Chemical "Infofuses" Communicate Without Electricity 115
Al writes "Researchers at Harvard and Tufts University have developed a way to send coded messages without using electricity. David Walt, professor of chemistry at Tufts, and Harvard's George Whitesides have developed 'infofuses' that can transmit information simply by burning. The fuses — metallic salts depositing on a nitrocellulose strand — emit pulses of infrared and visible light of different colors whose sequence encodes information. They were developed in response to a call from the Defense Advanced Research Projects Agency for technologies to allow soldiers stranded without a power source to communicate. In the first demonstration of the idea, they used the infofuses to transmit the message look mom no electricity." Currently the researchers are "trying to figure out a way to dynamically encode a message on the fly in the field without specialized equipment."
cause... (Score:4, Interesting)
Weird (Score:5, Interesting)
Step 1, smoke a cigarette under a poncho. Step 2, light an "infofuse". Step 3, get shot in the face.
My Drill Sargent demonstrated how easy it is to spot someone smoking in the dark.
Is a crank-powered radio really out of the question? I mean, it would even work during the day.
-Peter
hand cranked flashlight (Score:3, Interesting)
in the end, why would a hand cranked flashlight not be better. maybe one of the shake up ones.
Darpa keeps reinventing the wheel (Score:2, Interesting)
DARPA keeps reinventing the wheel. Isn't it simpler to use a portable hand cranked generator to power a normal radio using spread spectrum communications? Using spread spectrum gives reasonable safety level and hand cranked generator is power source which works as long as you have hands. This solution is so obvious, that it amazes me why DARPA would even think of something else.
Doesn't seem terribly practical. (Score:4, Interesting)
So it only transmits 2 km, and presumably someone has to be looking in the right direction to receive your signal, and you need some kind of special equipment to encode a long message. This just looks like the wrong approach. It seems to me there's always a trade-off between distance, information transmitted, and signal power (a rough restating of Shannon/Hartley). I don't know how far flares can be seen, but that's already a chemical means of sending a short message a limited distance.
One thing that might be interesting, the ability to produce a powerful radio signal by some chemical means. You wouldn't be able to transmit much information beyond say "help!", but if you had a satellite in geo-stationary orbit looking for these signals (and somehow triangulating the position) that might solve the "has to be someone looking" problem. Whether there are chemical reactions that produce radio signals, I have no idea.
New version of Old tech. (Score:2, Interesting)
The only reason I see for this item, is when you are someplace electricity doesn't work. Of course, then the sensor package used to read the infofuse signal would need power also, and be within 1.5km/0.9 miles. Guess it's not really that good in an EMP field.
Of course, what about the gear to encode the message?
They are trying to make it simpler and smaller, but it doesn't sound like it's going to be an easy piece of gear to run without electricity. Of course, the troops could be sent out with a packet of pre-recorded messages. Or maybe just extra batteries for their radios...
Maybe I'm being a little hypercritical, but it seems as if they are trying to solve a non-existent problem with an overcomplicated solution.
(Kind of like trying to move the 15' from your parking space to the mailbox when you don't have your car keys but think you can hotwire the car with a screwdriver... Just walk over there stupid!)
Here's another idea, give the troopies binoculars and semaphore flags. Of course they'd then have to be trained in semaphore, but it's technology that's available and works without electricity, even after your choice of nuclear apocalypse or alien invasion.
Re:Tarps, flags, semaphore, mirrors.... (Score:2, Interesting)
Re:hand cranked flashlight (Score:4, Interesting)
I guess if they have a airman down in hostile territory with the enemy having access to frequency monitoring equipment, how does the person transmit his coordinates without broadcasting anything.
Reminds me of those experiments that we used to to do in cub scouts - sticking a small mirror onto a thin sheet of clingfilm and watching how sound waves changed the direction of reflected light - to demonstrate how sound was just air moving rapidly.