7 ms·

The Electric Flight of Spiders

206 points by GW150914 8y ago

ChuckMcM 8y ago
In freshman physics, when you first learn about electrostatics, one of the problems you get to work is the "how much charge would you need to float yourself off the ground." It is enough that you usually violate the dielectric constant of the air and discharge into the air around you but still, its a fun exercise. To see that Spiders use this to fly is pretty amazing to me.
- zackmorris 8y ago
  I'm also interested in this, perhaps using an aluminized mylar balloon or a large wire mesh with a Van der Graaf Generator and/or electron gun to maintain the charge. There's been a fair amount of research on electrohydrodynamic (EHD) vehicles (lifters), but I haven't seen any experiments using a large charged surface area to create an effect like buoyancy. http://jnaudin.free.fr/lifters/main.htm http://jnaudin.free.fr/lifters/main.htm
  - ChuckMcM 8y ago
    If you wanted to be super cool you would use a graphene sphere. Manufacturing such a sphere would be a fun challenge.
EarthIsHome 8y ago
I'm loving all these spider articles that have cropped up on hacker news and elsewhere [0]-[4]. I used to be deathly afraid of spiders, but all these articles and videos over the years have eliminated my fear of them. I like having some around. [0]: The extraordinary life and death of the world's oldest known spider - https://news.ycombinator.com/item?id=16992596 https://news.ycombinator.com/item?id=16992596 [1]: Spiders eat an astronomical amount of insects - https://news.ycombinator.com/item?id=15887468 https://news.ycombinator.com/item?id=15887468 [2]: How spiders fly - https://news.ycombinator.com/item?id=17398383 https://news.ycombinator.com/item?id=17398383 [3]: How I ended up with pet jumping spiders - https://medium.com/@melissamcewen/how-i-ended-up-with-pet-jumping-spiders-187d70a3e296 https://medium.com/@melissamcewen/how-i-ended-up-with-pet-ju... [4]: Lucas the spider - https://www.youtube.com/user/joshuaslice https://www.youtube.com/user/joshuaslice
- nickpsecurity 8y ago
  The jumping/portia spiders are the coolest. Cracked.com had an article on diabolical insects with them featured in it. http://www.cracked.com/article_109_natures-6-most-diabolical-predators.html http://www.cracked.com/article_109_natures-6-most-diabolical... I'll excerpt the relevant part for folks that are squeamish or at work given Cracked is a bit NSFW: "Each individual Portia employs their own unique and vast arsenal of dastardly impersonations to trick, ensnare and consume their prey. A Portia spider might strum a pattern on a strand to impersonate the buzzing of a fly caught in another spider's web, while a different spider of the same exact species might opt to catch a real fly to throw in the web and, while the prey spider is distracted, sneak up behind it. It may pretend to be inanimate by moving only in the wind, it may observe and duplicate another spider's entire mating ritual or sometimes it might even build a complete web of its own that attaches to its victim's, thereby creating a trap out of the spider's own trap." They're just too friggin' smart! I make sure nobody squashes them at my house so they do their important work of eating other spiders. One time I watched one do a nice ambush. Target spider had a web in the corner it almost always sat on. The invisible, jumping spider apparently waited until the target descended from its web to (I guess) start extending it. Jumping spider ran out of nowhere full-speed across ceiling, jumped past web onto that single strand, and started climbing down at spider. Brief battle ensued. The jumping spider was literally sitting between the target's ass and web with nowhere for it to go. It dropped a few inches to create distance. Then, just cut its own supporting line to drop off the ceiling abandoning its original web. Jumping spider climbed back up it going back where it came from. Fun to watch.
  - greenhatman 8y ago
    I loved watching this: https://www.youtube.com/watch?v=UDtlvZGmHYk https://www.youtube.com/watch?v=UDtlvZGmHYk
- stronglikedan 8y ago
  > I like having some around. As long as they don't make webs and aren't aggressive, such as Wolf Spiders, then they're okay by me.
cwkoss 8y ago
> Even on sunny days with cloudless skies, the air carries a voltage of around 100 volts for every meter above the ground. This is interesting. Is there any way we could use a tethered balloon as a power generation system to harvest this energy?
