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Gieljan de Vries

@gieljandevries.bsky.social
1.7K followers 890 following 1K posts

Writes about science, specialises in physics, nuclear and astro — ideally all at the same time. Em-dasher, forever-DM. Bluesky account #188,507, born at 338 ppm CO2. Dutch & English. He / him.

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Gieljan de Vries @gieljandevries.bsky.social · 05/10/2026
Bam. Rosalind Franlin toch eerder met inzicht dat DNA een dubbele helix is dan Watson en Crick, volgens haar aantekening bij eerdere röntgenopname. Niet toevallig dat deze paper uitkomt tijdens de Nobelweek; Watson en Crick bouwden hun DNA-model op Franklins opname en kregen de Nobelprijs. Zij niet.
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worm @rfksbrainworm.bsky.social · 05/10/2026
reading up on mosh pits
Collective Motion of Humans in Mosh and Circle Pits at Heavy Metal Concerts
Jesse L. Silverberg,* Matthew Bierbaum, James P. Sethna, and Itai Cohen
Department of Physics and Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA
(Received 13 February 2013; published 29 May 2013)
Human collective behavior can vary from calm to panicked depending on social context. Using videos
publicly available online, we study the highly energized collective motion of attendees at heavy metal
concerts. We find these extreme social gatherings generate similarly extreme behaviors: a disordered
gaslike state called a mosh pit and an ordered vortexlike state called a circle pit. Both phenomena are
reproduced in flocking simulations demonstrating that human collective behavior is consistent with the
predictions of simplified models.
DOI: 10.1103/PhysRevLett.110.228701 We explored the model’s phase space by varying
and  for the active MASHers over the intervals [0,1]
and [0,3], respectively [Fig. 3(a)]. This led to 4:8  105
individual simulations sampled on 4:8  103 grid
points. For each run, we measured the active MASHer
rms angular momentum about their center of mass xc:m: ¼
ðL=2Þ arctan½ImðAÞ=ReðAފ, where L ¼ 1:03
ffiffiffiffiffiffiffiffiffiffiffiffi
r2
0N
q
is
the simulation box size, A ¼ PNa
i¼1 expð2ixi=LÞ, Na is
the number of active MASHers, xi is the x position of the
ith MASHer, and a similar expression holds for yc:m:. In the
low-flocking, high-noise limit, we found the angular
momentum was near zero, and upon closer inspection,
discovered a gaslike region [Fig. 3(b)] where MASHers
quantitatively reproduced the statistics found in experi-
mentally observed mosh pits
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Yoïn van Spijk @yvanspijk.bsky.social · 29/09/2026
De afgelopen generaties hebben elkaar flink zitten opjutten tegen ‘groter als’. Hoe goed je ook met woorden bent, je hoeft maar één keer het gehate ‘als’ in plaats van het heilige ‘dan’ op papier te zetten en je krijgt een brevet van onvermogen. In 1933 was het nog niet zo zwart-wit. Draadje:
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Robert "The Bobby Yaga" McNees @mcnees.bsky.social · 26/09/2026
Today is the big one-two-one for special relativity. In honor of this momentous occation here is a 121-post-long thread. (I am just kidding, the thread is from last year so it is only 120 posts long. [No, I am still just kidding, it is only 35 posts.]) Happy birthday, special relativity! 🧪 ⚛️ 🔭
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Emily Atkin @emorwee.bsky.social · 17/09/2026
A few weekends ago I went to Miami and attended 9 open houses in extremely high-risk flood areas to see what agents are telling prospective buyers about them. Here is my journey
heated.world
The open houses at the edge of disaster
What are buyers being told about climate risk in Miami? I posed as one to find out.
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Gieljan de Vries @gieljandevries.bsky.social · 19/09/2026
Playing D&D today. High-level oneshot. Their mission, should they not try to wriggle out of it?
Farmer Maggot needs help with a giant rat problem.
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Gieljan de Vries @gieljandevries.bsky.social · 17/09/2026
Ik heb die NS-conducteurs steeds hoger zitten. Dit is al de tweede in korte tijd die vraagt: “routebeschrijving naar de aarde aan de hand van pulsars, toch?” Nerds 💌
