
The Electric Flight of Spiders - GW150914
https://www.theatlantic.com/science/archive/2018/07/the-electric-flight-of-spiders/564437/?single_page=true
======
EarthIsHome
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-
ju...](https://medium.com/@melissamcewen/how-i-ended-up-with-pet-jumping-
spiders-187d70a3e296)

[4]: Lucas the spider -
[https://www.youtube.com/user/joshuaslice](https://www.youtube.com/user/joshuaslice)

~~~
nickpsecurity
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...](http://www.cracked.com/article_109_natures-6-most-diabolical-
predators.html)

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
I loved watching this:
[https://www.youtube.com/watch?v=UDtlvZGmHYk](https://www.youtube.com/watch?v=UDtlvZGmHYk)

------
ChuckMcM
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
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
If you wanted to be super cool you would use a graphene sphere. Manufacturing
such a sphere would be a fun challenge.

------
anonytrary
"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.

------
cwkoss
> 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?

~~~
kwhitefoot
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.

------
atlantic
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
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.

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lolc
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?

------
maweki
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.

------
FriedPickles
Official video summary:
[https://youtu.be/GRrUxi6d7so](https://youtu.be/GRrUxi6d7so)

------
dmix
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)

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

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pasta
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?

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

~~~
ggg9990
If there wasn’t, how would lightning happen?

~~~
ASalazarMX
Without knowing meteorology, I would think it had to do with storm clouds /
volcanoes more than height.

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king_nothing
Anyone live in eastern Australia? ;)

