Adrian Fraser

See, e.g. bsky.app/profile/atru...

(Oops, switch “upper” and “lower” in the above)

Nonmodal growth and optimal perturbations in magnetohydrodynamic shear flows In astrophysical shear flows, the Kelvin-Helmholtz (KH) instability is generally suppressed by magnetic tension provided a sufficiently strong streamwise magnetic field. This is often used to infer up...

Hey astrophysicists, a presence (absence) of KH billows in some astrophysical shear flow doesn't always imply a lower (upper) bound on the local magnetic field strength! See arxiv.org/abs/2510.031...

Trump is pronouncing "acetaminophen" the right way.

by Ezra Klein

Friends, colleagues, my heart is heavy as I share with you some deeply saddening news: “asymptotically spicy” will not, in fact, survive to final publication of this manuscript. But it will live on in the arXiv preprint, at least

Where do people study MHD turbulence in The Netherlands? Asking for a friend looking for a job

It was a good point, though! There were some pertinent examples on academic twitter ca. 2020ish where the same point could’ve been made

Just trying to prepare myself to argue why my research actually does align with the WH’s priorities

Like most modern astrophysicists, Trump is quickly realizing that he can’t keep neglecting magnetic fields

Suddenly thinking this old proposal idea might have a chance

Accepted for publication in JFM Rapids 🎉

Trump’s Tactics Mean Many International Students Won’t Make It to Campus

If this continues, the most talented American students will want to study abroad, because they'll want to study with the most talented students and faculty from around the world, and those people won't want to come to the United States even if they can. www.nytimes.com/2025/08/20/u...

NYT spelling bee takes all kinds of niche words but NOT “adiabatic”??? Anti-science sentiments from NYT in the Trump era, you hate to see it

BREAKING: The NIH director has ordered an immediate review of all the agency's research activities. Any projects that don't fit agency priorities "may be restricted, paused, not renewed, or terminated." My story:

So bad.The EO institutionalizes and intensifies the politicization of federal research funding. The provisions weaken scientific expertise in funding decisions and effectively cede control to political appointees. The basic logistics here will also further slow walk release of federal research funds

Obnoxious!

Inspired by a certain program I’m submitting to requiring TEN PAGES for TWO YEARS of support for ONE PERSON, while the RSURF requires FOUR PAGES for like 4-8 years plus additional support for a student and postdoc. Wild range

The ratio (length of proposal in pages)/(years of funding awarded) is an important thing. Too large, and the proposal writing process feels like a waste of time if the program is competitive. Too small, and it’s hard to convince people you know your stuff. No idea what the optimal value is.

the one thing i genuinely did not anticipate from this administration was its vicious, know nothing hostility to any and everything that might even be adjacent to science and scientific research. they genuinely one to destroy the entirety of the nation’s research capacity. and for what, exactly?

Fresh on the arXiv today: if you take a thermally stably stratified (AKA subadiabatic AKA Schwartzchild- & Ledoux-stable) layer and sprinkle just a tiny bit of salt on the top, the salt fingers that form drive a helical mean flow that twists them into corkscrews arxiv.org/abs/2506.22581

Pass-through businesses, of which he owned one!

Volume rendering from a fluid dynamics simulation shows several corkscrew-shaped structures dancing about each other

Figure from the paper shows snapshots of the corkscrew structures

What the things actually look like. First image is a volume rendering of the vertical velocity, which gets twisted about by the helical flow

A screenshot of the first page of a paper on salt fingers. Abstract reads: We study the dynamics of salt fingers in the regime of slow salinity diffusion (small inverse Lewis number) and strong stratification (large density ratio), focusing on regimes relevant to Earth’s oceans. Using three-dimensional direct numerical simulations in periodic domains, we show that salt fingers exhibit rich, multiscale dynamics in this regime, with vertically elongated fingers that are twisted into helical shapes at large scales by mean flows and disrupted at small scales by isotropic eddies. We use a multiscale asymptotic analysis to motivate a reduced set of partial differential equations that filters internal gravity waves and removes inertia from all parts of the momentum equation except for the Reynolds stress that drives the helical mean flow. When simulated numerically, the reduced equations capture the same dynamics and fluxes as the full equations in the appropriate regime. The reduced equations enforce zero helicity in all fluctuations about the mean flow, implying that the symmetry-breaking helical flow is spontaneously generated by strictly non-helical fluctuations.

Screenshot of a later part of the paper, where the phrase “the dynamics are neutrally buoyant (or asymptotically spicy)” is slipped in and highlighted

Submitted! See abstract in first image and highlighted text in second image

I have a coauthor who is extremely skilled at cutting down text to fit a word/page limit, and I’m immeasurably pleased to see that they’ve retained “asymptotically spicy” in the draft

The cruelty in today's politics feels horribly corrosive. Bringing up that hard-working immigrant families — undocumented, yes, but not violent criminals — are being ripped apart based on immigration status doesn't bring compassion or even pause, but gleeful cheers.

must be incredibly frustrating and disheartening to have federal funding that was promised to you for important work suddenly and arbitrarily ripped away

AAS and 52 other science societies and organizations sent a letter to Congress this morning expressing concern over recent organizational and financial developments at NSF, and urging Congress to exercise its oversight authority to preserve American STEM leadership. aas.org/press/letter... 🔭

Accepted into ApJ Letters 🥳

What happens to science under autocracy? The rise of the National Socialist Party in 1930s Germany provides an (admittedly extreme) example. Prior to the early 1930s, scientists at German institutions won a third of Nobels. 10 years later, that number was 5%, and has never recovered.

Boooooooo!