That had a crooked vane
Solving its crooked behavior
Became a crooked pain
A fairly comprehensive discussion of the wrong and (probably) right answers for the rotation of a Crookes radiometer.
via Fine Structure
Category Archives: History
Decisions, Decisions
No one knows why anyone does anything.
Why did I choose these socks today?
Trinity +1: the Decision to Use the Bomb, 17 July-6 August, 1945
The truth of the matter was that it was a very complex issue, an easily misunderstood tapestry of circumstance and consequence. The major issue of course was that the Japanese would not surrender, and that there would be “fanatical resistance” once the invasion of the Japanese islands had begun. The battle of Okinawa had just been fought—it was a horrible confrontation taking 12,5000 American lives and more than 1000,000 Japanese , demonstrating that even in impossible circumstances that the Japanese simply would not surrender (unconditionally). This is just one instance—there are many others, not the least of which was t he recent firebombing of Tokyo, taking 150,000 lives. Air strikes in general seemed to not make a difference in the will of Japan to fight—as was demonstrated again and again in the British and American bombing of Germany—as was further demonstrated in General Curtis LeMay’s and General Hap Arnold’s 60-city attack in the May-August span. The thought was that if there was an invasion that it could well cost the U.S. 1000,000+ casualties and would be completely devastating to Japan.
Something odd (in a US-centric way) going on with the numbers — 12,5000 and 1000,000 correlate to 12,500 and 100,000, respectively, when I compare to other accounts of the battle of Okinawa.
via Physics Buzz
The Wavelength of Money
Physicists of the 20th Century on Banknotes (pdf)
Feynman on the $20! Feynman on the $20!
It’ll never happen. We’re too stodgy about this in the States, and we do some ugly things with our currency.
a reminder, via Kottke
Seftonomics
Via Kottke, The Economic Organisation of a P.O.W. Camp
Stories circulated of a padre who started off round the camp with a tin of cheese and five cigarettes and returned to his bed with a complete parcel in addition to his original cheese and cigarettes; the market was not yet perfect. Within a week or two, as the volume of trade grew, rough scales of exchange values came into existence. Sikhs, who had at first exchanged tinned beef for practically any other foodstuff, began to insist on jam and margarine. It was realized that a tin of jam was worth 1/2 lb. of margarine plus something else; that a cigarette issue was worth several chocolates issues, and a tin of diced carrots was worth practically nothing.
In this camp we did not visit other bungalows very much and prices varied from place to place; hence the germ of truth in the story of the itinerant priest. By the end of a month, when we reached our permanent camp, there was a lively trade in all commodities and their relative values were well known, and expressed not in terms of one another – one didn’t quote bully in terms of sugar – but in terms of cigarettes. The cigarette became the standard of value. In the permanent camp people started by wandering through the bungalows calling their offers – “cheese for seven” (cigarettes) – and the hours after parcel issue were Bedlam. The inconveniences of this system soon led to its replacement by an Exchange and Mart notice board in every bungalow, where under the headings “name,” “room number,” “wanted” and “offered” sales and wants were advertised. When a deal went through, it was crossed off the board. The public and semipermanent records of transactions led to cigarette prices being well known and thus tending to equality throughout the camp, although there were always opportunities for an astute trader to make a profit from arbitrage. With this development everyone, including non-smokers, was willing to sell for cigarettes, using them to buy at another time and place. Cigarettes became the normal currency, though, of course, barter was never extinguished.
Fifth Law, Redux
Survival of the Sudsiest, or George Will happens upon the fifth law of thermodynamics.
“The search for unpolluted drinking water is as old as civilization itself. As soon as there were mass human settlements, waterborne diseases like dysentery became a crucial population bottleneck. For much of human history, the solution to this chronic public-health issue was not purifying the water supply. The solution was to drink alcohol.”
Often the most pure fluid available was alcohol — in beer and, later, wine — which has antibacterial properties. Sure, alcohol has its hazards, but as Johnson breezily observes, “Dying of cirrhosis of the liver in your forties was better than dying of dysentery in your twenties.” Besides, alcohol, although it is a poison, and an addictive one, became, especially in beer, a driver of a species-strengthening selection process.
