Theory of Everything
Is there an end to Physics?
What is a Theory of Everything
• The unification of
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General Relativity and
Quantum Mechanics
Relationship between
the four fundamental
forces
Explains properties of
fundamental particles
Benefits of a Theory of Everything
• Simplification of concepts allows deeper
understanding
• Better understanding of cosmology, black
holes, and The Big Bang
• Better understanding of time/spacetime
Strongest possibilities for a ToE
• String Theory/M-Theory
• Loop Quantum Gravity
String Theory
• Makes gravity an integral part of the quantum
•
•
•
•
realm-graviton
All fundamental particles are string excitations
Can involve up to 26 dimensions
Promising because it does away with infinities in
calculations (gets rid of the idea of infinitely
small particles)
Supersymmetry- is there a boson for every
fermion and vice-versa
Loop Quantum Gravity
• Main goal is to quantize gravity
• Views spacetime as pieces that are
connected to each other
Difficulties for String Theory
• Supersymmetry was expected to be
discovered by now
• The large number of dimensions are have
never been detected
• It doesn’t make any precise predictions
Weaknesses of a ToE
• Gödel's Incompleteness Theorem
• Difficulty Testing Theories
Physicists for/against a ToE
• Einstein
• Stephen Hawking- Once believed that it
was inevitable now he believes it is
improbable
Implications for Physicists
• Would a theory of everything be
invigorating/inspiring ,or would it take
away the thrill of physics