A blog about condensed matter and nanoscale physics. Why should high energy and astro folks have all the fun?
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Tuesday, September 30, 2025
Annual Nobel speculation thread
Sunday, September 28, 2025
Fluid mechanics of electrons
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Adapted from Fig. 1 of this preprint |
Saturday, September 20, 2025
H-1B visas and academia
Thursday, September 11, 2025
DOE Experimental Condensed Matter Physics PI Meeting 2025 - Day 3 and wrap-up
A few more interesting tidbits from the concluding half-day of the DOE ECMP PI meeting:
- Dmitri Basov showed some of the remarkable experiments enabled by layers of MoOCl2, which in the IR is an intrinsically hyperbolic optical material. This material has unusual plasmonic properties considering its high resistivity. These include peculiar cavity effects such as modifying superfluid density of a proximally coupled superconductor.
- Leonid Butov explained some remarkable evidence for superfluidity of indirect excitons excited in the moire bilayer of MoSe2/WSe2. Low temperature mean free paths of these objects can exceed hundreds of microns (!).
- Cui-Zu Chang showed evidence that truly stoichiometric FeTe is actually a superconductor with a critical temperature of about 13.5 K, rather than the usual thinking that it is an antiferromagnetic metal. Apparently an extra 2% of interstitial iron is enough to kill superconductivity and induce AFM order.
- James McIver presented an example of how nonlinear optical effects in an optically driven (Floquet) Weyl semimetal seem to vary linearly with driving field - anomalously strong.
- Dmytro Bozhko showed a really neat technique, using Brillouin light scattering to map out the dispersion of phonons and magnons in YIG, and to extend this approach with a special hollow-core optical fiber to low temperatures with the motivation of probing magnon superfluidity in a particular antiferromagnetic insulator.
- Ray Ashoori used his characteristically pretty quantum capacitance measurement technique to examine the density+displacement field+magnetic field phase diagram of 5-layer rhombohedral graphene, revealing some surprising fractional Chern insulator states.
- Claudia Ojeda-Aristizabal discussed some mesoscopic transport measurements in bilayer graphene, where an adsorbed layer of spin-containing CuPc molecules seems to affect both decoherence and the trigonal warping contribution to it (related to intervalley scattering).
- Feng Wang and You Zhou both discussed recent measurements looking at Wigner crystals and their properties in 2D TMDs, through a variety of means.
- Liuyan Zhao showed some very rich physics obtained in studies that moiré stack bilayers of the van der Waals insulating magnet CrI3.
Wednesday, September 10, 2025
DOE Experimental Condensed Matter Physics PI Meeting 2025 - Day 2
It was another very full day. I had to pop in and out to attend to some things so I didn't get everything, but here are some physics items I learned:
- Dillon Fong introduced me to a technique I didn't know about before, x-ray photon correlation spectroscopy (see this paper). You can look at time correlations of x-ray speckle near a particular Bragg spot and learn about dynamics and kinetics of transitions and materials growth. Very cute.
- Charles Ahn presented work on high magnetic field superconductivity in Nd(1-x)Eu(x)NiO2, and I learned about the Jaccarino-Peter effect, in which an external magnetic field can counter the interaction between magnetic dopants and the conduction electrons. This leads to "reentrant" superconductivity at high magnetic fields.
- Danny Phelan showed that you can have two different crystal structures for La3Ni2O7, one that is stacked bilayers ("2222"), and one that is stacked monolayer/trilayer ("1313").
- Ian Fisher talked about using the elastocaloric effect (rapidly and therefore adiabatically stretch or compress a material, leading to a change in its temperature) to identify phase transitions, since the effect is proportional to \( (\partial S/\partial \epsilon)_{T}\), the change in entropy with strain.
- Dan Dessau presented an interesting analysis of data in cuprates suggesting a form for the electronic self-energy that is called a power law liquid, and that this analysis implies that there is not a quantum critical point under the middle of the superconducting dome.
- Jak Chakhalian showed that epitaxially growing an iridate Weyl semimetal directly on top of insulating Dy2Ti2O7 spin ice leads to a dramatic anisotropic magnetoresistance at high in-plane fields that identifies interesting previously unknown physics.
- Daniel Rhodes showed some pretty work on superconductivity in T_d-MoTe2. This material is extremely air-sensitive, and all of the device fabrication has to be done with great care in a glovebox. This led to the following exchange. Audience question: "It is notoriously difficult to make electrical contact to this material. How did you do this?" Answer: "Through tears and blood." This was followed by a serious answer that concluded "The glovebox is always the problem."
