[HN Gopher] The electrostatic world of insects
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The electrostatic world of insects
Author : noleary
Score : 141 points
Date : 2024-10-29 01:31 UTC (21 hours ago)
(HTM) web link (www.wired.com)
(TXT) w3m dump (www.wired.com)
| amelius wrote:
| 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?
| chmod775 wrote:
| When they fly, there's no current. They just have potential
| compared to ground. Also presumably their electrical charge is
| very low and there's going to be hardly any amps when they
| discharge.
|
| In the same vein, if your carpet gives you a static shock,
| that's likely going to be thousands of volts. But obviously
| there isn't actually a lot of energy stored (all you did was
| convert some friction), so there's next to no amperes, little
| work the electricity can do, and thus no harm.
| codeflo wrote:
| 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 allowed to
| flow. And that's where the harm comes from. For static
| electricity, when you touch something, you get maybe a
| microcoulomb, once, and it's gone. For a power socket, you get
| up to 16 coulombs per second _continuously_.
| ocfnash wrote:
| As a kid, the alliterative mnemonic we were taught was
| "current kills".
| dmd wrote:
| "It's the volts that jolt but the mils [milliamps] that
| kills."
| metalman wrote:
| thats all theory thing is that I mess with large two
| volt(nominal) storage cells,the largest are over 250lbs
| and sit like dumb beasts,waiting to oblige anyones low
| voltage requests,hundreds of amps on tap be nothing to
| bolt ,some nice shiny copper handles to the terminals and
| mist them down with some warm salt water I also mess
| around with microscopes,and compared to bugs,humans are
| very poorly made,so many tiny things are flawless living
| perfection,and some like wolf(jumping) spiders are
| smart,smart enough that they see us seeing them,and are
| ok with that one thing that I have observed that plays
| into the static electricity thing,is that many of the
| tiny critters that I watch,are impecably clean,no dust or
| dirt on them at all,perfectly clean,unlike a human
| finger,which is one zillabutt uggly thing,under
| magnification
| dmd wrote:
| are you ok man
| BoxOfRain wrote:
| Hence the saying 'it's the volts that jolt and the mills that
| kill'.
| tgv wrote:
| 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.
| mecsred wrote:
| 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.
| rtkwe wrote:
| 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.
| hobs wrote:
| As shown in StyroPyro's video of him laying across dozens
| of car batteries (and then shorting them through various
| things) https://www.youtube.com/watch?v=ywaTX-nLm6Y
|
| His entire rig at one point delivered >80k amps, but he's
| fine.
| capitainenemo wrote:
| Speaking of, he also had this great video on lethality of
| electricity.
|
| https://www.youtube.com/watch?v=BGD-oSwJv3E
| BoxOfRain wrote:
| 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.
| jcdny wrote:
| Which is why if caught in a lightning storm you should
| crouch with feet together and why I try very hard to only
| use one hand when doing something that might have the
| potential to shock me.
| howenterprisey wrote:
| I've usually heard "volts hurt, amps kill".
| brk wrote:
| For many of the same reasons that birds can land on high
| voltage lines without risk of being electrocuted. A flying
| insect has stored voltage with no path to ground, or any point
| with low resistance and lower potential.
|
| When you hit a flying insect with a zapper you are supplying a
| high potential and low potential electrode. The insects body
| completes the circuit and the stored voltage is routed through
| the insect, rendering it a flightless blob of goo.
| ggm wrote:
| Could a cloud of midges make a path to ground for lightning?
| hagbard_c wrote:
| "Assume a cloud of midges 10 cm wide and 2500 m high" [1]
|
| [1] https://www.sphericalcowblog.com/spherical-cows
| palata wrote:
| > Webs deformed instantly when jolted with static from flies,
| aphids, honeybees, and even water droplets. Spiders caught
| charged insects more easily.
|
| This is all so fascinating!
| anthk wrote:
| There was an electric/bug Pokemon ensembling an spider, now I
| know why.
|
| https://m.bulbapedia.bulbagarden.net/wiki/Galvantula_(Pok%C3...
