How to spot bogus science

There is a great, free article in the Chronicle of Higher Education from back in 2003 that has just come to my attention, about how to spot bogus science. The article is by Bob Park, who writes a weekly "What's New" column that used to grace the APS webpage.

This is an important read, particularly as there seems to be a steady flux these days of news items that seem pretty weird to me. For example, these folks are a bunch of cold fusion advocates, who last week put out a big press release about how happy they are that Martin Fleischmann is joining their product development team. For another example, take this announcement by the European Space Agency that their researchers think they've spotted a funny gravitomagnetic effect near rotating (low Tc) superconductors. The data look pretty marginal to me, and I think it's pretty indicative that on the one hand they put out a big, glossy press release, while on the other hand they submitted the paper to Physica C. I don't want to knock Physica C too badly, but they aren't exactly a high impact journal. At least the ESA researchers are using the peer-reviewed literature, though, and seem to be reasonably careful. They need to be, though - they're claiming big deviations from general relativity, and extraordinary claims require extraordinary evidence.

Wow - a really surprising result!

The cover story on the latest issue of Phys. Rev. Letters is quite surprising! A group in Italy have performed what a colleague of mine called a "hero experiment": they've taken linearly polarized light, and passed it through a 3 m long ultrahigh vacuum cavity in a rotating 5.5 T magnetic field. The shocking result is that they observe that the polarization of the light rotates because of the magnetic field. Basically they've measured a magnetic dichroism of vacuum. This is unexpected, and ordinarily it really shouldn't happen - it implies that the photons from their laser are interacting in a very nontrivial way with the (virtual) photons that make up the magnetic field. One way this could happen would be via a two-photon scattering process involving a never-before-seen neutral, spinless, very low mass particle. The paper is also remarkable for being the only PRL I've ever seen that's over the four page length limit of the journal, and for appearing without some enormously overblown marketing in the form of press releases.

This could be a very very big deal if confirmed. There is already one idea for an independent test of this. I would imagine that it would have major astrophysical consequences, too. After all, the hypothesized mechanism would lead to an effect quadratic in magnetic field, and the fields around astrophysical objects like neutron stars can be millions of times bigger than the field used in this experiment....

This week in cond-mat

Slightly delayed because of the joys of grant proposals, here is this week's installment of my quasi-periodic snippets of things I find interesting on the arxiv preprint server....


cond-mat/0603598 - Siemons et al., Origin of the unusual transport properties observed at hetero-interfaces of LaAlO3 on SrTiO3
This paper is interesting for a couple of reasons. First, the author list includes some luminaries in the field, including Ted Geballe, Mac Beasley, and Walt Harrison. They're all extremely nice guys, and Walt literally wrote the book(s) on electronic structure calculation methods. It's great that these folks are not just still active, but really pushing new ground, at a point in their careers when many full professors decide to kick back. Second, this paper reports data on a relatively new material system, a heterojunction between two oxide materials. Like the GaAs/AlGaAs case, the conduction band offset between the two materials leads to the formation of a potential well right at the interface, so that electrons can be trapped there in a two-dimensional layer. This result studies electronic transport in those layers, and tries to address the question of where the free carriers come from, given that the materials are ideally not doped.

cond-mat/0603482 - Pickett, Design for a room temperature superconductor
Bonus points for the provocative title. This paper (part of a commemorative volume in honor of Vitaly Ginzburg), looks at MgB2, a superconductor that is not a copper oxide, but nonetheless has a transition temperature of nearly 40 K, and tries to argue from that material what would be necessary to have (phonon-mediated) room temperature superconductivity. Thought provoking, and with references to good MgB2 literature for those interested in how that material was discovered to superconduct at the shockingly recent date of 2001.

