Universe(s) Origin(s) 6 of 7 - Einstein /
Big Bang / Superstrings
(Top Posts - Science - 072802)

Excerpts from "The Elegant Universe - Superstrings, Hidden
Dimensions, and the Quest for the Ultimate Theory" (Brian
Greene, ISBN 0-393-04688-5) ...
http://www.amazon.com/exec/obidos/ASIN/0393046885

During the last thirty years of his life, Albert Einstein sought
relentlessly for a so-called unified field theory -- a theory
capable of describing nature's forces within a single, all-
encompassing coherent framework.

... Einstein wanted to illuminate the workings of the universe
with a clarity never before achieved, allowing us all to stand
in awe of its sheer beauty and elegance.

Einstein never realized his dream, in large part because the
deck was stacked against him: In his day, a number of essen-
tial features of matter and the forces of nature were either
unknown or, at best, poorly understood.

... now, long after Einstein articulated his quest for a unified
theory but came up empty-handed, physicists believe they
have finally found a framework for stitching these insights
together into a seamless whole -- a single theory that, in
principle, is capable of describing all physical phenomena.

The theory, superstring theory, is the subject of this book.

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Tuesday, 23 May, 2000, 21:15 GMT 22:15 UK
'Theory of everything' scoops top prize
http://news.bbc.co.uk/hi/english/sci/tech/newsid_760000/760730.stm
Excerpt: ... This proclaims that all the wondrous happenings
in the Universe are reflections of one grand physical principle
and manifestations of one single entity: microscopically tiny
vibrating loops of energy, a billionth of a billionth the size of
an atom. ...

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... Superstring theory casts a wide net. It is a broad and
deep subject that draws on many central discoveries in
physics. ... I have chosen to focus on our evolving under-
standing of space and time.

... Einstein showed the world that space and time behave
in astoundingly unfamiliar ways. Now, cutting-edge research
has integrated his discoveries into a quantum universe with
numerous hidden dimensions coiled into the fabric of the
cosmos -- dimensions whose lavishly entwined geometry
may well hold the key to some of the most profound ques-
tions ever posed.

... There are two foundational pillars upon which modern
physics rests.

One is Albert Einstein's general relativity,which provides
a theoretical framework for understanding the universe on
the largest of scales: stars, galaxies, clusters of galaxies,
and beyond to the immense expanse of the universe itself.

The other is quantum mechanics, which provides a theor-
etical framework for understanding the universe on the
smallest of scales: molecules, atoms, and all the way down
to subatomic particles like electrons and quarks.

... these same theoretical tools inexorably lead to another
conclusion: As they are currently formulated, general rela-
tivity and quantum mechanics cannot both be right.

... In all but the most extreme situations, physicists study
things that are either small and light (like atoms and their
constituents) or things that are huge and heavy (like stars
and galaxies), but not both.

... But the universe can be extreme. In the central depths
of a black hole an enormous mass is crushed to a minis-
cule size. At the moment of the big bang the whole of the
universe erupted from a microscopic nugget whose size
makes a grain of sand look colossal.

These are realms that are tiny and yet incredibly massive,
therefore requiring that both quantum mechanics and gen-
eral relativity simultaneously be brought to bear.

... Can it really be that the universe at its most fundamental
level is divided, requiring one set of laws when things are
large and a different, incompatible set when things are small?

Superstring theory, a young upstart compared with the ven-
erable edifices of quantum mechanics and general relativity,
answers with a resounding no.

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Interview with Brian Greene
http://superstringtheory.com/people/bgreene.html
Excerpt: ... So Brian, the title of your new book is The
Elegant Universe. What does that phrase mean to you?

Physicists often use the term elegant to describe a solution
to a problem that is as powerful as it is simple. It's a solution
which cuts to the heart of an important problem with such
clarity that it almost leaves no doubt that the solution is either
right or at least on the right track. And string theory is just
that kind of solution. It provides the first way of putting
quantum mechanics and general relativity together -- that is,
merging the laws of the small and the laws of the large -- and
it does it in such a sleek manner that it is quite breathtaking.
And the term elegant really describes that kind of solution. ...

