String Theory is Retarded:
An Objective Analysis
Jared Snyder
Scott Goodrow
Raphael Balke
PHYS43 Modern Physics, SRJC
Section 5756
Instructor: Dr. Younes Ataiiyan
Modern Physics Project
Fundamental Forces
• There are four forces.
• Each is associated with
force-carrying particles:




Strong force: gluon
Weak force: W boson, Z boson
Electromagnetic force: photon
Gravitational force: graviton (maybe)
• The Standard Model
describes all of them except
the gravitational force.
The Standard Model and Gravity
• The Standard Model uses
the discrete fields of
Quantum Mechanics, as
required by Heisenberg’s
Uncertainty Principle.
•Gravity is best described
by Einstein’s Relativity,
which requires
continuous fields.
•When you try and put them
together, you get a mess!
www.nasa.gov
The Problem
• The Standard Model
and Relativity can be
used to describe some
fundamental forces,
but there is no theory
which can describes
all fundamental forces.
“Just because things get a little
dingy at the subatomic level doesn't
mean all bets are off.”
–Murray Gell-Mann
String Theory
• String theory suggests that the elementary particles are
one-dimensional strings as opposed to zero-dimensional
point particles.
• All known elementary particles are made up of one
building block: the string.
• The resonance of each string determines the properties
(mass, charge, spin, etc.) of the particle, thus different
resonant frequencies correspond to different particles.
• Strings are on the order of the Planck length (10-35 m),
or 1020 times smaller than the diameter of an atomic
nucleus!
The Five Main String Theories
•
Type I:
•
Type IIA: Supersymmetry between forces and matter, closed strings, open
strings bound to D-branes, massless fermions spin both ways
(achiral).
•
Type IIB: Supersymmetry between forces and matter, closed strings, open
strings bound to D-branes; massless fermions only spin one way
(chiral).
•
Type HO: Supersymmetry between forces and matter, closed strings,
heterotic (right moving and left moving strings differ), group
symmetry is SO(32).
•
Type HE: Supersymmetry between forces and matter, closed strings,
heterotic (right moving and left moving strings differ), group
symmetry is E8×E8.
Supersymmetry between forces and matter, open and closed
strings; group symmetry is SO(32)
http://superstringtheory.com/basics/basic5.html
Predictions of String Theory
• The five main theories suggest an 11-dimensional
universe, composed of 3 space dimensions, 1 time
dimension and 6 (or 7) spatially coiled dimensions!
• These coiled dimensions form the Calabi-Yau manifolds.
http://en.wikipedia.org/wiki/Image:Calabi-Yau.png
Calabi-Yau Shapes on a Surface
http://members.wri.com/jeffb/visualization/calabi-grid.gif
A Brief History of String Theory:
The String Idea
• 1968: Gabriele Veneziano, struggling to make sense
of various experiments at CERN, discovered Euler’s
beta-function:
• The beta-function surprisingly seemed to describe
features of the strong force.
• What was the physics behind this description?
http://en.wikipedia.org/wiki/Beta_function
The Next Step
• 1970: Yoichiro Nambu, Holger Nielsen and Leonard
Susskin came up with the idea to model elementary
particles as strings.
• Based on the beta function, it seemed they had
discovered a pleasing theory for the strong force.
String Theory Initially Dismissed
• 1970: The same year, improved experiments showed
inconsistencies in the theory.
• The success of the point-particle quantum field theory of
quantum chromo-dynamics resulted in the first dismissal
of string theory.
• John Schwarz continues to work on it.
“The mathematical structure of string theory was so beautiful and had so many
miraculous properties that it had to be pointing toward something deep.”
-John Schwarz
String Theory and the Graviton
• 1971: Supersymmetry is discovered in both the
Standard Model and string theory.
• 1974: John Schwarz and Joel Scherk discovered that
string theory had failed because its scope was
constrained.
• String theory not only described quantum effects, but
also the graviton, thus the idea developed that string
theory might be the key to the grand unified theory.
Greene, Brian. The Elegant Universe
The First String Revolution
• 1976: Supersymmetry is added to gravity,
resulting in SUPERGRAVITY.
• 1980: SUPERSTRINGS discovered.
• 1984: John Schwarz and Michael Green published
their 12 years of work in a paper on string theory,
resolving many conflicts of quantum mechanics.
