Writing exams.

Writing (or perhaps I should say "creating", for the benefit of UK/Canada/Australia/NZ grammarians) good exams is not a trivial task.  You want very much to test certain concepts, and you don't want the exam to measure thing you consider comparatively unimportant.  For example, the first exam I ever took in college was in honors mechanics; out of a possible 30 points, the mean was a 9 (!), and I got a 6 (!!).  Apart from being a real wake-up call about how hard I would have to apply myself to succeed academically, that test was a classic example of an exam that did not do its job.  The reason the scores were so low is that the test was considerably too long for the time allotted.  Rather than measuring knowledge of mechanics or problem solving ability, the test largely measured people's speed of work - not an unimportant indicator (brilliant, well-prepared people do often work relatively quickly), but surely not what the instructor cared most about, since there usually isn't a need for raw speed in real physics or engineering.  

Ideally, the exam will have enough "dynamic range" that you can get a good idea of the spread of knowledge in the students.  If the test is too easy, you end up with a grade distribution that is very top-heavy, and you can't distinguish between the good and the excellent.  If the test is too difficult, the distribution is soul-crushingly bottom-heavy (leading to great angst among the students), and again you can't tell between those who really don't know what's going on and those who just slipped up.  Along these lines, you also need the test to be comparatively straightforward to take (step-by-step multipart problems, where there are still paths forward even if one part is wrong) and to grade.

Finally, in an ideal world, you'd actually like students to learn something from the test, not just have it act purely as a hurdle to be overcome.  This last goal is almost impossible to achieve in classes so large that multiple choice exams are the only real option.  It is where exam writing can be educational for the instructor as well, though - nothing quite like starting out to write a problem, only to realize partway through that the situation is more subtle than you'd first thought!  Ahh well.  Back to working on my test questions.

Memristors - how fundamental, and how useful?

You may have heard about an electronic device called a memristor, a term originally coined by Leon Chua back in 1971, and billed as the "missing fourth fundamental circuit element".  It's worth taking a look at what that means, and whether memristors are fundamental in the physics sense that resistors, capacitors, and inductors are.  Note that this is an entirely separate question from whether such devices and their relatives are technologically useful! 

In a resistor, electronic current flows in phase with the voltage drop across the resistor (assuming the voltage is cycled in an ac fashion).  In the dc limit, current flows in steady state proportional to the voltage, and power is dissipated.  In a capacitor, in contrast, the flow of current builds up charge (in the usual parallel plate concept, charge on the plates) that leads to the formation of an electric field between conducting parts, and hence a voltage difference.  The current leads the voltage (current is proportional to the rate of change of the voltage); when a constant voltage is specified, the current decreases to zero once that voltage is achieved, and energy is stored in the electric field of the capacitor.  In an inductor, the voltage leads the current - the voltage across an inductor, through Faraday's law, is proportional to the rate at which the current is changing.  Note that in a standard inductor (usually drawn as a coil of wire), the magnetic flux through the inductor is proportional to the current (flux = L I, where L is the inductance).  That means that if a certain current is specified through the inductor, the voltage drops to zero (in the ideal, zero-resistance case), and there is energy stored in the magnetic field of the inductor.  Notice that there is a duality between the inductor and capacitor cases (current and voltage swapping roles; energy stored in either electric or magnetic field).

Prof. Chua said that one could think of things a bit differently, and consider a circuit element where the magnetic flux (remember, in an inductor this would be proportional to the time integral of the voltage) is proportional to the charge that has passed through the device (the time integral of the current (rather than the current itself in an inductor)).  No one has actually made such a device, in terms of magnetic flux.  However, what people have made are any number of devices where the relationship between current and voltage depends on the past history of the current flow through the device.  One special case of this is the gadget marketed by HP as a memristor, consisting of two metal electrodes separated by a titanium oxide film.  In that particular example, at sufficiently high bias voltage, the flow of current through the device performs electrochemistry on the titanium oxide, either reducing it to titanium metal, or oxidizing it further, depending on the polarity of the flow.  The result is that the resistance (the proportionality between voltage and current; in the memristor language, the proportionality between the time integral of the voltage and the time integral of the current) depends on how much charge has flowed through the device.  Voila, a memristor.

