And even if we succeed in figuring out how the strong force fits into the puzzle, we will still need to look to even higher energies to combine these forces with gravity. But it will be worth it.

## The physics of elementary particles: Part I

Understanding whether the known subatomic forces have a common origin is key to creating a Theory of Everything. Predicted by Einstein and discovered in , gravitational lensing helps astrophysicists understand the evolving shape of the universe. Not only are we made of fundamental particles, we also produce them and are constantly bombarded by them throughout the day. Theorists began to invoke the concept of local gauge invariance, which postulates symmetries of the basic field equations at each point in space and time see gauge theory. Both electromagnetism and general relativity already involved such symmetries, but the important step was the discovery that a gauge-invariant quantum field theory of the weak force had to include an additional interactionâ€”namely, the electromagnetic interaction.

During the s a similar quantum field theory for the strong force, called quantum chromodynamics QCD , was developed. In QCD, quarks interact through the exchange of particles called gluons.

## A Brief History of the Grand Unified Theory of Physics

The aim of researchers now is to discover whether the strong force can be unified with the electroweak force in a grand unified theory GUT. There is evidence that the strengths of the different forces vary with energy in such a way that they converge at high energies. However, the energies involved are extremely high, more than a million million times as great as the energy scale of electroweak unification, which has already been verified by many experiments.

Grand unified theories describe the interactions of quarks and leptons within the same theoretical structure. This gives rise to the possibility that quarks can decay to leptons and specifically that the proton can decay.

rempnetpcountsancdweb.ga This prediction has been tested in experiments that monitor large amounts of matter containing on the order of 10 32 protons, but there is no evidence that protons decay. If they do in fact decay, they must do so with a lifetime greater than that predicted by the simplest GUTs.

There is also evidence to suggest that the strengths of the forces do not converge exactly unless new effects come into play at higher energies.

- Discrete and Continuous Nonlinear SchrĂ¶dinger Systems!
- The Complete Tommy & Tuppence Collection.
- The Great Erasure: The Reconstruction of White Identity;
- Introduction to Mathematical Physics. Methods and Concepts 2nd Ed!
- Gravitation!
- The Brothers Karamazov (Bantam Classic).

A successful GUT will still not include gravity. The problem here is that theorists do not yet know how to formulate a workable quantum field theory of gravity based on the exchange of a hypothesized graviton. See also quantum field theory.

Scientific Program. SUSY The goal of the International Conference on Supersymmetry and Unification of Fundamental Interactions SUSY is to review and discuss recent progress in theoretical, phenomenological, and experimental aspects of supersymmetric theories and other approaches to physics beyond the Standard Model of particles and interactions.

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