APS March Meeting

No cond-mat update this week. I just returned from the March Meeting of the American Physical Society, that annual opportunity to get together with 7000 of my closest condensed matter physics colleagues and stay in over-priced hotels with malfunctioning wireless internet access. The meeting was good - I'll mention just a few observations:

• There was a particularly nice session on the recent transport experiments in graphene that I've mentioned in previous posts. The talks were interesting, and there were rumors of cool new data not yet in print (i.e. observation of the quantum Hall effect in graphene at room temperature (!!) and 30 Tesla).
• There was an invited session on topological quantum computation with a couple of talks that were almost utterly incomprehensible to the nonspecialist.
• The fire marshals kicked a bunch of people out of a ridiculously small room housing a single-molecule electronics talk, and closed the door right in the face of a Nobel laureate, who took that with good grace.
• Speaking of single-molecule devices, there continues to be lots of interest and lots of effort in that area - a very exciting topic I should write more about later.
• Apparently, if you're a big enough name in a given field, you can coin new vocabulary and assume that everyone will figure out what you mean.

I'll write more about some science later.

This week in cond-mat

Here's a couple of preprints that I've found interesting in the last week. Note that I'm not going to be surveying the published literature as much, since there are other resources such as the Virtual Journal of Nanoscale Science that do an excellent job of that (though they miss papers in ACS journals, which increasingly contain results at the border between chemistry and condensed matter physics).

cond-mat/0603173 - Manfra et al., Reentrant anisotropic phases in a two-dimensional hole system
I'm not writing about this one just because Mike Manfra and I used to share an office at Bell Labs. Two-dimensional electron gases (2degs) have been a workhorse physical system over the last 25 years, showing a number of fascinating many-body pieces of physics, including the integer quantum Hall effect (which has led to the definition of the standard Ohm!), the fractional quantum Hall effect (a demonstration of a correlated electronic state that has excitations with fractional quantum numbers, including fractional charge), apparent zero-resistance states under microwave illumination, and interlayer quantum coherence in bilayer electron-hole systems. Another weird effect observed recently is the onset of big anisotropies in the electrical resistance of such 2degs in very clean material at very low temperatures. The explanation for this spontaneous anisotropy is generally thought to involve the electronic system breaking up into some kind of stripes. With the recent development of new high quality two-dimensional hole systems, now one can test this idea. In the new cond-mat paper, Manfra et al. find that the anisotropies are very different in the hole system than the electronic analog, and discuss how details of the single-electron states (like the presence of strong spin-orbit scattering in the hole case that is absent in the electron case) can matter greatly.

cond-mat/0603108 - Badzey and Mohanty, Coherent signal amplification in bistable nanomechanical oscillators by stochastic resonance (also Nature 437, 995 (2005)).
Stochastic resonance is a neat phenomenon, when nonlinear systems can sometimes exhibit improved signal to noise when additional noise is introduced deliberately(!). This paper is a cute implementation of this idea, using bistable nanomechanical resonators as the nonlinear element. When you think about it, bistability (the resonators seem to have two competing, well-defined oscillatory states, one with high amplitude and one with low amplitude) is about as nonlinear a response as you can get. While some of this group's earlier work with these resonators has engendered some controversy, this paper is very pretty.

HIgh Tc: where are we

As I said in my previous post, Nature Physics has run a fascinating piece surveying a number of theorists about the current state of the high Tc problem. I encourage you to read it, and I'll summarize very briefly for those without access to the journal. Things that everyone seems to agree on:

• The symmetry of the superconducting pairing is d-wave.
• The parent compounds of the high Tcs are "Mott Insulators". In the absence of strong electron-electron interactions, these materials would be metals; however, strong on-site repulsions on the coppers (so that no copper site d-orbital can be doubly occupied) lead to insulating behavior, and antiferromagnetic ordering at low temperatures.
• The normal phase above Tc for the optimally doped compounds is really weird. It appears that the normal concept of quasiparticles fails there. When superconductivity is killed by whopping huge magnetic fields, the weirdness of the normal state persists down to T=0.
  
• Understanding the normal phase is probably a good idea for understanding superconductivity.
• There are signs, even within the superconducting phase, that there can be some kind of charge ordering ("stripe order" is a phrase that is used a lot).
• In the underdoped compounds, there is a pseudogap in the density of states that exists to temperatures far higher than Tc.
  

