Can someone explain to me what renormalization is?

In summary, renormalization is a mathematical technique used to obtain finite results by canceling infinities in quantum mechanics. While general relativity does not require renormalization, it becomes necessary when incorporating gravity into the equations. However, this method has not been successful in producing finite results for all theories involving both quantum mechanics and gravity. The exact reason for this failure is not yet known.
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KrisOhn
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Can someone explain to me what renormalization is? And why General Relativity isn't renormalizable?
 
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KrisOhn said:
Can someone explain to me what renormalization is? And why General Relativity isn't renormalizable?

'Renormalization' is a catch-all term used to describe mathematical tricks that are used to get finite results by canceling infinities and whatnot.

General relativity does not need 'renormalization', quantum mechanics does.

When you extend quantum mechanics to include gravity (general relativity) the final theory must be re-normalized as a consequence of it's mathematical formulation. With some possible theories (formulations of quantum mechanics including gravity) renormalization tricks will succeed in producing a finite answer (like the electron has X much magnetic moment etc.) but with all of the theories we have tried so far (with the possibly exception of string theory, but they have other problems such as choosing a vacuum) renormalization fails to produce any finite results.

The reasons that renormalization fails to work when you combine quantum mechanics and gravity is just because.

(or something like that)
 

1. What is the purpose of renormalization in science?

Renormalization is a mathematical technique used in theoretical physics and other scientific fields to eliminate or reduce infinities that arise in certain calculations. It allows us to make meaningful predictions and understand the behavior of complex systems.

2. How does renormalization work?

Renormalization involves a process of rescaling or changing the parameters in a theoretical model in order to remove divergences or infinities. This allows for a more accurate and meaningful description of the system being studied. It is often used in conjunction with other mathematical techniques to solve complex problems.

3. What is the history of renormalization?

The concept of renormalization was first introduced in the 1930s by physicist Wolfgang Pauli to deal with infinities in quantum electrodynamics. It was further developed by many other scientists, including Richard Feynman, Freeman Dyson, and Murray Gell-Mann, and has since become an essential tool in modern theoretical physics.

4. Why is renormalization important in quantum field theory?

In quantum field theory, renormalization is essential for making predictions and calculations that are consistent with experiments. Without renormalization, the theory would produce nonsensical results and would not be useful in describing the behavior of particles at the quantum level.

5. Are there any limitations to renormalization?

Renormalization is a powerful tool, but it does have its limitations. It can only be applied to certain types of physical systems, and in some cases, it may not completely eliminate all infinities. Additionally, the mathematical techniques used in renormalization can be complex and difficult to apply in certain situations.

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