Which branch...

[Royston]

I'm approaching the end of my first year physics degree (part time, so second year of study) and I aim to go as far as Phd level. My question is, there's a lot of talk on here of 'string theory is good because of blah blah blah', and 'string theory is bad, because of blah blah blah', from experienced and inexperienced members. I can understand why experienced members may find views on string theory, perhaps, sometimes insulting, because the views are from people who don't have the knowledge to give a truly informed opinion.

 

However it's up to the authorities in string camp, and say (an example) LQG camp, and whatever other branch you care to mention, to inform people in my position, what is the area of interest I should be focusing on, when eventually I wish to study for my Phd.

 

From my point of view, I try and grab as much info on different opinions concerning the (somewhat) segregated branches of theoretical physics, to try and ascertain what I should be planning to concentrate my study on. This is all I have, I have the basics to intermediate in applied maths / physics / chemistry / biology et.c As well as all the further reading, and learning on here. However, I don't possess the level of knowledge to understand highly technical explanations, that would favour one theory over another, I have hand wavy ideas, but it's not enough. I've heard lots of convincing arguments, primarily about testing said theories, and I'm now at a loss whether there's sources of bias, or uncertainty, or perhaps bitterness fueling the whole string debate.

 

So lets suppose I've completed my masters today, and I now have to make a choice between what area of research I wish to concentrate on, I've heard arguments on both sides, advocating string theory, and slamming string theory. What really should I be choosing, string or no string...and why ?

 

EDIT: If it's impossible to answer, please say.

[Realitycheck]

IMO, string theory is a fad. Stick to the fundamentals and play with the fringes. The simpler a theory is, the more it satisfies all of the rules, but doesn't really define anything, ie. the actual atoms showing up on the electron microscope. This is the way I see string theory. Why categorize existence as atoms, compounds, and quanta, when you can just say that it's all nothing but little stringy things?

 

Of course, this is from the frame of reference of someone who knows very little about string theory, just because it smacks of oversimplicity so much. Maybe someone will correct me on this. Nevertheless, I would still stick to the classical core that the mainstream espouses.

[ajb]

I would not set your heart on studying string theory or particle theory in general as it is such a competitive area.

 

If you want to do "fundamental physics" then you should apply to all groups that are open to you that study quantum field theory, string theory, cosmology, HEP phenomenology and related mathematical topics. Apply everywhere and have a backup plan. To a large extent is will not be up to you to decide if you work on string theory or not, but upon which university accepts you and the supervisors.

 

Without a very good first in your degree you will find it very difficult. I was forced to do get a MSc (I got a distinction) and still I was unable to work on particle theory directly; I study the mathematical framework of classical and quantum theory.

 

Other areas you should consider are theoretical condensed matter physics and statistical mechanics.

 

IMO, string theory is a fad.

 

A 30 year old fad!

[BenTheMan]

This is, of course, classic.

 

IMO, string theory is a fad...Of course, this is from the frame of reference of someone who knows very little about string theory

 

Soccer is a terrible game. I've never played it, and I've never seen a full match, but nonetheless it's a terrible sport.

 

Sigh.

 

Snail---ajb may be a bit of a pessimist when it comes to these things, but he is right---string theory is a highly competitive field. You will have much time to decide what kinds of things interest you, and during those discoveries, you will decide what you want to do.

 

If you DO decide on strings (it is much more than a fad, I can assure you), then keep an open mind as to which programs you go to. If your only desire is to study string theory, then you may be better off going to a lesser known program---there will be less competition for spots in the theory group, and your advisor may not be as well-known. This will mean that it may be difficult or impossible for you to find a post-doc, and will probably mean that you won't be doing physics past your PhD. This is ok, because even if you go to a very good grad school (like Princeton or Stanford in the US), you still probably will end up leaving physics in the long run---I have friends in finance, AI R&D, and software engineering, all who have PhD's in string theory.

 

Another good option is to do particle phenomenology or cosmology. There will be very much interest in these fields in the coming decade, with the LHC opening up in Switzerland. You could also try to do cosmology---the Planck satellite is the next world-wide collaboration, and there will be many new and interesting insights in to things like inflation and such. I think that there may be less competition in these things because many students choose to do string theory instead.