This fits right in with concepts from Jared Diamond’s Guns, Germs and Steel, in that civilization which didn’t develop the kind of population densities (i.e. towns) compelling people to drink alcohol did not see the genes for alcohol tolerance selected for (along with diseases that mutated and jumped from domesticated animals to humans in these regions with high densities)
Did I Read That Right?
This is the kind of post I start reading, and I begin to furrow my eyebrows as phrases and sentences pop up that don’t seem right or are obviously wrong. I though it was just bad science journalism, but realized it’s a rant-y agenda piece, with the supposed “science” reporting as a setup.
Superfluids, BECs and Bosenovas: The Ultimate Experiment
It starts off OK, giving some history, but then there was
Bosons are force carriers like photons of light and fermions are the matter we can touch.
Force carriers are bosons, but not all bosons are force carriers (universal affirmatives can only be partially converted, quoth the logician) — you can construct bosonic systems from an even number of fermions. Bosons have integral spin angular momentum, and fermions have half-integral spin, and the statistics that describe their behavior is different. An attempt to bridge the gap between science and a lay explanation that fails because it’s scientifically incorrect.
[helium is] produced by nuclear decay, as from radium and polonium, dangerous alpha radiation releasing, in fact bare nuclei of helium that eventually pick up electrons and form stable helium isotopes.
Here’s a journalistic archaeologism (it’s certainly not neo-) dangerous radiation. Nuclear radiation in invariably dangerous. Actually alpha radiation is pretty much harmless as an external dose, as it deposits its energy in a very short distance, so it doesn’t tend to penetrate even a layer of dead skin. The source is dangerous when ingested or inhaled. But the Helium nucleus is already stable (it doesn’t decay) even before it picks up the electrons — that makes it electrically neutral, not stable.
In This Corner, Wearing the Red Trunks . . .
Particle and wave descriptions of light, duking it out in the early 19th century. What a drag: Arago’s Experiment (1810) over at Skulls in the Stars.
Before 1800, most scientists were proponents of the so-called corpuscular theory of light propagation. In this view, which was championed and solidified by Isaac Newton in his 1704 book Opticks, held that light consisted of a stream of particles. Newton explicitly argued against the wave theory of light and (seemingly) refuted arguments by early wave theory proponents such as Christiaan Huygens. Newton’s arguments, and his personal gravitas, left his particle theory mostly unchallenged until the early 1800s.
Reminder: The Giant's Shoulders
A reminder that the submission deadline for “classic” science posts is coming up on the 15th, and the inaugural compendium of The Giant’s Shoulders will be hosted at Blog Around the Clock
It's a Quarter Past 'Dragon Eats the Sun'
Narrowing down some historical dates with astronomy
Marcelo Magnasco and Constantino Baikouzis identified four astronomical events in the epic poem [The Odyssey] and calculated dates within 100 years of the fall of Troy that would fit in with the events described around Odysseus’s return home and the ensuing slaughter of men propositioning his wife. April 16, 1178 BCE was what they came up with
I hope that the language tutors prepositioning his wife were spared, but Homer was silent about that. Anyway, there’s also a correction to the dates for Caesar’s invasion of England, based on the tides.
And last week, Matt explained more over at Built on Facts
On June 15, 763 BC a total eclipse appeared in Assyria. Mentioned both in Assyrian records and (possibly) the Biblical book of Amos, it’s the oldest specific date of which I’m aware in ancient near eastern history. More spectacularly but later, an eclipse on May 28, 585 BC ended a battle between the Medes and the Lydians by terrifying the combatants into an immediate peace agreement. If you don’t count an eclipse by itself as being a historical event, I believe this is the single oldest event which can be pinned to a specific date.
Give My Creature LIFE
Or at least make it spin a little. A simple motor: battery, magnet and wire.
Magnetic field sees a changing current and that results in a force, which gives you a motor. Quite similar to the Faraday motor, but then, he was allowed to play with mercury (and he never wore a bike helmet, either)
Update: Give MY creature life. Built one myself this afternoon, and even figured out how to upload it to YouTube. She may not look as pretty as these other motors, but she loves to spin. (First attempt didn’t go so well, but I found lighter wire that was still stiff)