I would maintain that this is conceptually very different and less fundamental than the resistor, capacitor, or inductor elements.  The resistor is the simplest possible relationship between current and voltage; the capacitor and inductor have a dual relationship and each involve energy storage in electromagnetic fields.  The memristor does not have a deep connection to electromagnetism - it is one particular example of the general "mem"device, which has a complex electrical impedance that depends on the current/voltage history of the device.  Indeed, my friend Max di Ventra has, with a colleague, written a review of the general case, which can be said to include "memcapacitors" and "meminductors".  The various memgizmos are certainly fun to think about, and in their simplest implementation have great potential for certain applications, such as nonvolatile memory.

Great moments in consumer electronics

It's been an extremely busy time of the semester, and there appears to be no end in sight.  There will be more physics posts soon, but in the meantime, I have a question for those of you out there that have Nintendo Wii consoles.  (The Wii is a great example of micromachining technology, by the way, since the controller contains a 3-axis MEMS accelerometer, and the Wii Motion Plus also contains a micromachined gyroscope.)  Apparently, if there is a power glitch, it is necessary to "reset your AC adapter" in order to power on the console.  The AC adapter looks for all the world like an ordinary "brick" power supply, which I would think should contain a transformer, some diodes, capacitors, and probably voltage regulators.  Resetting it involves unplugging it from both ends (the Wii and the power strip), letting it sit for two solid minutes, and then plugging it back directly into a wall outlet (not a power strip).  What the heck did Nintendo put in this thing, and why does that procedure work, when plugging it back into a power strip does not?!  Does Nintendo rely on poorly conditioned power to keep the adapter happy?  Is this all some scheme so that they can make sure you're not trying to use a gray-market adapter?  This is so odd that it seemed like the only natural way to try to get to the bottom of it (without following my physicist's inclination of ripping the adapter apart) was to ask the internet.

Paul Barbara

I was shocked and saddened to learn of the death of Paul Barbara, a tremendous physical chemist and National Academy of Sciences member at the University of Texas.  Prof. Barbara's research focused largely on electron transfer and single-molecule spectroscopy, and I met him originally because of a mutual interest in organic semiconductors.  He was very smart, funny, and a class act all the way, happy to talk science with me even when I was a brand new assistant professor just getting into our field of mutual interest.  He will be missed.

Two cool videos, + science funding

Here are two extremely interesting videos related to physics topics.  Both combine two things I enjoy in life:  physics and coffee.  Here is a video made by scientists at the Institut Laue-Langevin, a neutron science laboratory in Grenoble funded by the EU.  The scientists decided to use a neutron beam to image through a little espresso maker as it brews.  They did this partly for fun, and partly to demonstrate how neutrons may be used to examine materials - for example, one could use this sort of imaging to look for flaws or cracks in turbine blades.  The cross-section for absorbing neutrons varies quite strongly from element to element, giving good material contrast.  The aluminum housing for the espresso maker shows up as very light gray, while the water (and resulting espresso, which is still mostly water, even when my old friend Sven makes it) shows up as very dark.  This is because the hydrogen in the water has a relatively large cross-section for capturing a neutron and becoming deuterium.

