[-empyre-] String Theory.....Swan Song?

David Hughes 19 davidhughes19 at btinternet.com
Tue Nov 1 11:02:04 EST 2011


I'd be very interested in a practical workshop that developed this
discussion into some kind of action.
Also to continue the threads. I wonder if anyone would object to linking up
on FaceBook, say? Or if anyone would have an objection to receiving emails
to continue the discussion to their private addresses.
I really want to thank Johannes for very subtle and elegant hosting.
David


-----Original Message-----
From: empyre-bounces at lists.cofa.unsw.edu.au
[mailto:empyre-bounces at lists.cofa.unsw.edu.au] On Behalf Of Akram Khan
Sent: 31 October 2011 23:17
To: soft_skinned_space
Subject: [-empyre-] String Theory.....Swan Song?

Dear all, 

this has be a fun month for a scientist to hear such sweet and creative
voices, it would be wonderful to meet up or arrange a workshop where we can
explore in greater depth the complexity of the interfaces in particular with
science! I can not resist but to copy an over i gave on the development of
string theory and its the importance of scientific dream in the 21st
century......please excuse me for the long email....

---------------


Introduction
--------------

It seems that what most distinguishes our species from the rest of creation
is our capacity for abstraction...a facility for the symbolic representation
of the world in which we find ourselves....this allows us to rise above the
stream of our senses and ask questions about the meaning of it all...what
are we? Where have we come from? Where might we be going? What & how can we
change it at all....these are the questions that've been asked by our
species since time immemorial...many & varied've been the answers
reached...but with the turning of the years there's been an ever insistent
desire to transcend the limits of our cultural contexts & our narrow need
for narratives that provide consolation in a hostile, indifferent world...&
then, some 400 years ago, with the crucial development of the Scientific
Method, we had what is now known as the Scientific Revolution, leading to
such spectacular successes in our quantitative understanding of the world,
on all human scales, that we felt by the end of the 19th century as if
Nature had no more to give...& as the great scientists of the age
congratulated one & all, on a job well done, there came an almighty
storm...& we found in the wreckage left behind that what we'd thought was
the holy grail of physics, a 'Theory of Everything', was no such thing at
all...we'd looked into the mirror of Nature & only seen the universe cut
down to our size...& we are so small a part of all there is that what we'd
seen was a shocking caricature of reality...& so Modern Physics was born,
with quantum mechanics to guide us on our journey over distance scales that
take us to the very heart of the atom, & relativity to help us over distance
scales that span the cosmos, & with entities that travel at speeds
approaching that of light...

The 20th century has been, for fundamental physics, the most exciting
yet...opening up hitherto unimaginable regions of the physical...& as our
understanding has exponentially increased so has the possibility of a Theory
of Everything become a reality again...with an all-inclusive, aesthetically
pleasing, mathematically consistent framework incorporating all the basic
principles of physical reality, tantalisingly close...
The Standard Model of particle physics offers a detailed understanding of
all the forces of Nature but leaves gravity out... it has, also, many
parameters that need to be precisely adjusted within certain experimentally
measured values, in order to make it a successful predictive model. How is
it possible that the final theory of science could be so delicate... &,
furthermore,  require one scheme - relativity - for the very large, and
another - quantum mechanics - for the very small. 

So some brave souls resurrected an idea that had long been rejected by the
mainstream - String Theory. It postulated that particles were not
zero-dimensional points, as the Standard Model supposed, but instead were
tiny strings whose vibrations are reflected in the observed properties of
the fundamental particles. 

Though its possibilities are still being intensively explored, many
physicists are coming to believe that String Theory, or one of its
derivatives, will ultimately prove to be the long-sought final "Theory of
Everything".