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Intense research over the past decade by physicists and
mathematicians around the world has revealed that this new
approach to describing matter at its most fundamental level
resolves the tension between general relativity and quantum
mechanics.

In fact, superstring theory shows more: Within this new
framework, general relativity and quantum mechanics re-
quire one another for the theory to make sense. According
to superstring theory, the marriage of the laws of the large
and the small is not only happy but inevitable.

... According to string theory, if we could examine these
particles with even greater precision -- a precision many
orders of magnitude beyond our present technological
capacity -- we would find that each is not pointlike, but
instead consists of a tiny one-dimensional loop.

[Reference a drawing of an apple consisting of matter
composed of atoms, which in turn are made from quarks
and electrons. According to string theory, all such parti-
cles are actually tiny loops of vibrating string.]

Like an infinitely thin rubber band, each particle contains
a vibrating, oscillating, dancing filament that physicists ...
have named a string. ... this simple replacement of point-
particle material constituents with strings resolves the
incompatibility between quantum mechanics and general
relativity.

... string theory should be viewed as a work in progress
whose partial completion has already revealed astonishing
insights into the nature of space, time, and matter. The
harmonious union of general relativity and quantum
mechanics is a major success. Furthermore, unlike any
previous theory, string theory has the capacity to answer
primordial questions having to do with nature's most
fundamental constituents and forces.

... If string theory is right, the microscopic fabric of our
universe is a richly intertwined multidimensional labyrinth
within which the strings of the universe endlessly twist
and vibrate, rhythmically beating out the laws of the cos-
mos. Far from being accidental details, the properties of
nature's basic building blocks are deeply entwined with
the fabric of space and time.

In the final analysis, though, nothing is a substitute for
definitive, testable predictions that can determine whether
string theory has truly lifted the veil of mystery hiding the
deepest truths of our universe. It may be some time before
our level of comprehension has reached sufficient depth
to achieve this aim, although ... experimental tests could
provide strong circumstantial support for string theory
within the next ten years or so.

... Progress in science proceeds in fits and starts. Some
periods are filled with great breakthroughs; at other times
researchers experience dry spells. Scientists put forward
results, both theoretical and experimental. The results
are debated by the community, sometimes they are dis-
carded, sometimes they are modified, and sometimes
they provide inspirational jumping-off points for new
and more accurate ways of understanding the physical
universe.

In other words, science proceeds along a zig-zag path
toward what we hope will be ultimate truth, a path that be-
gan with humanity's earliest attempts to fathom the cosmos
and whose end we cannot predict.

Whether string theory is an incidental rest stop along this
path, a landmark turning point, or in fact the final destina-
tion we do not know. But the last two decades of research
by hundreds of dedicated physicists and mathematicians
from numerous countries have given us well-founded hope
that we are on the right and possibly final track.

It is a telling testament of the rich and far-reaching nature
of string theory that even our present level of understanding
has allowed us to gain striking new insights into the work-
ings of the universe. A central thread in what follows will
be those developments that carry forward the revolution
in our understanding of space and time initiated by Ein-
stein's special and general theories of relativity.

We will see that if string theory is correct, the fabric of
our universe has properties that would likely have daz-
zled even Einstein. ...

... physicists by their nature will not be satisfied until they
feel that the deepest and most fundamental understanding
of the universe has been unveiled. ... there is ample evi-
dence that quantum mechanics and general relativity do
not provide this deepest level of understanding. Since
their usual domains of applicability are so different, most
situations require the use of quantum mechanics or gen-
eral relativity, but not both.

Under extreme conditions, however, where things are very
massive and very small -- near the central point of black
holes or the whole universe at the moment of the big bang,
to name two examples -- we require both general relativity
and quantum mechanics for proper understanding.

Superstrings Unite General Relativity & Quantum Mechanics?
Point Particles Result from Strands of String?

... With the discovery of superstring theory, musical meta-
phors take on a startling reality, for the theory suggests
that the microscopic landscape is suffused with tiny strings
whose vibrational patterns orchestrate the evolution of the
cosmos.

... By contrast, the standard model views the elementary
constituents of the universe as pointlike ingredients with no
internal structure. As powerful as this approach is ... the
standard model cannot be a complete or final theory be-
cause it does not include gravity.

