# why is the Right Hand Rule in electromagnetism true?

198 views

Here is a description of the right hand rule – https://www.khanacademy.org/test-prep/mcat/physical-processes/magnetism-mcat/a/using-the-right-hand-rule

I understand THAT this is true, and have even directly seen experimental evidence that it is true, but what i cannot wrap my brain around is WHY this is true.

So please internet, why is the field always to the right?

In: Physics Because it’s defined that way. We could have just as easily built the mathematical structure such that there was a ‘left hand rule’ – all that we’d be doing is reversing some polarities. It depends on the charge under consideration – positive charges right hand rule, negative charges left hand rule. This all comes about because like charges repel and opposite charges attract. That it is a right hand rule is arbitrary and depend on what we have defined as positive. The definition of a positive charge and negative charge is arbitrary and it they was swapped you get a left hand rule.

The charge was defined back in the day it in a way. The charge particle was then considered to be positive and move from the negative to positive in a electrical circuit. This is decade before the electrons were discovered. They are the particle that move in a electrical circuit but the opposite way of what is defined as electrical current. If the electron charge was know a lot earlier the likely result is they would be defined as positive and we would use a left hand rule.

The question of why a electrical and magnetic field and charge particles interact that way is perhaps a question that is impossible to answer. Electo-magnetism is one of four fundamental forces in the universe. So the best you can get might just be that is how the universe works.
If there is a lower level explanation the question you just move the problem one step down. 