Things that some people agree on:

• The resonating valence bond picture accurately describes the superconducting phase; there is something called a spin liquid, and the pseudogap essentially corresponds to the formation of some kind of pair-like correlations without global phase coherence.
• The pairing mechanism is purely electronic (as opposed to phonons in conventional superconductors).
• The superconductivity is a general feature of doped Mott insulators.
• There are quasi-2d Mott insulators that do not superconduct at all when doped.
• There is no quantum phase transition (that is, at T=0 as a function of, say, doping) in these materials.
• There is a quantum phase transition in these materials, and therefore there is a well-defined (if very hard to detect) breaking of symmetry when going from the strange metal phase to the pseudogap phase.
• The stripe order is crucial, and competes with superconductivity.
• The stripe order is incidental and unimportant.

What I think is interesting, as a bystander:

• Everyone has their favorite handful of experiments that they treasure, and is appreciative that the materials growers have gotten so good at making clean samples of these nasty quaternary compounds.
• Only Chandra Varma explicitly addresses the reason why copper is special, chemically, in his microscopic picture (which has almost no relation at all to simple concepts of pairing, as far as I can tell).
• Very few people bother to address the existence of electron-doped superconductivity in these systems.
• It is clear that the whole field is strongly hampered by the fact that chemical doping is a real bear at these levels - it introduces large amounts of disorder. Field-effect experiments would be great, if only they could really change the charge density by chemically interesting amounts.

The field continues to progress, though it's not for the faint of heart. The holy grail of room temperature superconductivity still beckons, though there are those who make reasonably persuasive arguments that the copper compounds are awfully special, and may be as good as it gets. For me, I'll stick to nanostructures for now.

20 Years of High Tc

There is a very interesting article in the new issue of Nature Physics regarding the twentieth anniversary of the discovery of high temperature superconductivity. In case you've been living under a rock since 1986, the high temperature superconductors are generally based on perovskite quasi-two-dimensional compounds that have extraordinarily rich (read: so complicated they're hard to understand) phase diagrams. The parent compounds are antiferromagnetic insulators in their ground state. In doped compounds (done by substitutional chemical doping at the ten percent sort of scale, which introduces significant disorder), the superconducting state is well-described by a BCS-like state with spin singlet d-wave Cooper pairs (and just establishing that firmly took years, and an enormous effort at sample growth, and several brilliant experiments).

The normal state of these materials is a real mess. At very high doping levels, the materials seem to be well-described as Fermi liquids, which is the standard picture of ordinary metals. You can think of the electrons as partially filling a band of states that look very much like non-interacting single-particle states. Excitations above the ground state look like well-defined electron quasiparticles, as demonstrated by, e.g., a resistivity that varies like the temperature squared. Near optimal doping for the superconductivity, the normal state is a "strange metal", meaning that the resistivity varies with temperature like T, implying that quasiparticles are not a sensible way to think about excitations of this material. In underdoped materials, the normal state looks like a strange metal with a "pseudogap", vaguely reminiscent of the superconducting gap in the density of states, but persisting up to much higher temperatures than the superconducting state.

The Nature Physics article is a collection of comments by a bunch of big-name condensed matter theorists. Interestingly, and I'll write more about this in a day or two, there still is suprisingly little concensus about what's really going on in these materials. Definitely worth a read!

