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String theory
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Particles as vibrating strings in extra dimensions.
Fundamental objects are tiny vibrating strings (~10⁻³⁵ m) in 10 or 11 dimensions; different modes appear as different particles, including the graviton. Not yet testable.
Offers quantum gravity.
Needs extra compactified dimensions.
In more detail
String theory proposes that fundamental particles are tiny vibrating strings, and it aims to unify gravity with quantum mechanics. It requires extra dimensions and has not yet made testable predictions.
Real-world uses
- String theory has inspired new mathematics and quantum field theory methods.
- It is studied as a candidate for a unified theory of physics.
- String theory is studied as a candidate for unifying gravity with quantum mechanics.
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Frequently asked questions
Is string theory proven?
No. It is a theoretical framework without direct experimental confirmation.
Why extra dimensions?
The mathematics of string theory is consistent only in ten or eleven dimensions.
Is string theory tested?
Not yet directly, because its characteristic energies are far beyond current accelerators.
Related topics in Particle Physics & Cosmology
Matter–antimatter asymmetry · Grand unified theories · Supersymmetry · Our Sun · Stellar life cycle · Hertzsprung–Russell diagram