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.
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The most popular blog posts about science & space on Hacker News. 76 posts.
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.
So I got this new attitude. Now that I am burned out and I'll never accomplish anything, I've got this nice position at the university teaching classes which I rather enjoy, and just like I read the Arabian Nights for pleasure, I'm going to play with physics, whenever I want to, without worrying about any importance…
On 13 June 1944, a week after the allied invasion of Normandy, a loud buzzing sound rattled through the skies of battle-worn London. The source of the sound was a newly developed German instrument …
Ernst Stuhlinger wrote this letter on May 6, 1970, to Sister Mary Jucunda, a nun who worked among the starving children of Kabwe, Zambia, in Africa, who questioned the value of space exploration. A…
Restoration of distorted images is one of the most interesting and important problems of image processing - from the theoretical, as well as from the practical point of view. There are especial cases: blurring due to incorrect focus and blurring due to movement - and these very defects, which each of you knows very…
Now that Discovery is safely delivered to the Smithsonian, I think I can tell the story of how we nearly lost her in July of 2005, and how well-intentioned, highly motivated, hard-working, smart p…
A statement upon 23andMe reaching its first one million customers.
In the 1840s, hospitals were dangerous places. Mothers who went in to give birth often didn’t make it out. For example, at Vienna General Hospital’s First Obstetrical Clinic, as many as 10% of mothers died of puerperal fever after giving birth. But there was some good news: at the Second Clinic, the number was just…
What do you think are the odds that you will die during the next year? Try to put a number to it — 1 in 100? 1 in 10,000? Whatever it is, it will be twice as large 8 years from now. This s…
Water is complicated and fascinating stuff! There are at least sixteen known crystal phases of ice, many shown in this diagram based on the work of Martin Chaplin: (Click for a larger version.) For…
Usually when I speculate about the future, I stick to two areas; either the really near future (within the next couple of decades), or the really far future (so far out that signs of continental drift should be glaringly obvious). But what about the medium term?
This is the first post of probably several in my concern about textmining. You do NOT have to be a scientist to understand the point with total clarity. This topic is one of the most important I have written about this year. We are at a critical point where unless we take action our scholarly rights will be further…
You may remember The Bell Curve. The book was published in 1994 by Richard Herrnstein and Charles Murray, and it argued that IQ is largely determined by genetics and little by the environment. It...
Ketamine may regenerate synaptic connections between brain cells damaged by stress and depression, according to new Yale-led research.
For a while now there have been tantalizing hints that Elon Musk is at it again. His usual way of approaching a problem is to look at an industry, find some fatal flaw in it, fix that flaw and then leave everybody else in the dust, wondering why they didn’t do what he did. He’s one of the most interesting people on…
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…
A new information-theoretical model of human sensory perception and memory sheds light on some peculiarities of the nervous system.
Technology Academy Finland (TAF) awards the global one-million-euro Millennium Technology Prize and runs associated events and initiatives.
Update: This post was an Editor’s pick by Cristy Gelling at Science Seeker, and was included in Bora Zivkovic’s top 10 science blog posts of the week. Lately, I’ve got colors on t…
Investigation to find a better rational approximation for pi. Can we get out more digits than we put in? Chance to win a prize if you can do bette
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