The Monty Hall problem

One more item for the "we don't know everything we think we do" files.

Here’s how Monty’s deal works, in the math problem, anyway. (On the real show it was a bit messier.) He shows you three closed doors, with a car behind one and a goat behind each of the others. If you open the one with the car, you win it. You start by picking a door, but before it’s opened Monty will always open another door to reveal a goat. Then he’ll let you open either remaining door.

Suppose you start by picking Door 1, and Monty opens Door 3 to reveal a goat. Now what should you do? Stick with Door 1 or switch to Door 2?

[...]

This answer goes against our intuition that, with two unopened doors left, the odds are 50-50 that the car is behind one of them. But when you stick with Door 1, you’ll win only if your original choice was correct, which happens only 1 in 3 times on average. If you switch, you’ll win whenever your original choice was wrong, which happens 2 out of 3 times.

What does this have to do with anything? It points out a serious flaw in a 1956 experiment on cognitive dissonance.

I am always interested in these bits of information that show we don't know as much as we think we do.

Pictures of Matchstick Minas Tirith

At hemmy.net: Minas Tirith Matchstick Model. Built by matchstick artist Patrick Acton of Iowa.

Tubular!

Oddee, which is updated even less frequently than yours truly but which is always worth linking to, has posted a collection of 10 Incredible Old Magazine Covers like the one above, from 1949, featuring a radio helmet that used only two tubes!

Follow the link for a 1942 Cosmopolitan cover featuring Gerald Ford back when he was working as a model, and some other notable bits of history.

DYI Enigma

Downloadable plans for building your own Paper Enigma Machine.

Cassiopeia, the Handgun

Here's an article on a proposal to rename constellations as things that modern folks can more easily relate to. In this picture, Cassiopeia becomes The Handgun. It doesn't really look like either one, to me.

And here's one for Fodder and Sailorcurt, and any other bikers who read this blog but I've forgotten to mention:

Meet Ted, the satellite spotter

From the New York Times:

“If Ted can track all these satellites,” Mr. Pike said, “so can the Chinese.”

Interesting article about hobbyists who track satellites with nothing more than a telescope or a set of binoculars.

Look closely...

Look very closely...

Things are not always what they seem.

And if you have a pipe, then of course you'll also need a lighter.



Dark Roasted Blend has an article on miniature spy guns, most of them antique, and as usual with DRB, lots and lots of pictures.

I'm somewhat disturbed by the pipe. The discoloration on the stem appears to be oxidation which would be caused by someone actually carrying it around in his mouth. "Shot by his own pipe" would be a stupid way to die.

The pucker factor

Oddee has photos of some of the World's Most Dangerous Airports. Although "airport" may be a somewhat loose usage of the term for some of them.

2000-year-old superglue

The Romans had it. At Discovery News:

Willer found traces of the superglue while examining a helmet unearthed in 1986 near the German town of Xanten, on what was once the bed of the Rhine.

"The helmet, which dates from the 1st century B.C., was given to the museum for restoration. I discovered the glue accidentally, while removing a tiny sample of metal from the helmet with a fine saw. The heat from the tool caused the silver laurel leaves on the helmet to peel off, leaving thread-like traces of the glue behind," Willer said.

Willer was amazed to discover that despite such a long exposure to water, time and air, the superglue did not lose its bonding properties.

Hmmm... I saved this as a note a few weeks ago, but forgot to record where I originally read it. Anyhow, I thought it was interesting.

The Petticoat Duel

Curious Expeditions posts an interesting article on dueling, including this account of a duel between women:

The most famous of these female duels is the 1792 duel between Lady Almeria Braddock and Mrs. Elphinstone, regarding a comment over Lady Braddock’s true age. The ladies dueled first with single shot pistols. The duel came within a foot of fatal when Mrs. Elpinstone’s shot went through Lady Braddock’s hat. Despite the calls of their seconds (every principle duelist must have a second, a sort of right hand man - or madame, in this case) to cease and desist, the determined ladies switched to swords. A short round of fencing ensued, and Mrs. Elphinstone was wounded in the arm. Through her pain, she agreed to write a letter of apology. Honor restored, the ladies curtsied and headed home.

Over a comment about her age. Sheesh.

"Thinking outside the box"

Oh man, that's a great pun. I wish I had thought of it.

This is a selection from the 2008 Coffin Glamour Calendar at cofanifunebri.com, an Italian coffin manufacturer.