Tuesday, September 09, 2025
DOE Experimental Condensed Matter Physics PI Meeting 2025 - Day 1
That was a full day. Here are some things I learned, beyond the fact that the ballroom here is clearly kept at about 15°C by default. (Apologies for not getting everything....)
- About 40% of the DOE ECMP program is related to 2D materials these days.
- Long Ju showed some interesting work trying to understand rhombohedral (ABC-stacked) 5-layer graphene encapsulated by hBN. Trying to get rid of moiré effects from the hBN/graphene interfaces leads not to more robust quantum anomalous Hall response, but instead leads to very peculiar superconductivity that survives up to very large in-plane and moderately large out-of-plane magnetic fields. This happens in the same regime of charge and gate that would otherwise show QAH. Looks like some kind of chiral superconductivity that may be topological.
- Andrea Young, meanwhile, in fewer layer rhombohedral systems, showed experiments pointing to superconductivity happening at the verge of a canting transition, where spins are reorienting.
- Eva Andrei gave a nice talk looking at the variety of states one can get when interfacing moiré systems with other moiré systems, and explaining what is meant by intercrystals.
- Gleb Finkelstein showed how a measurement intended to look at shot noise instead became a very cute noise thermometry probe of thermal transport at the boundary between (graphene) quantum Hall currents and a superconducting electrode.
- Xiao-Xiao Zhang showed a really cute experiment, where the resonance of a drumhead made from an atomically thin film of MnPS3 convey information about magnetic transitions in that material as a function of magnetic field.
- Dan Ralph gave a nice talk about the challenges of electrically generating currents of properly oriented spins to drive magnetic switching in films magnetized perpendicular to the film plane, for spin-orbit torque memories (and fundamental understanding).
- Philip Kim gave a great overview of some remarkable results in electronic interferometers made on graphene, in which telegraph noise shows signatures
- Lu Li spoke about recent measurements showing magnetic oscillations and specific heat signatures of possible neutral fermions in a kagome lattice Mott insulator.
- Xavier Roy talked about CeSiI, a 2D material that is also a heavy fermion metal. This and its related compounds look like a fascinating family of (unfortunately extremely air sensitive) materials.
- Harold Hwang gave a great overview of recent work in nickelate superconductors, highlighting the similarities to the cuprates as well as the profound differences (like how electronic configurations other than d9 can also lead to superconductivity).
Monday, September 08, 2025
DOE experimental condensed matter PI meeting, + other items
This week I am attending the every-two-years DOE Experimental Condensed Matter Physics PI meeting. Previously I have written up highlights of these meetings (see here, here, here, here, here), though two years I was unable to do so because I was attending virtually. I will do my best to hit some high points (though I will restrict myself to talking only about already published work, to avoid any issues of confidentiality).
In the meantime, here are a couple of topics of interest from the last couple of weeks.
- I just learned about the existence of Mathos AI, an AI product that can function as a math solver and calculator, as well as a tutor for students. It is pretty impressive.
- I liked this historical piece about Subrahmanyan Chandrasekhar (he of the “Chandrasekhar limit”, which describes the degeneracy physics + gravitation that limits the upper size of compact stellar objects like white dwarfs and neutron stars before they collapse into black holes) and his interactions with Stephen Hawking. It's pretty humanizing to see an intellectual giant like Chandra sending a brief letter to Hawking in 1967 asking for advice on what to read so that Chandra can understand Hawking’s work on singularities in cosmology. Hawking’s handwritten response is clear and direct.
- In an online discussion about what people will do if Google decides to stop supporting Google Scholar, I was introduced to OpenAlex. This seems like an interesting, also-free alternative. Certainly worth watching. There is no obvious reason to think that Google Scholar is going away, but Alphabet has retired many free products, and it’s far from obvious how they are making any money on this. Anyone from Google who reads the blog, please chime in. (Note to self: keep regularly backing up this blog, since blogger is also not guaranteed future existence.)
Thursday, August 28, 2025
25 years of Nano Letters
Sunday, August 24, 2025
Learning and AI/LLMs - Why do we need to know or teach anything anymore?
Saturday, August 16, 2025
20 years of Nanoscale Views, + a couple of things to read
- Total views: 8.3M
- Most views in one day, this past May 31, with 272K
- Top two most-viewed posts are this one from 2023 with a comment thread about Ranga Dias, and this one from 2009 titled "What is a plasmon?"
