The 4 Most Compelling Theories of Everything
Published on 11/15/2007
1
A theory of everything (ToE) is a hypothetical theory of theoretical
physics that fully explains and links together all known physical
phenomena. There have been numerous theories of everything proposed by
theoretical physicists over the last century, but as yet none has been
able to stand up to experimental scrutiny, there being tremendous
difficulty in getting the theories to produce experimentally testable
results. So here are the top 4 most important Theories of Everything
nowdays:
Superstring theory: "Everything comes from excited strings"
Think of a guitar string that has been tuned by stretching the string
under tension across the guitar. Depending on how the string is
plucked and how much tension is in the string, different musical notes
will be created by the string. These musical notes could be said to be
excitation modes of that guitar string under tension.
In a similar manner, in string theory, the elementary particles we
observe in particle accelerators could be thought of as the "musical
notes" or excitation modes of elementary strings.
In string theory, as in guitar playing, the string must be stretched
under tension in order to become excited. However, the strings in
string theory are floating in spacetime, they aren't tied down to a
guitar. Nonetheless, they have tension. The string tension in string
theory is denoted by the quantity 1/(2 p a'), where a' is pronounced
"alpha prime" and is equal to the square of the string length scale.
If string theory is to be a theory of quantum gravity, then the
average size of a string should be somewhere near the length scale of
quantum gravity, called the Planck length, which is about 10-33
centimeters, or about a millionth of a billionth of a billionth of a
billionth of a centimeter. Unfortunately, this means that strings are
way too small to see by current or expected particle physics
technology (or financing!!) and so string theorists must devise more
clever methods to test the theory than just looking for little strings
in particle experiments.
String theories are classified according to whether or not the strings
are required to be closed loops, and whether or not the particle
spectrum includes fermions. In order to include fermions in string
theory, there must be a special kind of symmetry called supersymmetry,
which means for every boson (particle that transmits a force) there is
a corresponding fermion (particle that makes up matter). So
supersymmetry relates the particles that transmit forces to the
particles that make up matter.
Supersymmetric partners to to currently known particles have not been
observed in particle experiments, but theorists believe this is
because supersymmetric particles are too massive to be detected at
current accelerators. Particle accelerators could be on the verge of
finding evidence for high energy supersymmetry in the next decade.
Evidence for supersymmetry at high energy would be compelling evidence
that string theory was a good mathematical model for Nature at the
smallest distance scales.
2
Holographic paradigm: "The universe is an Hologram"
# The holographic paradigm is joining of two concepts that were
developed independently: That the universe is in some sense a
by Karl Pribram
This paradigm posits that theories utilizing holographic structures
may lead to a unified understanding of consciousness and the universe.
The physicist David Bohm, who died in 1992, developed a sophisticated
approach to this concept of the universe, which he termed 'undivided
wholeness'. Bohm outlined his approach in the classic 1980 book,
'Wholeness and the Implicate Order'. He used the analogy of the
hologram to illustrate the concept of undivided wholeness. A hologram
is a special kind of photographic plate produced with the highly
coherent light of a laser source, i.e. light which is all of the same
frequency and which does not disperse. Whereas an ordinary
photographic plate records a flat image of an illuminated object, a
hologram provides a three-dimensional reconstruction of the object. If
a hologram is illuminated with the same coherent light with which it
was produced, then the optical effect is as if the original object
were being observed. When the observer moves his/her head around,
different perspectives of the object can be seen. A remarkable
property of holograms is that even if only a portion of the plate is
illuminated the whole of the object is reconstructed, although the
resolution of the reconstruction is not as great as when the complete
plate is illuminated. One may say that the reconstructed object is
embedded in any arbitrary segment of the plate.
Now, the physics of holograms is well understood. The point here is
that the hologram serves as a simple analogy for Bohm's concept of
undivided wholeness. The universe is like a hologram, in which the
whole image is contained within every segment. In other words, the
whole is enfolded within each segment. By shining laser light on a
part of the hologram, an unfolding occurs in which the form and
structure of the whole become apparent. Similarly, processes of
unfolding occur continually in the universe, yielding the patterns and
structures which we can see and measure.
3
E8-based Theory of Everything: "Our universe is this beautiful shape"
On November 6, 2007, Antony Garrett Lisi, an American-born theoretical
physicist, published the paper called "An Exceptionally Simple Theory
of Everything", describing a new unified field theory that connects
the theories of quantum physics and gravitation using the mathematical
shape E8.