This week in cond-mat

I'm going to try to get more serious about regularly blogging condensed matter physics issues. First, I intend to have a weekly discussion of cool results on the arxiv preprint server, and here is my inaugural attempt. Think of it as a poor man's Condensed Matter Journal Club. The Bell Labs version is fine, but their tastes run rather to the theory side for me....

cond-mat/0602623 - Troisi and Ratner, Molecular Transport Junctions: Propensity Rules for Inelastic Electron Tunneling Spectroscopy
This paper is a snapshot of a whole subfield that lies at the interface between physics and physical chemistry. The molecular electronics community has long been interested in ways of characterizing molecular layers or even single molecules by their "fingerprint" one electronic conduction. Correctly formulating a theoretical approach to electron transport through a realistic system is very challenging: this is basically a nonequilibrium problem, with both electronic and vibrational degrees of freedom driven far from thermal equilibrium. This paper shows that IETS intensities can often be strongly affected by symmetry considerations.

cond-mat/0602608 - Wunderlich et al., Coulomb blockade anisotropic magnetoresistance: single electronics meets spintronics
The anisotropic magnetoresistance (AMR) is a band structure effect relevant in ferromagnets, in which the resistance of the material depends on the relative orientation of the current and the magnetization. Large versions of AMR have recently been observed in ferromagnetic constrictions here, here, and here, as well as in dilute magnetic semiconductors here. This paper reports a very interesting experiment, in which single-electron transistors are formed from a dilute magnetic semiconductor (GaMnAs). The resulting devices show single-electron charging effects in their conduction, but strongly modified by large tunneling AMR. Neat stuff.

cond-mat/0602565 - Novoselov et al., Unconventional quantum Hall effect and Berry's phase of 2pi in bilayer graphene
This is another great example of the work going on in a comparatively newly examined material system: electronic transport in essentially single (or in this case double) graphene layers. Because of the unusual band structure of graphene, charge carriers have an effective mass of (ideally) zero (!), which has all kinds of strange consequences. This material was first examined essentially simultaneously by about four groups (1, 2, 3, 4), three of whom spoke in a session I organized last year at the March Meeting of the APS. It absolutely blows me away that one can put single sheets of graphene down on surfaces, wire them up, and not have disorder completely bugger all the transport.

Out of gas....

Last week David Goodstein from Cal Tech came to Rice and gave a great lecture based on his book, Out of Gas, about the "end of the age of oil". The lecture was so distressing that I'm still thinking about it quite a bit almost two weeks later. Goodstein's main point is that our ever growing energy needs, coupled with the rising demand from the rest of the world (read: China and India, who for some wacky reason would like to enjoy standards of living similar to ours), make it highly highly likely that we will run out of fossil fuels sometime this century. Indeed, his one prediction is that "Civilization as we know it will end in the next 100 years, as we run out of fuel."

I know, I know - there are lots of "peak oil" nutjobs out there, but Goodstein isn't one of them. He's just a very bright guy who makes a really convincing case.

What are our options, according to him? Basically fusion (which is and might always be about 40 years away), or solar. Fission runs into trouble from problems of capacity (to satisfy 10 TW of demand will require building typical 1 GW reactors at a rate of one per day for 30 years), let along issues of fuel reprocessing.

Frankly I think the time is right for an Apollo/Manhattan Project style investment in this problem. Dumping less than 1% of the GDP ($100B, or, in better units, a few months in Iraq, or 1/3 of the annual service on the federal debt) into this per year at one or two re-dedicated national labs makes a lot of sense to me. It's much easier to invest now than when things get really desparate....

Stem cells and Jan Hendrik Schon

Unless you're living under a rock, you've heard about the scandal unfolding involving Dr. Hwang Woo Suk of Seoul National University. He is the world-famous scientist now accused of falsifying his stem cell research, the most recent paper of which had been published in Science. I want to point out something that has been entirely neglected in the media, as far as I can tell: the amazing similarity between this and the J. Hendrik Schon fiasco. For example:

* Huge impact articles in major journals, with talk of Nobel prizes.
* Multiple big-name coauthors who did not spot anything wrong.
* Progress in an exceedingly demanding field far in excess of reasonable expectations, yet attracting no suspicion at the time.
* The first hints of impropriety raised due to duplication of figures (!), a sloppy mistake virtually guaranteed to be noticed eventually.
* Immediate denial by the PI, with claims that the whole problem comes down to poor record keeping.
* Initial institutional announcements that while some particular result may be flawed, the body of work is still good, pretty much because the PI is a "genius".
* Claims by the PI in the face of mounting evidence of fraud that the results are true.
* Complete denial of any responsibility by the journal editors, who may or may not have downplayed negative referee reports because the results are potentially so important.