- Just a reminder that I have collected a bunch of condensed matter terms and concept posts here.
- I've also written some career-related posts, like a guide to faculty job searches, advice on choosing a graduate school, needs-to-be-updated advice on postdoc positions, etc.
- Some personal favorite posts, some of which I wish had gotten more notice, include the physics of drying your hands, the physics of why whiskey stones aren't as good as ice to cool your drink, materials and condensed matter in science fiction, the physics of vibranium, the physics of beskar, the physics of ornithopters, and why curving your pizza slice keeps if from flopping over. I'm also happy with why soft matter is hard, which was a well-viewed post.
- I also like to point out my essay about J. Henrik Schön, because I worry that people have forgotten about that episode.
- This post about Maxwell's Demon from the Skull in the Stars blog (which has been around nearly as long as mine!) is an excellent and informative piece of writing. I'm definitely pointing my statistical and thermal physics undergraduate class to this next month.
- Ross McKenzie has a very nice looking review article up on the arXiv about emergence. I haven't read it yet, but I have no doubt that it will be well-written and thought-provoking.
Thursday, August 07, 2025
Brief items - Static electricity, quantum geometry, Hubbard model, + news
It's been a busy time that has cut into my blogging, but I wanted to point out some links from the past couple of weeks.
- Physics Today has a cover article this past issue about what is colloquially known as static electricity, but what is more technically described as triboelectricity, the transfer of charge between materials by rubbing. I just wrote about this six months ago, and the detailed mechanisms remain poorly understood. Large surface charge densities (like \(10^{12}\) electronic charges per square cm) can be created this way on insulators, leading to potential differences large enough to jump a spark from your finger to the door handle. This can also lead to static electric fields near surfaces that are not small and can reveal local variations in material properties.
- That leads right into this paper (which I learned about from here) about the extreme shapes of the heads of a family of insects called treehoppers. These little crawlies have head and body shapes that often have cuspy, pointy bits that stick out - spines, horns, etc. As we learn early on about electrostatics, elongated and pointy shapes tend to lead to large local electric fields and field gradients. The argument of this paper is that the spiky body and cranial morphology can help these insects better sense electric field distributions, and this makes it easier for them to find their way and avoid predators.
- This manuscript on the arXiv this week is a particularly nice, pedagogical review article (formatted for Rev Mod Phys) about quantum geometry and Berry curvature in condensed matter systems. I haven't had the chance to read it through, but I think this will end up being very impactful and a true resource for students to learn about these topics.
- Another very pretty recent preprint is this one, which examines the electronic phase diagram of twisted bilayers of WSe2, with a relative twist angle of 4.6°. Much attention has been paid to the idea that moiré lattices can be in a regime seemingly well described by a Hubbard-like model, with an on-site Coulomb repulsion energy \(U\) and an electronic bandwidth \(W\). This paper shows an exceptionally clean example of this, where disorder seems to be very weak, electron temperatures are quite cold, and phase diagrams are revealed that look remarkably like the phenomena seen in the cuprate superconductors (superconducting "domes" as a function of charge density adjacent to antiferromagnetic insulating states, and with "strange metal" linear-in-\(T\) resistance in the normal state near the superconducting charge density). Results like this make me more optimistic about overcoming some of the major challenges in using twisted van der Waals materials as simulators of hard-to-solve hamilitonians.
Wednesday, July 23, 2025
Research experience for teachers - why NSF education funds matter
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The beginning of a RET poster session |
Readers may be more familiar with the sibling Research Experience for Undergraduates (REU) programs, which give undergraduate students the chance to work for 10 weeks or so in a lab that is very likely not at their home institution. REUs are a great way for students interested in research to get broad exposure to new topics, meet people and acquire new skills, and for some, figure out whether they like research (and maybe which topics are exciting to them). The educational goal of REUs is clear: providing direct research experience to interested undergrads, ideally while advancing a research project and for some small fraction of students resulting in an eventual publication.
RET programs are different: They are intended as professional development. The teachers are exposed to new topics, hopefully a fun research environment, and they are encouraged to think carefully about how they can take the concepts they learn and translate those for the classroom. I am very much not an expert in education research, but there is evidence (see here, for example) that teachers who participate in these programs get a great deal of satisfaction and have lower attrition from teaching professions. (Note that it's hard to do statistics well on questions like that, since the population of teachers that seek out opportunities like this may be a special subset of the total population of teachers.) An idea that makes sense to me: Enhancing the motivation and job satisfaction of a teacher can have a larger cumulative impact on educating students than an individual research project for a single student.
