I had planned to spend some time this weekend trying to make sense of this new result on topological insulators, and maybe even write up the relevant paper for ResearchBlogging. Family life intervened, though, and I didn't have the time. I get enough of it to understand the basics of what's going on, but there's a whole lot I don't understand about topological insulators generally, so I'd need to do a bunch of reference chasing to get to something I can understand well enough to work back up to this week's Nature paper.
And, to put it bluntly, there just isn't that much reward for the work that would be required. While this is one of the hottest topics in condensed matter physics at the moment, very few people outside that area of physics care. And very few of the people who care read blogs (at least based on my impression of post traffic and comments). So while I feel like I ought to understand this field more, and reading up on this would be a good way to do it, in the end most of that work would feel wasted-- I'd spend hours writing a blog post that nobody would read or comment on.
So, this article is likely to end up on the big pile of stuff I ought to read and write up, but won't ever get to. Because this problem isn't specific to topological insulators-- it's a very general problem in physics outreach. If I write even half-assed stuff about particle physics or cosmology, people are all over that, but posts about my own field of AMO physics or condensed matter physics generally go nowhere. The same is true with regard to popular physics in general-- there are shelves full of books about arcana of particle physics and cosmology, but if you look for books that deal with lower-energy physics, most of what you find are textbooks. And good luck finding condensed matter physics on the Science Channel.
It's a vexing problem, particularly since research into topological insulators is vastly more likely to lead to useful, real-world applications than anything the LHC will ever observe. Which is not necessarily a statement about the technological relevance of topological insulators, but more a statement about the extreme irrelevance of particle physics. Yes, there's the warm fuzzy philosophical satisfaction of (potentially) knowing where the observable universe came from, but that and a dollar still won't get you a cup of coffee these days.
Some of the problem is just the usual fear of math. Condensed matter physics is a highly mathematical subject, and requires a great deal of apparatus to understand it. For good reason-- you're dealing with absurdly large numbers of particles in any macroscopic sample of material, and there's no way to explain what's going on in terms of individual particle trajectories. The action is all in collective effects and statistical approximations, and the language used to talk about it is highly abstract.
But then, it's not like string theory is algebra-based physics, and Brain Greene has sold a bazillion books. Some of the complex math is very similar-- both theoretical particle physics and condensed matter physics make a lot of use of symmetry transformations and the like. It ought to be possible to construct explanations for these systems that could work at the same level as the pop-level explanations of particle theory. Those don't seem to exist, though, both because nobody seems to write them, and because nobody wants to buy them.
I suppose there's enough money in condensed matter-- due to the many applications in industry-- that they don't feel that much need to do popular outreach. Less immediately relevant but more expensive fields need to rely on capturing the public imagination to ensure funding for their big projects, but fields that tie directly into industrial application can take a more relaxed approach.
But it's kind of maddening, from the perspective of someone who isn't a particle physicist or cosmologist, to see the ridiculously inaccurate view of physics presented to and held by the general public. The majority of the work done in physics is done on real systems involving stable particles, but you'd never know that from looking at the tv or the shelves in your local Barnes & Noble.
I haven't got the foggiest idea how to make people care about the physics the most physicists actually study, though.
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If you can't beat em, join em. Spread "ridiculously inaccurate" rumors that the condensed matter state could spread uncontrollably, crushing the whole Earth to the size of a golf ball. The fear will trigger public interest.
Urgh. All the way with you (although I'd actually love to read that post). My six-month bachelor research project was in complex fluids excited about it. You'd think other people would be as well, since it's, you know, very handy if you want to do stuff like clean oil out of water. But somehow it doesn't seem to interest people at all.
(On the other hand, when was the last time someone came up with a quack explanation of high temperature superconductivity? That must be the upside of being non-notorious: less people to take your theory, mangle it beyond belief, and then insist on you accepting it. Or at least reading. I don't envy the cosmologists for that.)
For me, the key in starting to like "non-extreme" physics was precisely that it's non-extreme. So cosmologists get to play with the entire universe, and particle physicists have the Tevatron... but complex fluids are in every fridge and condensed matter is the stuff that makes it possible to type this! I love being able to understand why the ketchup doesn't come out of the bottle. And maybe that's something we can use in popularisation as well.