- blattimwind 8y ago
  Electric field (in this case the ambient e-field of 100-300 V/m without clouds; up to a dozen or so kV/m when you're under a thunderstorm) does not imply power. Cf. static electricity.
- jws 8y ago
  You can see videos of people doing this. It is very low power, but they can turn their corona motors. e.g. https://youtu.be/qhXxSAv6rMg https://youtu.be/qhXxSAv6rMg
- wiml 8y ago
  The impedance is ridiculously high; there isn't very much power available at all. Even just to get enough current to sense accurately can be difficult. Some googling suggests that even if you somehow extracted all the current from the entire planetary atmosphere's charge-separating processes you'd get maybe a gigawatt.
- kwhitefoot 8y ago
  Not really, the energy density is fairly low. Except during thunderstorms of course. Shoudn't be too hard to check. Get ten metres of rigid plastic pipe and ten metres of insulated wire bared at the ends so that you can measure the voltage between the top and ground. Set it up vertically at least 20 m from everything else. Measure the voltage between top and bottom with a good quality high impedance voltmeter. Now add another ten metre length of wire and a resistor to complete the circuit and use some of the power. Measure the voltage again. The voltages and the resistance allow you to calculate the equivalent impedance of the source. I'd be very surprised if no one has already done this and probably in a much more sophisticated fashion.
king_nothing 8y ago
Anyone live in eastern Australia? ;)
deleted 8y ago
[deleted]
lolc 8y ago
Oooh that's how they take off! One time I was on a high mountain and there were so many tiny spiders floating above they made a glittering halo around the sun. I still wonder how they get so high though. Shouldn't the charge diffuse as they lose their connection to the ground?
deleted 8y ago
[deleted]
sebringj 8y ago
Marvel will have to rethink Spiderman's powers. So interesting of a finding.
deleted 8y ago
[deleted]
dmix 8y ago
A video demonstration of this phenomenon by NYTimes: https://www.youtube.com/watch?v=VDL9VxLqdvw https://www.youtube.com/watch?v=VDL9VxLqdvw and David Attenborough: https://www.youtube.com/watch?v=wnV4f2oXKUs https://www.youtube.com/watch?v=wnV4f2oXKUs
mchahn 8y ago
I didn't know there was an electrical variation in altitude.
- ggg9990 8y ago
  If there wasn’t, how would lightning happen?
  - ASalazarMX 8y ago
    Without knowing meteorology, I would think it had to do with storm clouds / volcanoes more than height.
  - sliken 8y ago
    Usually it doesn't.
maweki 8y ago
At first I thought the spiders' abilities were ballooning due to our electricity consumption and I was slightly afraid. But it's about their ability to balloon and electrical variation in altitude.
atlantic 8y ago
Could this electrostatically-based flight phenomenon be reproduced at a larger scale, or is there some natural limit to the amount of upward force generated?
- martin-adams 8y ago
  So if you could produce a device to create the electricity field that could work at a larger scale, and such device could be carried by the field itself, then could it be possible to create a hovering or flying vehicle.
pasta 8y ago
The front of my car sometimes looks like a insect horror movie. What about airplanes? Do spiders end up at the nose of an airplane? Or are they pushed away by the pressure in front of the plane?
FriedPickles 8y ago
Official video summary: https://youtu.be/GRrUxi6d7so https://youtu.be/GRrUxi6d7so
anonytrary 8y ago
"Spiders float in the air using electric fields" might be a better title. I initially thought this was going to be a detailed explanation of how spiders use water's surface tension (due to water's electric dipole) to float on ponds. This article is actually about "ballooning". Here's an excerpt from the abstract: > To disperse, spiders “balloon,” whereby they climb to the top of a prominence, let out silk, and float away. The prevailing view is that drag forces from light wind allow spiders to become airborne, yet ballooning mechanisms are not fully explained by current aerodynamic models. The global atmospheric electric circuit and the resulting atmospheric potential gradient (APG) provide an additional force that has been proposed to explain ballooning. I've left out some of their in-line references.