It would be a great shame if RET and REU programs are victims of large-scale cuts at NSF. The NSF is the only science agency with education as part of its mission (at least historically). All the more reason to try to persuade appropriators to not follow the draconian presidential budget request for the agency.
Friday, July 18, 2025
The latest on US science funding
The US House and Senate appropriations subcommittees have now completed their markups on the bills relevant to the FY26 appropriations for NSF, NASA, and NIST. The AAAS has an interactive dashboard with current information here if you want to click and look at all the science-related agencies. Other agencies still need to go through the Senate subcommittees.
Just a reminder of how this is supposed to work. The House and Senate mark up their own versions of the detailed appropriations bills. In principle these are passed by each chamber (with the Senate versions for practical purposes requiring 60/100 votes of support because of the filibuster). Then a conference committee hashes out the differences between the bills, and the conference version of the bills is then voted on by each chamber (again, needing 60/100 votes to pass in the Senate). Finally, the president signs the spending bills. In the fantasy land of Schoolhouse Rock, which largely described events until the 1990s, these annual spending bills are supposed to be passed in time for the start of the new fiscal year on October 1. In practice, Congress has been deeply dysfunctional for years, and there have been a lot of continuing resolutions, late budgets, and mammoth omnibus spending bills.
To summarize:
- NSF - House recommendation = $6.997B (a 20.7% cut from FY25), Senate = $9B (a 2% increase from FY25). These are in sharp contrast to the presidential budget request (PBR) of a 55.8% cut.
- NASA - House = flat from FY25, Senate = $24.9B (0.2% increase).
- NIST - House = $1.28B (10.6% increase from FY25), Senate = $1.6B (38.3% increase from FY25)
- NOAA - House = $5.7B (28.3% increase from FY25), Senate = $6.1B (36.3% increase from FY25)
Friday, July 11, 2025
US science funding - now time to push on the House appropriators
Tuesday, July 08, 2025
New updates + tetrahedra, tunneling times, and more
- Essentially all the news pertaining to the US federal funding of science continues to be awful. This article from Science summarizes the situation well, as does this from The Guardian and this editorial in the Washington Post. I do like the idea of a science fair of cancelled grants as a way to try to get alleged bipartisan appropriator notice of just how bad the consequences would be of the proposed cuts.
- On a more uplifting note, mathematicians have empirically demonstrated a conjecture originally made by John Conway, that it is possible to make a tetrahedral pyramid that, under gravity, has only one stable orientation. Quanta has a nice piece on this with a cool animated gif, and here is the actual preprint about it. It's all about mass distributions and moments of inertia about edges. As others have pointed out including the authors, this could be quite useful for situations like recent lunar lander attempts that seem to have a difficult time not topping over.
- A paper last week in Nature uses photons and a microcavity to try to test how long it takes photons to tunnel through a classically forbidden region. In this setup, it is mathematically legit to model the photons as if they have an effective mass, and one can model the barrier they need to traverse in terms of an effective potential energy. Classically, if the kinetic energy of the particle of interest is less than the potential energy of the barrier, the particle is forbidden inside the barrier. I've posted about the issue of tunneling time repeatedly over the years (see here for a 2020 post containing links), because I think it's a fascinating problem both conceptually and as a puzzle for experimentalists (how does one truly do a fair test of this?). The take-away from this paper is, the more classically forbidden the motion, the faster the deduced tunneling time. This has been seen in other experiments testing this idea. A key element of novelty in the new paper is the claim that the present experiment seems (according to the authors) to not be reasonably modeled by Bohmian mechanics. I'd need to read this in more depth to better understand it, as I had thought that Bohmian mechanics applied to problems like this is generally indistinguishable in predictions from conventional quantum mechanics, basically by design.
- In other non-condensed matter news, there is an interstellar comet transiting the solar system right now. This is very cool - it's only the third such object detected by humans, but to be fair we've only really been looking for a few years. This suggests that moderately sized hunks of material are likely passing through from interstellar space all the time, and the Vera C. Rubin Observatory will detect a boatload of them. My inner science fiction fan is hoping that the object changes its orbit at perihelion by mysterious means.
