Cicadas Are So Loud, Fiber Optic Cables Can 'Hear' Them (wired.com) 22
An anonymous reader quotes a report from Wired: One of the world's most peculiar test beds stretches above Princeton, New Jersey. It's a fiber optic cable strung between three utility poles that then runs underground before feeding into an "interrogator." This device fires a laser through the cable and analyzes the light that bounces back. It can pick up tiny perturbations in that light caused by seismic activity or even loud sounds, like from a passing ambulance. It's a newfangled technique known as distributed acoustic sensing, or DAS. Because DAS can track seismicity, other scientists are increasingly using it to monitor earthquakes and volcanic activity. (A buried system is so sensitive, in fact, that it can detect people walking and driving above.) But the scientists in Princeton just stumbled upon a rather noisier use of the technology.
In the spring of 2021, Sarper Ozharar -- a physicist at NEC Laboratories, which operates the Princeton test bed -- noticed a strange signal in the DAS data. "We realized there were some weird things happening," says Ozharar. "Something that shouldn't be there. There was a distinct frequency buzzing everywhere." The team suspected the "something" wasn't a rumbling volcano -- not inNew Jersey -- but the cacophony of the giant swarm of cicadas that had just emerged from underground, a population known as Brood X. A colleague suggested reaching out to Jessica Ware, an entomologist and cicada expert at the American Museum of Natural History, to confirm it. "I had been observing the cicadas and had gone around Princeton because we were collecting them for biological samples," says Ware. "So when Sarper and the team showed that you could actually hear the volume of the cicadas, and it kind of matched their patterns, I was really excited."
Add insects to the quickly growing list of things DAS can spy on. Thanks to some specialized anatomy, cicadas are the loudest insects on the planet, but all sorts of other six-legged species make a lot of noise, like crickets and grasshoppers. With fiber optic cables, entomologists might have stumbled upon a powerful new way to cheaply and constantly listen in on species -- from afar. "Part of the challenge that we face in a time when there's insect decline is that we still need to collect data about what population sizes are, and what insects are where," says Ware. "Once we are able to familiarize ourselves with what's possible with this type of remote sensing, I think we can be really creative."
In the spring of 2021, Sarper Ozharar -- a physicist at NEC Laboratories, which operates the Princeton test bed -- noticed a strange signal in the DAS data. "We realized there were some weird things happening," says Ozharar. "Something that shouldn't be there. There was a distinct frequency buzzing everywhere." The team suspected the "something" wasn't a rumbling volcano -- not inNew Jersey -- but the cacophony of the giant swarm of cicadas that had just emerged from underground, a population known as Brood X. A colleague suggested reaching out to Jessica Ware, an entomologist and cicada expert at the American Museum of Natural History, to confirm it. "I had been observing the cicadas and had gone around Princeton because we were collecting them for biological samples," says Ware. "So when Sarper and the team showed that you could actually hear the volume of the cicadas, and it kind of matched their patterns, I was really excited."
Add insects to the quickly growing list of things DAS can spy on. Thanks to some specialized anatomy, cicadas are the loudest insects on the planet, but all sorts of other six-legged species make a lot of noise, like crickets and grasshoppers. With fiber optic cables, entomologists might have stumbled upon a powerful new way to cheaply and constantly listen in on species -- from afar. "Part of the challenge that we face in a time when there's insect decline is that we still need to collect data about what population sizes are, and what insects are where," says Ware. "Once we are able to familiarize ourselves with what's possible with this type of remote sensing, I think we can be really creative."
This has absolutely nothing to do with cicads (Score:4, Informative)
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The spring/summer of 21 was particularly bad with the cicadas on the East Coast, nonetheless. I was in the Brood X region and it was awful. Mindnumbing sound for months.
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Well, at least it's a seasonal phenomenon!
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Areas with periodical cicadas don't have to deal with it often. Down here in Florida we have annual varieties, so the cicadas are an everyday thing here throughout the warmer months.
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Re:This has absolutely nothing to do with cicads (Score:4, Interesting)
Acoustic, even. What it really shows is how sensitive our sensors have become.
Re:This has absolutely nothing to do with cicads (Score:5, Informative)
The military has been using fiber optic sensors around sensitive military installations for decades. They can monitor approaching vehicles and foot traffic around remote missile silos, areas where the public isn't allowed, etc.
Here is a report from the Rand corporation showing areas of research for fiber optic applications in 1989.
https://www.rand.org/content/d... [rand.org]
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Nice find. In 1989 it prolly cost arm and leg and today you can easily do it with a $25 SiPM, $5 dsp chip and a raspberry pie or a beaglebone.
So loud? (Score:2)
There are bugs in the system (Score:1)
...literally.
Good (Score:2)
When they tell you to "eat ze bugs", you will have a method of finding them.
It is wrong that I want one? (Score:2)
It'd be kind of cool to have an optical seismometer connected to a pre-coded filter that could identify footsteps, passing cars, nearby trains, etc. and pass them to my computer.
Even better would be to have three of them to triangulate the signals.
So much hate for the sound of cicadas (Score:2)
Race traitor! (Score:2)
Only good bug is a dead bug!
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Would you like to know more?
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Count me as the other side. I never even heard of a cicada, not a thing in my part of California. Until I visited Tokyo this summer. That fingernails on chalkboard sound (to me) is everywhere. Gives me chills thinking about it though I did find myself able to filter out the noise later in the trip. Ugly AF too.
So - all good, worked as designed. (Score:2)
Since the device was designed to pick up mechanical stimulation, the audio waves made by cicadas was sensed correctly.
Back in the my works we design very sensitive electronic instruments and the vibration of cooling fans can be noticeable in the signals, usually as very faint modulation but still observable in the frequency spectrum. We call these signals 'acoustics' or 'microphonics'.
A microphone in every building? (Score:1)
It seems to me this could be used as a microphone everywhere the fiber goes. Buildings, houses, public spaces, etc. Add some AI voice filtering and you could listen to or locate any person anywhere. To be used only for righteous purposes of course.
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You asked for fiber to the curb didn't you?
Slashdotters know data likes the silence (Score:2)
We have a sign in our server room asking people not to shout :
https://www.youtube.com/watch?... [youtube.com]
monitoring (Score:2)