# How does theoretical physics advance?

1. Dec 9, 2014

### Ponderer

I've read about scientists such as Einstein who have advanced the field of physics. When Einstein was working on solving the grand unified theory, what were the obstacles? Was he trying to find patterns that could reveal something? Or did he have sufficient data, but solving certain math problems was a challenge?

I'm very curious. Thanks for any replies.

2. Dec 9, 2014

### Danger

Hi, and Welcome. I can't speak for any particular scientist. One of the best things to happen in working stuff into a viable theory is when theoreticians and observational scientists work back-and-forth with each other. ie: Sheldon postulates a new particle; Leonard whips a cyclotron out of his wallet and finds a living example of one, but the charge is off by a tad; Sheldon then alters his calculations to explain that; they retest...
Some of Einstein's ideas such as relativistic time dilation weren't physically provable until the space age.

3. Dec 9, 2014

### Ponderer

That must be nice to have people test your theory. I just can't imagine how they create such equations or where they even begin. Actually it just occurred to me that it would be interesting to see how E = m c^2 is derived. Has math software reached the level of being able to help theoretical physicist? My uncle used to tell me during his early days as a scientist how they would use these wooden gadgets to solve math equations. In don't recall exactly what it was. Perhaps one of those gadgets where they slide pegs around? It's been a long time since I went to school, but the calculator was a common acceptable tool.

4. Dec 9, 2014

### Danger

That would probably be a slide-rule (slip-stick in common usage). It's what I had to use in high-school. There's one little bugger running around here who collects them and loves them more than women (except for his lovely wife, of course). In fact, his avatar is a picture of one.
It's a pretty good bet that some lab rat or another somewhere will physically test every hypothesis that is made public, even if there is no contact with the theoretician. It's a kind of natural symbiotic relationship, like pilot-fish and sharks or directors and actors.

5. Dec 9, 2014

### Staff: Mentor

$E=mc^2$ may not be the most logical starting point in the logical progression of special relativity.... it's more of a destination. However, Google will find you some nice derivations and SR doesn't have to require a lot of math; there are quite good presentations that use nothing more than high school algebra.

6. Dec 9, 2014

### Ponderer

Thanks for the advice. Google took me to youtube where there are a lot of amazing videos that describe how to derive Einstein's equations. It's like being at the candy store.

7. Dec 9, 2014

### mrspeedybob

Feynman starts addressing your question at about 16 - 17 minutes in and continues with it the rest of the lecture.