?

Is there some law of physics that says that
the greater the volume of gas, the more prone are its particles to be
attracted to each other?

Each particle is attracted to *all* of the other particles in the gas.
So the more particles there are, the more attraction there is. There's
no mystery here -- you are attracted to the Earth more strongly than to,
say, your computer terminal because the Earth has "more particles" (more
mass).

if all the other particles in the gas cloud are attracted to all other
particles, then the "big bang" should have produced a single, giant
star, shouldn't it? What is the proposed mechanism for the separation
of the gas cloud into billions of stars and planets?


The big bang is supposed to have produced spacetime, which then
experienced
a period of faster than light acceleration that cosmologists call
"inflation". There
seems to be increasing evidence in favor of inflation.


How does that work, especially if the gas is
spreading out, according to 2LoT (if such a law exists out there)? I
mean, gases on earth do not tend to pack more closely depending on the
quantity, do they?

You're mixing up things that happen on different scales. You need a *lot*
of gas before the gravitational attraction of the gas to itself is strong
enough to be very noticeable.

this seems to be similar to the requirement for evolution -- you need
a LOT of time before mutations will accumulate sufficiently and
fortuitously enough to produce the life forms we see today. Isn't
this all rather vague and unscientific? A lot of time will do it. A
lot of gas will do it. With no step-by-step description of how it is
done.

There is a lot of gas out there. There also was a lot of time for
evolution. Personal
incredulity doesn't really work.




Are there instruments powerful enough to detect fractions of degrees
of difference in gravitation attraction between gas clouds of
different sizes here on earth?

By observing the motions of bodies in space, it is possible to infer
the local
gravitational attraction. Indeed, this is where the missing mass idea
comes
from.



And how does a star that starts out consisting of strictly hydrogen
and/or helium become the kind of world that we know today, with
minerals and rocks and dense masses that today are heavier than gases?

All the heavy elements are produced in supernovae explosions, so the
notion
is that to get heavy elements, these elements had to have be the result
of recycled material, from one or more stars. Supermassive stars do not
last very long so it is quite possible in a universe of 13 billion
years of age to
have a few recycling phases.


And does gas always have to go to liquid form before it becomes a
solid? Or can a gas go straight from gas to solid under certain
circumstances? Because if your hydrogen gas cloud goes through a
liquid phase, at -399.8 degree F, it would be so cold that you'll be
getting no sun out of that one.

I don't understand the reference. The state of matter in a star is
plasma, which is what
you get when you ionize a gas.

Of course if material is lumped together by mutual gravitational
attraction, the potential
energy of bringing the matter together will be released in the form of
heat.



Remember, a star like the Sun is hundreds
of thousands of times more massive than the whole Earth.

if the sun is composed of 75% hydrogen and 25% helium, why has it not
coalesced into the kind of happily evolving stars of which you speak?
It is far bigger than the earth. Its gravitational attraction to
itself should have made it more advanced than the earth, if, as you
imply, the earth evolved to what it is through gravitational
attraction to itself.

I really don't know what you are saying here. The radiation pressure,
and pressure due
to the kinetic energy of the atoms inside the sun
balances the gravitational force preventing the sun from collapsing.


-John Stockwell

.

Relevant Pages

  • Re: The Laws of Intelligence Examined
    ... gravity propagates at the speed of light, ... checked against quantum mechanics, it appears to be not correct? ... stars and planets) and valleys so that any change in the ... there are in a gas, the higher the chance is that the gas will become ...
    (talk.origins)
  • Re: The Laws of Intelligence Examined
    ... There is as yet no direct measurement of the "speed of gravity." ... stars and planets) and valleys so that any change in the ... they would behave the way particles ... there are in a gas, the higher the chance is that the gas will become ...
    (talk.origins)
  • Re: The Laws of Intelligence Examined
    ... There is as yet no direct measurement of the "speed of gravity." ... there are in a gas, the higher the chance is that the gas will become ... Each particle is attracted to *all* of the other particles in the gas. ... So the more particles there are, the more attraction there is. ...
    (talk.origins)
  • Re: The Laws of Intelligence Examined
    ... possible that at speeds nearing the speed of c, that the atoms, ... they would behave the way particles ... Each particle is attracted to *all* of the other particles in the gas. ... over from the formation of young, hot stars. ...
    (talk.origins)
  • Re: Giant gas planets and how they gathered their gas at formation
    ... Gas by itself does not possess enough gravity. ... You have just "proved" that stars can't be made of mostly hydrogen and ... Get enough hydrogen and helium together and you get plenty of gravity, ...
    (uk.sci.astronomy)
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