Quantum physics is the field of physics that explains how everything works.

It is the best description of the nature of the particles that make up matter and the forces with which they interact. If you want to explain how photons on light ...

Three different quantum field theories deal with three of the four fundamental forces by which matter interacts:

• Electromagnetism: It explains how atoms hold together.
• The strong nuclear force: It describes the stability of the nucleus at th...

Understanding how electrons move or not through a solid material and so make a material a metal, an insulator or a semiconductor, for example, requires the development of "effective field theories" that don't go into all the details.

But it is difficult to constru...

• A fourth fundamental force of nature that quantum theory cannot explain, namely gravity, doesn't even involve particles. None of the decades of effort can bring gravity under the quantum umbrella to explain all of fundamental physics within one "theory of everything."
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