 

This is all assuming you want to do theory. You will know that you want to do theory when you take your first advanced mechanics course---this is the trend that I've noticed, at least...if you really like classical mechanics, then chances are you'll like theory.

 

Good luck!

 

So after rereading your original post, I have realized that very little of what I said actually applies to it.

 

Strings vs. LQG. Got it. Do strings. Like it or not physics is trendy---that is, people tend to follow trends. The theory departments at most universities do not have any LQG researchers, but they do have one or two string theorists. This means that there are more opportunities to DO string theory, both in grad school, and afterwards when you look for a post doc.

 

And by no means does doing one mean you can't do the other---this is a misconception about grad school. You are not locked to your thesis topic for the rest of your life. If you do strings, there's no reason why you can't read LQG papers if you're interested in them---who knows, you may find something that everyone else has missed.

[Royston]

I would not set your heart on studying string theory or particle theory in general as it is such a competitive area.

 

I must admit I didn't realize it was still very competitive in the UK, not the standard, but the number of students.

 

If you want to do "fundamental physics" then you should apply to all groups that are open to you that study quantum field theory, string theory, cosmology, HEP phenomenology and related mathematical topics. Apply everywhere and have a backup plan. To a large extent is will not be up to you to decide if you work on string theory or not, but upon which university accepts you and the supervisors.

 

I realize I'm completely tied by my performance, and the positions available...I think I was over estimating the influence string theory had on other fields, hence my question. Overlooking the numerous specialized areas in QFT, string theory, cosmology et.c the areas of research (I thought) are geared towards falsifying theories such as string, so I thought this may have a heavy influence, whichever field I may end up in.

 

Without a very good first in your degree you will find it very difficult. I was forced to do get a MSc (I got a distinction) and still I was unable to work on particle theory directly; I study the mathematical framework of classical and quantum theory.

 

Thanks for the advice. I'd personally be more than happy just to pass my degree, plus what I aim for, and what actually happens are obviously different. It was more a hypothetical question...i.e if I were given the choice.

 

Other areas you should consider are theoretical condensed matter physics and statistical mechanics.

 

I'll look into it, thanks.

 

EDIT: BenTheMan, thanks as well...that's all very useful information.

[Martin]

... If your only desire is to study string theory, then you may be better off going to a lesser known program---there will be less competition for spots in the theory group, and your advisor may not be as well-known. This will mean that it may be difficult or impossible for you to find a post-doc, and will probably mean that you won't be doing physics past your PhD. This is ok, because even if you go to a very good grad school (like Princeton or Stanford in the US), you still probably will end up leaving physics in the long run---I have friends in finance, AI R&D, and software engineering, all who have PhD's in string theory.

 

Another good option is to do particle phenomenology or cosmology. There will be very much interest in these fields in the coming decade, with the LHC opening up in Switzerland. You could also try to do cosmology---the Planck satellite is the next world-wide collaboration, and there will be many new and interesting insights in to things like inflation and such. I think that there may be less competition in these things because many students choose to do string theory instead...

...

 

this agrees with what i've picked up, based more on anecdotal evidence, not much in the way of reliable statistics.

 

I wouldn't suggest anyone look into cosmology unless they already love the subject (in which case they don't need my advice) but it's taking a growth spurt.

 

I don't think that when (if) Snail gets to grad school the issue will be Loops versus String.

 

Let us say it is 6 years from now, in 2013. We have a Mr. X, in the UK, who starts thinking seriously about what PhD program.

 

It is not necessarily Snail. Snail could have gone off into CONDENSE MATTER physics, or very low temperature, electronics, laser-optics, atmospheric and climate modeling, quantum IT, super-microscopes----he could have gone TWENTY DIFFERENT WAYS.

 

But for sake of discussion let's say we have this guy in UK, in 2013, who wants to specialize in some kind of theoretical quantum gravity/unification physics.

 

Hmmm. I don't know. Have the feeling the issue will not be Loops vs. Strings---at least the way we picture that choice now.

 

I can see trends though. I can see cosmology getting hot. And I see a regular trickle of cosmologists moving over into quantum cosmology.

And I see a gradual shifting in the list of INVITED SPEAKERS at the major international conferences.

 

the one going on right now in Sydney Australia, called GRG 18, is indicative.

[BenTheMan]

I wouldn't suggest anyone look into cosmology unless they already love the subject

 

Out of curiosity, why? I think cosmology is the place to be if you want a job.

