Acoustic "Superlens" Could Make Subs Invisible 136
Al writes "Nicholas Fang and colleagues at the University of Illinois at Urbana-Champaign have created the first acoustic superlens, which could be used to create high-resolution ultrasound images, and perhaps ultimately make subs and ships invisible to sonar. Researchers have previously developed materials that bend light in ways that appear to violate the laws of physics, creating so-called optical superlenses. The acoustic superlens consists of an aluminum array of narrow-necked resonant cavities filed with water — the dimensions of the cavities are tuned to interact with ultrasound waves. When ultrasound waves move through the array, the cavities resonate and the sound is refocused."
Re:invisible != inaudible (Score:5, Insightful)
No. They may still be audible, but ultrasound will appear to go through them as if they were water.
Invisible to *active* sonar, maybe. (Score:5, Insightful)
Passive sonar, on the other hand, still works fine.
After all, the thing's got to have a tailpipe.
Re:Save the whales! (Score:2, Insightful)
Oh noes! Teh whales! You're right - the entire western Navy should just pack up and go home. I'm sure our enemies, being the reasonable and thoughtful people they seem to be, will follow suit.
Re:Save the whales! (Score:1, Insightful)
I think there's room for the GP on Obama's cabinet! Mr. Prez seems to like people who make knee-jerk decisions/comments without thought to their long-term ramifications.
Violate the laws of physics? (Score:5, Insightful)
If they have developed materials that bend light in ways that appear to violate the laws of physics, then it means the laws of physics need to be redefined. That's what science is. Formulas made from observations. New observations may modify your existing understanding of how things work.
And if you can't accept that, you shouldn't call yourself a scientist.
Re:Violate the laws of physics? (Score:3, Insightful)
The key word here is 'appear'. Meta-materials (which is what this is, just on a large scale) appear to violate the laws of physics but if you look more closely they don't. The point is that if you showed it to a college undergrad with decent physics knowledge they would say it violates the laws of physics, that doesn't mean the college kid is right.
Re:This brings up an important point (Score:3, Insightful)
The trivial solution would be a cavity filled with water same shape and size as the submarine, at the same position as the submarine.
Why is this marked interesting? Clearly it's funny, since the above suggestion is to have the so-called submarine actually just be a pocket of water. i.e. no submarine.
Re:This brings up an important point (Score:3, Insightful)
Most 3 digit ID posters have long ago stopped worrying about karma.