YY Ahn
@yyahn.bsky.social
Prof @ School of Data Science, University of Virginia. Formerly at IU. Networks, data science, and machine learning. https://yyahn.com 🚲🚲🚲
Princeton Institute for International & Regional Studies has a two year postdoc program for recent PhDs in the soical sciences. Applications due Sep 15 2026. piirs.princeton.edu/funding-fell...
PIIRS Postdoctoral Fellows
Provides opportunities for talented early-career scholars in the social sciences to spend a dedicated period of time pursuing their research with access to Princeton’s world-renowned resources.
piirs.princeton.edu
We are excited to announce our next webinar: “Homelessness in Charlottesville: What’s the Plan?” on Wed, August 19th at 6:30pm. If the state of homelessness in Cville has you concerned, confused, and/or looking to help out, this event is for you. Sign up: events.humanitix.com/webinar-home...
Homelessness in Charlottesville: What’s the plan?
Learn about the current state of homelessness in Charlottesville, what is being done to address it, and what needs to happen to achieve workable solutions.
events.humanitix.com
I'm incredibly honored to be one of the inaugural winners of the Ctrl-Z award. The sequence of events preceding and following this retraction were harrowing (and are honestly still stressful), but I hope this will be an opportunity for more open dialogue about mistakes + self-retraction in science.
Retraction Watch@retractionwatch.com · yesterdayThe Center for Scientific Integrity is proud to announce the inaugural winners of the 2026 Ctrl-Z Award. Named for the universal keyboard shortcut for “undo,” the Ctrl-Z Award this year honors @cetaceanneeded.bsky.social and @katelaskowski.bsky.social for choosing transparency over reputation.
www.seangoedecke.com/ai-models-ne... interesting. Maybe on the same line, it's also hilarious to see LLMs estimate that it'll take weeks to build something and then one-shot it within 5 minutes when you actually ask to build it.
AI models need moral support to make discoveries
seangoedecke.com
Update: Google just sent me a statement saying it is “rolling back” this AI feature that let anyone make completely bullshit satellite images. Comes after our demos of the tool and those from OSINT researchers. One of the worst AI tools I’ve ever seen bsky.app/profile/jose...
Joseph Cox@josephcox.bsky.social · 5d agoNew from 404 Media: Google Earth has introduced an AI feature that lets anyone fabricate completely bullshit satellite images. In our own tests, we added a “bomb blast and crater” to an area of Los Angeles. This is a misinformation time bomb, will 100% be abused www.404media.co/google-earth...
This is cool but a crazy expensive way to solve the problem as pointed out. There is a insanely cheaper way: traffic calming See @justineunderhill.bsky.social video section about policing: youtu.be/v6LIYQRglnM?... and what I posted about traffic calming: yyahn.com/wiki/Traffic...
Why speed limits don't matter
YouTube video by Justine Underhill
youtu.be
The War on Cars@thewaroncars.bsky.social · 5d agoCatching 74 distracted drivers in six hours is good, but what would be better is redesigning the street so drivers are forced to pay attention.
What’s the best way to handle the shifting bottleneck? - quota - submission payment - paying reviewers - AI review - …
Gautam Kamath@gautamkamath.com · 6d agoICLR 2027 has authorship quotas: - No more than 20 submissions per author - No more than 1 submission where no author has a paper previously accepted to a major ML conference From iclr.cc/Conferences/...
Too Lazy to Read the Paper just passed 10,000 downloads (17,873 if we count YouTube). Not bad for unedited, hour-long conversations with my favorite scientists. The whole story, including both season trailers – one features me on a ukulele: sunelehmann.com/blog/too-laz...
From @wfp.org's statement following its recent cyber incident: "Recent reports indicate the [humanitarian] sector is now the second most targeted globally with increasingly sophisticated attacks." docs.wfp.org/api/document... [pdf] Does anyone know where this data originates from?
Updated schedule for the Cville bike bus testing, starting tomorrow morning
My paper is out today in PNAS documenting how ICE activity in Trump 2.0 compares to the last 10 years and the mismatch between the action and the rhetoric. Joint with the fabulous @caitlinpatler.bsky.social and @elizabethacox.bsky.social www.pnas.org/doi/10.1073/...
Claude Opus 5 has a strange benchmark curve. On DeepSWE, medium effort scores the best, and then the score drops with effort (and then springs back). More "thinking" does not monotonically improve performance.
Insane new research. Scientists gave asthma patients free electric stoves to replace their gas stoves, then checked to see if symptoms improved. Not only did symptoms improve, ditching gas was *better than medicine.* Details in today's newsletter: www.climatecoloredgoggles.com/p/electric-s...
Researchers used electric stoves to treat asthma. It worked.
The latest evidence that gas is bad for your health.
climatecoloredgoggles.com
the Dinitz-Garg-Goemans conjecture, a graph theory problem that’s gone unsolved for 30 years, was solved with this prompt
Mark Zuckerberg's assistant at Meta, Josh Felker, who was responsible for Meta's "digital experiences for kids," was arrested after admitting he tried to sext a 13-year-old during an undercover sting. nypost.com/2026/07/20/u...