... String theory offers a novel and profound modification
to our theoretical description of the ultramicroscopic prop-
erties of the universe -- a modification that, physicists slowly
realized, alters Einstein's general relativity in just the right
way to make it fully compatible with the laws of quantum
mechanics.

... the simple replacement of point particles with strands
of string as the fundamental ingredients of everything has
far-reaching consequences.

Dimensions In Our Universe

... Researchers have gradually realized that string theory
is not a theory that contains only strings. A crucial obser-
vation, central to the second superstring revolution initi-
ated by Witten and others in 1995, is that string theory
actually includes ingredients with a variety of different
dimensions.

... String theory so thoroughly shakes the foundations of
modern physics that even the generally accepted number
of dimensions in our universe -- something so basic that
you might think it beyond questioning -- is dramatically
and convincingly overthrown.

... Because the patterns of string vibrations appear to us
as the masses and charges of the elementary particles,
we conclude that these fundamental properties of the
universe are determined, in large measure, by the geo-
metrical size and shape of the extra dimensions. That's
one of the most far-reaching insights of string theory.

Experimental Verification / Gravity

... Certainly, there is no way to establish that any theory
describes our world without subjecting it to experimental
verification. ... Edward Witten is fond of declaring that
string theory has already made a dramatic and experimen-
tally confirmed prediction: "String theory has the remark-
able property of predicting gravity."

... As Witten has said, "the fact that gravity is a conse-
quence of string theory is one of the greatest theoretical
insights ever." ... although string theory has the potential
to be the most predictive theory that physicists have
ever studied -- a theory that has the capacity to explain
the most fundamental of nature's properties -- physi-
cists have not as yet been able to make predictions with
the precision necessary to confront experimental data.

Experimental Verification / Superpartner Pairs

... with a bit of luck, one central feature of string theory
could receive experimental verification within the next
decade. And with a good deal more luck, indirect finger-
prints of the theory could be confirmed at any moment.

... patterns of string vibrations come in pairs -- super-
partner pairs -- ... string theory makes the prediction that
each such known particle will have a superpartner.

Physicists are now constructing a mammoth accelerator
in Geneva, Switzerland, called the Large Hadron Collider.
Hopes run high that this machine will be powerful enough
to find the superpartner particles. The accelerator should
be ready for operation before 2010, and shortly there-
after supersymmetry may be confirmed experimentally.

... Even if superpartner particles are found, this fact alone
will not establish that string theory is correct. ... if in fact
the superpartner particles are found, it will most definitely
be strong and exciting circumstantial evidence for string
theory.

M-theory

... all five string theories are actually part of a single, uni-
fied framework, tentatively called M-theory. ... Seemingly
disconnected threads of research in string theory have now
been woven together into a single tapestry -- a unique, all-
encompassing theory that may well be the long-sought
theory of everything.

... M-theory has eleven dimensions (ten space and one
time). ... it contains vibrating strings, but it also includes
other objects: vibrating two-dimensional membranes, un-
dulating three-dimensional blobs (called "three-branes"),
and a host of other ingredients as well.

... M-theory is closely related to yet a sixth theory -- eleven
dimensional supergravity. M-theory, although only partially
understood at the moment, unifies those of all of the form-
ulations of string theory.

M-theory is the theoretical elephant [reference proverb of
three blind men and an elephant in which each had a differ-
ent vision based on the part of the elephant they were exam-
ining] that has opened the eyes of string theorists to a far
grander unifying framework.

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Superstring Theory and M-Theory
http://www.superstring-theory.com/EnglishVersion.html

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Black Holes

... The pre-string theory conflict between general relativity
and quantum mechanics was an affront to our visceral
sense that the laws of nature should fit together in a seam-
less, coherent whole. But this antagonism was more than
a towering abstract disjunction.

The extreme physical conditions that occurred at the mo-
ment of the big bang and that prevail within black holes
cannot be understood without a quantum mechanical
formulation of the gravitational force. With the discovery
of string theory, we now have a hope of solving these
deep mysteries.

