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Mervyn, Bwanika,
Absolutely spot on! Many questions, little
answers...so far. As far as Twistors are concerned I recommend reading a
book by F. David Peat, the title being Superstrings and the
search for the theory of everything which has a whole section on Twistor
theory. The book is dated though, especially in regards to string theory but
provides a good first look into Twistor theory. A good book an string theory/M
theory that discusses quite a lot of the implications of string theory for our
underlying conception of space-time, a must read, is Brian Greene's The
Elegant Universe. Check out that lecture by Ed Witten on the ITP web site
as well. Going back to Twistors, although he does not discuss the theory at
length, you can get a good underlying feel for the motivations of
Roger Penrose by reading his book Shadows of the Mind. Especially
part two. Indeed this, and his earlier book (which has the best description of
Physics available in the non technical literature I have read) The Emperor's
New Mind. You will find that there exists an underlying philosophy
motivating his work...Realism!
I read Mervyn's discussion of the anthropic
principle with great interest, especially about God! Bhaskar is indeed
perceptive for John Barrow and Frank Tipler in (dated) The Anthropic
Cosmological Principle present an argument demonstrating that indeed the
Anthropic principle must lead to God! But that that God is us! That we will, at
the big crunch, totally dominate the physical universe and become omniscient,
omnipotent etc! Their reasoning however relies on some heroic assumptions.
Indeed Frank Tipler has gone on further in The Physics of Immortality
claiming that we shall all be resurrected at the final stages of the
universe and live in heaven! But the weak anthropic principle is quite
uncontroversial and does not imply the above. It merely asserts that the laws of
physics must be such to have enabled us to evolve otherwise we would not be
here. Barrow and Tipler's argument rests on what they refer to as the
final anthropic principle "intelligent information processing must come into
existence in the universe, and, once it comes into existence, it will never die
out". Basically Barrow and Tipler are teleologists. It is interesting to observe
however on page 675 of their book they state "that in chapter 3 and 7 we
gave a teleological argument, based on Action Principles, for the closure
of the universe. We also pointed out in section 10.3 that only in a closed
universe is it possible for all timelike curves to be forever in casual contact
with one another. For these reasons, it seems on antropic grounds (by which they
mean the final anthropic principle) that the universe is more likely to be
closed than open, but this is only a weak prediction". Notice however that with
the recently discovered accelerating expansion of the universe that the
universe, as it expands faster and faster, will escape the pull of gravity and
expand forever. That is the universe is open contra Barrow and Tipler.
Furthermore the accelerating expansion of the universe implies that the
cosmological constant is greater than 0. Tipler and Barrow state on page 668
that "if there exists a non zero positive cosmological constant then an
ever expanding universe inevitably approaches de Sitter space-time. In this case
information processing dies out, event horizons exist and indefinite survival is
ruled out". In other words Tipler and Barrow have been proven wrong by
experiment. Of course it was brave of them to make such predictions, but that's
science! Of course Barrow, and especially Tipler's, desire to use Physics to
support his religious biases is a good example of the pitfalls that befalls a
social constructionist! Of course one can get far along this route, for instance
a group of Japanese dialectical materialists, hanging out in some mountain,
made some seminal contributions to quantum field theory trying to prove
dialectical materialism. In the end they went too far and got hit in the head
just like Tipler. Still aspects of their work still stand and are accepted by
non dialectical materialists because it is objectively correct.
Marko.
----- Original Message -----
Sent: Tuesday, March 26, 2002 9:27
PM
Subject: RE: Re: BHA: Re: Critical
Realism for Natural Sciences
Mervy
I do not think Marko has an answer either! I
have read Hartle but
but with more question than answers.
One
future which has confounded me is the simirality
in the nature of things
here and there in the cosmos,
atleast in some ways.
Look critically
at the pictures of the so called collapsing
star and transpose that same
image on the top of a tarnado
assuming that the atomspehere is a
somwhat flat or curved sheet.
Once again i might say the statement can
be put differently.
Bwanika.
Mervyn Hartwig <mh@xxxxxxxxxxxxxxxxxxx>
wrote:
>Hi Marko (and Bwanika)
>
>Many thanks for this,
especially the details of the websites.
>
>Pardon my ignorance,
but who espouses the weak anthropic principle? Is
>it widely accepted
within physics and other sciences? I ask in
>particular because it has
some resemblance to the intrinsic cosmic
>structure of possibility the
later Bhaskar refers to as
'God'.
