The 30-second test, to be overseen by the Federal Emergency Management Agency and the Federal Communications Commission, will run on radio, satellite radio and TV stations in all 50 states and U.S. territories. It will include alert “beeps” and the words “This is a test.”

Here’s how FEMA explains it:

We need to know that the system will work as intended should public safety officials ever need to send an alert or warning to a large region of the United States. Only a complete test of the Emergency Alert System can help us identify any changes and improvements needed to modernize this system and make it fully accessible.

The name most closely associated with the invention of wireless telegraphy — what we now know simply as radio — is Guglielmo Marconi, but as with so many technologies, there were a number of hands stirring the pot, chief among them Heinrich Hertz, Alexander Popov and Nicola Tesla. Marconi’s claim to primacy was no doubt helped by the fact that he obtained the British patent for wireless in 1896, when Britannia still ruled the waves.

Radio communication at sea quickly evolved into an indispensable safety aid for mariners. By the early 20th century ships were able to communicate with each other as well as with shore-based stations. The Japanese navy used radio communication to scout the Russian fleet during the Battle of Tsushima in 1905, a crushing Japanese victory and a turning point in the Russo-Japanese War.

The failure of radio communication played a major role in the Titanic disaster in 1912. The lone radio operator aboard the Californian had switched off his set for the night (as was common aboard vessels carrying a single operator) and never received the Titanic’s distress signals. Had someone been at his post, the Californian — by far the closest ship to the stricken liner — could have arrived soon enough to save many of the lives that were lost.’

Source: Wired Magazine. This article first appeared on Wired.com Aug. 23, 2007.

“Morris was prosecuted for creating and releasing the Morris worm, generally recognized as the first computer worm to infect the internet. He released the worm from computers at MIT in order to keep the light of suspicion away from Cornell.

Morris said later that his intentions were purely intellectual, that he created the worm in an attempt to measure the size of the internet. A design flaw in the worm’s delivery system, however, caused some infected computers to keep replicating the worm until they became unusable. A number of systems were disabled by the Morris worm.

Damage estimates from the worm’s impact vary greatly, as do the actual number of systems and individual computers that were affected. But the numbers applied to Morris are concrete: After some plea bargaining, he was sentenced in December 1990 to three years’ probation and fined $10,000 (about $17,000 in today’s money).

The Computer Fraud and Abuse Act has been amended several times (and folded into the Patriot Act) since its inception, and Morris’ activities might bring down a much harsher sentence today.”

(Source: Wired Magazine Online)

“Bell believed that the photophone was his most important invention. The device allowed the transmission of sound on a beam of light. Of the eighteen patents granted in Bell’s name alone, and the twelve that he shared with his collaborators, four were for the photophone.

Bell’s photophone worked by projecting the voice through an instrument toward a mirror. Vibrations in the voice caused similar vibrations in the mirror. Bell directed sunlight into the mirror, which captured and projected the mirror’s vibrations. The vibrations were transformed back into sound at the receiving end of the projection. The photophone functioned similarly to the telephone, except that the photophone used light as a means of projecting the information and the telephone relied on electricity.

Although the photophone was an extremely important invention, it was many years before the significance of Bell’s work was fully recognized. Bell’s original photophone failed to protect transmissions from outside interferences—such as clouds, that easily disrupted transport. Until the development of modern fiber optics, technology for the secure transport of light inhibited use of Bell’s invention. Bell’s photophone is recognized as the progenitor of modern fiber optics.”

(Source: The Library of Congress)

• This is why you shouldn’t click on everything that someone sends you in Facebook – or email or Twitter or… (CNN Tech)

• Here’s a helpful guide that pretty much says it all – What to do if your iPhone falls in the toilet, a mug of beer or pile of snow (Tech News World)

• If you are cursing your XM/Sirius technology today, here is easy access to the new channel line-up.

• We had no idea that this existed but apparently today is “Star Wars Day” so be prepared to hear geeks everywhere say “May the 4th be with you” – you’ve been warned.

Hope everyone is having a great week!

• Motion-controlled email and other Web pranks from CNN Tech

• Tech-Crunch is running a series of funny but completely untrue technology stories today…

• Here is a fun list of technology companies that tried to get it on the joke today (USA Today)

• And finally, an oldie but goodie from Wired magazine: Top 10 April Fools’ Pranks for Nerds

Have a great weekend everyone!

• Geometry: Half the circumference of a circle with a radius of 1 is exactly pi

• Record for calculation: 5 trillion, by Shigeru Kondo (Japan) and Alexander J. Yee (United States) in August 2010

• Record for memorization: 67,890 digits, by Chao Lu (China) in November 2005

• How random? There are no occurences of the sequence 123456 in the first million digits of pi

• Pi Day: In 2009, Congress voted in favor of supporting March 14 as Pi Day

Source: “The Joy of Pi,” Guinness World Records

(courtesy of About.com)