... A straightforward application of general relativity ...
shows that the enormous mass and energy crushed to-
gether at the black hole's center causes the fabric of
spacetime to suffer a devastating rift, to be radically
warped into a state of infinite curvature -- to be punc-
tured by a spacetime singularity.

One conclusion that physicists drew from this is that
since all of the matter that has crossed the event horizon
is inexorably drawn to the center of the black hole, and
since once there the matter has no future, time itself
comes to an end at the heart of a black hole.

Other physicists, who over the years have explored the
properties of the black hole's core using Einstein's equa-
tions, revealed the wild possibility that it might be a gate-
way to another universe that tenuously attaches to ours
only at a black hole's center. Roughly, where time in our
universe comes to an end, time in the attached universe
just begins.

... Extremes of huge mass and small size leading to un-
imaginably large density invalidate the sole use of Ein-
stein's classical theory and require that quantum mechan-
ics be brought to bear as well.

Origin(s) of the Universe(s)

... Humans throughout history have had a passionate
drive to understand the origin of the universe. There is,
perhaps, no single question that so transcends cultural
and temporal divides, inspiring the imagination of our
ancient forebears as well as the research of the modern
cosmologist. ... The astounding thing is that humanity
has now come to a point where a framework is emerging
for answering some of these questions scientifically.

... between the big bang and Planck time [1 divided by
10 to the 43rd power seconds] ... Nature is telling us em-
phatically that under such conditions we must merge gen-
eral relativity and quantum mechanics -- in other words,
we must make use of string theory.

Currently, research on the implications of string theory
for cosmology is at an early stage ... there may be a whole
prehistory to the universe -- starting long before what we
have been calling time zero -- that leads up to the Planck-
ian cosmic embryo.

In this so-called pre-big bang scenario, the universe began
in a vastly different state than it does in the big bang frame-
work.

... The study of superstring cosmology is rapidly becoming
an active and fertile arena of research. ... During the coming
years, as the non-perturbative tools of string/M-theory are
sharpened, physicists anticipate that some of the most pro-
found insights will emerge from their application to cosmo-
logical questions.

... Valiant attempts by physicists such as Hawking and
James Hartle ... have tried to bring the question of cosmo-
logical conditions within the umbrella of physical theory,
but all such attempts remain inconclusive.

... Imagine that what we call the universe is actually only
one part of a vastly larger cosmological expanse, one of
an enormous number of island universes scattered across
a grand cosmological archipelago. ... Andre Linde has
suggested a concrete mechanism that might lead to such
a gargantuan universe. Linde has found that the brief but
crucial burst of inflationary expansion ... may not have
been a unique, one-time event.

Instead ... the conditions for inflationary expansion may
happen repeatedly throughout the cosmos, which then
undergo their own inflationary ballooning in size, evolving
into new, separate universes. And in each of these uni-
verses, the process continues.

... superstring cosmology is a young field, even by the
youthful standards set by string theory itself. It will, un-
doubtedly, be an area of primary research focus for years
to come ...

(end excerpts)

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Posts in this series:

Universe(s) Origin(s) Preface
http://prohuman.net/universes_origins_preface.htm

Universe(s) Origin(s) - 1 of 7
}}} String Theory / Infinities / Singularities {{{
http://prohuman.net/universes_origins_1_of_7.htm

Universe(s) Origin(s) - 2 of 7
}}} No Origin of the Universe? {{{
http://prohuman.net/universes_origins_2_of_7.htm

Universe(s) Origin(s) - 3 of 7
}}} Multiverse? {{{
http://prohuman.net/universes_origins_3_of_7.htm

Universe(s) Origin(s) - 4 of 7
}}} Universes from Black Holes? {{{
http://prohuman.net/universes_origins_4_of_7.htm

Universe(s) Origin(s) - 5 of 7
}}} Cyclic Universe? {{{
http://prohuman.net/universes_origins_5_of_7.htm

Universe(s) Origin(s) - 6 of 7
}}} Einstein / Big Bang / Superstrings {{{
http://prohuman.net/universes_origins_6_of_7.htm

Universe(s) Origin(s) - 7 of 7
}}} Nothing / Everything {{{

http://prohuman.net/universes_origins_7_of_7.htm

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