>
>Mervyn
>
>
>Marko Beljac <beljac@xxxxxxxxxxxxxxxx>
writes
>>Bwanika,
>>
>>The theory of evolution is
objectively correct. If we take the weak anthropic
>>principle,
which asserts that the laws of physics must be of such a nature to
>>enable us to evolve and exist, it follows then that every theory
of the origin
>>of the universe, including the Hartle-Hawking
theory, cannot violate the weak
>>anthropic principle therefore it
cannot contradict Darwin. Of course if
>>evolution is a mere social
construction then of course anything goes but
>>thankfully science
is not a social construction!
>>
>>Also you should be
careful and not confuse Hawking's work on black holes with
>>his
work on the origin of the universe. It seems to me that you are thinking of
>>the Hawking-Penrose singularity theorems? These assert that,
according to
>>Einstein's theory of general relativity, the end
point of gravitational collapse
>>of a star of mass greater than 3
suns must end in a black hole and a space-time
>>singularity.
Conversely they also demonstrate that the universe must have began
>>with a space-time singularity, which can be conceived as
gravitational collapse
>>of a star in reverse. I think this what you
are alluding to in your post.
>>
>>Now what the singularity
theorems ultimately suggest, and both Penrose and
>>Hawking agree,
is that Einstein's theory of general relativity is incomplete for
>>physics collapses at a space-time singularity. In other words
General Relativity
>>cannot tell us what is the end point of the
gravitational collapse of a star nor
>>the origin of the universe.
To do this we need a quantum theory of gravity, a
>>combination of
general relativity with quantum mechanics. This is where
>>agreement
ends. So Penrose is working on his Twistor Theory approach to quantum
>>gravity, Hawking on Euclidean quantum gravity, Lee Smolin and
others at Penn
>>State on loop quantum gravity and its variants and
just about everybody else on
>>string/M theory. Without a quantum
theory of gravity there exists no ultimate
>>theory on the
gravitational collapse of a star or the origin of the universe.
>>Evolution theory by contrast is objectively
correct.
>>
>>To explore these issues further if you haven't
already checked them out check
>>out these web sites which have
plenty of authoritative info on these matters.
>>1.) The official
superstring theory web site: www.superstringtheory.com
>>2.)
The Institute for Theoretical Physics at Santa Barbara public lecture web
>>sites (there's lectures here by Hartle on gravity and Ed Witten,
the god of
>>string theory on space-time and M theory) at www.itp.ucsb.edu/activities/public/
>>3.)
For the accelerating expansion of the universe and infinite/finite debate
>>see a really good lecture online by Michael Turner, a leading
theorist on the
>>issue, at the Fermi National Lab at www.fnal.gov/
>>
>>I think
you will find these sites informative and fun to check out! Also I
>>apologise for not picking up earlier that you were referring to
Hawking's
>>singularity theorems in your original
post.
>>
>>Regards,
>>Marko.
>>
----- Original Message -----
>> From: dbbwanika@xxxxxxxxxxxx
>> To: bhaskar@xxxxxxxxxxxxxxxxxxxxxxxxxx
>> Sent: Friday, March 22, 2002 8:21 PM
>>
Subject: RE: BHA: Re: Critical Realism for Natural Sciences
>>
>>
>>
Marko!
>>
>> Thank for
yours!
>>
>> I do largely agree that Hawking Black
holes might not be a theory in it's
>>entirety. Shouldn't we ask
then, if Hawking black holes, matter and anti-matter
>>are the very
essence of nature? I'll suppose so, if his explanation of the
>>origins of the universe is based on super nova's characteristic
changes in
>>gravitation and body mass. You believed I suppose,
there was no evidence to
>>this? But there is, the only hurdle is
explaining what it is that matter and
>>anti-matter is, after
atomist Democritus fall.
>>
>> The string theory is
going full circle to Aristotle's original observations.
>>Now, just
imagine the catalytic nature of light in plant food making processes.
>>Wouldn't you like to ask what is light? A wave or a particle
? At least if it
>>is a particle, Hawking has a theory vis - a -vis
the virtual particles and anti-
>>particles is spot on from a chemist
point of view.
>>
>> The problem Hawking and
other faces is gravitation and mass, re-light particle
>>definition
and its physical properties. At least I only see color spectrum in
>>exploding stars. On the one hand, it will be interesting to
know from Hawking
>>himself if he believes particles in the absence
of anti-particles disintegrate
>>i.e. to generate gravitation
entropy or that this happens only where there anti-
>>particles.
>>
>> But then, I imagined I sitting in a
speeding car at 70 km/hr with my light
>>weight body. Indeed at that
speed, I will become a heavy weight. But why do
>>light particles do
not hit the earth for example, in a thunderous bust but
>>rather end
up making the earth and universe beautiful as it is?