 

Well, that and biophysics. I think the next 30 years or so are going to be HUGE for biophysics. Probably some Nobel Prizes to be won...

[Martin]

Out of curiosity, why? I think cosmology is the place to be if you want a job.

 

Well, that and biophysics. I think the next 30 years or so are going to be HUGE for biophysics. Probably some Nobel Prizes to be won...

 

You have a point, Ben. I was thinking of biophysics too and then decided I wouldnt mention it because maybe it is more connected with biology, genetics, biochem---I wasnt sure it would be taken as "real physics" by the people in the discussion. (in a sense I think biophysics is one of the keys to solving problems of energy, resources, climate---a strategic branch of science)

 

about three blocks from here is the Melvin Calvin lab. he figured out photosynthesis. if you could improve photosynthesis and harness it to do new jobs that would be something. I walk past it every time I go for the 51 bus.

 

=============

 

but when it is a theory PhD, as a general rule (just my own private attitude) I tend not to advise anybody to go into a field that is not already a passionate obsession, because I don't see how their work can do humanity any good if they don't love it.

 

they might get a job, even a good job, by being smart and hardworking, in some branch of theory

[abskebabs]

You have a point, Ben. I was thinking of biophysics too and then decided I wouldnt mention it because maybe it is more connected with biology, genetics, biochem---I wasnt sure it would be taken as "real physics" by the people in the discussion. (in a sense I think biophysics is one of the keys to solving problems of energy, resources, climate---a strategic branch of science)

I for one certainly don't take a negative view of biophysics, and I find the mention of such "real physics" actually amusing. Doesn't everything in the natural sciences involve physics(admittedly rhetorical question:eyebrow: )?

More seriously, I find the nonlinear and chaotic phenomena that are described everywhere in nature highly interesting, and I think a lot of the more advanced biophysics research is based roughly around this area. I also find interesting highly speculative theories about DNA, RNA and protein messenging via modulated light solitons, as well as the idea of a quantum brain but thats another story.... Guess those ideas just capture the imagination.

 

And that would be the key message I would suggest to you Snail. Even though I am even further from the point of taking a Phd than you, if I were to pick a subject it would have to be along the lines of something that I pondered or thought I had some rough, sketchy kind of inspiration about(my words betray me here, I don't think I can quite describe what I mean).

 

I can only explain by parable I suppose. When learning about thermodynamics and entropy but also about probabillity, I found it amazing how aspects of probabillity theory manifest themselves in the physical world over time, and make up the nature of the 2nd law of themodynamics. At the time I had sketchy rough ideas, but I am sure with a lot more hard worked mathematical skill, I could have pursued and found something in the mumblings through my head. Maybe...... I may well be talking out of my *** but thats kinda the way I felt and thought.

 

I would suggest if you ever had these kinds of feelings about a specific field or area of study then I would advise going for it. As for the practicalities of getting a job and careerwise.... I don't think I can give advice; I gave up a course and lucrative career in Chemical Engineering to study Theoretical physics:-p (and I'm glad I did too).

[Realitycheck]

 

 

 

Soccer is a terrible game. I've never played it, and I've never seen a full match, but nonetheless it's a terrible sport.

 

 

I've never really been much of a soccer fan either, but thanks for the input.

[ajb]

I didn't want to sound pessimistic, but realistic of the situation at least here in the UK. Not enough PhD places, too many students and little funding.

 

Because of that you will need as well as good undergrad results a lot of drive.

 

As for the influence of string theory, I think it has had a lot of influence on theoretical and mathematical physics especially HEP theory, QFT and geometry.

[BenTheMan]

The situation may be slightly different in the states, ajb. Maybe not at the top top tier places, though---I got my master's degree at Baylor (pretty much bottom tier) and amd at Ohio State for my PhD, which is top 25 or so.

[Royston]

And that would be the key message I would suggest to you Snail. Even though I am even further from the point of taking a Phd than you, if I were to pick a subject it would have to be along the lines of something that I pondered or thought I had some rough, sketchy kind of inspiration about(my words betray me here, I don't think I can quite describe what I mean).

