My hottest parenting take is that Raffi is not only the great to ever do it, but he’ll probably never be bested. Michael Phelps-ass children’s songwriter.

A fun journey back to the early days of photonic crystals for us, with a twist: defects, but only lossy ones, in a non-Hermitian photonic crystal, cause the formation of singularities that are topologically non-trivial. Lossy defects yield large improvements in gain. journals.aps.org/prapplied/ab...

We've always designed space solar cells to capture as much spectrum as possible. Our new paper in Device shows that's the wrong approach. When you're thermally limited by radiative cooling, absorbing less light can produce more power. 🧵 Link: authors.elsevier.com/a/1n5rC9UPy1...

Poking around the Truman library photograph collections, I have discovered that first NSF director Alan Waterman knew how to party www.trumanlibrary.gov/photograph-r...

Because the Moon is tidally locked to the Earth, if you build your habitat on some plot of near-side regolith you can put the little Earth anywhere in the sky you want & it’ll stay there, lazily meandering around just a little as the Moon wobbles in its orbit. A view of Earthset from #Artemis II.

Artemis launch watch party!

ArXiv lately has been putting everything I submit on hold, and has rejected manuscripts that are clearly part of their purview/ the physics.optics category (ie: there's stuff on there from a month ago on the exact topic!) Really not sure what's going on.. having to appeal is tiresome

I am excited to share our latest paper, Uniform bacterial genetic diversity along the gut, now out in Nature Communications! www.nature.com/articles/s41.... (1/n)

Time to do some theory again.. new preprint that we think will be pretty useful for understanding and designing nonreciprocal photonic systems for thermal emission arxiv.org/abs/2603.23538

Project Hail Mary was great! Stuck to the spirit and overall plot of the book, though obviously less of the science exposition. First time I've gone to a movie on opening weekend in a very long time..

Enjoyed Preskill’s keynote at APS

If you're at the @apsphysics.bsky.social Global Physics Summit, I'll be speaking at the FIAP prize session this afternoon at 4pm along with some other cool applied physics talks!

I'm.. randomly.. remembering the Newfoundland referendums of 1948: "President Harry S. Truman's administration had little incentive to pursue annexation. With respect to foreign policy, such a territorial ambition would have only served to antagonize two key allies." en.wikipedia.org/wiki/1948_Ne...

Grateful to share our paper on gene-specific selective sweeps in human gut microbiomes, now out in Nature! It has been a joy to work with @rwolff.bsky.social, whose insights and hard work made this possible. www.nature.com/articles/s41...

I was on a DARPA project with a program officer who came from industry and didn't go to grad school One day the program officer told us that before working at DARPA, he thought universities were inefficient, but now was shocked at how much we and other university performers got done for so little $

Well this is getting confusing, there’s a new (Wiley) journal also named Nanophotonics: onlinelibrary.wiley.com/journal/2192... not to be confused with the established De Gruyter one: www.degruyterbrill.com/journal/key/...

If students are getting 4.0s in their high schools math classes but unable to do 1st-8th grade math, the SAT has to be back on the table (as it already is at many other places). www.insidehighered.com/news/quick-t...

Here's a poem by one of the old Chinese scholar bureaucrats that I think captures a certain Vibe very well

New preprint! Turns out that there is a thermal penalty to harvesting longer wavelength solar photons when your operating temperature is constrained by your radiating surface area (ie: in space). arxiv.org/abs/2506.16588

We have a new preprint on arXiv, "Passive radiative cooling using temperature-dependent emissivity can sometimes outperform static emitters", led by Yeonghoon Jin We show how one can design a thermal emitter with temperature-dependent emissivity to optimize radiative-cooling performance 💡🧪

John Tyler became US president in 1841. His youngest grandson just died this past weekend. www.richmonder.org/harrison-ruf...

New online! Efficient outdoor thermal comfort via radiant cooling and infrared-reflective walls

How can we keep people safe outdoors in extreme heat? In a paper out today in @naturesustain.bsky.social we demonstrate that active radiant cooling and IR-reflective walls can deliver thermal comfort and be accepted by members of heat-vulnerable communities. rdcu.be/ekMzN

Why Lawrence of Arabia Still Looks Like a Billion Bucks. “I got to see Lawrence of Arabia on a big screen last fall and it was stunning — the colors, the amount of detail, the cinematography in general.” [kottke.org]

is ds9 called terok nor again

It is notable that Steve Blank felt that he had to write this, but a sign of the times... steveblank.com/2025/04/15/h...