Interesting, eh?

The most important similarity in both cases, of course, is that they got caught - the scientific process did work, albeit slowly.

One other comment: I hate it when ethicists insist that the real problem is the lack of formal ethics training in the scientific curriculum. That is absolute garbage. Does anyone really think that Hwang or Schon didn't realize what they were doing was wrong? Does anyone really think that one more ethics course would have prevented either case? Come on. Seriously.

A long break....

Sorry for the long break. It's been a very busy time in academia. I did finally finish my 100 page review article about single-molecule transistors, though. I also spoke at the Bat Sheva Seminar on Electron Transport in Molecular Junctions, possibly the best scientific meeting I've ever attended.

I heard two striking things at the meeting. First, Europeans and Israelis were shocked at how much time Americans spend writing grant proposals. Interesting. Second, there are still real problems in our understanding of interfaces at the atomic scale, and charge transfer. There is even still debate about whether the theory prediction vs. experimental data divide is converging. On the side saying that real progress is being made are folks like Stuart Lindsay and Mark Ratner. Those arguing that there are still major discrepancies include Amir Yacoby. Fascinating discussions.

I'll discuss a couple of specific recent results next time.

Least action and non-classical paths

Here's a funky piece of physics discovered in condensed matter research that deserves broader attention because it is so weird.

So, the Feynmann-Hibbs path integral approach to quantum mechanics says that the way to calculate the probability of a quantum system starting at configuration {a} and ending at configuration {b} is to add up the complex amplitudes for all possible paths between {a} and {b}. For each path, you can compute the classical action, S, by integrating the Lagrangian along the path, and the amplitude for such a path is given by exp^(i S / \hbar). This is particularly nice because paths that extremize S end up constructively interfering (having very similar phases). So, when one passes to the classical limit (\hbar -> 0), one finds that the dominant classical trajectory for the system is the one that extremizes the action. Unsurprisingly, the trajectory that dominates is something smooth that looks like a sensible classical path (e.g. for a particle propagating in free space, it's a straight line from point a to point b).

Here's the weirdness, though. There is at least one system (quantum tunneling of spin in molecular magnets) for which the action-extremizing paths are discontinuous. In our free particle discussion, these would be analogous to trajectories where the particle's path in space looks like _____----____--__ , complete with discontinuous changes in coordinates. Such trajectories are always in the calculations (in fact, in quantum field theory you need to include paths with space-like discontinuities (!) in order to get the calculations to come out correctly), but this is the only case I've ever seen where they can be the dominant trajectories.

Intelligent design

Thank goodness the President doesn't really have much to do with setting educational practices in this country. From the transcript of his Aug. 1 press event in the Roosevelt Room at the White House:

Q I wanted to ask you about the -- what seems to be a growing debate over evolution versus intelligent design. What are your personal views on that, and do you think both should be taught in public schools?

THE PRESIDENT: I think -- as I said, harking back to my days as my governor -- both you and Herman are doing a fine job of dragging me back to the past. (Laughter.) Then, I said that, first of all, that decision should be made to local school districts, but I felt like both sides ought to be properly taught.

Q Both sides should be properly taught?

THE PRESIDENT: Yes, people -- so people can understand what the debate is about.

Q So the answer accepts the validity of intelligent design as an alternative to evolution?

THE PRESIDENT: I think that part of education is to expose people to different schools of thought, and I'm not suggesting -- you're asking me whether or not people ought to be exposed to different ideas, and the answer is yes.

Sigh. The President clearly doesn't understand that "Intelligent Design" is not science. It is unfalsefiable. It makes no predictions - it makes assertions. Saying that it deserves something like equal time with evolution in school science classes is absurd.

