Transcript String theory 1

String Theory
Mihir John
What are the most basic constituents that make
up the universe around us?
Why use String Theory?
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String Theory is believed to bridge the gap
between General Relativity and Quantum
Mechanics
This is because Relativistic Quantum Field
Theory only works when gravity is ignored (very
weak)
General Relativity only works when we can
assume the universe can be described by
classical physics (no quantum mechanics)
String Theory Suppositions
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In string theory, particles come from excitations
of the string
The theorized particle with gravitational force,
with zero mass and two units of spin, is
called the Graviton
Even though the graviton is compatible with
quantum theory, the mathematics of the
interactions does not follow
String Theory allows that these particles collide
over a small, finite distance
String Theory Basics
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With string theory attempting the explain
Quantum Gravity, the strings exist near Planck
length (10^-33cm)
Multiple types of string theory exist, and are
classified by open/closed strings and also
supersymmetry. (bosons and fermions)
Different string theories require different
spacetime dimensions to work—Range from 10
to 26
String Theory Unification
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If “strings” are the most basic constituents of the
universe, and all particles arise from their
excititation, then all matter and the forces of
nature arise from strings
If everything arises from one system, is a
unified theory not possible?
Supporting String Theory
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Experimental data from particle accelerators
such as CERN could provide insight
Primarily, comparing energy levels from
collisions could support the theory of additional
dimensions
Particle accelerators could also provide data for
theorized particles such as the graviton
Additional Sources
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TEDTalk- Brian Greene-Making Sense of String
Theory