Never underestimate the "pretty pictures" factor. People who talk about string theory/particle physics/cosmology/astrophysics get to bring in pictures from the Hubble and other telescopes about the large scale structure of the universe, or a piece of apparatus which doesn't look like a mad scientist's lab concoction, or if all else fails a picture of a Calabi-Yau manifold. For other areas of physics, this is much harder to pull off. Superfluidity researchers might be able to show off what helium can do below the lambda point, and a long carbon nanotube might be of interest, but wiggles on a graph aren't going to impress Joe Sixpack.
Several months ago I was curious about what "topological insulators" are (and why they're not the same thing as the quantum Hall effect), and I found this lecture by Shoucheng Zhang pretty clear and interesting.
I don't know what the answer is to making condensed matter physics more interesting to the public, but I wish it was! I went all the way through my physics education without ever learning it in any depth, and now I try to catch up in my spare time. It's an interesting field, just as theoretically amusing as particle physics, but with much more data. If I had read popular books about CMT when I was young, maybe I would have ended up there instead of particle physics.
Of course, these days all the string theorists are doing something at least vaguely resembling condensed matter physics, so maybe one of them will write a bestselling book about it.
On the other hand, when was the last time someone came up with a quack explanation of high temperature superconductivity?
My guess would be within the last week, somewhere on cond-mat, or maybe even hep-th. Unless you mean non-professionals coming up with quack explanations of high-Tc superconductivity.
Is it weird that I first thought "Oh boy! Chad's gonna talk about topological insulators!" and was slightly disappointed to find a post about popularizing condensed matter? But I'm probably not representative of your readership, since I'm actually going into condensed matter.
See, now you've gone and got me curious and I'm not a physicist. I'll start with wiki and see where that leads.
I would also like a post on topological insulators.
As for popularization one way to induce interest is to talk about some puzzles/challenges for example I would think that a post like "10 unsolved problems in condensed matter physics" would generate interest (assuming the problems can be made comprehensible). Talking about unsolved problems is also a good way to inspire someone to study a particular field.
Posts about how everything works as expected are usually less interesting.
I think there is lots of stuff cool stuff people could use to draw people into Condensed Matter. "Supersolid" Helium would be one. And when you are talking about pretty pictures, I find good STM pictures hard to beat. The public's imagination has also been peaked with the "invisibility" stuff coming out of Terahertz spectroscopy. Those were three examples off of the top of my head, but there are lots more.
I do think Chad might be onto something though, with the fact that CMP researchers are a little bit more relaxed with their connection to industry. It seems unlikely that funding for superconductivity, or nanoscale magnetism is going to dry up anytime soon and so the CMP community doesn't feel nearly as strong of a need to popularize it, which is a shame. Its such a rich field, and also the biggest overall in physics if I am not mistaken.
So, ironically, if I were the type of person that told you what to do on your blog, the topological insulator thign is one of the ones I woudl have forwarded to you as a suggestion, a while ago....
I lurk alot,
I'd love to hear more about topological insulators/AMO physics (and please don't skimp on the juicy mathematical details :) )
Play up the puzzle angle; the cosmology and quantum do this through the various headliner oddities.
I don't know what a topological insulator *is*. So there's a puzzle from the start! Answer that fast and lead into some puzzle about how they work or what they make possible.
Archimede's Principle is old hat on the face of it, until you ask people to apply it -- explain how a cartesian diver works, or (in the (in)famous? quiz) what the water level does in the pool after you move the scrap iron from the boat to the bottom of the pool -- and applying the old-hat Principle causes its meaning to unfold more clearly, and thus we see the world in new and interesting ways.
I agree completely with you, ultimately this is why I stopped blogging, I think this cuts across fields. I'd think that the natural audience for popular physics is people with some technical education, or at least interest in how things work on a reasonably detailed level. But, as much as I'd like that to be true, my impression is that this is not the bulk of the audience that reads blogs. In my field, most people would come for the "spiritual" stuff (plenty of that in quantum anything), or for the science fiction sounding stuff (plenty of that in nano-anything), or simply to argue with me (that last one is probably unique to my field...). As soon as I'd get just a little bit technical or detailed, complete silenceâ¦Maybe that is simply the wrong outlet, or maybe one has to be content with a smaller audience and carry on, I'm not in a position to give advice.
(On a side note, I would not go very far with the utilitarian argument you are making, it can be very easily extend to an argument against any sort of basic research.)
I do think Chad might be onto something though, with the fact that CMP researchers are a little bit more relaxed with their connection to industry. It seems unlikely that funding for superconductivity, or nanoscale magnetism is going to dry up anytime soon and so the CMP community doesn't feel nearly as strong of a need to popularize it, which is a shame. Its such a rich field, and also the biggest overall in physics if I am not mistaken.
