The Electric Flight of Spiders

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...

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.

> 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.

I'm sure any programmer who's spent enough time watching spiders build their webs must have given some thought to the algorithmic simulation of spiderweb construction. Different species create different structures, and some of them are excellent architects. I remember scouring the web for any programs doing this, and there are definitely research papers and MATLAB or similar implementations, but surprisingly little outside of that. It seems like a fun little project to explore this in a more accessible language/platform, eg. in-browser.

May I contribute:

Peacock Spiders https://m.youtube.com/watch?t=1m19s&v=d_yYC5r8xMI

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

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.

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

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.

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.

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.

If there wasn’t, how would lightning happen?