Tag Archives: academia

What if there’s nothing new?

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In the weeks after the folks at the Large Hadron Collider announced that they had found the Higgs, people I met would ask if I was excited. After all, the Higgs was what particle physicists were searching for, right?

 As usual in this blog, the answer is “Not really.”

We were all pretty sure the Higgs had to exist; we just didn’t know what its mass would be. And while many people had predictions for what properties the Higgs might have (including some string theorists), fundamentally they were interested for other reasons.

Those reasons, for the most part, are supersymmetry. If the Higgs had different properties than we expected, it could be evidence for one or another proposed form of supersymmetry. Supersymmetry is still probably the best explanation for dark matter, and it’s necessary in some form or another for string theory. It also helps with other goals of particle physics, like unifying the fundamental forces and getting rid of fine-tuned parameters.

Fundamentally, though, the Higgs isn’t likely to answer these questions. To get enough useful information we’ll need to discover an actual superpartner particle. And so far…we haven’t.

That’s why we’re not all that excited about the Higgs anymore. And that’s why, increasingly, particle physics is falling into doom and gloom.

Sure, when physicists talk about the situation, they’re quick to claim that they’re just as hopeful as ever. We still may well see supersymmetry in later runs of the LHC, as it still has yet to reach its highest energies. But people are starting, quietly and behind closed doors, to ask: what if we don’t?

What happens if we don’t see any new particles in the LHC?

There are good mathematical reasons to think that some form of supersymmetry holds. Even if we don’t see supersymmetric particles in the LHC, they may still exist. We just won’t know anything new about them.

That’s a problem.

We’ve been spinning our wheels for too long, and it’s becoming more and more obvious. With no new information from experiments, it’s not clear what we can do anymore.

And while, yes, many theorists are studying theories that aren’t true, sometimes without even an inkling of a connection to the real world, we’re all part of the same zeitgeist. We may not be studying reality itself, but at least we’re studying parts of reality, rearranged in novel ways. Without the support of experiment the rest of the field starts to decay. And one by one, those who can are starting to leave.

Despite how it may seem, most of physics doesn’t depend on supersymmetry. If you’re investigating novel materials, or the coolest temperatures ever achieved, or doing other awesome things with lasers, then the LHC’s failure to find supersymmetry will mean absolutely nothing to you. It’s only a rather small area of physics that will progressively fall into self-doubt until the only people left are the insane or the desperate.

But those of us in that area? If there really is nothing new? Yeah, we’re screwed.

A physicist by any other trade

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Physicists have a tendency to stick their noses in other peoples’ work. We’ve conquered Wall Street (and maybe ruined it), studied communication networks and neural networks, and in a surprising number of cases turned from the study of death to the study of life. Pretty much everyone in physics knows someone who left physics to work on something more interesting, or better-funded, or just straight-up more lucrative. Occasionally, they even remember their roots.

What about the reverse, though? Where are the stories of people in other fields taking up physics?

Aside from a few very early-career examples, that just doesn’t happen. You might say that’s just because physics is hard, but that would be discounting the challenges present in other fields. A better point is that physics is hard, and old.

 Physics is arguably the oldest science, with only a few fields like mathematics and astronomy having claim to an older pedigree. A freshman physics student spends their first semester studying ideas that would have been recognizable three hundred years ago.

Of course, the same (and more) could be said about philosophy. The difference is that in physics, we teach ideas from three hundred years ago because we need them to teach ideas from two hundred years ago. And the ideas from two hundred years ago are only there so we can fill them in with information from a hundred years ago. The purpose of an education in physics, in a sense, is to catch students up with the last three hundred years of work in as concise a manner as possible.

Naturally, this leads to a lot of shortcuts, and over the years an enormous amount of notational cruft has built up around the field, to the point where nothing can be understood without understanding the last three hundred years. In a field where just getting students used to the built-up lingo takes an entire undergraduate education, it’s borderline impossible to just pick it up in the middle and expect to make progress.

Of course, this only explains why people who were trained in other fields don’t take up physics mid-career. What about physicists who go over to other fields? Do they ever come back?

I can’t think of any examples, but I can’t think of a good reason either. Maybe it’s hard to get back in to physics after you’ve been gone for a while. Maybe other fields are just so fun, or physics so miserable, no-one ever wants to come back. We shall never know.

So what do you actually do?

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A few days ago, my sister asked me what I do at work. What do I actually do in order to do my job? What sort of tasks does it involve?

I answered by showing her this:

WhatIDo

Needless to say, that wasn’t very helpful, so I thought a bit and now I have a better answer.

Doing theoretical physics is basically like doing homework. In particular, it’s like doing difficult, interesting homework.

Think of the toughest homework assignment you’ve ever had to do. A homework assignment so tough, you and all your friends in the class worked together to finish it, and none of you were sure you were going to get it right.

Chances are, you handled the situation in one of two ways, depending on whether this was a group project, or an individual one.

Group Project:

This is what you do when you’re supposed to be in a group. Maybe you’re putting together a presentation, or building a rocket. Whatever you’re doing, you’ve got a lot of little tasks that need to get done in order to achieve your goals, so you parcel them out: each group member is assigned a specific task, and at the end everyone meets and puts it all together.

This sort of situation is common in theoretical physics as well, and it happens when different people have different skills to contribute. If one theorist is good at programming, while another understands a particular esoteric type of mathematics, then the math person will do the calculations and then give the results to the programming person, who makes a program to implement it.

Individual Project:

On the other hand, if everyone needs to submit their own work, you can’t very well just do part of it (not without cheating, anyway). Still, it’s not as if you’re doing this on your own. You do your own work to solve the problem, but you keep in contact with your classmates, and when you get stuck, you ask one of them for help.

This sort of situation happens in theoretical physics when everyone is relatively on the same page. Everyone works through the problem individually, doing the calculation and making their own programs, and whenever someone gets stuck, they talk to the others. Everyone periodically compares their results, which serves as a cross-check to make sure nobody made a mistake. The only difference from doing homework is that you and your collaborators write your own problems…which means, none of you know if there is a solution!

In both cases (group and individual), theoretical physics is a matter of doing calculations, writing programs, and thinking through thought experiments. Sometimes that means specific tasks as part of one huge project; sometimes it means working side by side on the same calculation. Either way, it all boils down to one thing: I’m someone who does homework for a living.