To the extent that this is about research funding, I think you're right, CMP and optics and biophysics and other applied areas of physics don't need to worry about making their case and capturing the public imagination.
However, from an educational perspective it is unhealthy for the public to think that physicists only deal in quantum mysticism and the origin of matter and whatnot. They think we're philosophers with big equipment budgets, basically. I can't put a finger on the direct harm, but it just seems wrong.
Also, the irony is that while our high-level research is in no danger of losing support because of its technological relevance, at the undergraduate level we struggle to recruit majors because the typical conversation goes something like this:
Student: I'm really fascinated by physics and black holes and quantum mechanics.
Professor: Ever think of majoring in physics?
Student: Oh, no, that's cool stuff to read about and take an elective on, but I need to find a job after graduation. I'm sticking with engineering [or chemistry, or biology, or whatever].
So we've got a field that is of undisputed technological importance, and whose research funding is safe, but departments that try to teach it to undergrads are always short of students and sometimes threatened with closure because everybody thinks it's about the Meaning of Life, The Universe, and Everything rather than practical stuff. This is an unbalanced situation.
I know I said earlier that I'd be excited to hear Chad talk about topological insulators, but I also think that it would be much less exciting in reality than in imagination. Last time I asked a professor about topological insulators, I could not understand what it was or its practical applications--and I have a BS in physics! Making the subject interesting would indeed require a lot of extra work. I agree with Chad, writing about astronomy or particle physics generates far more interest with less effort, even if you don't specialize in those fields.
The part of CMP that I personally find glamorous is the heavy use of quantum mechanics. Maybe that's the angle that we should play up? Perhaps we could find the most success by talking about the basic science behind CMP rather than the cutting edge research.
I like Miller's idea. Condensed matter physics (well, a large portion of it) is all about quantum mechanics. Tell people that the same theory that they invest all this mystical meaning in is also the theory that describes all of the electronic gadgets in their houses. Will blow your mind, man!
Have teachers/professors introduce set theory earlier so as to make topology make sense in early calculus courses.
Meh. I wish.
Until then, Physics bloggers could introduce the basics of abstract mathematics in their writing. Sure, you'll turn a lot of people off, but those people were never on.
The popular interest in particle physics, quantum mechanics, and cosmology is aesthetic, not rigorous, consumed and treated in the same way as one might enjoy poetry. It functions as fiction, and if you give a real world, practical application, you actively turn off the sensibilités.
If you discuss science with any seriousness, you will have a small audience. That's the consequence of working in an abstruse field like physics, chemistry, cancer research, or mathematics.
That said, I would be interested in exploring my ignorance of physics via a post on topological insulators. The point is that you could correct any misconceptions and send me to better resources. Then, it's up to me. I have the advantage of a background in mathematics, though mostly algebra, not analysis, and even then, a serious understanding will likely be a tremendous effort.
I enjoy that sort of thing, but I guess that we can't expect a popular audience to do so.
You need to be the new Asimov writing his F&SF columns. The thing is, and I'm complaining and asking for somebody else to do work here ... one thing these kinds of fields (and I'd include physical chemistry here also) is consistency. You aren't going to get readers on you first or 10th article/essay. On your 50th though there will be interested people. That is what Asimov had going for him. And he talked about all sorts of esoteric chemistry in his columns over time. At a very simplified level of course. Anyway, that consistency doesn't happen with blogs very much.
I think I've seen you be dismissive in the past of repeating topics over and over, but I do think there is a place for that. This sounds perhaps a little too much like work though, so I don't really know how realistic it is. We all have only so many minutes a day.
If you do decide to do a post on topological insulators, start with the 2D case to explain how an insulator can have a conducting edge. Does anyone understand the quantum Hall effect? I sure don't. Then you can move into three dimensions and compare conduction on a sphere and on a torus with the usual hairball theory. (You can't comb all the hair neatly on a sphere without a cowlick or two, but you can on a torus.) That gets you into genus and the topology part. (I recently read Euler's Gem which is a history of topology, so I'll plug the book here.) Then you can explain why quantum mechanics lets the genus constrain the system. I'd love to understand this, or at least find out if I've guessed right.
It's kind of weird, but surfaces are a lot different from their containing volumes. I know in mechanics, all the stress is on the surface, but in quantum mechanics the surface-volume distinction gets even weirder. Aren't their plasmons, quantum surface states, or something that can conduct light along a surface?
Thanks to the quantum revolution, we're in a golden age of materials science, and we even have a clue as to what is going on.