The second video I saw thanks to Charles Day's blog.  To me, a former mechanical engineer, this is rather jaw-dropping.  Hod Lipson and his graduate students at Cornell have managed to leverage a great piece of physics called the jamming transition.  Many physics students are surprised to learn that some "simple" problems of classical statistical physics can exhibit complex phenomenon and remain active subjects of research, even though they seem on the surface like they should have been solved by 19th century French mathematician whose name started with L.  The jamming transition is one of these problems.  Take a bunch of dry grains (in this case, ground coffee).  When there is a bit of air mixed in with the grains, the grains can slide over and past each other relatively easily.  A latex balloon filled with this mixture is squishy.  If the air is removed, however, the grains jam up, and the grain-filled balloon becomes very hard (as if the effective viscosity of the blob of grains diverges).  The Cornell researchers have used this phenomenon to make a universal "gripper" for picking up objects.  Just watch the movie.  It's very impressive.

Finally, a tidbit about science funding.  Well, it didn't take long.  The Heritage Foundation (a US conservative think-tank) is already proposing cutting the research budgets of NSF, DOE, and NIST, as well as eliminating NSF support for K12 education.  This isn't a surprise - they do this all the time - though it's interesting that they propose absolutely zero cuts to the Department of Defense (though they have no problem suggesting cuts for veterans benefits).   

Data and backups

I don't talk too much on here about the university service stuff that I do - frankly, much of it wouldn't be very interesting to most of my readers.  However, this year I'm chairing Rice University's Committee on Research, and we're discussing an issue that many of you may care about:  data management and preservation.   Generally, principal investigators are assumed to be "responsible custodians" of data taken during research.  Note that "data" can mean many things in this context - see here, for example.   US federal agencies that sponsor research typically expect the PIs to hold on to their data for several years following the conclusion of a project, and that PIs will make their data available if requested.  The university is legally responsible to ensure that the data is retained, in fact.  There are many issues that crop up here, but the particular one on which I'd like some feedback is university storage of electronic data.  If you're at a university, does your institution provide electronic (or physical, for that matter) storage space for the retention of research data?  Do they charge the investigators for that storage?  What kind of storage is it, and is the transfer of data from a PI's lab, say, to that storage automated?  I'd be very interested in hearing either success stories about university or institutional data management, or alternately horror stories. 

Wrap-up, Osheroff-fest

The symposium in honor of Doug Osheroff was great fun. It was great to see old friends again, to hear some stories that I didn't know, and to find out what other former group members are up to. The actual talks were generally pretty good, with a number of speakers focusing on how exciting and vibrant the whole field of low temperature physics was in its heyday. There were a total of seven Nobel Laureates there (DDO, Steve Chu, Bob Laughlin, Bob Richardson, Dave Lee, Phil Anderson, and Tony Leggett), and a bunch of other luminaries (Michael Fisher, Daniel Fisher, Bill Brinkman, Ted Geballe, and even a special and unexpected (by me, at least) appearance by Ed Witten). Steve Chu's talk was remarkable in part because he so clearly loved the chance to give an actual technical talk about some of his research, which you get the feeling he doesn't do so much at the DOE. Fun stuff, even when Bob Laughlin was giving me a hard time :-)

Osheroff-fest

I am currently visiting Stanford for my thesis advisor's big birthday bash/retirement festivities. It's really great to see so many former students, postdocs, and collaborators, and it's more than a little surreal to be back here after so long. It's a shame taht a few couldn't make it - they're sorely missed. There is going to be a day-long symposium tomorrow in his honor that should be very interesting. I'll post some brief description of some of the talks, if they seem like they are of general interest.

Excellent talk today + the point of colloquia.

Today I was fortunate to host my department's weekly colloquium, with Prof. Wilson Ho from UC Irvine as the speaker.  He gave a great talk about "Visualizing Quantum Mechanics", in which he showed (using experiments from his own group) how scanning tunneling microscopy can be a great teaching tool for illustrating concepts from undergraduate quantum mechanics.  He covered the exponential dependence of tunneling on distance, imaging of molecular orbitals, the crossover between classical (activated) diffusion and quantum (tunneling-based) diffusion, particle-in-a-box physics in 1d atomic chains, visualization of Fermi's Golden Rule via light emission experiments, and other neat results.  The audience included not just the usual collection of faculty and grad students, but also a bunch of the current undergrad quantum students as well.  