Join us in Marseille this July! 💡

Power demand in the US was up 3% last year! Mostly due to greater AC use due to heat waves (hello hottest year on record), plus some "help" from data centers (and EVs). We'd better get used to it though: it's time for growth mode! We need to build new clean supply (at least) 2x as fast as load grows

Feasibility of keeping Mars warm with nanoparticles

All I want for Christmas is a new preprint.. arxiv.org/abs/2412.17659

Solstice, what solstice? It's warmer on Dec. 18 (79F/ 26C) than Jun. 18 (73F/ 23C) here in the western part of LA. A testament to the power of the large thermal mass otherwise known as the Pacific Ocean!

“Williams’s painting conveys a proud visual message: I, Francis Williams, free Black gentleman and scholar, born in Jamaica and educated in Britain, witnessed the return of Halley’s comet and I calculated its exact trajectory, according to the rules of the third edition of Isaac Newton’s Principia.”

Could California’s effectively deciding to drive up energy prices, partly to help build out clean energy faster, cost lives in the face of more extreme heatwaves? A sobering thought..

New preprint out on arXiv, "Large tuning of the optical properties of nanoscale NdNiO3 via electron doping" arxiv.org/abs/2411.15679 🧪💡 Led by Yeonghoon Jin from our lab at UW-Madison, Teng Qu from Nanfang Yu's lab at Columbia, and Siddharth Kumar from Shriram Ramanathan's lab at Rutgers

This is wild - hundreds more yet left to discover per the authors www.nytimes.com/2024/11/23/s...

In a new preprint led by Dr. Parthi Santhanam we demonstrate a monolithically integrated optoelectronic platform for voltage boost conversion. Voltage conversion is a foundational power electronic capability: we show how to do it more compactly and effectively arxiv.org/abs/2410.13220 💡

We are recruiting for multiple faculty positions in our department - please share widely! Deadline is Dec. 1 recruit.apo.ucla.edu/JPF09729

Some thoughts and comments from me on radiative cooling and textiles.. cen.acs.org/materials/To...

Some thoughts and comments from me on radiative cooling and textiles.. cen.acs.org/materials/To...

We are recruiting for multiple faculty positions in our department - please share widely! Deadline is Dec. 1 recruit.apo.ucla.edu/JPF09729

Delighted to share that our paper on discovering selective sweeps with haplotype statistics in aDNA is now out in Nat. Comm! www.nature.com/articles/s41... Wonderful collaboration with Vagheesh Narasimhan, Devansh Pandey, and @mharris.bsky.social

In a new preprint led by Dr. Parthi Santhanam we demonstrate a monolithically integrated optoelectronic platform for voltage boost conversion. Voltage conversion is a foundational power electronic capability: we show how to do it more compactly and effectively arxiv.org/abs/2410.13220 💡

I think I'm on some kind of arXiv (bad) list.. every time I submit a preprint it gets put on hold. If my students/ postdocs do, it's not.... anyone have experience with this? 💡

In collaborative work with Harry Atwater's group and Bo Zhao we experimentally demonstrate broadband nonreciprocal thermal emission using gradient ENZ materials. A critical step for nonreciprocal thermal emission's use in energy applications. 🧪💡 www.nature.com/articles/s41...

Hmmm... (I'm one of the sceptics on the record) www.chemistryworld.com/news/impossi...

"Bush’s pivotal contribution was his creation of the “research contract,” whereby public funds are awarded to civilian scientists based on effort, not outcomes (as had been normal before World War II). This freedom to try new things transformed academia." spectrum.ieee.org/vannevar-bush

Check out our new paper in Laser & Photonics Reviews demonstrating how a solution-processed disordered plasmonic surface can be an excellent long-wave IR specular reflector and a diffuse solar absorber. This makes it a great optic for thermal imaging systems 💡 onlinelibrary.wiley.com/doi/full/10....

On a 55 min Waymo ride from the Westside to Downtown LA, AMA

If you're at #F23MRS our group will have three talks, including two invited talks I'll be giving. In the first of them, since my first rooftop experiment demonstrating daytime radiative cooling was almost exactly 10 years ago (!) I'll try to both summarize progress and look to the future. 💡