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The electrostatic world of insects

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Re: The electrostatic world of insects

#11

Post by BoxOfRain »

codeflo wrote: post #4
amelius wrote: post #2

If insects can build up 5 kilovolts while flying, then why can I zap flies with a fly-zapping tool that presumably runs at a similar or lower voltage?

It's not a bad question, these units of measurements are always a bit confusing. You can similarly ask why for humans, rubbing a balloon is harmless, although that builds up 30 kV of static electricity, while touching a 230 V power socket can kill you. Voltage is merely the "pressure" that charged particles experience. Voltage alone tells you nothing about how much charge is actually available once electricity is all…

Hence the saying 'it's the volts that jolt and the mills that kill'.

Re: The electrostatic world of insects

#12

Post by highfrequency »

> The magic of animal electrostatics is all about size. Large animals don’t meaningfully experience nature’s static—we’re too big to feel it. “As humans, we are living mostly in a gravitational or fluid-dynamics world,” Ortega-Jiménez said. But for tiny beings, gravity is an afterthought. Insects can feel air’s viscosity. While the same laws of physics reign over Earth’s smallest and largest species, the balance of forces shifts with size.

Very cool article. For example: butterflies accumulate a positive charge when beating their wings, which causes pollen to jump through the air toward them when they land on flowers.

Re: The electrostatic world of insects

#13

Post by j_bum »

Excellent article, and some fascinating discoveries. The idea of passive pollen spread via static buildup on pollinators make sense, but is kind of mind blowing to me at the same time.

For a much more enjoyable reading experience (at least on mobile):

https://www.quantamagazine.org/the-hidden-world-of-electrost...

Re: The electrostatic world of insects

#14

Post by rsynnott »

> A few years after Ortega-Jiménez noticed spiderwebs nabbing bugs, Robert’s team found that bees can gather negatively charged pollen without brushing up against it.

It's arguably kind of weird that this is just being noticed now. I suppose possibly modern camera equipment helps, for purposes of actually _seeing_ it happen...

Re: The electrostatic world of insects

#15

Post by tgv »

BoxOfRain wrote: post #11
codeflo wrote: post #4

Earlier quoted context omitted.

It's not a bad question, these units of measurements are always a bit confusing. You can similarly ask why for humans, rubbing a balloon is harmless, although that builds up 30 kV of static electricity, while touching a 230 V power socket can kill you. Voltage is merely the "pressure" that charged particles experience. Voltage alone tells you nothing about how much charge is actually available once electricity is all…

Hence the saying 'it's the volts that jolt and the mills that kill'.

But can e.g. 3V DC kill? Perhaps by using the body's resistance, but I have the idea that the effect would be different from say 220V AC, which affects the nerves.

Re: The electrostatic world of insects

#16

Post by mecsred »

tgv wrote: post #15
BoxOfRain wrote: post #11

Earlier quoted context omitted.

Hence the saying 'it's the volts that jolt and the mills that kill'.

But can e.g. 3V DC kill? Perhaps by using the body's resistance, but I have the idea that the effect would be different from say 220V AC, which affects the nerves.

Depends how it's applied and what's sourcing it. 3v does basically nothing to dry skin, but would be quite bad on wires implanted in your chest across your heart.

Re: The electrostatic world of insects

#17

Post by HPsquared »

See also magnetic sensing (magnetoreception) in animals used for orientation and navigation.

https://en.wikipedia.org/wiki/Magnetoreception

There are other electromagnetic type things too, like use of light (camouflage, bioluminescence, eyes) and electricity (electric eels, bioelectrical cues for stem cell differentiation).

EDIT: Also the literal electrical potential within cells: the membrane potential, that is the voltage difference between inside and outside every cell.

An interesting area!

Re: The electrostatic world of insects

#18

Post by rtkwe »

tgv wrote: post #15
BoxOfRain wrote: post #11

Earlier quoted context omitted.

Hence the saying 'it's the volts that jolt and the mills that kill'.

But can e.g. 3V DC kill? Perhaps by using the body's resistance, but I have the idea that the effect would be different from say 220V AC, which affects the nerves.

Not generally, remember Ohm's Law I = V/R. Internally the body has a resistance of ~300 Ohms as a rough rule while our skin is 1000-10000 depending on the condition and contact area involved.

So 3V isn't going to pose any real risk unless it's applied internally and right across a critical nerve leading to your heart or a muscle directly on the heart. For reference pacemakers are generally set to 2-3 volts. Applied externally up to ~12V is generally considered low enough voltage there's a low risk of truly adverse effects.

Re: The electrostatic world of insects

#19

Post by BoxOfRain »

tgv wrote: post #15
BoxOfRain wrote: post #11

Earlier quoted context omitted.

Hence the saying 'it's the volts that jolt and the mills that kill'.

But can e.g. 3V DC kill? Perhaps by using the body's resistance, but I have the idea that the effect would be different from say 220V AC, which affects the nerves.

You'd have to really try.

10 milliamps across your heart can kill but using Ohm's law we can calculate 3V / 0.010 A to get a resistance of 300 ohms. This means you're probably still going to have a bad time if you apply it directly across your heart during open-heart surgery but other than that 3 volts just isn't enough to drive a lethal current through your skin.

Re: The electrostatic world of insects

#20

Post by Swizec »

highfrequency wrote: post #12

> The magic of animal electrostatics is all about size. Large animals don’t meaningfully experience nature’s static—we’re too big to feel it. “As humans, we are living mostly in a gravitational or fluid-dynamics world,” Ortega-Jiménez said. But for tiny beings, gravity is an afterthought. Insects can feel air’s viscosity. While the same laws of physics reign over Earth’s smallest and largest species, the balance of f…

Similar to this, one of the most mind-blowing papers I’ve read was Life at Low Reynold’s Number about how at the microorganism level water is virtually solid and inertia does not exist.

https://www.damtp.cam.ac.uk/user/gold/pdfs/purcell.pdf https://swizec.com/blog/week-9-life-at-low-reynolds-number/

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