211
Why three prongs?
Why do AC cords need three prongs? If there is no positive or negative in AC systems, why do we have HOT and NEUTRAL? I attempt to shed light on some of these mysteries.
Most cited
Posts that commenters keep linking to, ranked by how many different people have cited them in Hacker News comments. 431 posts.
212
Vitamin D, part 1: back to basics
Vitamin D is a big deal. Recent studies have shown that patients with low Vitamin D levels are more likely to die from Covid-19 than their Vitamin D-rich counterparts,(1) and deficiency in the…
213
Chemistry of Cast-Iron Seasoning (2010)
The post after this one on “black rust” describes why you should heat the pan before applying oil for seasoning. This helps the seasoning to adhere and makes the pan pleasantly black.
214
Gluten Free Antarctica
Far below the Antarctic circle, I watch a woman cry real tears because she can’t get gluten-free toast.
215
The main thing about Phenylacetone meth is that there's so much of it
Since around 2009, methamphetamines have been made with phenylacetone (P2P). Is there a chemical different causing schizophrenia?
216
217
SLS vs. Starship
NASA just announced the lunar landers for the Artemis program. To everyone’s surprise, SpaceX’s massive Starship is one of three landers NASA chose alongside Blue Origin and Dynetics. Understandably, this is bringing up a lot of questions. Some of which we will answer in my next video/article: “Should NASA just cancel…
218
An Iron Curtain Has Descended Upon Psychopharmacology
Imagine if a chemist told you offhandedly that the Russians had different chemical elements than we did. Here in America, we use elements like lithium and silicon and bismuth. We have figured out l…
219
How to assign partial credit on an exam of true-false questions?
Note: the following is a record of some whimsical mathematical thoughts and computations I had after doing some grading. It is likely that the sort of problems discussed here are in fact well studi…
220
Solar’s Future is Insanely Cheap
This is part 1 of a series where I’ll look at the future costs of clean energy and mobility technologies.
221
The Shape of a Mars Mission
“From a mathematics and trajectory standpoint and with a certain kind of technology, there’s not too many different ways to go to Mars. It’s been pretty well figured out. You can adjust the decimal places here and there, but basically if you're talking about chemical rockets, there's a certain way you're going to go…
222
In Defense of Myers Briggs (2020)
examines claims that the big five personality traits is more scientifically valid than the myers briggs personality indicator
223
The Great Filter – Are We Almost Past It? (1998)
Combining standard stories of biologists, astronomers, physicists, and social scientists would lead us to expect a much smaller filter than we observe. Thus one of these stories must be wrong. To find out who is wrong, and to inform our choices, we should study and reconsider all these areas. For example, we should…
224
Terry Tao on how to compute non-converging infinite sums (2010)
The Riemann zeta function $latex {\zeta(s)}&fg=000000$ is defined in the region $latex {\hbox{Re}(s)>1}&fg=000000$ by the absolutely convergent series $latex \displaystyle \zeta(s) = \su…
225
Keeping David MacKay's 'Sustainable Energy – without the hot air' up-to-date
As the anniversary of Sir David MacKay’s untimely death approaches, I think we should honour his memory by trying to update Sustainable Energy as a crowd-sourced project. I have made an initial attempt to suggest how we might develop the section on photovoltaics but others will want to suggest other
226
How we gave colors names
“Who in the rainbow can draw the line where the violet tint ends and the orange tint begins? Distinctly we see the difference of the colors, but where exactly does the one first blendingly enter in…
227
228
We're going to need a lot of solar panels
The team at Terraform Industries is now 11 people working towards a near term future where atmospheric CO2, much of it centuries of unpriced industrial waste, becomes the preferred default source o…
229
230
Feynman’s Breakthrough: Disregard Others
Feynman (just off centre) at Wangerooge in 1987 I started my career as a theoretical physicist, and in the late-80s I co-organised a specialist workshop on a small island, Wangerooge, off the coast…
231
What Happens Next? Covid-19 Futures, Explained with Playable Simulations
an interactive guide
232
My Left Kidney
...
233
LaTeX Coffee Stains (2009)
This package provides an essential feature to LaTeX that has been missing for too long. It adds a coffee stain to your documents. A lot of time can be saved by printing stains directly on the page rather than adding it manually.
234
Quantum computing bombshells that are not April Fools
For those of you who haven’t seen, there were actually two “bombshell” QC announcements this week. One, from Caltech, including friend-of-the-blog John Preskill, showed how to do quantum faul…
235
The Cuboid: A DIY air purifier that's better than a box fan
Designs for a quieter, more energy efficient purifier, and data proving it really works.
236
How To Deconstruct Almost Anything (1993)
This is the story of one computer professional's explorations in the world of postmodern literary criticism. I'm a working software engineer, not a student nor an academic nor a person with any real background in the humanities. Consequently, I've approached the whole subject with a somewhat different frame of mind…
237
World map of the difference between solar and clock time
A better map of the difference between solar and standard time, and some trivia
238
Exploring the Supply Chain of the Pfizer/BioNTech and Moderna Covid-19 Vaccines
Sections of this post were co-authored by Cornelia Scheitz. Noah Leidinger created a German translation. Piotr Kwapin created a Polish translation. Last updated on February 7, 2021. Bert Hubert’s excellent and widely shared article about Reverse Engineering the source code of the Pfizer-BioNTech SARS-CoV-2 Vaccine is…
239
Feynman’s Maze-Running Story
Richard Feynman recounts an amazing anecdote about philosophy of science; we trace it to a forgotten University of Michigan research programme into ‘floor cues’.
240
When His SR-71 Blackbird Disintegrated, This Pilot Free Fell from Space
During the early days of testing for the legendary SR-71 Blackbird there were some harrowing mishaps, the details of which have rarely come to light. On January 25, 1966, test pilot Bill Weaver and Lockheed flight test reconnaissance and navigation systems specialist Jim Zwayer experienced their plane vanishing around…