 

You've pretty much summed up my thoughts, and it's the fundamentals and possible connections between fundamental theories that constantly keep me up at night....this may seem rather pretentious, because I don't hold the technical know how, but a lot of my time is spent, quite literally, sitting in the back garden and pondering on the fundamentals, and how they are part descriptions of some unique and not yet considered view of nature...yeargh, that really does sound pretentious.

Martin summed up what this thread was really about.

So really, it was a hopelessly naive question, not only that, I came across as though I presumed I had what it takes to reach PhD level, which really wasn't what I intended...so I apologize if that caused offence to anybody.

 

Taxi for Snail

[BenTheMan]

but a lot of my time is spent, quite literally, sitting in the back garden and pondering on the fundamentals,

 

Why don't you spend time learning the physics you are studying, before trying to understand things more deeply?

 

Don't get me wrong, it's great that you're interested in things like htis. But if you spend all of your time pondering the fundamentals, you'll never actually understand anything. Like Pink Floyd says---``How can you have your pudding if you haven't had your meat?'' Or like Feynman said---``Shut up and calculate.'' You have to be able to CALCULATE things before you can understand them at any deeper level---it's like trying to go to the Olympics without actually training.

 

It's never too early to start learning these things, because no matter who you are, or how much you study, or how much you want it, there is another person who wants it more, who studies harder, and who is trying to get the same job or PhD slot that you are.

[fredrik]

I tend not to advise anybody to go into a field that is not already a passionate obsession, because I don't see how their work can do humanity any good if they don't love it.

 

This sounds like great advice to me.

 

Snail, asking for opinions is good, but to speak for myself I would under no circumstances taken anybody elses advice on anything like this, unless I could stand up for it on my own. If I did, I would have done so way back I might have done string theory today. But I just couldn't.

 

As with many levels of education people do it for many reasons. Some people just want a good job, some people love the subject and barley has the formal "carrier part" in their plans. I don't know what plans you have but if you can, broaden yourself in all fields of life until you can find your own answers pointing you one way or the other.

 

Like Martin also mentioned, neither life nor physics end if you don't get a academic carrier. I really love physics and philosophy but I made the choice to not go the academic route at all for various reasons. Not because I couldn't, I had top grades, but because the politics of academic reality seemed unacceptable for me at the time. I didn't spend much thinking of carrier plans until the last years, I just wanted answers, and the answers I received during asking the carrier questions, made me change direction.

 

But I have a good life, a job outside the academics in the measurement technology business. And best of all is that I have my interests left uninterfered with. I do exactly what I want, and I do not have to allow any constraints get in my way (except time constraints, but that only encourages me to optmize the approach). Of course beeing a hobby projects extends over longer periods, but that's not bad, because it gives you time to ponder in between, if you like that

 

My personal goal is not recognition from others becuse I'm so "clever", all I want is to understand the world, and wether that is best done in the academic world or not, may be individual. The rest is just plain normal life we are all constrained to.

 

/Fredrik

[Royston]

Why don't you spend time learning the physics you are studying, before trying to understand things more deeply?

 

I agree, it was really in response to abskebabs, spending a lot of time was probably a slight exaggeration, but if you asked me 'what rocks my world', it's meditating (for want of a better word) on the principles and possible relationships of the fundamentals...I don't see any problem at thrashing out ideas, that could possibly be used, or disregarded later on.

 

Going back to the OP, I was really concerned with should I start on further reading / study outside my degree, in a particular field. This now appears to be rather fruitless, my main concerns now, are getting my mathematical ability to a level that I could produce my own theoretical papers, and obviously making every effort to attain a good grade for my degree. That way, whatever the field of physics is doing in X amount of years, I wouldn't of spent a lot of time chasing the ideas of a particular field e.g string. I realize now, I was completely jumping the gun, and whatever path I take, it's my technical ability that really needs attention, so I can start calculating my pondering (that is what I'd really like to do), whatever career I may be doing at the time.

 

I realize this may all sound far too hopeful, and naive, but theory is really what I'm interested in. I'm completely aware that I may end up with no results whatsoever, like Fredrik, it may end up just as a hobby, which personally would be great...I can set my own deadlines

 

However, this has all been invaluable advice, so thanks all for your responses.

