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The US Defense Advanced Research Projects Agency (DARPA) is funding a new ship defense technology that uses massive acoustic waves to disable incoming torpedoes. The design calls for a large array of three hundred and sixty loudspeakers beneath the waterline on each side of a ship’s hull. These flat, one-meter-square transducers can send focused, destructive pressure pulses in any direction with crushing force, disabling or breaking up enemy torpedoes. Some new designs of supercavitating torpedoes envelop themselves in a bubble of air to reduce friction and dramatically increase speed… these sonic pulses could also disrupt that air pocket and destabilize the torpedo.

An obvious concern is the impact this system will have on oceanic wildlife, particularly in the testing phase. Among other problems, whales have been known to beach themselves following underwater acoustic weapon tests. But the risks may be not be quite as bad as they seem at first. For one, this new system will probably use a phased array of loudspeakers, which creates a localized point of high intensity sound surrounded by less-than-dangerous sound levels on all sides. Secondly, in real combat defense, the system will probably lower the impact upon the ocean’s ecosystem, since the potential damage to the environment is much, much worse in the event of a successful torpedo impact. A destroyed ship would result in explosions, wreckage, fuel/oil pollution, and in some cases nuclear pollution. I am no fan of war, but if it’s going to happen, the better our defenses, the safer our soldiers.

Of course the best solution is for humans to stop trying to blow each other up all the time, but as long as unscrupulous people in power have something to gain by throwing away young lives, they’ll continue to do it.

New Scientist article