>>
>> Marko as of the above this is what you
wrote;
>>
>> >But notice how this has
flied right in the face of the recent discovery
>>that the
>Universe is speeding up in its expansion, which could very
well be
>>the result of the >vacuum or zero point energy what is
called dark energy,
>>meaning that the >cosmological
constant is non zero (which has string
>>theorists increasingly in a
spin) >meaning that the universe will not
>>contract,
it will expand forever (this discussion >is to ignore quintessence
>>which may imply that the universes speed up is
>temporary).
>>
>> In this regard, one might wonder
where the particle from the sun ends on
>>hitting plant leaf for
example or the earth surface? Reflected or travels on?
>>This is
rather a curious and dubious question too, for it will presuppose the
>>infinite chemical process i.e. infinite nature of expansion of the
universe or
>>evolution for that matter!
>>
>> Do you still believe the universe as per
Hawking argument is finite?
>>
>> Last night to make
sure that I had understood you, I looked at the clear sky
>>and I
did not see a lot of stars but rather a large dark patches in space with
>>twinkling stars in between large and at time very large
spaces!
>>
>>
>>
bwanika.
>>
>>
>> Marko Beljac <beljac@xxxxxxxxxxxxxxxx>
wrote:
>>
>> >Bwanika,
>>
>
>> >I am somewhat puzzled by the argument presented
here. As far as I am aware
>>Hawking does indeed have a theory in
regards to the origin and evolution of the
>>Universe. In a joint
paper with James Hartle in the 1980's entitled "wave
>>function of
the universe" Hawking and Hartle developed what is called the no
>>boundary condition theory. Now this is an application of his
Euclidean quantum
>>gravity to the question of the origin of the
Universe. Notice that this does not
>>have anything to do with black
holes. Also it must be stressed that the Hartle-
>>Hawking
theory is quite speculative being an example of the genre of quantum
>>cosmology. On the other hand Hawking's work on gravitational
entropy, i.e.
>>exploding black holes, must be a part of any quantum
theory of gravity. For
>>instance Juan Maladcena, a string theorist,
has derived Hawking's gravitational
>>entropy using string theory.
So by no means is Hawking's theory on the origin of
>>the universe
an established theory. Indeed for years Hawking was arguing that
>>the Universe is finite, that is that it will expand and eventually
contract. But
>>notice how this has flied right in the face of the
recent discovery that the
>>Universe is speeding up in its
expansion, which could very well be the result of
>>the vacuum or
zero point energy what is called dark energy, meaning that the
>>cosmological constant is non zero (which has string theorists
increasingly in a
>>spin) meaning that the universe will not
contract, it will expand forever (this
>>discussion is to ignore
quintessence which may imply that the universes speed up
>>is
temporary). There is an interesting exchange between Stephen Hawking and
>>Roger Penrose in The Nature of Space and Time where Hawking
emphatically states
>>(before the recent discovery) he wants the
universe to be finite because of the
>>no boundary proposal whereas
Penrose argues, given his approach to quantum
>>gravity i.e. twistor
theory, he wants the universe to be infinite and to keep on
>>expanding forever! So Hawking could very well be
wrong!
>> >
>> >Evolution on the other
hand is a tried and tested theory. It is objectively
>>correct.,
although I am aware that in saying this I am inviting trouble! At any
>>rate there is no connection between cosmology and evolutionary
theory. If
>>Hawking is wrong the evolutionary biologist would be
quite right in exclaiming,
>>so what!
>>
>
>> > The second part of your thesis is very interesting
with serious
>>implications. I would be very interested in reading a
further elaboration of it.
>>Also in regards to black holes and
evolution theory, does this steam from a
>>reading of Lee
Smolin?
>> >
>>
>Marko.
>>
>> --
>>
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____________
>>
>>
>>
>>
Bwanika
>>
>> url: http://www.uganda.co.ug
>>
e-mail: dbbwanika@xxxxxxxxxxxx
>>
>>
>>
>>
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>>
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>
>--
>Mervyn Hartwig
>Editor, Journal of
Critical Realism (incorporating 'Alethia')
>13 Spenser Road
>Herne
Hill
>London SE24 ONS
>United Kingdom
>Tel: 020 7 737
2892
>Email: <mh@xxxxxxxxxxxxxxxxxxx>
>
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forms:
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>
>
>
>
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____________
Bwanika
url:
http://www.uganda.co.ug
e-mail: dbbwanika@xxxxxxxxxxxx
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