The miniature art of David Kucer

It is important to place David Kucer’s work into an historical perspective. Miniature firearms were the invention of the Renaissance. Their appearance coincided with the acceptance by the aristocracy of the wheel-lock. Wheel-lock arms were complex and costly, their manufacture requiring highly specialized and advanced technical skills. What was true of full scale firearms was equally true of miniature wheel-lock guns which were made in the 1500s and early 1600s. Miniature firearms were the most extreme test of the abilities of the virtuoso metal-smiths. They equaled in their demands upon the abilities of their makers the most intricate and delicate achievements of goldsmiths and jewelers. In addition, they were an extension of Late Renaissance and Mannerist fascination with small scale works of art such as the bronze statuette, plaquette, and medal.

In his notes for the catalogue of the Kucer exhibition at the Royal Armouries of H.M. Tower of London, Howard L. Blackmore refers to Michael Mann of Augsburg (he died c.1630), who made both miniature caskets and miniature firearms. For artists like him, the careful making of miniature arms was an extension of a whole, complex field of decorative arts and applied technology. There was in a sense no real separation of art and science; they were part of the same phenomenon of human development.

It is appropriate that in the Royal Ontario Museum, David Kucer’s miniature firearms were put on display contiguous to masterpieces of Medieval, Renaissance, and Baroque silver and goldsmiths’ work, to which they are in no way inferior.

Lots more info and pictures at David Kucer Miniature Arms.

A dark matter of faith

"Scientists Say Dark Matter Doesn't Exist":

Two Canadian astronomers think there is a good reason dark matter, a mysterious substance thought to make up the bulk of matter in the universe, has never been directly detected: It doesn't exist.

Dark matter was invoked to explain how galaxies stick together. The visible matter alone in galaxies—stars, gas and dust—is nowhere near enough to hold them together, so scientists reasoned there must be something invisible that exerts gravity and is central to all galaxies.

Now John Moffat, an astronomer at the University of Waterloo in Canada, and Joel Brownstein, his graduate student, say those announcements were premature.

In a study detailed in the Nov. 21 issue of the Monthly Notices of the Royal Astronomical Society, the pair says their Modified Gravity (MOG) theory can explain the Bullet Cluster observation. MOG differs from other modified gravity theories in its details, but is similar in that it predict that the force of gravity changes with distance.

"MOG gravity is stronger if you go out from the center of the galaxy than it is in Newtonian gravity," Moffat explained. "The stronger gravity mimics what dark matter does. With dark matter, you take Einstein and Newtonian gravity and you shovel in more dark matter. If there's more matter, you get more gravity. Whereas for me, I say dark matter doesn't exist. It's the gravity that's changed."

[...]

Moffat compares the modern interest with dark matter to the insistence by scientists in the early 20th century on the existence of a "luminiferous ether," a hypothetical substance thought to fill the universe and through which light waves were thought to propagate.

"They saw a glimpse of special relativity, but they weren't willing to give up the ether," Moffat told SPACE.com. "Then Einstein came along and said we don't need the ether. The rest was history."

Douglas Clowe, the lead astronomer of the team that linked the Bullet Cluster observations with dark matter (and now at Ohio University), says he still stands by his original claim. For him and many other astronomers, conjuring up new particles that might account for dark matter is more palatable than turning a fundamental theory of how the univese works on its head.

"As far as we're concerned, [Moffat] hasn't done anything that makes us retract our earlier statement that the Bullet Cluster shows us that we have to have dark matter," Clowe said. "We're still open to modifying gravity to reduce the amount of dark matter, but we're pretty sure that you have to have most of the mass of the universe still in some form of dark matter."

Posted only because I often find it interesting--an amusing--when scientists are at odds with each other over something that's never been conclusively proven or "detected."

It's a long way from design to prototype...

But still, this is pretty cool.

Waterspout, a small helicopter that can take off underwater from a submarine, has been designed by students at the Technion-Israel Institute of Technology in Haifa and the University of Pennsylvania. The joint team of students have won first prize in a US helicopter design competition.

Kinetic Totems

Danse Macabre by Patrice Hubert.

One last Halloween-ish post for the day.

A corny tribute

A corn maze of the late Gerald Ford at Gull Meadow Farms.

Amazing (hee hee).

The Grotesque and Sublime

Art by Kris Kuski. More at kuski.com.