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Navy Scientists Develop Laser For Underwater Communication
Researchers at the Naval Research Laboratory claim to have come up with a better tool for underwater acoustics. The new system uses laser light to create sound underwater from a distance. This technology could allow planes a much easier method of communicating with submarines without the need for a floating buoy. "Efficient conversion of light into sound can be achieved by concentrating the light sufficiently to ionize a small amount of water, which then absorbs laser energy and superheats. The result is a small explosion of steam, which can generate a 220 decibel pulse of sound. Optical properties of water can be manipulated with very intense laser light to act like a focusing lens, allowing nonlinear self-focusing (NSF) to take place. In addition, the slightly different colors of the laser, which travel at different speeds in water due to group velocity dispersion (GVD), can be arranged so that the pulse also compresses in time as it travels through water, further concentrating the light. By using a combination of GVD and NSF, controlled underwater compression of optical pulses can be attained."
So what's to prevent someone's hydrophones from picking this up and realizing that there's a submarine within audible range of the communication?
#fuckbeta #iamslashdot #dicemustdie
To Swimmers and wildlife, when a plane is shooting this giant high-powered laser into the water, to communicate with the submarine?
achieved by concentrating the light sufficiently to ionize a small amount of water, which then absorbs laser energy and superheats. The result is a small explosion of steam, which can generate a 220 decibel pulse of sound.
will this kill flipper?
The 220 db figure is probably the sound pressure right at the surface of the bubble. That tells you nothing useful as to the hazard to wildlife: depending on the pulse energy and repetition rate the bubbles could be as small as a few microns in diameter and the sound level nearby quite modest. The ability to create large "virtual" phased arrays should also reduce the need for the very high energy pulses used in some current systems.
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
Really?
Let's play devil's advocate and assume the Navy is needed and capable of "defending ourselves."
How many whales are worth one human life? How much whale misery is equal to human misery? What are the ethics of letting humans (of any nation) die in order to save a whale or give said whale a better life?
I ask this simply because you put it in the context of defense, not (financial) cost.
This is the one environmental question I don't see asked enough. Choosing the less effective method for environmental reasons - be it the less effective military communication method or the more costly energy production method - can directly harm (or put in harms way) people in order to protect animals.
Get back to me when there are 6 billion whales with and expected increase of 3 billion over the next decade or so. I would be willing to give up a nation of people if I could put the ocean back the way it was a hundred years ago.
Intro to moral philosophy was not my best class. But a lottery would certainly be fair. Instead I would suggest we outlaw those activities that cause harm, let's not argue about the method of measurement, to the ocean, or specifically whales. And if in fact as some ancestor post suggested this will result in human death, then so be it. You know, it is demonstrable that lowering the speed limit on highways reduces death by collision, but we re perfectly happy to leave the limit high for our convenience. Seems like a similar argument to me.