206 points by GW150914 8y ago

In freshman physics, when you first learn about electrostatics, one of the problems you get to work is the "how much charge would you need to float yourself off the ground." It is enough that you usually violate the dielectric constant of the air and discharge into the air around you but still, its a fun exercise. To see that Spiders use this to fly is pretty amazing to me.

zackmorris 8y ago
I'm also interested in this, perhaps using an aluminized mylar balloon or a large wire mesh with a Van der Graaf Generator and/or electron gun to maintain the charge. There's been a fair amount of research on electrohydrodynamic (EHD) vehicles (lifters), but I haven't seen any experiments using a large charged surface area to create an effect like buoyancy. http://jnaudin.free.fr/lifters/main.htm http://jnaudin.free.fr/lifters/main.htm
- ChuckMcM 8y ago
  If you wanted to be super cool you would use a graphene sphere. Manufacturing such a sphere would be a fun challenge.

EarthIsHome 8y ago

I'm loving all these spider articles that have cropped up on hacker news and elsewhere [0]-[4]. I used to be deathly afraid of spiders, but all these articles and videos over the years have eliminated my fear of them. I like having some around. [0]: The extraordinary life and death of the world's oldest known spider - https://news.ycombinator.com/item?id=16992596 https://news.ycombinator.com/item?id=16992596 [1]: Spiders eat an astronomical amount of insects - https://news.ycombinator.com/item?id=15887468 https://news.ycombinator.com/item?id=15887468 [2]: How spiders fly - https://news.ycombinator.com/item?id=17398383 https://news.ycombinator.com/item?id=17398383 [3]: How I ended up with pet jumping spiders - https://medium.com/@melissamcewen/how-i-ended-up-with-pet-jumping-spiders-187d70a3e296 https://medium.com/@melissamcewen/how-i-ended-up-with-pet-ju... [4]: Lucas the spider - https://www.youtube.com/user/joshuaslice https://www.youtube.com/user/joshuaslice

nickpsecurity 8y ago
The jumping/portia spiders are the coolest. Cracked.com had an article on diabolical insects with them featured in it. http://www.cracked.com/article_109_natures-6-most-diabolical-predators.html http://www.cracked.com/article_109_natures-6-most-diabolical... I'll excerpt the relevant part for folks that are squeamish or at work given Cracked is a bit NSFW: "Each individual Portia employs their own unique and vast arsenal of dastardly impersonations to trick, ensnare and consume their prey. A Portia spider might strum a pattern on a strand to impersonate the buzzing of a fly caught in another spider's web, while a different spider of the same exact species might opt to catch a real fly to throw in the web and, while the prey spider is distracted, sneak up behind it. It may pretend to be inanimate by moving only in the wind, it may observe and duplicate another spider's entire mating ritual or sometimes it might even build a complete web of its own that attaches to its victim's, thereby creating a trap out of the spider's own trap." They're just too friggin' smart! I make sure nobody squashes them at my house so they do their important work of eating other spiders. One time I watched one do a nice ambush. Target spider had a web in the corner it almost always sat on. The invisible, jumping spider apparently waited until the target descended from its web to (I guess) start extending it. Jumping spider ran out of nowhere full-speed across ceiling, jumped past web onto that single strand, and started climbing down at spider. Brief battle ensued. The jumping spider was literally sitting between the target's ass and web with nowhere for it to go. It dropped a few inches to create distance. Then, just cut its own supporting line to drop off the ceiling abandoning its original web. Jumping spider climbed back up it going back where it came from. Fun to watch.
- greenhatman 8y ago
  I loved watching this: https://www.youtube.com/watch?v=UDtlvZGmHYk https://www.youtube.com/watch?v=UDtlvZGmHYk
stronglikedan 8y ago
> I like having some around. As long as they don't make webs and aren't aggressive, such as Wolf Spiders, then they're okay by me.

cwkoss 8y ago

> Even on sunny days with cloudless skies, the air carries a voltage of around 100 volts for every meter above the ground. This is interesting. Is there any way we could use a tethered balloon as a power generation system to harvest this energy?