The Central Conflict
-----------------------

The incompatibility of relativity and quantum mechanics has been called the
"central conflict" of modern theoretical physics. The conflict arises from
the quantum chaos generated by the properties of the Uncertainty Principle.
Over regions of space smaller than the Planck length, the quantum chaos
becomes manifest, & the smooth "fabric" of spacetime necessary if general
relativity is to be applicable becomes disrupted. When attempts are made to
merge quantum mechanics and general relativity, many calculations yield
infinities...obvious impossibilities that are a clear signal of the need for
a new theory. Although many were forced into accepting a pragmatic approach
by simply choosing the theory appropriate to their calculational regime -
relativity for cosmological applications and quantum mechanics for particle
physics - there are a few cases where the two theories must be merged in
order to accurately describe conditions: The cores of black holes and the
original singularity at the beginning of the universe. So there is nothing
for it...we must understand how these theories merge or except that we do
not understand the universe at its most fundamental...with every attempt
having failed, String Theory seems to be offering us a way...
History of String Theory

Back in 1968, Gabriele Veneziano, a research fellow at CERN, observed a
strange coincidence - many properties of the strong nuclear force seemed to
be perfectly described by the Euler beta-function, an obscure formula
devised for purely mathematical reasons two hundred years earlier by
Leonhard Euler. In the flurry of research that followed, Yoichiro Nambu of
the University of Chicago, Holger Nielsen of the Niels Bohr Institute, and
Leonard Susskind of Stanford University revealed that the nuclear
interactions of elementary particles, modelled as one-dimensional strings
instead of zero-dimensional particles, were described exactly by the Euler
beta-function. This was, in effect, the birth of String Theory. However,
later experiments, in the early '70s, revealed that many of the theory's
predictions were at odds with experimental data. As the Standard Model of
point particles met success after success, String Theory fell by the
wayside. 

Initially, most had seen one major problem with String Theory. The
observable properties of the fundamental particles are a manifestation of
string vibrations. So, for example, String Theory described vibrational
configurations that corresponded to the properties of gluons, the force
carriers of the strong force. The theory also generated other vibrational
patterns that seemed to have no physical manifestation. These "extra"
patterns, however, were soon shown to correspond exactly with the postulated
properties of the graviton, the force carrier of the gravitational force,
whose existence is predicted, but which has not as yet been experimentally
confirmed. The vibrations were found to relate exactly to theorized
properties of gravitons. This discovery was not, however, received by the
scientific community with open arms; subtle conflicts between it and
point-particle physics were again discovered, and the theory was once again
abandoned by all but a dedicated few. 

The First Superstring Revolution
--------------------------------------

In 1984, a paper by Michael Green, then of Queen Mary College, and John
Schwarz of the California Institute of Technology presented the fruits of
over a dozen years of research often belittled by "mainstream" physicists.
The paper not only resolved the conflict between String Theory and quantum
mechanics, but also showed that String Theory could encompass all of the
four fundamental forces of Nature, and all the matter in existence. The
result was the 1st Superstring Revolution, during which physicists around
the world rushed to join the research on the very same theory they'd
"snubbed" in the past.
The years from '84 to '86 saw more than a thousand papers published on
String Theory, showing that the features of the Standard Model could be
logically and naturally derived from the new theory. However, the equations
of the theory proved difficult - so difficult, in fact, that their exact
form could not be determined and approximations had to be used to replace
their correct, impossibly complex form. After years of using these
approximate methods, they were found inadequate for the types of research
being performed. Frustrated scientists, lacking a plan of attack on the
dizzyingly complex theoretical calculations, once again abandoned strings
and returned to previous projects. 

The Second Superstring Revolution
------------------------------------------

And then at a conference called Strings 1995, held at the University of
Southern California, Edward Witten launched, in dramatic fashion, what came
to known as the 2nd Superstring Revolution. He announced a cohesive plan for
moving past the approximations used during the 1st Superstring Revolution
and thus into even deeper regions of this vast and complex theory. In fact,
the full implications of his intervention are still being analyzed by string
theorists seeking a way through to what they believe will prove to be the
"Theory of Everything."
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