Can someone help me understand... In layman's terms... Just what the Unified Field Theory is supposed to be/accomplish?
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Can someone help me understand... In layman's terms... Just what the Unified Field Theory is supposed to be/accomplish?
A (not "the" as we don't have one yet!) unified field theory is an attempt to produce a single description of all of the fundamental forces (electromagnetic, weak, strong and gravity).
These are currently described by four separate fields. Each field has associated "force carriers" (photons for the electromagnetic field, gluons for the strong, etc.). Apart from gravity which doesn't have a quantised description yet.
There is already a unification of the electromagnetic and weak forces as the electroweak interaction; i.e. at high enough energies, these two different forces merge into one.
I think that all the proposed unified theories are untestable because they require higher energies than we can achieve in order to test their predictions.
That's about all I know. After that it starts getting very mathematical.
Thankyou... And we will avoid the mathematics because I am an English Education major.
In very basic terms, there are three major theorems in Physics: Gravitation, Electromagnetism and Quantum Mechanics. James Maxwell wrote differential equations which described the effects of Electromagnetism from a very small limit to either very large limits or to infinity. The theory of Electromagnetism is considered "closed". You may think of it as a closed book and Maxwell wrote the book on Electromagnetism. Albert Einstein expanded on the work of Isaac Newton to formulate a mathematical set of equations to describe the effects of gravity from a very small limit to either very large limits or to infinity. The theory of Gravity is considered "closed". You may think of it as a closed book and Einstein, with Newton, wrote the book on gravity. This leaves the world of the very small in which limits to Electromagnetism, and maybe, perhaps, (eh), gravity are unpredictable. (A polite way of saying it). Edwin Schrodinger wrote a differential equation to describe the world of the very small which, with a stretch, we could say is a closed theory as soon as we can complete (or understand) Schrodinger's little equation. Now ... that being said: we have three equations which describe three different areas of physics; the unified field theory is an equation or set of equations which unites all three equations (theories) or gives an overall mathematical explanation of the effects described by all three theories. One of the most promising attempts so far has been string theory which has yet to be substantiated through experiment although much of its basis is from experimental work.
I hope that helps.
I believe that I've confused a Grand Unification Theory (GUT) with unified field theory. The former attempts to merge the strong nuclear force with the electroweak force, and the latter takes it one step further to include gravity. A theory of everything is unified field theory, correct?
Jagella
Hi Jagella,
It was Sheldon Glashow, Abdus Salam and Steven Weinberg who discovered that the weak nuclear force was electromagnetic in nature. They were awarded the 1979 Nobel Prize in Physics for their work. I have cut and pasted from wiki here. GUT deals with gauge symmetry linking electroweak, weak and strong forces, so you are on the money. Here is the link: Grand Unified Theory - Wikipedia, the free encyclopedia. However, since GUT is work in progress, some degree of leeway should be permitted.
The Unified Field Theory should fulfill two important mathematical requirements, namely existence and uniqueness. Therefore, should this theory exist, there would be only one of them. So we should say "the" Unified Field Theory. It is an important philosophical point that we are not attempting to make up such a theory, but to find it. If it had a twin, it would be a paradox.
The UFT as a Theory of Everything is an interesting postulate. It has been touted as such, but to take away the leeway, strictly speaking, it unites the theories of gravity, electromagnetism and quantum mechanics into one. (Strange is correct on that point). It may be that such a theory would include and explain biology or modern art, but that would be quite remarkable. However, it is believed that the UFT would explain everything concerning material or physical reality. Finding the boundary conditions of such a reality may prove to be a challenge.