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Mr. Wizard Explains the Laserdisc

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The Laserdisc format first hit the market in 1978, using massive 12" discs crammed full of shiny analog video to deliver awesome movies to your 80s-tastic home theater. The players were beastly -- large, heavy machines with complex laser systems and enough oomph to rotate the disc at up to 1,800 rpm. I have still have mine, along with a few movies on Laserdisc that were never released on DVD (for years, my copy of Koyaanisqatsi on Laserdisc was a prized possession, before DVD and Blu-ray versions finally appeared).

Today, the Laserdisc format feels positively retro, and a little clunky. For one thing, depending on the format of the disc, you had to get up and flip it over every 30 or 60 minutes -- unless you had a super-fancy player that could move its laser to the underside and continue playing automatically. There were also single-sided discs (these were less susceptible to laser rot, and were often used for Criterion Collection releases) that were unflippable, so you'd have to eject the big-ass platter and put in the next. In any case, there was no way you could sit through a feature film on Laserdisc without some fiddling; I recall seeing some films in college that required four or five disc swaps.

But despite its compromises and vague clunkiness, Laserdisc was a remarkable invention. It had special features (explained in the video below) sometimes called "trick play" that allowed for high-quality slow motion, full-fidelity still frames, and even individually addressable frames (some educational software allowed the user to pull up individual photographs by selecting a single frame on the disc -- this was how my high school biology class learned about a real condition called "black hairy tongue"). Laserdisc was clearly the best format for film buffs in the 70s and 80s, and some (like me) even held onto the format well into the 90s, even as DVDs came on the scene. I recall having a few geeky arguments about analog Laserdisc video quality versus the compressed MPEG-2 digital video you'd get from DVDs -- while the Laserdisc was truly better quality in some ways, it was hard to beat DVD for convenience (one tiny disc, dude!), and eventually formats like dual-layer DVD made the argument pointless. Laserdiscs were relegated to the bargain bin of history.

If you're curious about how Laserdiscs worked, here's Don Herbert (known to most of us as Mr. Wizard) explaining the Pioneer Laserdisc system in 1980. It's great stuff -- lots of Mr. Wizard-style props to explain the system, and bits of fun trivia. (For example, Herbert starts his presentation by pointing out that LASER is an acronym, and spelling it out.) Set aside ten minutes for some LASER FACTS:

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iStock // vuk8691
Creating a Water-Powered Hammer Using Stone Age Tools
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iStock // vuk8691

A "Monjolo" is a water-powered hammer made from a log and some sticks. It relies on flowing water from a stream to do its work.

In the video below, the anonymous laborer who goes by Primitive Technology on YouTube creates his own Monjolo from scratch. It's effectively a hollowed-out log placed in the path of a stream, supported by a structure of skinny beams. As the log fills up with water, it rises, then the water drains out the back and it comes crashing down again. When it crashes down, that's an opportunity for a hammer head on the end to do something useful—like crushing charcoal or grain.

The creator of Primitive Technology writes:

This is the first machine I’ve built using primitive technology that produces work without human effort. Falling water replaces human calories to perform a repetitive task. A permanent set up usually has a shed protecting the hammer and materials from the weather while the trough end sits outside under the spout. This type of hammer is used to pulverise grain into flour and I thought I might use one to mill dry cassava chips into flour when the garden matures. ...

Like all the Primitive Technology videos, this is done entirely without spoken or written language, and it's DIY paradise. Tune in for a look into what one man alone in the bush can create:

This Just In
Typewriter Sold at Flea Market Turns Out to Be Rare World War II Enigma Machine

An antique typewriter sold at a Romanian flea market for $114 turned out to be a rare piece of wartime history: a German Wehrmacht Enigma I machine worth tens of thousands of dollars, Reuters reports.

To the uninitiated, the rare electromechanical cipher machine—which was first developed in Germany in the 1920s, and was used to encode and decode Nazi military messages during World War II—resembles a writing machine. But when a cryptography professor spotted it, he knew the device’s true worth. He purchased the relic and later put it up for auction at the Bucharest auction house Artmark.

Artmark employee Vlad Georgescu told CNN that the machine was made in Germany in 1941. It was in near-perfect condition thanks to its owner, who cleaned and repaired it, and “took great care of it,” Georgescu said.

The Enigma I’s starting price was $10,300. On Tuesday, July 11, an online bidder purchased it for more than $51,000. "These machines are very rare, especially entirely functional ones," Georgescu said. Historians, however, say that Romania may still be home to more unidentified Engima I machines, as the country was once allied with Nazi Germany before joining forces with the Allies in 1944.

During World War II, Alan Turing and his colleagues at Bletchley Park, Britain's central codebreaking site, built a giant computer called the Bombe to calculate solutions that solved the Enigma’s supposedly unbreakable code. Some military historians believe that their efforts shortened the war by at least two years.

[h/t BBC News]


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