think you can sense magnetic fields? maybe you can - Page 1
Forum section: electronics / general

author: coppercone2
author_rank: Super Contributor
timestamp: March 22, 2019, 04:05:16 pm
content: https://news.slashdot.org/story/19/03/21/028222/humans-might-be-able-to-sense-earths-magnetic-field

author: SenseofScale
author_rank: Contributor
timestamp: March 22, 2019, 06:24:04 pm
content: I saw that the other day.It seems like all they alluded to was that changing the direction of a magnetic field had some affect on brain waves. I don't remember them delving much into the numbers that lead them to their conclusions.Who knows?

author: jmelson
author_rank: Super Contributor
timestamp: March 22, 2019, 07:57:51 pm
content: I have some friends that used to work on MRI scanners. I THINK that I could feel some effect from the magnetic field in those. It felt like being slightly tired and a bit "light-headed". I could have been imagining it, but I definitely had that feeling.Jon

author: helius
author_rank: Super Contributor
timestamp: March 22, 2019, 08:45:42 pm
content: Birds navigate by detecting the magnetic field's influence on small particles of ferrite suspended in their brains.Humans have similar structures in the inner ear called otoliths—they are not magnetic, but perhaps could be modified to become so.

author: TimNJ
author_rank: Super Contributor
timestamp: March 22, 2019, 08:52:11 pm
content: Quote from: helius on March 22, 2019, 08:45:42 pmWait do they actually? Article/reference/link?

author: helius
author_rank: Super Contributor
timestamp: March 22, 2019, 09:00:00 pm
content: It looks like I misremembered the location, it appears to be in the inner ear, after all:https://en.wikipedia.org/wiki/Cuticulosome

author: Rick Law
author_rank: Super Contributor
timestamp: March 22, 2019, 09:02:24 pm
content: Quote from: helius on March 22, 2019, 08:45:42 pmRe: "Birds navigate by detecting the magnetic field's influence..." I saw that on some documentary shows as well. I've been wondering since, when our magnetic poles do flip, how they are going to adjust with that up coming event.

author: Rerouter
author_rank: Super Contributor
timestamp: March 22, 2019, 09:09:18 pm
content: Birds fly the same path each year, so as the magnetic fields change (which is slow), the amount of change per year is small enough that the birds can make up for the error. as most of these birds also use landmarks.

author: Gyro
author_rank: Super Contributor
timestamp: March 22, 2019, 09:15:07 pm
content: Quote from: jmelson on March 22, 2019, 07:57:51 pmI've had loads of brain MRIs. On the first one thought I could see vague grey shapes moving but in hindsight it was just my mind playing tricks looking at closed eyelids.They do make me sleepy but that's just the effect of lying there for 45mins in a nice warm cosseted environment with my head sandwiched between the ear defenders and the sense coil cage, with all the muted rythmic thrumming of the various scan sequences. The Gadolinium contrast always leaves a horrible taste in my mouth and a dull headache when they pump it in but that's all.It's best not to think about all those kWs of RF going into the gradient and transmit coils, being surrounded by a big tank of liquid Helium, and all those youtube videos of magnet containments blowing up during transit!I think I can safely say then, that I've not experienced any magnetic field influence effects. I never could work out which way was North anyway, so no change there!

author: TimFox
author_rank: Super Contributor
timestamp: March 23, 2019, 01:13:31 pm
content: I used to work with MRI hardware, and often was the test subject. I never noticed any effect of the magnetic fields, but there were reports (especially at field strengths above 2.0 T = 20 kG) about magneto-hydrodynamic forces on the inner-ear fluid inducing nausea or vertigo, due to inappropriate feedback in the balance-sensing mechanism, when the subject's head moved slightly in the strong field.

author: PwrElectronics
author_rank: Regular Contributor
timestamp: March 23, 2019, 08:07:56 pm
content: In a early job, I worked for a place that did repairs on industrial motor drives. The "boss" had a lot of spare stuff stored in the basement, including many current transformers that would be used with panel meters. Some of them were pretty large.One Friday afternoon after hours, I gathered a few of those of various sizes and some heavy wire/cable. I chained a few of the transformers with loops of cable and fed the lowest current one from a variac. The final transformer had a loop of 0000 cable through it and I clipped on a clamp on ammeter.I was able to turn up the variac voltage and get a indicated 1200A AC on the meter in the cable loop at the end of the chain.I noticed that if I place my hand near that loop that it felt "strange". I was too timid to put my other hand with my watch on the wrist nearby to see what would happen with that.

author: apis
author_rank: Super Contributor
timestamp: March 23, 2019, 09:37:12 pm
content: https://www.caltech.edu/about/news/evidence-human-geomagnetic-sense