# Given Electro-Weak force why state four forces.

1. Jul 21, 2014

### hankaaron

Since the electromagnetic and the weak force unify at high energies, why do physicist continue to count four fundamental forces? With that kind of thinking why not break symmetry with the electromagnetic force and say there are five fundamental forces?

2. Jul 22, 2014

### Simon Bridge

It is possible to find a unification for any pair of the four fundamental forces - which one is correct?
Basically we still count four because we still use four.

This is somewhat different from the E-M force unification, because of the way in which EM was unified.

3. Jul 22, 2014

### kith

If you have only an electric field in your lab frame of reference, you can always transform to other frames of reference where a magnetic field is present by a Lorentz transform. So if one accepts that all inertial frames are on equal footing (principle of relativity), the magnetic and electric aspects of the electromagnetic force cannot be separated.