The talk was pretty much a letter-perfect example of what a colloquium is supposed to be.  It was accessible to a general audience, was genuinely educational, had appealing visuals, and contained enough intellectual "meat" to be satisfying for experts, including some not-yet published stuff.  It would be nice if every speaker realized the difference between a colloquium and a seminar....

On an unrelated note, I can't resist commenting on this awful article from Reuters hyping the LHC.  I'm as happy as anyone that the accelerator is running well, but does the CERN press office really need to keep churning out this kind of garbage?  Can't they just have a nice release/article talking about how nicely the experiment is running, and how they're hitting their targets, without making just laughable statements?  I think we can be pretty damned sure that the LHC is not about to discover incontrovertible evidence for parallel universes.   

Buckyball celebration/symposium

In honor of the 25th anniversary of the discovery of C₆₀ at Rice, the university is holding a symposium to celebrate.  In addition to the surviving members of the discovery team (laureates Curl and Kroto; Prof. Heath, Dr. O'Brien), there are many big names in the business (Millie Dresselhaus, Marvin Cohen, Phaedon Avouris, Hongjie Dai).  Andre Geim is going to skype in, apparently, since getting the Nobel Prize this past week has understandably scrambled his travel plans.  Unfortunately I'm flying to Washington, DC later this morning, so I will miss most of the fun, but I'm sure it will be a very interesting and lively event.

2010 Physics Nobel for graphene

The 2010 Nobel Prize in Physics has been awarded to Andre Geim and Konstantin Novoselov for graphene.  Congratulations to them!  Graphene, the single-atomic-layer limit of graphite, has been a very hot topic in consensed matter physics since late 2004, and I've posted about it here and here.  There is no question that graphene is a very interesting material, and the possibility of serious technological applications looms large, but as Joerg Haber points out, overhype is a real danger.  The prize is somewhat unusual in that it was very fast on the scale of these things.  I also find it interesting that only the Manchester group was given the prize, given the impact of the work going on in this area at other places at around the same time (for example, take a look at the first few talks in this session I put together at the 2005 APS March Meeting).  I do hope that those in the British scientific funding establishment take note that future prizes and innovations like this are at severe risk if research and educational funding cuts continue.

"Definitively inaccurate": One more comment about NRC rankings

One last post before the Nobel in physics is announced tomorrow.... As many people in the academic blogosphere have reported, there are some serious issues with the NRC rankings of graduate programs.  Some of these seem to be related to data entry, and others to nonuniform or overly simplistic interpretations of answers to survey questions.  Let me give a couple of examples.  I'm in the physics and astronomy department at Rice, and for several years I've helped oversee the interdisciplinary applied physics graduate program here (not a department - applied physics does not have faculty billets or its own courses, for example).  I filled out faculty NRC paperwork, and I was also in charge (with a colleague) of filling out the "department"-level NRC paperwork for the applied physics program.  I know, with certainty, that some of the stats for the two programs are very very similar, including the allocation of work space to graduate students and the approximate completion rates of the PhD program.  However, while these seem to show up correctly in the applied physics NRC data, they are both skewed bizarrely wrong (and very unfavorably, like the completion rate in the NRC data is too low when compared with reality by at least a factor of two!) in the physics & astronomy departmental NRC data.  Now, overall the department did reasonably well in the rankings, and if one looks particularly at just the research stuff per faculty member, physics and astronomy did quite well.  However, this issue with student data really stinks, because that's what some sites geared toward prospective students emphasize.  It's wrong, there's no fixing it, and it looks like it will be "definitively inaccurate" (to borrow a phrase from Douglas Adams) for at least a decade. 

