Hammerhead shark as electrometer front end - Page 1
Forum section: electronics / general

author: fcb
author_rank: Super Contributor
timestamp: May 18, 2021, 11:05:29 am
content: Does this sound right? Hammerhead sharks can detect fields of around 1nV/M??https://youtu.be/lgTbQlfOSKE?t=775

author: bsfeechannel
author_rank: Super Contributor
timestamp: May 19, 2021, 12:15:06 am
content: The only way to be sure is to connect a 1.5V battery between Long Island Sound and the waters of Florida and see if it detects it.

author: Gyro
author_rank: Super Contributor
timestamp: May 19, 2021, 10:56:30 am
content: Quote from: bsfeechannel on May 19, 2021, 12:15:06 amGiven the number of boats and ships around with sacrificial anodes, I think it would have a hell of a job.I suspect that its response is low frequency AC rather than DC too. You don't want a hammerhead with uncontrolled drift!

author: fcb
author_rank: Super Contributor
timestamp: May 19, 2021, 01:08:56 pm
content: Quote from: Gyro on May 19, 2021, 10:56:30 amUndoubtedly it will be tuned to pulses from muscles in prey, but that's still a hell of a front end, wonder what the bandwidth is, how it filters out noise and if there is a DC blinding effect?

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: May 19, 2021, 03:47:33 pm
content: Don't know about 1nV per meter... buthttps://en.wikipedia.org/wiki/Ampullae_of_Lorenzini"Sharks may be more sensitive to electric fields than any other animal, with a threshold of sensitivity as low as 5 nV/cm"

author: Gyro
author_rank: Super Contributor
timestamp: May 19, 2021, 05:53:30 pm
content: Quote from: Alex Eisenhut on May 19, 2021, 03:47:33 pmFrom the link, it looks as if Hammerheads have Geomagnetic sensing too. Given that they already have inherent biological accelerometers and gyroscopes, the only thing they're missing is GPS!

author: bsfeechannel
author_rank: Super Contributor
timestamp: May 20, 2021, 02:05:38 am
content: Quote from: Gyro on May 19, 2021, 10:56:30 amI guess they used that comparison in order to demonstrate the orders of magnitude involved to a lay audience. But if you have seen a hammerhead shark hunting, it searches for prey hidden in the sand, maintaining its receptors at a distance of no more than 10cm above the sea bed. These sharks know how to avoid interference.Quote from: Alex Eisenhut on May 19, 2021, 03:47:33 pmI think the OP's video got it wrong. They say 1nV/cm², however electric fields are expressed in V/m, not V/m². There's another video which claims that the receptors are capable of sensing 15nV of potential difference, regardless of distance.

author: cdev
author_rank: Super Contributor
timestamp: May 20, 2021, 02:10:19 am
content: That hammer head sure looks like an antenna or similar to me. this is pretty interesting. I am not a shark or even close. But I can sense small electric currents with my mouth.

author: chickenHeadKnob
author_rank: Super Contributor
timestamp: May 20, 2021, 05:29:28 am
content: Quote from: cdev on May 20, 2021, 02:10:19 amThis sounds impractical to me, if you try this at work.

author: Refrigerator
author_rank: Super Contributor
timestamp: May 20, 2021, 07:14:36 pm
content: Quote from: cdev on May 20, 2021, 02:10:19 amWe've all licked a 9V battery.