Quick question about theoretical physics research

[osnarf]

What is it?

By that I mean what does it consist of? My understanding is that experimental physics research is performing experiments and recording observations, then drawing conclusion from that.

Is theoretical physics research then just locking yourself in a room and posing problems and trying to solve them? Or is it usually more of a group of people discussing and trying to form new ideas? Or ... ?

If you could answer the same question about mathematics research, I'd be equally appreciative. Thanks again.

 

[ashishsinghal]

Research is about learning more about physics. Do it as you wish.

 

[Monocles]

I'll try to answer, but I'll add a disclaimer than I'm an undergrad who only spent one summer working in mathematical physics. The way I worked (and my adviser seemed to work) was to learn about an unsolved problem and then start asking yourself questions like a homework assignment. Well, what happens at this limit? What happens at that limit? What happens if there is spherical symmetry? This phenomenon seems to work intuitively - let's try to prove it. Etc. Working felt like a never-ending homework assignment where you had to come up with your own questions. So that is my brief experience - I would expect other theoretical/mathematical physicists work in different ways.

 

[Frion]

What is there even left to do in theoretical physics? It's just so hard to imagine given that media exposure has consisted exclusively of string theory and black holes.

 

[cgk]

The mistake here is to assume that theoretical physics consists exclusively of theoretical particle physics and cosmology. These areas only make up a tiny fraction of the actual physics (and theoretical physics) canon, it's just that they have a huge exposure in the public.

So what is theoretical physics? There is no Theoretical Physics[tm] (except for these two mentioned fields, because in these two fields experiments and real world problems are scarse). In general, if you take *any* branch in physics dealing with an area of problems, say condensed matter, materials, semiconductors, biophysics, plasmas, detector and instrument design, etc, you will find some people concentrating on using or building experiments and equipment (these are the experimentalists) and other people concentrating on doing calculations (these are the theorists). In large research areas, you will have people working exclusively computationally to support experimentalists, and in even larger fields you may also have people working only on theories and methods to support other theories and methods and so on.

In short: What theoretical physicists are doing depends on the area they work in; there is no "theoretical physics" per se. Some theorists may research ways to improve the lenses for electron microscopes, while others work on methods to calculate properties of solids or molecules, and yet others work exclusively on important model systems hoping to learn mechanisms behind real world behavior of complex systems (e.g., in super-conductivity). There is not much overlap.

 

[Nabeshin]

What is there even left to do in theoretical physics? It's just so hard to imagine given that media exposure has consisted exclusively of string theory and black holes.

Even within these narrow areas there are still so many open questions. The media likes to portray string theory as an actual theory, but it's not. It's much more just a loose collection of ideas at this point, with virtually no predictive power. Similarly, black holes have quite a rich theoretical framework but we're only just in the past few years starting to discover how they interact with each other in non-trivial cases. (The primary reason for this is because the equations are so complicated they need to be solved numerically, and only now do we have the computing power and algorithms to do so successfully).

 

[osnarf]

Interesting, thank you for clearing it up. Kind of what I expected, but not exactly.

I asked this with another question in mind, but it was more appropriate in the career guidance forum (I think):
https://www.physicsforums.com/showthread.php?t=478374"

 

[Frion]

Thanks for the good answers to my question. If I may hijack this thread, I'd like to ask a bit more about theoretical physics.

1. If mathematical physics considered theoretical physics?
2. How quickly are important theoretical questions generated in physics? By important, I guess I mean something like the physics equivalent of Hilbert's problems in terms of relative importance. How many important questions came up in, say, the last 20 years, just as a very rough estimate?