Monday, June 30, 2025
Science slow down - not a simple question
I participated in a program about 15 years ago that looked at science and technology challenges faced by a subset of the US government. I came away thinking that such problems fall into three broad categories.
- Actual science and engineering challenges, which require foundational research and creativity to solve.
- Technology that may be fervently desired but is incompatible with the laws of nature, economic reality, or both.
- Alleged science and engineering problems that are really human/sociology issues.
Part of science and engineering education and training is giving people the skills to recognize which problems belong to which categories. Confusing these can strongly shape the perception of whether science and engineering research is making progress.
There has been a lot of discussion in the last few years about whether scientific progress (however that is measured) has slowed down or stagnated. For example, see here:
https://www.theatlantic.com/science/archive/2018/11/diminishing-returns-science/575665/
https://news.uchicago.edu/scientific-progress-slowing-james-evans
https://theweek.com/science/world-losing-scientific-innovation-research
A lot of the recent talk is prompted by this 2023 study, which argues that despite the world having many more researchers than ever before (behold population growth) and more global investment in research, somehow "disruptive" innovations are coming less often, or are fewer and farther between these days. (Whether this is an accurate assessment is not a simple matter to resolve; more on this below.)
There is a whole tech bro culture that buys into this, however. For example, see this interview from last week in the New York Times with Peter Thiel, which points out that Thiel has been complaining about this for a decade and a half.
On some level, I get it emotionally. The unbounded future spun in a lot of science fiction seems very far away. Where is my flying car? Where is my jet pack? Where is my moon base? Where are my fusion power plants, my antigravity machine, my tractor beams, my faster-than-light drive? Why does the world today somehow not seem that different than the world of 1985, while the world of 1985 seems very different than that of 1945?
Some of the folks that buy into this think that science is deeply broken somehow - that we've screwed something up, because we are not getting the future they think we were "promised". Some of these people have this as an internal justification underpinning the dismantling of the NSF, the NIH, basically a huge swath of the research ecosystem in the US. These same people would likely say that I am part of the problem, and that I can't be objective about this because the whole research ecosystem as it currently exists is a groupthink self-reinforcing spiral of mediocrity.
Science and engineering are inherently human ventures, and I think a lot of these concerns have an emotional component. My take at the moment is this:
- Genuinely transformational breakthroughs are rare. They often require a combination of novel insights, previously unavailable technological capabilities, and luck. They don't come on a schedule.
- There is no hard and fast rule that guarantees continuous exponential technological progress. Indeed, in real life, exponential growth regimes never last. The 19th and 20th centuries were special. If we think of research as a quest for understanding, it's inherently hierarchal. Civilizational collapses aside, you can only discover how electricity works once. You can only discover the germ theory of disease, the nature of the immune system, and vaccination once (though in the US we appear to be trying really hard to test that by forgetting everything). You can only discover quantum mechanics once, and doing so doesn't imply that there will be an ongoing (infinite?) chain of discoveries of similar magnitude.
- People are bad at accurately perceiving rare events and their consequences, just like people have a serious problem evaluating risk or telling the difference between correlation and causation. We can't always recognize breakthroughs when they happen. Sure, I don't have a flying car. I do have a device in my pocket that weighs only a few ounces, gives me near-instantaneous access to the sum total of human knowledge, let's me video call people around the world, can monitor aspects of my fitness, and makes it possible for me to watch sweet videos about dogs. The argument that we don't have transformative, enormously disruptive breakthroughs as often as we used to or as often as we "should" is in my view based quite a bit on perception.
- Personally, I think we still have a lot more to learn about the natural world. AI tools will undoubtedly be helpful in making progress in many areas, but I think it is definitely premature to argue that the vast majority of future advances will come from artificial superintelligences and thus we can go ahead and abandon the strategies that got us the remarkable achievements of the last few decades.
- I think some of the loudest complainers (Thiel, for example) about perceived slowing advancement are software people. People who come from the software development world don't always appreciate that physical infrastructure and understanding are hard, and that there are not always clever or even brute-force ways to get to an end goal. Solving foundational problems in molecular biology or quantum information hardware or photonics or materials is not the same as software development. (The tech folks generally know this on an intellectual level, but I don't think all of them really understand it in their guts. That's why so many of them seem to ignore real world physical constraints when talking about AI.). Trying to apply software development inspired approaches to science and engineering research isn't bad as a component of a many-pronged strategy, but alone it may not give the desired results - as warned in part by this piece in Science this week.
