Optical Cellphones

foondog writes "Here is a story over at News.com about optical cellphones. It seems that the Department of Defense has given a grant to the University of California to develop optical cellphones that are faster and more secure. This sounds a little strange to me since you would need a line of site with no obstacles in the way to use this. The article doesn't explain how this might work."

Comments

Can you see me now?

[Anonymous Coward]

(sorry... had to be said)

Using a laser?

[bunyip]

Need line of sight. DoD likes lasers. Big lasers, with lots of power. Could be dangerous.

I wouldn't want to hold one of these up to the side of my head and start talking, it might make it's own line of sight to the nearest tower.

Ouch!

Re:Soldiers Have Been Carrying Optical Cell For Ye

[floydigus]

It's called a heliograph and a CD would make a very good substitute.
Take a CD and an ice lolly stick. Make a hole in one end of the stick and hold the CD up in front of your face, shiny side facing out. Be facing the sun, more or less.
Hold the lolly stick up in front of that (about 12 inches away) and sight through the hole in the CD and the hole in the lolly stick at the aeroplane, boat, visitor craft or whatever you are trying to signal to. Now wiggle the CD until the shadow of the hole in the middle of the CD falls over the hole in the lolly stick. Now you are shining your light right at your target. By flicking your hand, you can turn the light on and off and so make morse. Or binary. Whatever.
If you do do this to a visitor, they will probably just decode the information on the CD and try to work out the meaning. Do not expect to be rescued. Expect instead to get Barry Manilow's greatest hits beamed back to you some days later.
If this saves your life, paypal me! ;)