It's paper day 🎉🔭 arxiv.org/abs/2507.10719 Together with @sijme-jan.bsky.social we continue to look at dust instabilities in planet forming discs when considering many dust sizes (polydisperse). This time we probe the Dust Settling Instability (DSI) via hydro simulations in a local box 1/14

"we must not fall into the trap of mistaking the outputs of writing (which are increasingly substitutable through technology) from the value of the cognitive process of writing (which hones mental development and cannot be substituted by a machine)."

Our gift to the world.

It's not the biggest problem education is facing but at some point the preference of parents and students for coursework and fewer exams is going to collide with the fact that AI probably necessitates a big return to in-person exams

We are all in the gutter, but some of us are looking at our phones

I don’t know. I love this Joseph Fasano poem and have it pinned on my office door but I don’t know what to actually do about any of this.

Prediction was a few months off, but good riddance

The abstract submission for Rocky Worlds 4 is now open! groningen2026.rockyworlds.org/registration... 🌋🔭🧬😱

What the fuck, people. Do not do this.

A core feature of the Trump regime is its embrace of "authoritarian democracy", as a battering ram with which to demolish any obstacle to its power. The very notion of "authoritarian democracy" can sound contradictory. But it's an old & dangerous idea, that needs to be better understood. [THREAD]

It's final paper season.

A new, thorough reanalysis of the data that led to claims of biosignatures on K2-18b from @luiswel.bsky.social & friends - a nicely written lesson on why this stuff is hard. They find no significant evidence for DMS, the gas the Cambridge team claimed to have found. arxiv.org/abs/2504.21788

Blimey! Prof Madhusudhan’s response to my friendly discussion of the many unknowns was that I’m a ‘commentator not a practitioner’.

𝗡𝗼, 𝗮 𝗯𝗶𝗼𝘀𝗶𝗴𝗻𝗮𝘁𝘂𝗿𝗲 𝘄𝗮𝘀 𝗻𝗼𝘁 𝗷𝘂𝘀𝘁 𝗱𝗲𝘁𝗲𝗰𝘁𝗲𝗱 𝗶𝗻 𝗞𝟮-𝟭𝟴𝗯'𝘀 𝗮𝘁𝗺𝗼𝘀𝗽𝗵𝗲𝗿𝗲. K2-18b is back in the news, now with a bold claim that biosignature molecules (DMS and/or DMDS) have been 'detected at 3σ'. Most exoplanet astronomers are extremely sceptical about these claims, let's see why (1/n). 🔭🧪🪐 #exoplanet

An astonishing headline reporting on new observations from a team led to Nikku Madhusudhan claims they’ve found ‘hints of life’ on a planet orbiting a dwarf star some 124 light years away. What’s going on? (1/n) www.bbc.co.uk/news/article... 🔭 🧪

There are great conferences and science in the US, but with the way things are right now, it’s too risky to attend.

First the rumour was a 20% budget cut. Then, 50%. Now the president's NASA budget is out and it's a 68% cut to astrophysics ($1.5B to $487M). Even if this gets reversed in four years, we will *never* recover the missions, partners, people who will be gone. www.washingtonpost.com/science/2025...

Jerry Ostriker has died www.nytimes.com/2025/04/07/s...

A tricky thing about modern society is that no one has any idea when they don’t die. Like, the number of lives saved by controlling air pollution in America is probably over 200,000 per year, but the number of people who think their life was saved by controlling air pollution is zero.

Here we go paper II is out today 🔭 arxiv.org/abs/2503.09265 Here @sijme-jan.bsky.social and I continue looking at the linear theory of RDIs when you have dust with size distributions, but this time we focus on the streaming and settling instabilities, which are important for planet formation 1/14

A lot of people confuse writing with typing. Writing isn’t typing. It’s the entire process and yes that includes going for a walk or rearranging things in your office.

It's paper day! 🔭 arxiv.org/abs/2503.05359 This is a 1st of a series where @sijme-jan.bsky.social and I look at how dust instabilities change when you start treating dust as a continuum of species with different sizes, i.e; "Polydisperse", instead of a single size species 1/9

No. Never. I review 20+ of papers a year—it's my job as a scientist. The public pays my salary and trust me to use my time wisely to advance science. Through peer review, I do exactly that. I spend two or three weeks a year reviewing, but I’ve never wasted a day reviewing a paper, and never will.

The average American voter thinks that the government is too big but that it should spend more money on everything it does. This explains a decent share of the political chaos of this country.