More frequent breakthroughs in our understanding and capabilities would be wonderful. I don't think dynamiting the US research ecosystem is the way to get us there, and hoping that we can dismantle everything because AI will somehow herald a new golden age seems premature at best.
Saturday, June 28, 2025
Cryogenic CMOS - a key need for solid state quantum information processing
The basis for much of modern electronics is a set of silicon technologies called CMOS, which stands for complementary metal oxide semiconductor devices and processes. "Complementary" means using semiconductors (typically silicon) that is locally chemically doped so that you can have both n-type (carriers are negatively charged electrons in the conduction band) and p-type (carriers are positively charged holes in the valence band) material on the same substrate. With field-effect transistors (using oxide gate dielectrics), you can make very compact, comparatively low power devices like inverters and logic gates.
There are multiple different approaches to try to implement quantum information processing in solid state platforms, with the idea that the scaling lessons of microelectronics (in terms of device density and reliability) can be applied. I think that essentially all of these avenues require cryogenic operating conditions; all superconducting qubits need ultracold conditions for both superconductivity and to minimize extraneous quasiparticles and other decoherence sources. Semiconductor-based quantum dots (Intel's favorite) similarly need thermal perturbations and decoherence to be minimized. The wealth of solid state quantum computing research is the driver for the historically enormous (to me, anyway) growth of dilution refrigerator manufacturing (see my last point here).
So you eventually want to have thousands of error-corrected logical qubits at sub-Kelvin temperatures, which may involve millions of physical qubits at sub-Kelvin temperatures, all of which need to be controlled. Despite the absolute experimental fearlessness of people like John Martinis, you are not going to get this to work by running a million wires from room temperature into your dil fridge.
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Fig. 1 from here. |
In this most recent work, the aspect that I find most impressive is that the CMOS electronics are essentially a serious logic-based control board operating at milliKelvin temperatures right next to the chip with the qubits (in this case, spins-in-quantum-dots). I'm rather blown away that this works and with sufficiently low power dissipation that the fridge is happy. This is very impressive, and there is likely a very serious future in store for cryogenic CMOS.
Saturday, June 21, 2025
Brief items - fresh perspectives, some news bits
- First, it's a pleasure to see new long-form writing about condensed matter subjects, in an era where science blogging has unquestionably shrunk compared to its heyday. The new Quantum Matters substack by Justin Wilson (and William Shelton) looks like it will be a fun place to visit often.
- Similar in spirit, I've also just learned about the Knowmads podcast (here on youtube), put out by Prachi Garella and Bhavay Tyagi, two doctoral students at the University of Houston. Fun Interviews with interesting scientists about their science and how they get it done.
- There have been some additional news bits relevant to the present research funding/university-govt relations mess. Earlier this week, 200 business leaders published an open letter about how the slashing support for university research will seriously harm US economic competitiveness. More of this, please. I continue to be surprised by how quiet technology-related, pharma, and finance companies are being, at least in public. Crushing US science and engineering university research will lead to serious personnel and IP shortages down the line, definitely poor for US standing. Again, now is the time to push back on legislators about cuts mooted in the presidential budget request.
- The would-be 15% indirect cost rate at NSF has been found to be illegal, in a summary court judgment released yesterday. (Brief article here, pdf of the ruling here.)
- Along these lines, there are continued efforts for proposals about how to reform/alter indirect cost rates in a far less draconian manner. These are backed by collective organizations like the AAU and COGR. If you're interested in this, please go here, read the ideas, and give some feedback. (Note for future reference: the Joint Associations Group (JAG) may want to re-think their acronym. In local slang where I grew up, the word "jag" does not have pleasant connotations.)
- The punitive attempt to prevent Harvard from taking international students has also been stopped for now in the courts.
Sunday, June 15, 2025
So you want to build a science/engineering laboratory building
- The NSF awarded 500 more graduate fellowships this week, bringing the total for this year up to 1500. (Apologies for the X link.) This is still 25% lower than last year's number, and of course far below the original CHIPS and Science act target of 3000, but it's better than the alternative. I think we can now all agree that the supposed large-scale bipartisan support for the CHIPS and Science act was illusory.
- There seems to be some initial signs of pushback on the senate side regarding the proposed massive science funding cuts. Again, now is the time to make views known to legislators - I am told by multiple people with experience in this arena that it really can matter.