Photo - nerd with voyager pulsar map on a tshirt.
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Photography by Alfie Goodrich @alfie.photography · 13/09/2026
Getty makes a ton of money out of selling public domain footage. Which is crazy. But that’s Getty. The footage is usually available free elsewhere but it’s hard to find. Great video that helps you understand where and how to find it. youtu.be/2dzqQItDmdg?...
youtu.be
I Killed A Business Model
YouTube video by Elroddd
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Doug Saunders @dougsaunders.bsky.social · 26/08/2026
Since we’re considering trade reprisals — I wrote last year about how easy it would be for Canada to make toilet paper completely unavailable to Americans. It could be done without any tariffs or embargoes. It may be happening already. www.theglobeandmail.com/opinion/arti...
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Karthik Sankaran @rajakorman.bsky.social · 18/08/2026
Every country should have an Electrification Czar except that person should be called the Chargé d’Affaires d’Affaires de Charger.
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CosmicRami 🏳️‍🌈🏳️‍⚧️ @rami.spaceaustralia.com · 23/07/2026
The crystals have arrived! These are so fragile they can't be exposed to the air, nor moisture. They had to ship them over, instead of flying them, to avoid cosmic radiation during flights. They're going to be used in our dark matter detector: www.spaceaustralia.com/feature/aust... 🔭🧪
spaceaustralia.com
Australia’s Dark Matter Quest | Spaceaustralia
A kilometre beneath the surface of regional Victoria, scientists are preparing to switch on one of Australia’s most ambitious physics experiments. Nearing completion, the facility will soon host a sen...
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Joanna Bagniewska @joannabagniewska.com · 14/07/2026
Geologists have a higher death rate in movies than Sean Bean 💀 Of the 202 geologists in 141 movies released between 1919 and 2023, 69 die or are found dead, resulting in mortality rate of about a third. Movie geologists were mainly male, white and in khaki. 🧪 onlinelibrary.wiley.com/doi/10.1111/...
onlinelibrary.wiley.com
Geologists on the silver screen—the sequel
As geologists, our interest is piqued when geological processes—with varying degrees of accuracy—are portrayed in movies and especially when a geologist unexpectedly appears on screen, even in a mino...
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Gieljan de Vries @gieljandevries.bsky.social · 07/07/2026
'sup @throneofsalt.bsky.social @rosspayton.bsky.social
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Gieljan de Vries @gieljandevries.bsky.social · 06/07/2026
Being an in-house storyteller at the Dutch nuclear/radiation regulator has its perks. Like getting to tell the tale of how we stopped a container with mildly radioactive shoes, and helped trace the original caesium-137 contamination. english.autoriteitnvs.nl/latest/news/...
english.autoriteitnvs.nl
ANVS and RIVM help trace source of radioactive shoes | Autority for Nuclear Safety and Radiation Protection
In 2025, Dutch Customs' radiation portal monitors flagged a container full of faintly radioactive sneakers. The shoes were intercepted and never made it to the market. In this article, ANVS inspector ...
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Robert "The Bobby Yaga" McNees @mcnees.bsky.social · 02/07/2026
The nuclear physicist Harriet Brooks, who was probably the first person to notice the recoil of an atomic nucleus due to emissions during nuclear decay, was born #OTD in 1876. 🧪 ⚛️ 👩‍🔬 Credit: Notman Archives/Musée McCord
Black and white photo of Harriet Brooks. She has on a black dress with a high column collar, and she is looking to the right of the photographer.
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Simon Kuestenmacher @simongerman600.bsky.social · 28/06/2026
This awesome animated map shows the decade long journey taken by Odysseus' home from Troy. Best part is that more books are mapped: buff.ly/nbLfG9v
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𝕯𝖆𝖓𝖓𝖞 𝕱𝖊𝖓 @danfenlon.bsky.social · 28/06/2026
True! However this is hilarious so i chose to believe this
The smurfs (papa, brainy and smurfette) on a table facing mystique 