blattimwind 8y ago
Electric field (in this case the ambient e-field of 100-300 V/m without clouds; up to a dozen or so kV/m when you're under a thunderstorm) does not imply power. Cf. static electricity.
jws 8y ago
You can see videos of people doing this. It is very low power, but they can turn their corona motors. e.g. https://youtu.be/qhXxSAv6rMg https://youtu.be/qhXxSAv6rMg
wiml 8y ago
The impedance is ridiculously high; there isn't very much power available at all. Even just to get enough current to sense accurately can be difficult. Some googling suggests that even if you somehow extracted all the current from the entire planetary atmosphere's charge-separating processes you'd get maybe a gigawatt.
kwhitefoot 8y ago
Not really, the energy density is fairly low. Except during thunderstorms of course. Shoudn't be too hard to check. Get ten metres of rigid plastic pipe and ten metres of insulated wire bared at the ends so that you can measure the voltage between the top and ground. Set it up vertically at least 20 m from everything else. Measure the voltage between top and bottom with a good quality high impedance voltmeter. Now add another ten metre length of wire and a resistor to complete the circuit and use some of the power. Measure the voltage again. The voltages and the resistance allow you to calculate the equivalent impedance of the source. I'd be very surprised if no one has already done this and probably in a much more sophisticated fashion.

king_nothing 8y ago

Anyone live in eastern Australia? ;)

deleted 8y ago

[deleted]

lolc 8y ago

Oooh that's how they take off! One time I was on a high mountain and there were so many tiny spiders floating above they made a glittering halo around the sun. I still wonder how they get so high though. Shouldn't the charge diffuse as they lose their connection to the ground?

deleted 8y ago

[deleted]

sebringj 8y ago

Marvel will have to rethink Spiderman's powers. So interesting of a finding.

deleted 8y ago

[deleted]

dmix 8y ago

A video demonstration of this phenomenon by NYTimes: https://www.youtube.com/watch?v=VDL9VxLqdvw https://www.youtube.com/watch?v=VDL9VxLqdvw and David Attenborough: https://www.youtube.com/watch?v=wnV4f2oXKUs https://www.youtube.com/watch?v=wnV4f2oXKUs

mchahn 8y ago

I didn't know there was an electrical variation in altitude.

ggg9990 8y ago
If there wasn’t, how would lightning happen?
- ASalazarMX 8y ago
  Without knowing meteorology, I would think it had to do with storm clouds / volcanoes more than height.
- sliken 8y ago
  Usually it doesn't.

maweki 8y ago

At first I thought the spiders' abilities were ballooning due to our electricity consumption and I was slightly afraid. But it's about their ability to balloon and electrical variation in altitude.

atlantic 8y ago

Could this electrostatically-based flight phenomenon be reproduced at a larger scale, or is there some natural limit to the amount of upward force generated?

martin-adams 8y ago
So if you could produce a device to create the electricity field that could work at a larger scale, and such device could be carried by the field itself, then could it be possible to create a hovering or flying vehicle.

pasta 8y ago

The front of my car sometimes looks like a insect horror movie. What about airplanes? Do spiders end up at the nose of an airplane? Or are they pushed away by the pressure in front of the plane?

FriedPickles 8y ago

Official video summary: https://youtu.be/GRrUxi6d7so https://youtu.be/GRrUxi6d7so

anonytrary 8y ago

"Spiders float in the air using electric fields" might be a better title. I initially thought this was going to be a detailed explanation of how spiders use water's surface tension (due to water's electric dipole) to float on ponds. This article is actually about "ballooning". Here's an excerpt from the abstract: > To disperse, spiders “balloon,” whereby they climb to the top of a prominence, let out silk, and float away. The prevailing view is that drag forces from light wind allow spiders to become airborne, yet ballooning mechanisms are not fully explained by current aerodynamic models. The global atmospheric electric circuit and the resulting atmospheric potential gradient (APG) provide an additional force that has been proposed to explain ballooning. I've left out some of their in-line references.