- There was a statement earlier this week that apparently the US won't be going after Chinese student visas. This would carry more weight if it didn't look like US leadership was wandering ergodically through all possible things to say with no actual plan or memory.
- Any big laboratory building should have a dedicated loading dock with central receiving. If you're spending $100M-200M on a building, this is not something that you should "value engineer" away. The long term goal is a building that operates well for the PIs and is easy to maintain, and you're going to need to be able to bring in big crates for lab and service equipment. You should have a freight elevator adjacent to the dock.
- You should also think hard about what kind of equipment will have to be moved in and out of the building when designing hallways, floor layouts, and door widths. You don't want to have to take out walls, doorframes, or windows, or to need a crane to hoist equipment into upper floors because it can't get around corners.
- Think hard about process gasses and storage tanks at the beginning. Will PIs need to have gas cylinders and liquid nitrogen and argon tanks brought in and out in high volumes all the time, with all the attendant safety concerns? Would you be better off getting LN2 or LAr tanks even though campus architects will say they are unsightly?
- Likewise, consider whether you should have building-wide service for "lab vacuum", N2 gas, compressed air, DI water, etc. If not and PIs have those needs, you should plan ahead to deal with this.
- Gas cylinder and chemical storage - do you have enough on-site storage space for empty cylinders and back-up supply cylinders? If this is a very chemistry-heavy building, think hard about safety and storing solvents.
- Make sure you design for adequate exhaust capacity for fume hoods. Someone will always want to add more hoods. While all things are possible with huge expenditures, it's better to make sure you have capacity to spare, because adding hoods beyond the initial capacity would likely require a huge redo of the building HVAC systems.
- Speaking of HVAC, think really hard about controls and monitoring. Are you going to have labs that need tight requirements on temperature and humidity? When you set these up, put have enough sensors of the right types in the right places, and make sure that your system is designed to work even when the outside air conditions are at their seasonal extremes (hot and humid in the summer, cold and dry in the winter). Also, consider having a vestibule (air lock) for the main building entrance - you'd rather not scoop a bunch of hot, humid air (or freezing, super-dry air) into the building every time a student opens the door.
- Still on HVAC, make sure that power outages and restarts don't lead to weird situations like having the whole building at negative pressure relative to the outside, or duct work bulging or collapsing.
- Still on HVAC, actually think about where the condensate drains for the fan units will overflow if they get plugged up or overwhelmed. You really don't want water spilling all over a rack of networking equipment in an IT closet. Trust me.
- Chilled water: Whether it's the process chilled water for the air conditioning, or the secondary chilled water for lab equipment, make sure that the loop is built correctly. Incompatible metals (e.g., some genius throws in a cast iron fitting somewhere, or joints between dissimilar metals) can lead to years and years of problems down the line. Make sure lines are flushed and monitored for cleanliness, and have filters in each lab that can be checked and maintained easily.
- Electrical - design with future needs in mind. If possible, it's a good idea to have PI labs with their own isolation transformers, to try to mitigate inter-lab electrical noise issues. Make sure your electrical contractors understand the idea of having "clean" vs. "dirty" power and can set up the grounding accordingly while still being in code.
- Still on electrical, consider building-wide surge protection, and think about emergency power capacity. For those who don't know, emergency power is usually a motor-generator that kicks in after a few seconds to make sure that emergency lighting and critical systems (including lab exhaust) keep going.
- Ceiling heights, duct work, etc. - It's not unusual for some PIs to have tall pieces of equipment. Think about how you will accommodate these. Pits in the floors of basement labs? 5 meter slab-to-slab spacing? Think also about how ductwork and conduits are routed. You don't want someone to tell you that installation of a new apparatus is going to cost a bonus $100K because shifting a duct sideways by half a meter will require a complete HVAC redesign.
- Think about the balance between lab space and office space/student seating. No one likes giant cubicle farm student seating, but it does have capacity. In these days of zoom and remote access to experiments, the way students and postdocs use offices is evolving, which makes planning difficult. Health and safety folks would definitely prefer not to have personnel effectively headquartered directly in lab spaces. Seriously, though, when programming a building, you need to think about how many people per PI lab space will need places to sit. I have yet to see a building initially designed with enough seating to handle all the personnel needs if every PI lab were fully occupied and at a high level of research activity.
- Think about maintenance down the line. Every major building system has some lifespan. If a big air handler fails, is it accessible and serviceable, or would that require taking out walls or cutting equipment into pieces and disrupting the entire building? Do you want to set up a situation where you may have to do this every decade? (Asking for a friend.)