It's tempting to make an inflammatory statement that this demonstrates the anti-intellectual, anti-science attitude of the current administration (i.e. the "faith-based" community vs. the "reality-based" community). However, I'd be shocked if the President actually gave this that much thought; I suspect science funding and science policy (apart from firebrand issues with his base like stem cells and missle defense) rarely, if ever, cross his mind. In some ways, that's even more sad than a deliberate anti-science attitude: if it doesn't serve political ends, he just doesn't care.

The Templeton Foundation

There was an interesting story this morning on NPR about the Templeton Foundation and their efforts to fund physics research. The Templeton folks are interested in the interface between science and spirituality, and sponsor the Templeton Prize (which is intentionally larger than the Nobel). The occasion for this story is an upcoming conference at Berkeley in honor of Charles Townes' 90th birthday, sponsored by the Templeton Foundation. I know about this because, like pretty much all of my peers, I received an announcement about a Young Scholar's competition being held at this meeting.

I have no problem with increased dialog between science and religion, as long as people remember where the boundaries are. "God did it" is a rather inquiry-ending proposition to hold in a scientific investigation, so I prefer to assume that non-supernatural explanations exist for the world around me and go from there.

Anyway, the story is interesting food for thought. Physicists talked to who are skeptical of the Templeton Foundation's motives include Sean Carroll and Lawrence Krauss.

Science and today's politics

Rep. Joe Barton (R-TX), chairman of the House Committee on Energy and Commerce, has decided to threaten NSF-funded scientists who authored a peer-reviewed, published study on climate change that suggests that fossil fuel consumption influences global warming. Specifically, he has requested that these scientists turn over all records of their work to his committee, where (quoting Barton's letter to the director of the NSF) "The term 'records' is to be construed in the broadest sense ... whether printed or recorded electronically or magnetically or stored in any type of data bank, including, but not limited to ... summaries of personal conversations or interviews ... diaries ... checks and canceled checks ... bank statements." For more information, see the New York Times and BBC articles on the subject.

It is a huge understatement for me to say that I find this disturbing. Asking scientists to essentially open their personal financial records to him because he doesn't like their research is appalling. We all sign "conflict of interest" disclosure forms when we accept research funds - threats of congressional subpoenas are not the appropriate way for Barton to voice concerns about the objectivity of researchers! Indeed, given that Barton's campaigns through the years have been massively financed by the oil and energy industries, if anyone's objectivity should be of concern, it's not that of the scientists.

I am genuinely concerned that even writing about this in a public forum potentially puts my future funding at risk. It is only a short step from Barton's current actions to some future move to political litmus tests for research funding (i.e. Why should tax dollars go to someone who holds views contrary to those of the current administration?). To some degree this is already happening. Read this (go to the full report link (pdf) and read page 26.).

The whole point of the peer-review system is that scientists have the appropriate training to evaluate the work of other scientists! At a time when American preeminence in science and engineering is slipping (pdf), and when research funding in real dollars (let alone as a percentage of GDP) is being cut, is politicizing the process at all a smart thing to be doing?

Interesting recent papers....

Here are a couple of interesting papers I've seen in the last week or so:

Doh et al., Tunable supercurrent through semiconductor nanowires, Science 309, 272 (2005).

Very pretty use of InAs semiconducting nanowires grown by the now-usual VLS approach, and contacted by aluminum pads. When the Al goes superconducting, carriers in the InAs (controlled via field effect with a gate) become superconducting, too, via the proximity effect. Basically this results in a tunable Josephson junction with the InAs nanowire as the controllable weak link. Gorgeous, as is most of the stuff that comes out of Delft.

Ghosh et al., Zero-bias anomaly and Kondo-assisted quasi-ballistic 2d transport.

A preprint out of the Cambridge folks that looks at very clean mesoscale 2d GaAs/AlGaAs systems and argues that there is evidence (a temperature-dependent zero-bias peak in the differential conductance) that points to Kondo-assisted transport in these systems. The remarkable thing is that the orthodox Kondo effect relies on localized spin degrees of freedom, and there shouldn't be any in these materials. The authors suggest a more exotic (2-channel!) Kondo effect involving localized two-level defects. Very intriguing data, though the interpretation is likely to be controversial, if past 2-channel Kondo reports are any indication.