"You're not the first smurf to try and bring me back to the village dad"

Brainy: the skulls papa smurf!!


Papa: i know brainy. Dont lose your smurf


Art by Caanan Grall
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Gieljan de Vries @gieljandevries.bsky.social · 18/06/2026
This is almost a (conventional!) rerun of Project Plumbbob. The Orbital Bore Cap redux?
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Marcia Luyten @marcialuyten.bsky.social · 09/06/2026
Ik ben tegen fascisme. Sue me www.volkskrant.nl/columns-van-...
volkskrant.nl
Hallucinant: straks zijn de Nederlanders die zich verzetten tegen fascisme zelf nog verdacht
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Standplaats Kraków could really use some cash! @standplaatskrk.pl · 05/06/2026
Damnit I Ironed
[a field of straight lines]
My Joy Division Shirt
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Gieljan de Vries @gieljandevries.bsky.social · 30/05/2026
@skerples.bsky.social Can I ask for a judgment call? Running Kidnap the Archpriest for friends, finally. Awesome. Q: PCs had meeting with C.Gomstead, admitted kidnapping plan, got the Archpriest’s schedule. Does G murder Archpriest and frame them? (Would be 2nd game in row w/ surprise corpse.)
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DuckDuckGo @duckduckgo.com · 29/05/2026
Since Google revealed its plans for an AI search overhaul, visits to our "No AI" search page have tripled…and they’re still rising! Want to make it your default on Chrome or Firefox? Grab our No-AI extensions and banish AI-assisted answers, chat, and AI images. (1/3)
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Gieljan de Vries @gieljandevries.bsky.social · 29/05/2026
De bui komt om 16u, 18u, wacht 22u, nee nu echt 23u — meteorologisch edgen dit.
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Funranium (AKA Phil Broughton) @funranium.bsky.social · 28/05/2026
For @dankaszeta.bsky.social's future reference, I compiled the rant from the other day into a convenient and less typo-riddled post.
funraniumlabs.com
Welcome to Depleted Uranium Chat! - Funranium Labs
[rubs temples] Do I need to explain depleted uranium again? I don’t wanna explain depleted uranium again. Dammit @dankaszeta.bsky.social The primary bit is covered in the first section of this rant wh...
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Gieljan de Vries @gieljandevries.bsky.social · 27/05/2026
Couldn’t be arsed. Will issue.
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Gieljan de Vries @gieljandevries.bsky.social · 16/05/2026
Pick a Bond From Photos you already have in your phone
Screenshot of star trek’s Will Riker - text:
NASA warns alien life may not be fuckable
“Not with that attitude”
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Gieljan de Vries @gieljandevries.bsky.social · 16/05/2026
When the Dark comes rising, six shall turn it back; Three from the circle, three from the track; Wood, bronze, iron; water, fire, stone; Five will return, and one go alone.
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anil oza @aniloza.bsky.social · 14/05/2026
wow — the preprint host, arxiv, is banning authors for a year if they submit papers with hallucinated citations 🤖
Twitter thread from Thomas Dietterich, reading "Attention 
@arxiv
 authors: Our Code of Conduct states that by signing your name as an author of a paper, each author takes full responsibility for all its contents, irrespective of how the contents were generated. 1/
3:03 PM · May 14, 2026
·
66.7K
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Relevant
View quotes