Reductionism, emergence, and Sean Carroll

In the last couple of weeks, Sean Carroll has made two separate posts (here and here) on his widely read Cosmic Variance blog at Discover magazine, in which he points out, in a celebratory tone, that we fully understand the laws of physics that govern the everyday world.  In a reductionist sense, he's right, in that nonrelativistic quantum mechanics + electricity and magnetism (+ quantum electrodynamics and a little special relativity) are the basic rules underlying chemistry, biology, solid state physics, etc.  This is not a particularly new observation.  Fifteen years ago, when I was a grad student at Stanford, Bob Laughlin was making the same comments, but for a different reason:  to point out that this reductionist picture is in many ways hollow.  I think that Sean gets this, but the way he has addressed this topic, twice, really makes me wonder whether he believes it, since beneath all of the talk about how impressive it is that humanity has this much understanding, lurks the implication that all the rest of non-high energy physics (or non-cosmology) is somehow just detail work that isn't getting at profound, fundamental questions.   The emergence of rich, complex, often genuinely "new" physics out of systems that obey comparatively simple underlying rules is the whole point of condensed matter these days.  For example, the emergence, in 2d electronic systems in semiconductors, of low energy excitations that have fractional charge and obey non-Abelian statistics, is not just a detail - it's really wild stuff, and has profound connections to fundamental physics.  So while Sean is right, and we should be proud as a species of how much we've learned, not everything deep comes out of reductionism, and some fraction of physicists need to stop acting like it does. 

Grad school, rankings, and geniuses

At long last, the National Research Council has finally released their rankings of graduate programs, the first such ranking since 1993. Their methodology is extremely complicated, and the way they present the data is almost opaque. This is a side effect of an effort to address the traditional problem with rankings, the ridiculousness of trying to assign a single number to something as complex and multivariate as a graduate program. The NRC has gone out of their way to make it possible to compare programs on many issues, and that's generally a good thing, but at the same time it makes navigating the data painful. The best aid I've seen in this is this flash app by the Chronicle of Higher Education. It does a great job of showing, graphically, the range of rankings that is relevant for a particular program, and you can do side-by-side comparisons of multiple programs. As I had suspected, most programs have a fairly broad range of possible rankings, except those at the very top (e.g., Harvard's physics department is, according to the "S" rankings, which are those based on the metrics that faculty members themselves identified as important to them, somewhere between 1 and 3 in the country.). One thing to note: the "S" rankings probably mean more about department quality than the pure research "R" rankings, since the "R" rankings will naturally bias in favor of larger departments. The other thing that becomes obvious when playing with this app for a few minutes is that some departments had clear data entry problems in their NRC data. As an example, my own department appears to have "zero" interdisciplinary faculty, which is just wrong, and undoubtedly didn't help our ranking.

In other news, the MacArthur Foundation has released their 2010 list of Fellows, known colloquially as recipients of "Genius Grants". I'm only familiar with some of the ones that touch on physics, and the people involved are all very good and extremely creative, which is exactly the point, I guess! Congratulations, all. Now let the speculation begin on the Nobel Prizes, which are going to be announced next week.

Finally, I wanted to link to this great post by my friend Jennifer Rexford, who has intelligent advice for first-year graduate students.

Nanostructures as optical antennas

My student (with theorist collaborators) had a paper published online in Nature Nanotechnology yesterday, and this gives me an excuse to talk about using metal nanostructures as optical antennas. The short version: using metal electrodes separated by a sub-nanometer gap as a kind of antenna, we have been able to get local enhancement of the electromagnetic intensity by roughly a factor of a million (!), and we have been able to determine that enhancement experimentally via tunneling measurements.

As I've discussed previously, light can excite collective excitations (plasmons) of the electronic fluid in a metal. Because these plasmons involve displacing the electrons relative to the ions, they are associated with local electric fields at the metal surface. When the incident light is resonant with the natural frequency of these modes, the result can be local electromagnetic fields near the metal that can significantly exceed the fields from the incident light. These enhanced local fields can be useful for many things, from spectroscopy to nonlinear optics. One way to get particularly large field enhancements is to look at the region separating two very closely spaced plasmonic structures. For example, closely spaced metal nanoparticles have been used to enhance fields sufficiently in the interparticle gap to allow single-molecule Raman spectroscopy (see here and here).