Lisi's inspiration lies in this elegant and intricate shape known to
mathematics, called E8 - a complex, eight-dimensional mathematical
pattern with 248 points first found in 1887, but only fully understood
by mathematicians this year after workings, that, if written out in
tiny print, would cover an area the size of Manhattan. E8 encapsulates
the symmetries of a geometric object that is 57-dimensional and is
itself is 248-dimensional. Lisi says "I think our universe is this
beautiful shape."
What makes E8 so exciting is that Nature also seems to have embedded
it at the heart of many bits of physics. One interpretation of why we
have such a quirky list of fundamental particles is because they all
result from different facets of the strange symmetries of E8. Lisi's
breakthrough came when he noticed that some of the equations
describing E8's structure matched his own.
What Lisi had realised was that he could find a way to place the
various elementary particles and forces on E8's 248 points. What
remained was 20 gaps which he filled with notional particles, for
example those that some physicists predict to be associated with
gravity. Physicists have long puzzled over why elementary particles
appear to belong to families, but this arises naturally from the
geometry of E8, he says. So far, all the interactions predicted by the
complex geometrical relationships inside E8 match with observations in
the real world.
The crucial test of Lisi's work will come only when he has made
testable predictions. Lisi is now calculating the masses that the 20
new particles should have, in the hope that they may be spotted when
the Large Hadron Collider starts up.
"The theory is very young, and still in development," he says. "Right
now, I'd assign a low (but not tiny) likelyhood to this prediction.
For comparison, I think the chances are higher that LHC will see some
of these particles than it is that the LHC will see superparticles,
extra dimensions, or micro black holes as predicted by string theory.
I hope to get more (and different) predictions, with more confidence,
out of this E8 Theory over the next year, before the LHC comes
online."
4
Integral theory: "everything in creation --except perhaps creation
itself-- is a holon"
Integral theory is a term often used to describe the teachings and
work of the American writer Ken Wilber, referring either to the
synthesis of different perspectives and methodologies, or to his own
"AQAL" theory. More recently, the term has been adopted Hungarian
A key idea in Wilber's philosophical approach is the holon, which came
from the writings of Arthur Koestler. In considering what might be the
basic building blocks of existence, he observed that it seems every
entity and concept shares a dual nature: as a whole in itself, and as
a part of some other whole. For example, although you are made of
parts (your nervous system, your skeletal system, etc.), you are also
a part of your society, and of your nation-state. A letter is a
self-existing entity and simultaneously an integral part of a word.
Everything from quarks to matter to energy to ideas can be looked at
a holon.
AQAL (pronounced aqual or ah-qwul) represents the core of Wilber's
recent work. AQAL stands for "all quadrants all levels", but equally
connotes 'all lines', 'all states' and 'all types'. These are the five
irreducible categories of Wilber's model of manifest existence. In
order for an account of the Kosmos to be complete, Wilber believes
that it must include each of these five categories. All of Wilber's
to relative truth in the two truths doctrine of Buddhism, to which he
subscribes. According to Wilber, none of them are true in an absolute
sense: only formless awareness, "the simple feeling of being," exists
absolutely.
Each holon, or unit of reality that is both a whole and a part of a
larger whole, has an interior and an exterior. It also exists as an
individual and (assuming more than one of these entities exists) as a
collective. Observing the holon from the outside constitutes an
exterior perspective on that holon. Observing it from the inside is
the interior perspective, and so forth. If you map these four
perspectives into quadrants, you have four quadrants, or dimensions
(these are unrelated to the three spatial dimensions)
To give an example of how this works, consider four schools of social
science. Freudian psychoanalysis, which [interprets people's interior
experiences, is an account of the interior individual (or, in the
diagram, the upper-left) quadrant. B. F. Skinner's behaviorism, which
limits itself to the observation of the behavior of organisms, is an
exterior individual (upper-right) account. Gadamer's philosophical
hermeneutics interprets the collective consciousness of a society, and
is thus an interior plural (lower-left) perspective. Marxist economic
theory examines the external behavior of a society (lower-right).
contradictory, perspectives. It is possible for all to be correct and
necessary for a complete account of human existence. Wilber has
integrated these four areas of knowledge through an acknowledgement of
the four fundamental dimensions of existence. Further, these four
perspectives are equally valid at all levels of existence.
|
|