Thomas G. Dietterich
@tdietterich
·
1h
If generative AI tools generate inappropriate language, plagiarized content, biased content, errors, mistakes, incorrect references, or misleading content, and that output is included in scientific works, it is the responsibility of the author(s). 2/
Thomas G. Dietterich
@tdietterich
·
1h
We have recently clarified our penalties for this. If a submission contains incontrovertible evidence that the authors did not check the results of LLM generation, this means we can't trust anything in the paper. 3/
Thomas G. Dietterich
@tdietterich
·
1h
The penalty is a 1-year ban from arXiv followed by the requirement that subsequent arXiv submissions must first be accepted at a reputable peer-reviewed venue. 4/
Thomas G. Dietterich
@tdietterich
·
1h
Examples of incontrovertible evidence: hallucinated references, meta-comments from the LLM ("here is a 200 word summary; would you like me to make any changes?"; "the data in this table is illustrative, fill it in with the real numbers from your experiments") end/"
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Steffani Cameron 🇨🇦 @snarkysteff.bsky.social · 05/05/2026
Today is Dutch Heritage Day in Canada to honour our troops who died to liberate the Netherlands in WWIII. We spent months in the effort. Lost over 8,000 troops. We’re proud of the relationship we still have with the Dutch people.
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Old Man Greef @greef.eurosky.social · 05/05/2026
Links gaat helemaal nooit geen enkele verkiezing winnen als ze de hele tijd geschrokken naar de parelketting grijpen als er iemand met een bus verf de stad in gaat en er ondertussen extreemrechtse knokploegen met een herdenkingsmars meelopen. GOD. VER. DOMME.
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Rick CarBOOso’s Private Fire Crew @amandasmith.bsky.social · 29/04/2026
Incredible alt text, incredible turtle
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Gieljan de Vries @gieljandevries.bsky.social · 27/04/2026
Apartment.
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Chaosium @chaosium.bsky.social · 26/04/2026
Such a fun way to introduce Call of Cthulhu! The player characters are archeologists exploring an Egyptian tomb. The map gets slowly revealed by brushing the sand away... — at Armageddon Expo Auckland 🇳🇿 . #callofcthulhu #rpg #ttrpg
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Josephine beckbook.com Riesman @josie.zone · 25/04/2026
This isn't a joke. Cis male authors only do this when they're very stressed or feel threatened
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Gieljan de Vries @gieljandevries.bsky.social · 21/04/2026
Op 26 april 1986 ontplofte reactor 4 van Tsjernobyl. Voor de ANVS ging ik zoek naar de lessen uit de grootste kernramp in de geschiedenis. Over crisisbeheersing, veiliger kerncentrales, internationale samenwerking en voortdurend de lat hoger leggen. www.autoriteitnvs.nl/actueel/nieu...
Controlezaal in de kerncentrale Tsjernobyl. Foto: Laima Kurienė.
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Gieljan de Vries @gieljandevries.bsky.social · 20/04/2026
Jenkins! Have this printed on a t-shirt immediately!
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Tom Gauld @tomgauld.bsky.social · 19/04/2026
my latest books cartoon for @theguardian.com
Two hooded figures with lamps approach a moonlit, isolated cottage.
A woman answers the door.
We have come for the child, says the hooded figure
So soon? she asks
It is time, says the hooded figure.
The woman is distraught. We should never have got him a library card!
What is done cannot be undone, says the hooded figure
We couldn’t see the harm! We just wanted him to enjoy reading! 
For most, it ends there, says the hooded figure, turning away and walking into the wilderness
Oh lord, What have I done! says the woman,
the child walks past her and out into the darkness with them.
Do not cry mother. 
I am a writer now.
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Daniel Benneworth-Gray @danielgray.com · 17/04/2026
whoever this is, they are amazing
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Gieljan de Vries @gieljandevries.bsky.social · 17/04/2026
In ancient times, cats were worshipped as gods. They have not forgotten this.
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Zach Weinersmith @zachweinersmith.bsky.social · 14/04/2026
Bonus panel here: www.smbc-comics.com/comic/easier #smbc #math
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CosmicRami 🏳️‍🌈🏳️‍⚧️ @rami.spaceaustralia.com · 10/04/2026
Very cool example of atmospheric physics in motion -- save this for your students! Just north of the equator is Cyclone Sinlaku rotating counter clockwise. And just south of the equator is Maila, rotating clockwise. Coriolis effect! 🧪
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Leah McElrath @leahmcelrath.bsky.social · 10/04/2026
You’re right. That might not be enough time to bury the Statue of Liberty and distribute 400 million ape costumes.
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Follow the Money @ftm.nl · 03/04/2026
Vlak na de MH17-ramp en de inname van Krim, klopte Shell aan bij het ministerie van Buitenlandse Zaken. Of de oliemaatschappij een nieuwe Russische oliebron aan mocht boren. Met de afwijzing ‘Niet akkoord – en Shell zou dit ook niet moeten willen’, nam het bedrijf geen genoegen.
ftm.nl
Voor Shell en het ministerie bleef het na MH17 ‘business as usual’ in Rusland
Terwijl Rusland de Krim binnenviel, separatisten in Oost-Oekraïne steunde en betrokken was bij het neerschieten van een vliegtuig met 196 Nederlandse inzittenden, gaf Nederland toestemming aan Shell v...
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Jonathan McDowell @planet4589.bsky.social · 26/03/2026
Fair xkcd.com/3224/
xkcd.com
Centimeter Wavelengths
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Gieljan de Vries @gieljandevries.bsky.social · 23/03/2026
Al jaren zeg en schrijf ik ‘môgge’. Per abuis, leer ik hier van @fonolog.bsky.social - het mot mògge zijn! Of een hypercorrect ‘goedemorgen’, ook mooi. (Mist er trouwens een “bedienen” of “verenigen” in de tweede zin van het stuk? 429 woorden in dat geval 🙃)
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Brabanders en hun taal @brabanders-taal.bsky.social · 16/03/2026
In West-Brabant gaan ze naar de ‘mart’, maar in Oost-Brabant naar de ‘mert’ (en in 1937 in het zuidoosten zelfs naar de ‘mercht’). Dat verschil komt door een rivier. Hoe dat zit, kom je hieronder te weten.
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Jess Nevins @jessnevins.bsky.social · 08/03/2026
Happy International Women's Day! Remember, when in doubt, do as Stagecoach Mary Fields did, and either headbutt, shoot it, set it on fire, or let your horses trample it. "She broke more noses than any other person in central Montana."
A picture of all-time badass Stagecoach Mary Fields, holding her rifle.
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Gieljan de Vries @gieljandevries.bsky.social · 08/03/2026
Struggle to think of female scientists? It’s in the stories we tell. Or don’t tell. On International Women’s Day, Robert McNees shares stories about women who deserve more spotlight than they got:
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Erin Fogg says Free Link @criminalerin.bsky.social · 07/03/2026
Humanity runs on spite lmao
How Your AI slop bores me works lmao this is incredible I love it: 
your ai slop bores me in a world looming with the threat of ai stealing your job, save humanity by stealing ai's job. each text or image prompt costs 1 credit. to earn credits, switch to the AI tab and answer someone else's prompt.
if you're broke and the queue is empty, you get a free credit once per hour.
you can cancel while waiting, but not once someone picks it up.
send in a prompt and revel in your zero water Waste.
be nice. this is not grok.
bugs or feedback? hi@youraislopbores.me
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