Is QED a nonsense?
QED is hocus-pocus, meaningless theory. Though universities and the media repeatedly say relativistic quantum theory such as QED and standard model are “triumph of the present physics !”, it is a big lie. Even its founders, Feynman and Dirac said “QED is hocus-pocus, mathematically NOT legitimate”.
What is a non renormalizable theory?
Non-renormalizable theories, when regarded as an effective field theory below a cut-off Λ, is perfectly meaningful field theory. This is because non-renormalizable operators can be induced in the effective Lagrangian while integrating out high energy degrees of freedom.
What is renormalizable theory?
Now we consider a certain blocking transformation of the state variables , the number of must be lower than the number of . Now let us try to rewrite the function only in terms of the . If this is achievable by a certain change in the parameters, , then the theory is said to be renormalizable.
Who invented renormalization group?
Leo P. Kadanoff
Block spin. This section introduces pedagogically a picture of RG which may be easiest to grasp: the block spin RG, devised by Leo P. Kadanoff in 1966. Consider a 2D solid, a set of atoms in a perfect square array, as depicted in the figure.
Is QED accurate?
The agreement found this way is to within ten parts in a billion (10−8), based on the comparison of the electron anomalous magnetic dipole moment and the Rydberg constant from atom recoil measurements as described below. This makes QED one of the most accurate physical theories constructed thus far.
Why is General Relativity non renormalizable?
So yes, technically GR does not yield a renormalizable QFT because it requires an infinite number of counterterms.
Is there a quantum theory of gravity?
There are a number of proposed quantum gravity theories. Currently, there is still no complete and consistent quantum theory of gravity, and the candidate models still need to overcome major formal and conceptual problems.
How do you know if a theory is renormalizable?
You just use the following criterion: An interaction is superficially renormalizable if its coupling constant has dimensions of lengthd with d less than or equal to zero, but not if d is greater than zero.
What is renormalization group theory?
Application of Renormalization Group Theory highlighted how critical exponents are linked by scaling relations, so that only two of them are independent, and that their values are universal in large classes of materials, independently from the detailed atomic features of a substance.
Is renormalization mathematically rigorous?
Bookmark this question. Show activity on this post. In most physics books they give proofs of renormalization of quantum electrodynamics that are not mathematically rigorous.
Who invented QED?
The QED theory was refined and fully developed in the late 1940s by Richard P. Feynman, Julian S. Schwinger, and Tomonaga Shin’ichirō, independently of one another.
What is the difference between QFT and QED?
The comment by Aaron Stevens is right: QED is a specialization of QFT. QFT is a collection of general principles. It is a specialization of quantum theory (it respects all of the principles of quantum theory and includes some more), but it is still very broad. QED is a further specialization.
Why quantum of gravity is impossible?
One of the difficulties of formulating a quantum gravity theory is that quantum gravitational effects only appear at length scales near the Planck scale, around 10−35 meters, a scale far smaller, and hence only accessible with far higher energies, than those currently available in high energy particle accelerators.
What does Renormalizable mean in physics?
renormalization, the procedure in quantum field theory by which divergent parts of a calculation, leading to nonsensical infinite results, are absorbed by redefinition into a few measurable quantities, so yielding finite answers.
Why did Einstein oppose quantum mechanics?
Einstein always believed that everything is certain, and we can calculate everything. That’s why he rejected quantum mechanics, due to its factor of uncertainty.
What causes the Lamb shift?
The Lamb shift is a tiny difference in energy between two levels of a hydrogen atom that should otherwise have the same energy in classical empty space (see Fig. 1). It arises because zero-point fluctuations of the electromagnetic field in vacuum perturb the position of the hydrogen atom’s single bound electron.
What is renormalization QED?
renormalization, the procedure in quantum field theory by which divergent parts of a calculation, leading to nonsensical infinite results, are absorbed by redefinition into a few measurable quantities, so yielding finite answers. Related Topics: quantum field theory.
Why is quantum field theory not mathematically rigorous?
All of the difficulty in making QFT rigorous can be traced to what happens at very short distances and very high energies. And that’s certainly important to understand. But the great insight of Ken Wilson and the effective field theory approach is that, as far as particle physics is concerned, it just doesn’t matter.