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'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.
I like huntsmen, myself (alas wife does not). They're rather mean looking but otherwise mostly harmless - to humans, but definitely not all other kinds of bugs. This would make them most excellent house guests. :)
For the same reason, I have made my peace with house centipedes. My friends object that the way they move is horrifyingly creepy. I can't disagree; they are speedy little undulating aliens. But I'd rather have one of them scuttering around than silverfish eating my books. I actually rescued a centipede that had gotten trapped in my kitchen sink the other week.
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.
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.
"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.
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.
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.
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.
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?
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.
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?
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
[1]: Spiders eat an astronomical amount of insects - https://news.ycombinator.com/item?id=15887468
[2]: How spiders fly - 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...
[4]: Lucas the spider - https://www.youtube.com/user/joshuaslice