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efavdb

814 karma · joined December 24, 2014

Math blog at jslandy.com
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efavdb··on The UV index is not the warm sensation of sunlight on bare skin
Strange. I thought a pale person would reflect more light so they’d burn less (obviously contrary to what we see). But apparently the resolution is that the uv is absorbed safely not reflected
efavdb··on How do traffic signals work? (2019)
The two-adjacent signals causing extra traffic is something I encounter daily in Berkeley -- Ashby / Claremont & Ashby / Domingo. I probably blow an average of 5 minutes a day cause of that double intersection.

To highlight one other point from the video: You want a light to be able to clear the line built up each time. If not, flux in > flux out and that's a recipe for a growing line, which causes a traffic jam.

efavdb··on Why I didn’t sign the Fields medallists’ letter
I think they'll end up more like scientists. Landau famously advised his students to be proficient in math so that when they're working on a problem it's the scientific understanding that's the rate limiting step, not the math. Now mathematicians will be freed of some of the burden of proving things and their challenge will instead be to find interesting new things worth proving.
efavdb··on Show HN: An e-ink frame that hears birds and draws them as 1800s illustrations
Do you not like AI?
efavdb··on Growing proof that autonomous cars save lives
That’s the smart car
efavdb··on Navier-Stokes – Tristan Buckmaster [pdf]
Apparently Tristan was working on this problem for years, with AI providing help. Vs OpenAI spending a week with their new model, potentially having access to Tristan’s work.
efavdb··on On the Navier–Stokes Millennium Prize Problem
I am curious who if anyone will get a reward for this. It would seem unreasonable to give it to the worker who asked the robot to solve it.
efavdb··on On the Navier–Stokes Millennium Prize Problem
>> Keep in mind: natural science is different. It's not always a matter of computation.

Math is like this too. The big problems they've been solving have been identified as interesting only through lots of prior effort.

efavdb··on Harnessing the Universal Geometry of Embeddings
At a minimum posting to arxiv gives others a standard way to cite the work.
efavdb··on GPT-6 Astra
Seems like only yesterday that gpt 5 was supposed to mark our downfall
efavdb··on Coding expertise is going to collapse from AI reliance
I agree the tradeoffs are real but consider it obvious that reading and writing were in net a boon and I also expect the same for AI / programming. Of course having some understanding is still required in both cases to make good use of the tools.
efavdb··on Coding expertise is going to collapse from AI reliance
look to past examples. when the greeks developed writing, people complained that the youth were losing the ability to memorize much content. and that is true, but with writing they were able to do better still and that old skill -- though useful -- was lost.
efavdb··on Felony charges for citizen deleting phone data at US Border
Take him up on his bet then
efavdb··on Mathematics in the age of AI
one thought: AI can often help us solve a problem once posed. E.g., try to prove that X is True. But formulating good conjectures is something altogether different. right now we have a backlog of interesting / good conjectures that ai can grind on. but once those are done, will we still need people to sniff out interesting new ones?
efavdb··on Universality of Gradient Descent Neural Network Training
reminds me of perturbation theory -- start off with a nearby problem you know the answer to, then update it to get the answer to the problem at hand
efavdb··on The Amazon tax
Counterpoint: Amazon among the most favorable institutions in the US

https://harvardharrispoll.com/wp-content/uploads/2023/05/HHP...

efavdb··on How Claude's text watermarking works
The method of identifying authorship isn’t new. I guess the main new thing here is to ensure Claude has a specified word distribution so you can identify its writing.

https://towardsdatascience.com/text-classification-and-the-b...

efavdb··on Mario Meets Pareto
I guess that makes sense. as you get to higher dimensions, most points sit very close to the surface. So if we're trading off N things and N >> 1, expect to basically always be at the pareto boundary.
efavdb··on The Dunning-Kruger effect may just be a data artefact (2020)
for the last one, that's the whole story of Socrates being the wisest man because unlike others he knew the bounds of his knowledge:

"I seem, then, in just this little thing to be wiser than this man at any rate, that what I do not know I do not think I know either."

https://en.wikipedia.org/wiki/I_know_that_I_know_nothing

efavdb··on Ten advances in mathematics and theoretical computer science
best point in that first link: openai doesn't tell us if they only tried to solve these 10 and each was solved (amazing) or if they asked it to solve a million problems and it got these 10. Either is great, one is more so.
efavdb··on Elevators
I recently wrote an article about this problem, and detail one reasonable algo for minimizing wait time. (Doesn’t consider concept of cars being full though, interesting addition)

https://jslandy.com/elevators/

efavdb··on A digestion of the Jacobian conjecture counterexample
Thanks, I was curious for the motivation behind the conjecture, but it wasn’t mentioned in the Wikipedia article.
efavdb··on My two year old taught me constraint solving
My three year old taught me something he saw on a YouTube video: you can search through a maze and find your way out just by keeping your right hand on the wall at all times and continuing till exit. Does a DFS.
efavdb··on A Beautiful Theory Falls to Ugly Data
Indeed, having a hard time thinking of anything I desire that I wouldn’t want sooner rather than later. Maybe a grave yard plot — hopefully won’t need that anytime soon.
efavdb··on The power of collaboration: How we can reduce traffic congestion
Another question: they say road speeds increased, great. But that’s a different metric than average drive time. Curious if that also decreased.
efavdb··on The early History of the Singular Value Decomposition (1993) [pdf]
Great book: An Introduction to Statistical Learning

PDF here:

https://www.statlearning.com/

efavdb··on Synthesis is harder than analysis
FWIW in numerical analysis stable differentiation is harder than integration.
efavdb··on On the Skin-Furrows of the Hand (1880) [pdf]
Very cool historical doc, thanks for sharing.

Curious if his idea of determining the race of the individual from the fingerprint is possible. Never heard that idea before.

efavdb··on Algorithmic Monocultures in Hiring
They also say that if they do the analysis globally the effect goes away. Curious, does that not imply that if one domain is biased against some group there would be another where the bias was in its favor?
efavdb··on AI coding at home without going broke
Pleading has worked for me. “My job depends on this, please help me” and ChatGPT would do a task it previously claimed it wasn’t able to (extract text from an image, it claimed it couldn’t make it out at first)
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