Daniel Carney

"Why doesn't a charge sitting still on the surface of Earth radiate" has many good answers but this paper is my new favorite. If the earth was big enough that the radiation zone of the charge was within the "approximately flat" local region, the earth would be a black hole 😎

@martinmbauer All true, but many of those effects can also be explained by classical or semiclassical radiation. To really nail it down, add sub-Poisson photocounting, Bell violations with light, entanglement in light-matter experiments…

The quantisation of the electromagnetic field doesn’t just affect emission and absorption. It explains blackbody radiation, scattering, indirect effects of the electromagnetic field, for example the way energetic charged particles interact or precision measurements of fundamental constants, etc And not just qualitatively, but in agreement with some of the most precise measurements in history. It’s not a dumb question, many don’t appreciate how extraordinarily strong and consistent the evidence for photons is

Here is a thought experiment on the "physics is broken/dead/stuck" discourse that keeps showing up. Suppose Steve Weinberg was born in ~2006. Would he go into physics today? If so, what field?

Wonderful talk on 229-Th by Harry Morgan @KITP_UCSB

Filed under "I should have paid more attention to chemistry in high school"

@eviciium Totally reasonable question! Some answers: 1. Flex 2. It's a way to measure gas pressures at levels that are currently so low that existing sensors just measure 0 (arxiv.org/abs/2303.09922) 3. Characterizing backgrounds for fundamental physics measurements we want to do

@four_form Sounds interesting. A bit of a dumb question but what are the reasons to explore this? (The increased sensitivity is obviously an important result) But other than sensitivity are there any other motivations like some new physics?

2024: proposal to make a gas pressure measurement by literally counting every collision with a sensor 2026: measurement. Could not be happier to see this work exactly like we drew it up arxiv.org/abs/2604.18371

@Jess_Riedel Yeah, I think that's right. Cooling these spheres to the ground state (or even putting them in squeezed vacuum states) is possible, but it's not needed for these impulse measurements, fortunately... science.org/doi/10.1126/sc…

@four_form Oh this is cool. Does GPT’s estimate (based on the PRX Quantum paper) of 4*10^3 mean excitations for the nanoparticle sound right?

We invite applications for Research Fellow positions as part of a new initiative to be launched in late 2026 at the interface of quantum information theory and gravity! Please RT and let potentially interested researchers know. 1/

Dude, are there non-trivial non-pathological Lorentz-covariant Lindbladians in QFT or not? Are the current no-go arguments like Myrvold [1709.03219] as strong as we can hope for? Is the situation better understood in classical field theory?

this morning i have received emails about: -nuclear winter -claude can hack anything -fluffy animals wearing berkeley physics shirts this era is so fucking weird

@Muppetsexual @avfeyn137 @jonathon_gault Sound in solids can be quantized into phonons. Sound in dilute gases cannot. It depends on the condensed state you are expanding around

@avfeyn137 @jonathon_gault @four_form Even sound has phonons, if gravity doesn't have gravitons it doesn't call into question or understanding of gravity but of waves in general

Gravity is probably quantized into gravitons. If not, however, there are experimental consequences. In particular, some level of irreversibility/noise. We finally classified ~all such models and calculated the noise. arxiv.org/abs/2603.26075

@Cosmalano @Samuel_Gregson You can definitely treat theoretically as gravitons. The question is whether that accurately describes nature

@four_form @Samuel_Gregson I don’t understand this phrasing, “probably”? You can definitely treat quantum gravity with gravitons at low energies, but I doubt that you’re saying that at high energies gravitons are still the relevant degrees of freedom. Are you?

@jonathon_gault Gravitons are space time curvature. Just like photons are electromagnetic field

@four_form This makes no sense to me. Why is there a need for gravitons if the effect of gravity is due to space-time curvature?

@cosmicfibretion x.com/sineatrix/stat…

Where are the AI labs trying to make room-temperature superconductors? Why the fuck isn't this a priority? Stop yapping and start delivering the goods.

@WKCosmo Interesting. How does the bound work, what would go wrong with the warm light DM?

JWST quasar lensing ruling out thermal warm dark matter with m < 8 keV.

Come to @UCSDPhysics. We will continue to have human grad students.

@JosephPConlon Personal experience may vary, but when I talk to people outside high energy it's quite common to get questions like "but isn't string theory dead?" etc

People are thinking — for the first time in decades — about whether string theory describes the world. Apparently. Really? Quanta needs to get out of its bubble and talk to more people.