|
| Yes, Pokemon has tons of real life weird biologycs inside. Such
| as that volcano snail, (Slugma/Magcargo) which exists IRL:
|
| https://www.wired.com/2015/02/absurd-creature-of-the-week-sc...
| smolder wrote:
| Your pokemon example predates any of this research by a few
| years and so it certainly wouldn't have been known by the
| creators. It's a coincidence.
| anthk wrote:
| https://www.sciencedaily.com/releases/2014/01/140114113339.
| h...
| highfrequency wrote:
| > 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-Jimenez 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.
| Swizec wrote:
| 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/
| MrLeap wrote:
| Inertia doesn't exist? Wow that's hard to visualize. Perhaps
| the world does converge on cellular automata as you zoom in
| hermitcrab wrote:
| When you are very big (like an elephant), gravity is all
| important and surface tension barely matters.
|
| When you are very small (like an ant), it is the other way
| around.
|
| Toss a mouse from a building. It will land, shake itself off
| and scamper away. But if similarly dropped, "... a rat is
| killed, a man is broken, a horse splashes." So wrote J.B.S.
| Haldane in his 1926 essay "On Being the Right Size."
| https://www.edge.org/response-detail/27082
| tommiegannert wrote:
| The same question scales outwards. Are there forces taking over
| from gravity at galactic scale? Like, perhaps the galaxy
| filaments and voids come about due to something we can't even
| comprehend. It seems unlikely that humans just happen to be
| working with the force at the largest "scale."
|
| How complicated would it be for a small insect to explain
| gravity, if they're not normally affected by it in their daily
| routine?
|
| I recently thought about something similar: it seems like at
| certain scales, things turn into spheres, based on applicable
| forces. And then there are in-between regions with chaos. Atoms
| seem mostly round. Humans are not. If planets and stars are at
| the next spherical scale, are there even larger structures out
| there that once again show spherical nature, once you're past
| galaxies, clusters and filaments?
| deciplex wrote:
| The universe itself, if bounded, might be a hypersphere.
| hnuser123456 wrote:
| Since black holes grow with their radius proportional to mass
| (not volume), larger black holes are less dense. The current
| estimates for the size and mass of the universe fits right on
| the line of that curve of critical density.
| j_bum wrote:
| 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...
| rsynnott wrote:
| > A few years after Ortega-Jimenez 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...
| HPsquared wrote:
| 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!
| NotGMan wrote:
| (From the same article:)
|
| Interesting that ticks literally get pulled like a magnet towards
| their targets due to electrostatic forces.
|
| This article has multiple videos of it:
|
| https://www.cell.com/current-biology/fulltext/S0960-9822(23)...
| LinuxAmbulance wrote:
| I am not a fan of this evolutionary step in design.
| lofaszvanitt wrote:
| All this in 55 pages of text. Wired, never changes. They rob your
| time with unnecessary wall of text. blablablbla
| w33n1s wrote:
| Really interesting article. Highlights something I think is so
| cool but have a hard time really articulating: how even within
| our own 3+1 dimensions, just changing your scale is an entirely
| different experience.
| cartfisk wrote:
| https://archive.is/T1bds
| smolder wrote:
| This makes me wonder if cave dwelling species which live in
| darkness have any specially evolved features dealing with
| electric charge.
| ysofunny wrote:
| but if anybody regular worries about the (quite new) abundance of
| EM radiation one's the nutjob
| hermitcrab wrote:
| We've always lived amongst abundant EM radiation.
| paulorlando wrote:
| "They were using a toy wand that gathers static charge to
| levitate lightweight objects, such as a balloon." -- How much
| science progresses through play.
| hermitcrab wrote:
| >spiders take flight by extending a silk thread to catch charges
| in the sky
|
| I did some amateur research on spider ballooning many years ago
| and I believe part of the lift comes from rising air dragging
| along the silk thread. From my calculations, it wasn't enough to
| lift the spider on its own, but it might allow the spider to fall
| slower than the convective air currents were rising.
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