People who annoy me.

You know what really ticks me off? People with no technical background who have nonetheless become nanoscience and nanotechnology "talking heads". A lot of this is our fault - those of us who actually do research at these length scales. Why? Because we've done a lousy job of making sure that journalists can tell the difference between reality and hype. People on my "irresponsible talking head" list:

1) The Center for Responsible Nanotechnology. These folks act like a group who have put careful thought into the benefits and risks of nanotechnology. In fact, these folks don't have a physical science degree between them. I don't care how sincerely motivated you are, or how bright: if your idea of nanotechnology comes from reading nontechnical articles, you don't really know what's going on, and if you don't have the technical background to understand real technical articles, I am highly skeptical of your opinions.

2) Josh Wolfe. When he sticks to what he knows - giving investment advice about high technology companies - Josh Wolfe is as solid as they come. Very sharp. However, lately I've seen him making the rounds on CNBC and MSNBC talking as if he really is technically knowledgable about nanoscale science. He's not.

3) Michael Crichton. Apart from the massive plot holes in Prey, what really annoys me about Crichton is that he writes "nonfiction" articles about his novels' topics that get widely circulated (like in syndicated newspaper inserts). He's such an egomaniac that he thinks doing research for one of his novels makes him as qualified as a real expert to expound on science. This is true of his nano novel Prey, and true of his environmentalism novel State of Fear. Dude: you're an author, not a polyglot genius of science. Get over yourself.

"More" really is different.

Condensed matter physics gets a bum rap sometimes. Murray Gell-Mann referred to it as "squalid state" physics. Wolfgang Pauli called it "Physik der Dreckeffeckte", or "the physics of dirt effects". (That's particularly ironic since it's the Pauli principle that makes condensed matter at all tractable.)

In addition to being at the heart of essentially all modern electronics technology, condensed matter is actually much more intellectually profound than "junk" effects. As Phil Anderson pointed out in his now famous essay, "More is different". That is, large systems of smaller entities interacting through relatively simple rules can exhibit very surprising emergent, collective properties. For example, a single iron atom is pretty simple, but put a bunch together, and you end up with a rigid solid (!) that is also a metal (!) and, at ambient conditions, a ferromagnet (!). Try predicting all that a priori from the Standard Model of particle physics....

One of my former professors, Bob Laughlin, has written a good book on this subject. As a physicist it's tough for me to judge just how well it'll read to a lay audience, but I enjoyed it thoroughly. It's vintage Laughlin (who I once saw ask a seminar speaker, "It's late. We're all tired. Why should we care about any of this?!"), even if some of the Stanford anecdotes have some minor inaccuracies. Here's a review from the New York Times. I don't agree with everything he says (pretty much he thinks "nano" work is, in general, buzzword-laden crap rather than addressing real scientific questions. Oh wait - maybe I do agree with him.), but it's a fun read.

A condensed matter physicist blog: why not?

I was googling around for something the other day, and came upon physcomments.org, a website that purports to be the home of "scholarly discussions of physics" on the web. Upon going there, I discovered that the definition of physics used there apparently referred only to high energy physics (e.g. string theory, loop quantum gravity, accelerator-based experiments) and astrophysics/cosmology.

I assumed that this was due to intellectual snobbery on the part of that community, and set off to find all the condensed matter / AMO physics blogs out there, only to discover that, as far as I could tell, there aren't any.

So, here we are. I'll try to start one, and we'll see where this goes. I'll try to clearly delineate between science-related posts and other stuff (my comments on the weirdness of junior faculty life, or public science policy, or humor). If there are a bunch of you out there blogging the interesting things in condensed matter, nanoscale science, or AMO physics, please post and let me know, so I can link to your stuff....

Now back to the omnipresent task of proposal-writing....