A major challenge, however, has been to get an experimental measure of those local fields in such gaps. That is where tunneling comes in. In a tunnel junction, electrons are able to "tunnel" quantum mechanically from one electrode to the other. The resulting current as a function of voltage may be slightly nonlinear, meaning that (unlike in a simple resistor) the second derivative of current with respect to voltage (d²I/dV²) is non-zero. From a simple math argument, the presence of a nonlinearity like this means that an AC voltage applied across the junction gives rise to a DC current proportional to the nonlinearity, a process called "rectification". What we have done is turned this around. We use low frequency (kHz) electronic measurements to determine the nonlinearity. We then measure the component of the DC current due to light shining on the junction (for experts: we can do this with lock-in methods at the same time as measuring the nonlinearity). We can then use the measured nonlinearity and photocurrent to determine the optical-frequency voltage that must be driving the tunneling photocurrent. From the tunneling conductance, we can also estimate the distance scale over which tunneling takes place. Dividing the optical frequency voltage by that distance gives us the optical-frequency electric field at the tunneling gap, which may be compared with the field from the incident light to get the enhancement.

It's not at all obvious on the face of it that this should work. After all, the analysis relies on the idea that the tunneling nonlinearity measured at kHz frequencies is still valid at frequencies nearly 10¹² times higher. Experimentally, the data show that this does work, however, and our theorist colleagues are able to explain why.

When you think about it, it's pretty amazing. The radiation intensity in the little nanogap between our electrodes can be hundreds of thousands or millions of times higher than that from the incident laser. Wild stuff, and definitely food for thought.

Interesting links - nonphysics, mostly.

Nothing as interesting as this happens around here (at least, not to my knowledge), and I'm kind of glad. 

xkcd has once again done a far better job demonstrating some aspect of my existence than I ever could have myself.

Fascinating photography of nuclear weapons explosions here.

Tangentially related to nuclear weapons, I got a big kick out of Stephen Colbert's Dr. Strangelove tribute. 

Gravity

There has been a good deal of talk lately about gravity. We're all taught early on in our science education about the remarkable insight of Isaac Newton, that the force that causes, e.g., apples to fall from trees is, in fact, the same force that keeps the moon in orbit about the earth (or rather about a common center of gravity relatively close to the center of the earth). The Newtonian gravitational constant, G, is the least precisely known of all the fundamental constants, in part because gravity is a shockingly weak force and therefore difficult to measure. (As I demonstrated to my freshmen students, gravity is so weak that even with the feeble muscles in my legs I can jump up in the air in defiance of the opposing force of the gravitational pull of the entire earth.) More frustrating than the difficulty in precision measurement of G is the fact that different research groups using different techniques come up with experimental estimates of G that differ by surprisingly large amounts. This paper (published last week in Phys. Rev. Lett.) is another example. The authors sweated over the details of their systematic uncertainties for two years before publishing this result, which disagrees with the "official" CODATA value for G by 10 sigma (!). This is a classic showcase for the art, elegance, and necessary attention to detail required in precision measurement physics.

Also making many waves during 2010 is this paper by Erik Verlinde. The claim of this paper is that gravity is emergent, rather than a "real" force. It's been argued since Einstein published general relativity that gravity is different at a deep level than traditional forces. GR says that we should think of gravity as a deformation of spacetime due to the presence of stress/energy. Freely falling particles always travel on geodesics (locally straight lines), and those geodesics are determined by the distribution of mass and energy (including that due to spacetime deformation). In the appropriate limit, GR reduces to Newtonian gravity. Verlinde, striking out in a completely different direction, argues that one can start from very general considerations, and gravity emerges as an "entropic" force. An entropic force is an apparent force that results from the tendency of matter and energy to explore all available microscopic states. For example, a polymer will tend to ball up because there are many more microscopic states that describe the polymer wadded up than extended. Pulling on the two ends of the polymer chain to straighten it out will require overcoming this entropic tendency, and the result is a tension force. Verlinde argues that gravity arises similarly. I need to re-read the paper - it's slippery in places, especially on what underlying background assumptions are made about time and space, and what really plays the role of temperature here. Still, intriguing food for thought, and it's elegant that he can get both something GR-like and something Newtonian to fall out of such an analysis.

