Extra Credits
Published on 5 Mar 2019Charismatic leadership can conceal corruption, and Frank Herbert saw how dangerous this was in the political events he lived through. Leto Atreides, Valdimir Harkonnen, and Paul Atreides (Maud’dib) each represent different types of charismatic but very faulty leadership practices.
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March 6, 2019
Dune – Maud’dib – Extra Sci Fi – #4
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Finishing a Bowl with CRAYONS?! | Turning Tuesday #8
Matt Estlea
Published on 5 Mar 2019In this video, I turn a bowl on the lathe and finish it using crayons! This is a technique way back from my experimental finishes series.
You can see the playlist here:
https://www.youtube.com/watch?v=6Ej6o…Or view the Crayon Video here:
https://www.youtube.com/watch?v=BAEiB…
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_________________________________________________________________My name is Matt Estlea, I’m a 23 year old Woodworker from Basingstoke in England and my aim is to make your woodworking less s***.
I come from 5 years tuition at Rycotewood Furniture Centre and 4 years experience working at Axminster Tools and Machinery where I still currently work on weekends. During the week, I film woodworking projects, tutorials, reviews and a viewer favourite ‘Tool Duel’ where I compare two competitive manufacturers tools against one another to find out which is best.
I like to have a laugh and my videos are quite fast paced BUT you will learn a lot, I assure you.
Lets go make a mess.
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The “grandmother hypothesis”
Jonathan Lambert on the theory for why, almost alone among species, human females live on well past their reproductive years:
Killer whales, Japanese aphids and Homo sapiens — they’re among the few organisms whose females live on long past the age of reproduction.
Since the name of the evolutionary game is survival and reproduction, the phenomenon begs explanation — why live longer than you can reproduce? In the 1960s, researchers came up with the “grandmother hypothesis” to explain the human side of things. The hypothesis is that the help of grandmothers enables mothers to have more children. So women who had the genetic makeup for longer living would ultimately have more grandchildren carrying their longevity genes. (Sorry, grandfathers, you’re not included in this picture.)
Two studies published Thursday in Current Biology take another look at this hypothesis and add new insights into the role grandmothers play.
The first hard evidence for the grandmother hypothesis was gathered by Kristen Hawkes, an anthropologist at the University of Utah who was studying the Hadza people, a group of hunter-gatherers in northern Tanzania. Hawkes was struck by “how productive these old ladies were” at foraging for food, and she later documented how their help allowed mothers to have more children.
If our long post-reproductive lives evolved because of grandmothers, we should be able to find fingerprints of the benefits of grandmothering in many cultures. But the circumstances of modern life differ drastically from those we faced at the beginning of our evolutionary story.
The studies in Current Biology turned to the detailed records of two preindustrial populations, one in what is now Quebec and the other in Finland. The researchers mined these rich databases to quantify the reproductive boost that grandmothers provide and to help us better understand the limits of their help.
H/T to Claire Lehmann for the link.
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How Does it Work: Long Recoil
Forgotten Weapons
Published on 7 Feb 2019http://www.patreon.com/ForgottenWeapons
Cool Forgotten Weapons merch! http://shop.bbtv.com/collections/forg…
Long recoil operation is one of the most mechanically interesting of the main firearm operating systems. When the gun fires, the recoil energy generated forces the barrel to move rearward, and the bolt remains locked into the barrel until the two reach the full length of travel (the length of the whole cartridge). At that point the bolt is held rearward and the barrel unlocks and moves forward under pressure from a return spring. The empty cartridge case is held in the bolt face, and the barrel pulls forward off the front of it. An ejector kicks the empty case out when the barrel is fully clear, and when the barrel has returned to its firing position a trip releases the bolt, which moves forward under pressure of a second return spring and feeds the next cartridge into the chamber.
Long recoil system are very safe, as they allow the longest time of any system to let pressure vent from the barrel before unlocking. They are also mechanically complex, and tend to exhibit higher than normal felt recoil. The system was employed successfully in a wide variety of firearms including light machine guns (the Chauchat), rifles (the Remington Model 8/81), shotguns (the Browning Auto-5 and Winchester Model 1911), and handguns (the Former Stop). All of these date from the early 1900s, when designers were still exploring ways to safely and reliably build self-loading firearms.
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QotD: Teaching evolution in the “Bible Belt”
I teach college in a small city in Arkansas, deep in the American Bible Belt. I am a historian of Africa and in my department that means that I also teach a world history survey. I always start with the expansion of modern humans out of Africa and their encounter with other types of humans: Neanderthals, Homo erectus, Denesovians and what seems like an ever-growing list of newly discovered human-like creatures. It’s less the case now, but when I started twenty years ago this part of the course was initially met with polite but firm resistance, which gradually gave way to a sort of furtive curiosity. I eventually realized that even my cleverest students knew very little about human evolution except that it was false and that they were supposed to reject it. They came to the university having been taught that evolution was part of a larger attack on their faith and values, but they had never really been exposed to anything but a sort of parody version of it. A small number of them accepted evolutionary theory, but being a Darwinian in rural Arkansas was usually more about youthful rebellion and non-conformity than it was about informed, rational consideration of evidence.
Once we got past the denunciation or acceptance of evolutionary theory as a form of tribal affiliation, I found students to be deeply curious about it. It was such a taboo subject that their high school teachers had only skimmed over it and often with some careful personal distancing from the material. So the opportunity to delve into the details of this forbidden knowledge was intellectually thrilling for them. Despite the excitement engendered by the topic only a few changed their minds; most did not.
My students had grown up in communities where evolutionary theory was so wrong, so contrary to the accepted worldview of all decent people, that the only acceptable way to talk about it was to denounce it or reject it. The result was that most of my students rejected evolution, but getting a chance to learn about it was profoundly exciting, even if most of them were too conformist (these were Honors students after all) to change their positions.
Erik Gilbert, “Liberal Orthodoxy and the New Heresy”, Quillette, 2019-02-04.
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