Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 Internet speed test! ×

Bletchley Park WWII Staff Finally Recognized 122

99luftballon writes "Nearly 70 years after Station X (aka the Bletchley Park cryptanalysis unit) was set up, the surviving members are to be honored by the British government. Bletchley was one of the most important computing centers of its time and housed giants of the technology industry (as it was) like Tommy Flowers, who built Colossus, and Dr. Alan Turing. I was lucky enough to meet one of the staff at the site 11 years ago, and she was very bitter that their work was never recognized, and that they were bound by the Official Secrets Act and couldn't talk about it. It's just a shame that so few of the staff are still alive to receive the award."

Beware the Airport Wireless 120

schwit1 writes to tell us that a recent study by a Silicon Valley-based security company shows that black-hats have been ramping up their use of tempting free or unsecured wireless access points in high travel areas like airports and hotels. "According to their study, even the 'secure' networks weren't all too safe. Eighty percent of the private Wi-Fi networks at airports surveyed by Airtight were secured by the aging Wired Equivalent Privacy (WEP) protocol, which was cracked back in 2001. Almost as many — 77 percent — of the networks they surveyed were actually private, peer-to-peer networks, meaning they weren't official hotspots. Instead, they were running off someone else's computer."

Comment The 40-year old promise (Score 5, Insightful) 66

The promise of making a laser from indirect bandgap semiconductors, then gathering investors, then losing the investors' money goes back to the Sixties at least.

Some scientists showed off SiC blue LEDs in the '60s that shown brilliantly like laser light, but were not the read deal. The real blue room-temperature laser had to wait for Nakamura and a direct bandgap material.

Doping, adding nitrogen, and adding defects to the lattice to produce more light is nothing new. Look at your stop lights. It's working there, but don't count on these indirect materials suddenly turning into lasers. No need to hold your breath.

A quick scientific note. Photons have a lot of energy, but not much momentum. You get hot on a sunny day, but not blown over by the sun. Electrons fall almost directly down in the bandgap diagram to produce light. This makes direct-gap semiconductors useful for lasers. The trick one can use is to provide momentum-shifting impurities to the lattice of an indirect bandgap crystal. The electron creates a photon by dropping directly down, but some other mechanism shifts the electron momentum to create an overall diagonal transition. It's not efficient, but it works.

Slashdot Top Deals

Work is the crab grass in the lawn of life. -- Schulz