[fredrik]

I realize this may all sound far too hopeful, and naive, but theory is really what I'm interested in. I'm completely aware that I may end up with no results whatsoever, like Fredrik, it may end up just as a hobby, which personally would be great...I can set my own deadlines

 

I see your thinking but I don't think of it as "just a" hobby with no results, in the sense that a hobby is definition less serious than work. A hobby you do out of love and passion for free or you even pay for it, employed work you do for money becauase you need it. If you can get both the passion and the money, that would be great of course. But if it's a choice, then I made mine. I did however take a brake from physics thinking for 10 years, but I did other toying and modelling meanwhile, that actually brought me back to physics from a completely unexpected angle. I've tried to broaden my views and I have to say that a brief dive into biology was the best damn thing I've done for a while. It really does bring physics into a new light for me. I have collected inspiration.

 

Of course if I was born rich, there is no way on earth I would be employed anywhere. I could do full time research and still get time for other things and pay my bills.

 

Of course experimental disciplinces is another story because the labs you need access to.

 

Other will have to deny this, but my information on whihc I acted, was that at least for many years I wouldn't have had to any research anyways, I'd have to do other peoples research. That is - trying to answer other peoples questions. Some problems are I think also hard to solve in that environment, in particular those that go against the mainstream. Convinving your alikes is easy, but to convince a doubter takes more work, and politics. Perhaps at the point where you are a respected professor you get more freedom. These "issues" has nothing to do with what "physics" is for me, and make the choice easy. But I think this depends on what you want to do. I didn't feel that I fitted in any of the standard approaches. If you do, there isn't a problem.

 

The other fear I had was that beeing force to answer other peoples questions in physics, would compromise my own brain. If I was going to see the reasearch as just another "job" I would probably for this reason be better off working with something different.

 

/Fredrik

[Royston]

I see your thinking but I don't think of it as "just a" hobby with no results, in the sense that a hobby is definition less serious than work. A hobby you do out of love and passion for free or you even pay for it, employed work you do for money becauase you need it. If you can get both the passion and the money, that would be great of course. But if it's a choice, then I made mine. I did however take a brake from physics thinking for 10 years, but I did other toying and modelling meanwhile, that actually brought me back to physics from a completely unexpected angle. I've tried to broaden my views and I have to say that a brief dive into biology was the best damn thing I've done for a while. It really does bring physics into a new light for me. I have collected inspiration.

 

Well I have a 'passion' for music, I own a production studio...but I still consider it a hobby i.e I'm not in it for money or success or any other reason than just to write music. I have the same attitude with physics...I only stated 'no results', because I'm not going to sulk if I don't accomplish anything new e.g I'm serious about music, but I'm not serious about a success in music (if that makes sense.) I find the field of physics absolutely fascinating, and most important for me is having the ability to manipulate ideas i.e 'shut up and CALCULATE', I would consider a career in a scientific field as a very good added bonus.

 

For instance the university I'm with had a team of fifteen helping with the Cassini-Huygens mission, that would be a dream to work on, and if I'm lucky enough to get involved in such a project then great. For me, the career isn't so important, I just wanted to know, if I really want to be serious about theoretical physics, who should I be listening to, and going by the responses so far, it's a case of playing it by ear, and working very hard.

[BenTheMan]

I realize now, I was completely jumping the gun, and whatever path I take, it's my technical ability that really needs attention, so I can start calculating my pondering (that is what I'd really like to do), whatever career I may be doing at the time.

 

It's never too early. Do the work you need to do for your classes, and try to really understand the physics. It may help to write a set of notes as if you were actually giving the courses that you're taking.

 

You can always pick up the books from your next year's classes and start reading them---deriving every equation, and understanding every statement in the text.

[Xerxes]

It may help to write a set of notes as if you were actually giving the courses that you're taking.

Forgive my uninvited bolding, but I think this is great advice. For my sins, I subscribe to another couple of fora, where I try to "teach" what I have recently leaned. It really does test your understanding, when neophytes ask seemingly simple, but actually penetrating questions, likewise when experts challenge you for proof of your assertions.

 

Don't get me wrong, I am an experienced teacher at grad level (not in physics or math, though). But when students come to me, as they frequently do, begging for a place on a PhD programme, I always ask the same question: do you really believe, deep down, that you will be in the top 10th percentile of all (mostly worthless) PhD.s given out these days? Otherwise, forget it; you'll end up being a PhD car-parking attendant, or worse, a lab-technician