Archimedes Would Have Known Better If He Could Count To A Million

March 14, 2018 by Brian Benchoff 78 Comments

Today is March 14th, or Pi Day because 3.14 is March 14th rendered in month.day date format. A very slightly better way to celebrate the ratio of a circle’s circumference to its diameter is July 22nd, or 22/7 written in day/month order, a fractional approximation of pi that’s been used for thousands of years and is a better fit than 3.14. Celebrating Pi Day on July 22nd also has the advantage of eschewing middle-endian date formatting.

But Pi Day is completely wrong. We should be celebrating Tau Day, to celebrate the ratio of the circumference to the radius instead of the diameter. That’s June 28th, or 6.283185…. Nonetheless, today is Pi Day and in the absence of something truly new and insightful — we’re still waiting for someone to implement a spigot algorithm in 6502 assembly, by the way — this is a fantastic opportunity to discuss something tangentially related to pi, the history of mathematics, and the idea that human knowledge builds upon itself in an immense genealogy stretching back to the beginning of history.

This is our Pi Day article, but instead of complaining about date formats, or Tau, we’re going to do something different. This is how you approximate pi with the Monte Carlo method, and how anyone who can count to a million can get a better approximation of one the fundamental constants of the Universe than Archimedes.

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Stephanie Kwolek: Saving Lives With Kevlar

March 13, 2018 by Dan Maloney 41 Comments

Like most accidents, it happened in an instant that seemed to last an eternity. I had been felling trees for firewood all afternoon, and in the waning light of a cold November day, I was getting ready to call it quits. There was one tiny little white pine sapling left that I wanted to clear, no thicker than my arm. I walked over with my Stihl MS-290, with a brand new, razor sharp chain. I didn’t take this sapling seriously — my first mistake — and cut right through it rather than notching it. The tree fell safely, and I stood up with both hands on the saw. Somehow I lost my footing, swiveled, and struck my left knee hard with the still-running chainsaw. It kicked my knee back so hard that it knocked me to the ground.

In another world, that would likely have a been a fatal injury — I was alone, far from the house, and I would have had mere minutes to improvise a tourniquet before bleeding out. But as fate would have it, I was protected by my chainsaw chaps, full of long strands of the synthetic fiber Kevlar.

The chain ripped open the chaps, pulled the ultrastrong fibers out, and instantly jammed the saw. I walked away feeling very stupid, very lucky, and with not a scratch on me. Although I didn’t realize it at the time, I owed my life to Stephanie Kwolek.

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How To Test A B-52 Against EMP: Project ATLAS-I

March 9, 2018 by Dan Maloney 45 Comments

Audacious times generate audacious efforts, especially when national pride and security are perceived to be at stake. Such was the case in the 1950s and 1960s, with the Space Race that started with a Russian sphere whizzing around the planet and ended with Neil Armstrong’s footprint on the Moon. But at the same time, other efforts were underway to answer big questions of national import, such as determining how durable the United States’ strategic assets were, and whether they could withstand the known effects of electromagnetic pulse (EMP), a high-intensity burst of electromagnetic energy that could potentially disable a plane in flight. Finding out just what an EMP could do to a plane would take big engineering and a large forest’s worth of trees.

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You All Know Reginald Fessenden. Who?

February 19, 2018 by Al Williams 30 Comments

Quick, name someone influential in the history of radio. Who do did you think of? Marconi? Tesla? Armstrong? Hertz? Perhaps Sarnoff? We bet only a handful would have said Reginald Fessenden. That’s a shame because he was the first to do something that most of us do every day.

Few know this Canadian inventor’s name even though he developed quite a few innovations. Unlike Colpitts and Hartley we don’t have anything named after him. However, Fessenden was the first man to make a two-way transatlantic radio contact (Marconi’s was one way) and he was a pioneer in using voice over the radio.

He did even more than that. He patented transmitting with a continuous wave instead of a spark, which made modern radio practical. This was unpopular at the time because most thought the spark was necessary to generate enough energy. In 1906, John Fleming (who gave us tubes that are sometimes still called Fleming valves) wrote that “a simple sine-curve would not be likely to produce the required effect.” That was in 1906, five years after Fessenden’s patent.

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Hovercraft Of The Future

February 14, 2018 by Al Williams 32 Comments

We think of hovercraft as a modern conveyance. After all, any vision of the future usually includes hovercraft or flying cars along with all the other things we imagine in the future. So when do you think the hovercraft first appeared? The 1960s? The 1950s? Maybe it was a World War II development from the 1940s? Turns out, a human-powered hovercraft was dreamed up (but not built) in 1716 by [Emanuel Swedenborg]. You can see a sketch from his notebook below. OK, that’s not fair, though. Imagining it and building one are two different things.

[Swedenborg] realized a human couldn’t keep up the work to put his craft on an air cushion for any length of time. Throughout the 1800s, though, engineers kept thinking about the problem. Around 1870, [Sir John Thornycroft] built several test models of ship’s hulls that could trap air to reduce drag — an idea called air lubrication, that had been kicked around since 1865. However, with no practical internal combustion engine to power it, [Thornycroft’s] patents didn’t come to much. In America, around 1876 [John Ward] proposed a lightweight platform using rotary fans for lift but used wheels to get forward motion. Others built on the idea, but they still lacked the engines to make it completely practical.

But even 1940 is way too late for a working hovercraft. [Dagobert Müller] managed that in 1915. With five engines, the craft was like a wing that generated lift in motion. It was a warship with weapons and a top speed of around 32 knots, although it never saw actual combat. Because of its physical limitations it could only operate over water, unlike more modern craft.

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Mary Somerville: The First Scientist

February 13, 2018 by Brian Benchoff 14 Comments

Science, as a concept, is relatively new. Benjamin Franklin wasn’t a scientist probing the mysteries of amber and wool and electricity and ‘air baths’; he was a natural philosopher. Antonie van Leeuwenhoek was simply a man with a proclivity towards creating new and novel instruments. Robert Hooke was a naturalist and polymath, and Newton was simply a ‘man of science’. None of these men were ever called ‘scientists’ in their time; the term hadn’t even been coined yet.

The word ‘scientist’ wouldn’t come into vogue until the 1830s. The word itself was created by William Whewell, reviewing The Connexion of the Physical Sciences by Mary Somerville. The term used at the time, ‘a man of science’, didn’t apply to Mrs. Somerville, and, truth be told, the men of science of the day each filled a particular niche; Faraday was interested in electricity, Darwin was a naturalist. Mary Somerville was a woman and an interdisciplinarian, and the word ‘scientist’ was created for her.

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Salyut: How We Learned To Make Space Stations

February 12, 2018 by Steven Dufresne 61 Comments

When you think about space stations, which ones come to mind first? You might think Skylab, the International Space Station (ISS), or maybe Russia’s Mir. But before any of those took to the heavens, there was Salyut.

Russia’s Salyut 1 was humankind’s first space station. The ensuing Salyut program lasted fifteen years, from 1971 to 1986, and the lessons learned from this remarkable series of experiments are still in use today in the International Space Station (ISS). The program was so successful at a time when the US manned space program was dormant that one could say that the Russians lost the Moon but won the space race.

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