- Entering the realm of fantasy, use your vast power and influence to get your organization to emphasize preventative maintenance at an appropriate level, consistently over the years. Universities (and national labs and industrial labs) love "deferred maintenance" because kicking the can down the road can make a possible cost issue now into someone else's problem later. Saving money in the short term can be very tempting. It's also often easier and more glamorous to raise money for the new J. Smith Laboratory for Physical Sciences than it is to raise money to replace the HVAC system in the old D. Jones Engineering Building. Avoid this temptation, or one day (inevitably when times are tight) your university will notice that it has $300M in deferred maintenance needs.
Saturday, June 07, 2025
A precision measurement science mystery - new physics or incomplete calculations?
Sunday, June 01, 2025
Pushing back on US science cuts: Now is a critical time
Every week has brought more news about actions that, either as a collateral effect or a deliberate goal, will deeply damage science and engineering research in the US. Put aside for a moment the tremendously important issue of student visas (where there seems to be a policy of strategic vagueness, to maximize the implicit threat that there may be selective actions). Put aside the statement from a Justice Department official that there is a general plan is to "bring these universities to their knees", on the pretext that this is somehow about civil rights.
The detailed version of the presidential budget request for FY26 is now out (pdf here for the NSF portion). If enacted, it would be deeply damaging to science and engineering research in the US and the pipeline of trained students who support the technology sector. Taking NSF first: The topline NSF budget would be cut from $8.34B to $3.28B. Engineering would be cut by 75%, Math and Physical Science by 66.8%. The anticipated agency-wide success rate for grants would nominally drop below 7%, though that is misleading (basically taking the present average success rate and cutting it by 2/3, while some programs are already more competitive than others.). In practice, many programs already have future-year obligations, and any remaining funds will have to go there, meaning that many programs would likely have no awards at all in the coming fiscal year. The NSF's CAREER program (that agency's flagship young investigator program) would go away This plan would also close one of the LIGO observatories (see previous link). (This would be an extra bonus level of stupid, since LIGO's ability to do science relies on having two facilities, to avoid false positives and to identify event locations in the sky. You might as well say that you'll keep an accelerator running but not the detector.) Here is the table that I think hits hardest, dollars aside:
The number of people involved in NSF activities would drop by 240,000. The graduate research fellowship program would be cut by more than half. The NSF research training grant program (another vector for grad fellowships) would be eliminated.The situation at NIH and NASA is at least as bleak. See here for a discussion from Joshua Weitz at Maryland which includes this plot:
This proposed dismantling of US research and especially the pipeline of students who support the technology sector (including medical research, computer science, AI, the semiconductor industry, chemistry and chemical engineering, the energy industry) is astonishing in absolute terms. It also does not square with the claim of some of our elected officials and high tech CEOs to worry about US competitiveness in science and engineering. (These proposed cuts are not about fiscal responsibility; just the amount added in the proposed DOD budget dwarfs these cuts by more than a factor of 3.)
If you are a US citizen and think this is the wrong direction, now is the time to talk to your representatives in Congress. In the past, Congress has ignored presidential budget requests for big cuts. The American Physical Society, for example, has tools to help with this. Contacting legislators by phone is also made easy these days. From the standpoint of public outreach, Cornell has an effort backing large-scale writing of editorials and letters to the editor.
Thursday, May 29, 2025
Quick survey - machine shops and maker spaces
Thursday, May 22, 2025
How badly has NSF funding already been effectively cut?
This NY Times feature lets you see how each piece of NSF's funding has been reduced this year relative to the normalized average spanning in the last decade. Note: this fiscal year, thanks to the continuing resolution, the actual agency budget has not actually been cut like this. They are just not spending congressionally appropriated agency funds. The agency, fearing/assuming that its budget will get hammered next fiscal year, does not want to start awards that it won't be able to fund in out-years. The result is that this is effectively obeying in advance the presidential budget request for FY26. (And it's highly likely that some will point to unspent funds later in the year and use that as a justification for cuts, when in fact it's anticipation of possible cuts that has led to unspent funds. I'm sure the Germans have a polysyllabic word for this. In English, "Catch-22" is close.)
I encourage you to click the link and go to the article where the graphic is interactive (if it works in your location - not sure about whether the link works internationally). The different colored regions are approximately each of the NSF directorates (in their old organizational structure). Each subsection is a particular program.