Why is Quantum Field Theory considered more fundamental than General Relativity?

Question

I understand it is generally thought that because big things are made of small things that understanding the small things leads to an understanding of the big things, but is this necessarily so?

Answer 1

It isn't.

But QFT and GR are very difficult to combine, and an assumption is commonly made about which one will have to give. The assumption typically made is that GR will need corrections at very small scales or very high energies, largely because it assumes things are smooth at all levels (it is classical) whereas QF assumes things are lumpy. The principle is that things cannot be simultaneously smooth and lumpy.

I do not think this means GR is seen less fundamental, but it is an indication that it is seen as most likely to need modification.

Remember, QFT is the most accurate theory ever created, and the standard model uses it with remarkable effect.

Answer 2

They are as important as each other - they just describe very different aspects of the universe. Quantum Field Theory is preoccupied with the very, very small (the building blocks of matter) while general relativity deals with the effects of the very, very large.

I do know that the biggest search in physics currently is the "unified theory", which brings both together - at the moment they appear to be incompatible. This is the current holy grail of physics.

Answer 3

It is not. They are both considered the two corner stones of modern physics, and are of equal stature. They model different regimes (the very small vs. the very massive) and neither is derivable from the other (that is usually what is meant by being more or less "fundamental"). In fact, in some regimes they are inconsistent (like when things are both small and massive). So, another more generally applicable "theory of everything" is being sought. Got any ideas?

Answer 4

Because of the word "fundamental" which means first and foremost. As the universe as we know it started off with a quantum size, quantum mechanics is seen as prior to relativity.

My GUESS anyway.

Answer 5

The elusive quantum field theory is considered more fundamental because it deals with things on a very small or 'fundamental' level (i.e. sub atomic particles), whereas General Relativity describes how things work on a larger scale (i.e. planets, stars, black holes, galaxies)

Answer 6

Because as of yet there is no quantum theory of gravity.

Straing theory and such try to approach this, but they are for the moment ultimately theoretical