1831
Jean Bourgain
I have just learned that Jean Bourgain passed away last week in Belgium, aged 64, after a prolonged battle with cancer. He and Eli Stein were the two mathematicians who most influenced my early ca…
Top posts
Every blog post that took off on Hacker News, ranked by the votes of its best submission. 2,038 posts.
1832
Measuring the size of the Earth by watching a shadow on a wall
Recently I've been discussing the details of measuring the size of the Earth by watching a shadow descending a wall at sunrise, or ascending at sunset. The sums are easy enough if you do it at either Equinox, and at the Equator, and you can read about it here:
1833
Faster Than Light in Our Model of Physics: Some Preliminary Thoughts
Stephen Wolfram uses his fundamental physics model to analyze how to go faster than light as an engineering problem & discusses the structure of space & nature of time for the NASA Innovative Advanced Concepts Program keynote address.
1834
Aerobic exercise is good for the brain; easy wins for behaviour change
mood, memory, education; five easy wins for behaviour change
1835
Rotation curves: still flat after a million light-years
That rotation curves become flat at large radii is one of the most famous results in extragalactic astronomy. This had been established by Vera Rubin and her collaborators by the late 1970s. There …
1836
Space travel via tether between asteroids
I wish I knew if my math was correct...
1837
The Soviet Union’s Nuclear Icebreakers
If you want to watch the video first, it is below
1838
1839
Nitrogen Triiodide (2016)
Nitrogen Triiodide
1840
1841
Why Were Early Psychedelicists so Weird?
[Epistemic status: very speculative, asserted with only ~30% confidence. On the other hand, even though psychiatrists don’t really talk about this it’s possible other groups know this a…
1842
Why are amplitudes complex?
[By prior agreement, this post will be cross-posted on Microsoft’s Q# blog, even though it has nothing to do with the Q# programming language. It does, however, contain many examples th…
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1844
Two Birds with One Tone: I/Q Signals and Fourier Transform
An intuitive and ground-up introduction to I/Q signals. Learn the foundational concepts through clear geometric analogy perfect for beginners
1845
1846
Selection bias and bombers (2008)
During WWII, statistician Abraham Wald told the RAF to add armor where it didn't seem planes needed it. But he was right.
1847
The marvelous disappearing capacitor
The performance of photodiode amplifiers can be improved in a clever way.
1848
Is Faster-Than-Light Travel or Communication Possible? (1997)
It might be thought that special relativity provides a short negative answer to this question. In actual fact, there are many trivial ways in which things can be going faster than light (FTL) in a sense, and there may be other more genuine possibilities. On the other hand, there are also good reasons to believe that…
1849
The Wolfram Physics Project: A One-Year Update
An update from Stephen Wolfram on the Physics Project. Exploration of models, connections to existing frameworks, space and time, quantum mechanics, experimental implications, applications to other fields.
1850
1851
A relatively small amount of force applied at just the right place
Explaining Y Combinator
1852
Just how bad are we at treating age-related diseases?
Whether you believe in preventing damage (the core aim of the aging field, though that's not the focus of this post) or treating damage as it arises, our current best efforts in both treatment and mechanism selection haven't yielded promising results. None of the approved drugs for age-related diseases reverse any…
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What is an emotion? William James’s theory of how our bodies affect our feelings
“A purely disembodied human emotion is a nonentity.”
1856
Sputnik V: fraudulent clinical trial data
Sputnik V clinical trial data seems as trustworthy as Putin’s election results.
1857
How Dangerous Are Solar Storms?
Science News, Physics, Science, Philosophy, Philosophy of Science
1858
How is efficacy vs. severe disease strong if 60% of hospitalized are vaccinated?
A surge involving the rapidly-transmitting Delta variant in heavily vaccinated countries has led to much hand-wringing that the vaccines are not effective against Delta, or vaccine effectivenss wanes after 4-6 months. This has fueled anti-vaccine sentiment suggesting the vaccines are not working, and causing much…
1859
Does anybody know this fractal? (2012)
Experimenting with the "divisibility" of complex numbers, I stumbled across this thingy. It looks like a fractal. Although the formula does not do any iterations. It reminds me of something. But I dont know what. Doing a Google image search brings up a couple of galaxies :) This image shows the region from (-1/-1) to…
1860
Fractional Factorial Experiment Design: There Are Too Many Experiments to Do
Have you ever found yourself in a situation where you had a bunch of parameters to tune for a better result, but there were just too many to exhaustively search all possibilities? I recently saw a …