Regardless of how you may feel about Verlinde's speculations and the difficulty of measuring G, at least you can laugh in shocked disbelief that these people are serious.  (I should be careful making jokes.  Knowing Rick Perry, they'll start pushing this in Texas public schools next year.)

Two for the price of one.

I had noticed (and it was also pointed out by a colleague) the essentially simultaneous publication of this paper and this paper (which appear to have been submitted within a week of each other as well).  In both papers, the authors have created short-channel graphene-based transistors in a clever way. They take a conductive nanowire (doped GaN in the Nano Letters paper; CoSi in the Nature paper), coat it with thin aluminum oxide via atomic-layer deposition, and then lay it down on top of a piece of exfoliated graphene. Then they evaporate Pt on top of the device. On either side of the nanowire, the Pt lands on the graphene, making source and drain electrodes. The nanowire shadows part of the graphene (the channel), and then the nanowire itself acts as the gate. This is a nice, self-aligned process, and the resulting graphene devices appear to be very fast (the Nature paper has actual high frequency measurements). Looks like they managed to get two papers in good journals for the price of one technique advance.

Arguing from authority? Hawking, you're supposed to be better than that.

In Saturday's Wall Street Journal, there was an article by Stephen Hawking and Leonard Mlodinow clearly designed as a naked promotion of their new book.  In the article, they argue that modern physics removes the need for a divine being to have created the universe.  Religious arguments aside (seriously, guys, is that particular argument even news anymore?), one thing in the article especially annoyed me.  Toward the end, the authors state:

As recent advances in cosmology suggest, the laws of gravity and quantum theory allow universes to appear spontaneously from nothing. Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.

Our universe seems to be one of many, each with different laws.

You know what's wrong with this? It states, as if it is established fact, that we understand cosmology well enough to declare that universes spontaneously self-create. It states that the multiverse is a prediction of "many" theories, implying strongly that it's on firm ground. The problem is, this isn't science. It's not falsifiable, and in its present form it's not even close to being falsifiable in the foreseeable future. Seriously, name one PREdiction (as opposed to retrodiction) of these cosmological models, or more seriously, the multiverse/landscape idea, that is testable. Don't claim that our existence is such a test - the anthropic principle is weak sauce and is by no means evidence of the multiverse. Man, it annoys me when high profile theorists (it always seems to be theorists who do this) forget that physics is actually an experimental science that rests on predictive power.

This won't end well, because it's blindingly idiotic.

According to the Chronicle of Higher Education, my Texas A&M colleagues up the road in College Station now get the privilege of being evaluated based on their bottom-line "financial value" to the university.  Take how much money the professor brings in (including some $ from tuition of the number of students taught), subtract their salary, and there you go.  This raises problematic points that should be obvious to anyone with two brain cells to rub together.  First, I guess it sucks to be in the humanities and social sciences - you almost certainly have negative value in this ranking. Congratulations, you leeches who take salary and don't bring in big research funding!  Second, it firmly establishes that the service contributions of faculty to the university are worthless in this ranking scheme.  Third, it establishes that the only measure of your educational contribution is how many students you teach - purely quantity, so if you teach large intro classes you're somehow valuable, but if you teach smaller upper division courses, you're less valuable.  Gee, that's not simplistic at all.  Now, the article doesn't actually say how these rankings will be used, but I'm having a hard time imagining ways that this metric is a good idea.