• The “First String Theory Revolution” began, resulting in
thousands of research papers being published on the
topic between 1984 and 1986.
The Second String Revolution
• 1995: Edward Witten introduced M-theory, combining
the five different conflicting theories, beginning the
“Second String Theory Revolution”.
• What does the “M” stand for? Nobody knows, but there
are many suggestions:
– master, mathematical, mother, mystery, membrane, magic,
matrix theory, or is jut an upside down W?
• Today: M-Theory remains incomplete, and even
after long years of intense research string theory has
incredibly limited predictive power.
String Theory and Science
“I have deep faith that the principle of the universe
will be beautiful and simple.”
-Albert Einstein
String Theory attempts to solve a number
of the issues of the Standard Model.
It does so based on the attributes of:
1. Beauty
2. Elegance
3. Oneness
While these romantic attributes of the
universe satisfy us, does satisfaction
alone make them a valid basis for
constructing a theory of the Universe?
String Theorists say yes.
We say… maybe not.
http://www.wellingtongrey.net/miscellanea/archive/2007-01-15%20--%20science%20vs%20faith.png
Is String Theory Scientific
“In so far as a scientific statement speaks about
reality,it must be falsifiable; and in so far as it
is not falsifiable, it does not speak about reality.”
-Karl Popper
Many claim that String Theory is not
science because…
1. It is not corroborated empirically
2. It makes no testable predictions
3. It is not falsifiable by nature
Some argue that this is a limitation of
our technology and the observer.
But are these arguments valid?
If they are, String Theory should fit the
guidelines of the scientific method.
http://www.wellingtongrey.net/miscellanea/archive/2007-01-15%20--%20science%20vs%20faith.png
Is String Theory Scientific
“For
every fact there is an infinity of hypotheses.”
-Robert Pirsig
As a mathematical representation of both
particle physics and relativistic physics,
String Theory is a mathematical approach
to unifying the two aspects the Universe:
the very big and the very small.
Get an idea?
http://www.wellingtongrey.net/miscellanea/archive/2007-01-15%20--%20science%20vs%20faith.png
Is String Theory Scientific
“The strongest arguments prove nothing so long
as the conclusions are not verified by experience.”
-Roger Bacon
It is commonly believed that to test the
theory experimentally would require
energetic feats on the solar-system scale.
Hence, while methods of experimental
verification have been suggested, they are
all too conveniently out of reach.
Perform an Experiment?
http://www.wellingtongrey.net/miscellanea/archive/2007-01-15%20--%20science%20vs%20faith.png
Science or Mythology?
Qualities of myth include:
Qualities of science include:
•Explains the Universe
•Elegantly describes nature
•Fundamentally unfalsifiable
•Extends beyond observable world
•Explains the Universe
•Requires peer review before belief
•Describes nature as nature is to be described
•Fundamentally falsifiable
Verdict: Myth
http://www.mlahanas.de/Greeks/Mythology/RM/ZeusThunderbolt.jpg
http://www.phy.cuhk.edu.hk/phyworld/iq/lightning/return_stroke_e.jpg
How Did We Get Stuck Here?
The Culmination of Science:
In only 400 years, science and philosophy discovered…
•Newtonian Mechanics
•Electricity
•Maxwell’s Equations
•The Atom
•General Relativity
•Nuclear Physics
•Schrodinger’s Wave Equation
•Quantum Mechanics
•The Standard Model
…and then science grew silent.
Because of this progress, theoretical particle physics has become a victim of
its own success for the past quarter century.
Theories have emerged that are based on no evidence, such as String Theory.
http://imgs.xkcd.com/comics/string_theory.png
Where Do We Go From Here?
Before we get hooked into another charade, we must remember to work
One step at a time.
May 2008: The Search for Evidence Continues at the LHC!
•Where are the elusive Higgs bosons?
•Are more precise quark masses consistent with the Standard Model?
•Are particles locked in supersymmetry?
•What is the nature of dark matter and dark energy?
•Why is gravity so comparatively weak?
There are solutions to be found, but as Sherlock Holmes once said,
“It is a capital mistake to theorize before one has data. Insensibly one begins
to twist facts to suit theories instead of theories to suit facts.”
Quotations gathered from: http://www.lhup.edu/~dsimanek/sciquote.htm