Exclusive | Meta worker who developed ‘digital experiences for kids’ admits to trying to sext child in undercover NYC sting
He admitted he had been grooming and sexting someone he thought was a 13-year-old girl during a sting by vigilante group Predator Poachers Long Island.
nypost.com
I went down a rabbit hole on traffic calming. Firstly, it seems to work well, and the effect sizes are large. yyahn.com/wiki/Traffic...
Traffic calming works
Every residential street in your city comes in two versions. They cost about the same, and trips take about as long on either. But the slightly cheaper...
yyahn.com
The AI community failed to exit twitter. What implications can we draw about what people believe from this?
What it means that the AI community can't quit twitter
Some quickly jotted thoughts working through the implications of the AI community remaining on twitter
rl-blogging.leaflet.pub
Traffic calming is very cheap compared to any other road-related spending and also highly effective. London reported ~40% reduction in casualties. This 'speed hump' study from Ghana reports "a reduction of 77% in fatal/serious/minor injuries" injuryprevention.bmj.com/content/29/1...
Effect of speed humps on injury consequences on trunk roads traversing towns in Ghana: A quasi-experimental study
Background Speed calming interventions have been employed globally as a road safety measure to curb outcomes of RTCs such as injuries and deaths. In Ghana, few studies have reported on the effect of s...
injuryprevention.bmj.com
Matthew Gillikin@mtgillikin.bsky.social · 3w agoNote that speed humps are part of Somerville's traffic calming solution. For various reasons that don't really add up for me, portions of Charlottesville's city government are strongly opposed to speed humps.
OMG the new @3blue1brown.com video opens up with one of my favorite papers from my grad school www.youtube.com/watch?v=GlYg... The paper is "language trees and zipping" arxiv.org/abs/cond-mat...
But what is cross-entropy? | Compression is Intelligence Part 2
YouTube video by 3Blue1Brown
youtube.com
www.scientificamerican.com/article/scie...
Scientists overwhelmingly against rule change that would give political appointees say over science grants
Hundreds of thousands of scientists, including Nobel laureates, warn that changes to the way federal grants are approved would greatly damage American science
scientificamerican.com
Prevention efforts would always feel like a waste of money, *especially* when they work well. Maybe related: www.huffpost.com/entry/cdc-st...
CDC Stopped Monitoring Parasite Now Causing Explosive Diarrhea Across The Country
MAHA.
huffpost.com
If you have time to browse bluesky this weekend, you have time to submit your comment on the proposed OMB rule to politicize science funding agencies. This one is important. Here's my comment if some inspiration will help. 🧪 scienceforeveryone.science/submit-your-...
Submit your OMB comment this weekend.
This one is important. It's due on Monday.
scienceforeveryone.science
This cartoon barely qualifies as satire. Is there any other engineering discipline with such a normalized disregard for human life?
Warren Wells, AICP@warrenjwells.bsky.social · 4w agoThis use of "feasible" by traffic engineers drives me insane. Renovating your kitchen for $1k is not feasible. Building a bicycle-powered helicopter is not feasible. Deciding that safety is more important than delay is not a matter of feasibility, but a policy choice.
Any bike lane that goes right next to parked cars and in the door zone of those parked cars is an "anti-bike lane," not a "bike lane." Because you are likely in more danger when you use it.
Fietser@americanfietser.bsky.social · 4w agoDooring has taken so many lives now that it should trigger a full scale design revision that no longer makes door zone bike lanes legal to build. We know how to build safe infrastructure. Our elected leaders make a conscious choice not to do so. It's that simple.
"A lecture is the process whereby the notes of the professor become the notes of the student without passing through the mind of either." I think this may apply to lots of "LLM wiki" usage.
Neural Scaling Universality: If Exponents Are Fixed, Time to Understand Coefficients arxiv.org/abs/2606.25008
Neural Scaling Universality: If Exponents Are Fixed, Time to Understand Coefficients
Neural scaling laws describe how pre-training loss decays as power laws with training time, model size, and compute. This position paper argues that the exponents of these power laws are fixed by gene...
arxiv.org
Imagine turning this into housing... If we accept some inconvenience for some drivers, turning a parking lot into a more productive buildings will -> boost local economy -> downward pressure on rent -> more tax revenue for the city to do stuff -> make the neighborhood more walkable/bikeable
29News - Charlottesville@29news.bsky.social · last mo.Market Street Garage to temporarily lose nearly 300 parking spaces during repairs | https://www.29news.com/2026/06/30/market-street-garage-temporarily-lose-nearly-300-parking-spaces-during-repairs/
It was fun to join SICSS at KAIST! I talked about social contagion and belief dynamics. Here's my slide: yyahn.com/talks/sicss2...
The shape of what we believe
A geometry of social contagion and belief change. SICSS 2026, KAIST.
yyahn.com
