20 years of Nanoscale Views, + a couple of things to read

Amazingly, this blog has now been around for more than twenty years (!) - see this first post for reference from June of 2005, when I had much less gray hair and there were a lot more science blogs.  Thanks to all of you for sticking around. Back then, when I debuted my writing to my loyal readers (all five of them at the time), I never thought I'd keep this up.  Some info, including stats according to blogger:

• 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.

Real life has intruded quite a bit into my writing time the last couple of years, but I hope to keep doing this for a while longer.  I also still hope one day to find the right time and approach to write a popular book about the physics of materials, why they are amazing, and why our understanding of this physics, limited as it is, is still an astonishing intellectual achievement. 

Two other things to read that I came across this week:

• 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.

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.

I was all set to post this earlier today, with no awful news for once about science in the US that I felt compelled to discuss, but I got sidetracked by real work.  Then, late this afternoon, this executive order about federal grants was released.  

I can't sugar coat it - it's awful.  Ignoring a large volume of inflammatory rhetoric, it contains this gem, for instance:  "The grant review process itself also undermines the interests of American taxpayers."   It essentially tries to bar any new calls for proposals until a new (and problematic) process is put in place at every agency (see Sect. 3(c)).  Also, it says "All else being equal, preference for discretionary awards should be given to institutions with lower indirect cost rates."  Now, indirect cost rates are set by negotiations between institutions and the government.   Places that only do very small volumes of research have low rates, so get ready for MIT to get fewer grants and Slippery Rock University to get more.  The only certainty is that the nation's lawyers are going to have a field day with all the suits that will come out of this.