Chad:
The Nature of Solids by Alan Holden. It's a bit dated (1965, Dover reprint 1992), and I can't vouch for how popular it was back in the day, but it seems to fit your description.
I'd pay for your explanation of band gaps to Emmy!
I have been thinking about this, and my latest hypothesis is one I came up with while reading a popular science book on astronomy and cosmology. It struck me how the author was clear about the fact that talking to people about astronomy is talking about our place in the universe. It talks to people's sense of identity, it's basically storytelling about what we are -- myth, if you will. It's very easy to make cosmology and particle physics part of a story about the two-legged ape who looks up from the ground and rises above himself by trying to understand the world (and perhaps also talk about how this leads to change his circumstances and make life better, even if that is very tangential to the main subject). That could be why these branches of physics are sexier than the things you mention above.
If I'm right, this could be a problem of storytelling, of putting atoms and semiconductors and stuff into a grand context.
Semiconductor engineering, nanotechnology, optics, molecular design, these are when the two-legged ape decided to take control of the very fundamental building blocks of everything around him/her and make magical things. An ape named Maxwell pondered long and hard before writing down some new symbols, and those who beheld the symbols realized that they could send sound and pictures around the world. Apes named Bohr and Einstein and Schrodinger Dirac and Heisenberg and Planck and others pondered mysteries from glowing gases and eventually wrote down symbols, and those who beheld the symbols realized that they could understand the building blocks of matter, and reshape them do their own ends.
Alex: I know, but now you need to go out and tell this story in popular science blogs, books, news and so on. In case you want people to care, that is.
Hmm, given that I'm right and this is what really works. Maybe cut down on the use of the word "ape" also ;-)
I COMPLETELY disagree with miller and alex's comments above. condensed matter physics is *not* all about quantum mechanics, far from it. for example, a HUGE amount of condensed matter research focuses on materials where QM plays absolutely no role, and thermal effects govern material properties... just look at complex fluids, soft matter, many structural materials, etc. there are many, many deep questions in soft materials, particularly those relating microscopic structure to overall materials properties, that have nothing to do with quantum.
If you want to make the idea of topological insulators easy to understand and have a kind of "wow"-factor, I have an idea for you.
Recently a group at MIT succeeded in creating a photonic system by analogy to the topological insulators**. The photonic analog is much more intuitive and therefore easier to appreciate. Imagine light that just won't reflect, even if you put a mirror in front of it, it just going around!
See this page http://ab-initio.mit.edu/~zwang/ces/chiral_edge_state.html for lots of nice pictures and animations, both from simulations and from experiment (reference to their nature paper can be found there too).
**: They create the class of time reversal broken topological insulators, such as Integer Quantum Hall effect. But the main ideas are very similar to the new class with time reversal symmetry.
If you want to make the idea of topological insulators easy to understand and have a kind of "wow"-factor, I have an idea for you.
Recently a group at MIT succeeded in creating a photonic system by analogy to the topological insulators**. The photonic analog is much more intuitive and therefore easier to appreciate. Imagine light that just won't reflect, even if you put a mirror in front of it, it just going around!
See this page http://ab-initio.mit.edu/~zwang/ces/chiral_edge_state.html for lots of nice pictures and animations, both from simulations and from experiment (reference to their nature paper can be found there too).
**: They create the class of time reversal broken topological insulators, such as Integer Quantum Hall effect. But the main ideas are very similar to the new class with time reversal symmetry.
I disagree that it's a particular problem for condensed matter physics. Most science is difficult to popularize on the basis of its own aesthetic principles. Seen any good chemistry popularizations lately? Engineering stories are even harder, because most of the issues cannot be understood without getting into details.
Cosmology/string theory is actually the exception to this trend, not condensed matter. Particle physics at merely high energies is not: what attention it has gotten recently traces to the tangible, shiny, and expensive machine known as LHC.
If it means anything (and I know I'm probably too late..) I care and I read your posts!
But I'm a graduate student, so probably not that statistically significant.
Hi Chad
Your post has certainly inspired me to think about launching my own blog that also covers condensed matter physics. I will try my best to cover cool topics such as topological insulators, plus other areas that also fit into my expertise as editor for Nature Materials.
Maybe you will find my blog interesting... the link is http://blog.joerg.heber.name
Joerg
I haven't read it and don't really know much about it (I just did a search after reading your post), but Anthony Leggett's "The Problems of Physics" adds condensed matter to the more common pop-physics topics in a book for non-specialists.