Good luck today to the fellows of the Royal Society who are gathering in London to discuss “public pronouncements and behaviours of other fellows.” I trust there will be a candid and informed exchange of views. 1/4

When I worked in UK academia I recall hearing of a Japanese man who was baffled at how Britain had decided to run its universities like firms. “Why? Your universities are excellent and your firms are terrible.”

It's paper day! Together with @sijme-jan.bsky.social and led by exceptional (2nd year!) PhD student Jip Matthijsse, we look at the Streaming Instability in dust with size distributions and how the resulting clumps have different size distribution from the initial one arxiv.org/abs/2502.01752 1/n

In 2014 Dutch scientists left a hamster wheel outside, to see if wild animals would use it like their domesticated counterparts. The answer: hell yes! 734 visits from wild mice - plus rats, shrews, slugs ("running" being subjective here) & even frogs and snails. The apparent reason: fun. Just fun.

I am prepared to buy MORE LEGO to assist the Danish economy should it prove necessary.

Sverre Aarseth, a great influence on open astro software, has died. ascl.net/wordpress/20...

You can call them New Year Doughnuts or Dutch Doughnuts or, more properly, Oliebollen, but what matters to me most is that they are, appropriately, #RecipeOfTheDay, and I commend them to you! www.nigella.com/recipes/new-...

Hate freeloaders who join in the New Year's Eve countdown for the last 10 seconds. I've been doing this all year. Where were you back in May

Interviewer: Can you explain this gap in your resume? Protoplanetary disc modeller: unseen planets 🤞 (but other mechanisms are available)

A new analysis of data from the Juno spacecraft suggests that the ice shell covering the ocean on Jupiter's moon Europa might be WAY thicker than anticipated. (With comments from @theplanetaryguy.bsky.social) Possibly bad news for any hope of life signs from Europa Clipper, currently en route. 🧪🔭

Our institute is advertising a Tenure Track Assistant Professor position on Astronomical Data Science and Machine Learning: aas.org/jobregister/.... The position is broadly defined and explicitly also open to researchers with a background in planetary and exoplanetary research. Please share! 🔭💻👩‍💻

#RecipeOfTheDay borrows gratefully from the Dutch Christmas canon. That’s to say, this is my take on their glorious almond pastries – and, don’t worry, these Banket Bars use shop-bought puff pastry, which makes them alluringly do-able! www.nigella.com/recipes/bank...

Antonia Rowlinson (UvA, ASTRON) en Else Starkenburg (RUG) ontvangen ERC Consolidator Grant www.astronomie.nl/nieuws/anton...

Royal Society fellow Dorothy Bishop (@deevybee.bsky.social) resigns over Elon Musk membership. Bishop claims Musk has violated RS code of conduct, and is not prepared to treat him "collegially and with courtesy" as that code requires. Free to read. www.researchprofessionalnews.com/rr-news-uk-c...

Check out the latest find from the Young Worlds Lab, led by UNC Graduate Student Madyson Barber (madysonb.github.io). Newborn planet found in a warped system www.nature.com/articles/d41... www.nature.com/articles/s41... 🧪🔭🪐⚛️🌌⭐

THE SECRET DIARY OF ELON MUSK AGED 53 3/4 Monday November 18th History may well want a clear account by an unprejudiced observer of what happened on our Alphas trip to the UFC. I am the only person qualified. RFK Jr, for all his qualities, does not possess my nerves of steel. Thread 1/10

Academia was invented by Big Coffee to sell more coffee

Long thread on how Brexitism started and evolved over 75 years, drawing from Benjamin Grob-Fitzgibbon's 'Continental Drift'. Global Britain, Free Trade, Cakeism, Federalism, anti-federalism, EEA, Winston Churchill, Empire, 52-48 referendums, Enoch Powell, 1975, Thatcher.... It's all here. /1

The UK having our election this year on 4th July and America having theirs on 5th November feels like an odd sort of cultural exchange between our two countries.

Here’s the slides from my talk about the promise and dangers of machine learning at University of Michigan: dwh.gg/umstat

The Astropy Project, developers of an open-source software used to analyze astronomical data—which STScI has contributed to since 2011—has been awarded the 2025 Lancelot M. Berkeley–New York Community Trust Prize for Meritorious Work by AAS: bit.ly/3B08mmF 🔭 🧪

New paper this week, led by Kevin Chan: stability of dusty rings in protoplanetary discs. arxiv.org/abs/2401.04517

Prediction: forming a government will take longer than the resulting government will govern. #dutchelections

Finally migrating over from the other place (thanks @benmonreal.bsky.social !). Astrophysicist in Delft (NL), left UK because Brexit, trying to figure out how planets form and how this new site works...