In some cultures, spiders are bringers of good luck (China), trickster gods (Anansi), or the unfortunate victims of a celestial vendetta (Aracne), but for many people, their spindly legs range from creepy to full-on terrifying. Just in case their uncanny ability to infest walls, devour their own mothers and weave spiderwebs to trap their victims weren't terrifying enough, science just proved that spiders can fly! And apparently, they do this in a very comic booky way: by using the Earth's magnetic field.
At first, scientists thought that spiders were simply climbing to a (relatively) high point, excreting thin strands of silk and using these to float away in the breeze, but it has been proven that they can float in the air within a flat box with no air currents. Spiders have been seen flying up to 4,000 meters high into the sky, and 1600 km away from land. So how do they do it?
Spiders are actually the living proof that the 19th Century theory of electrostatic propulsion works: the spiders balloon their abdomens and extrude silk not to catch the air currents, but to pick up negative electrons that will push them up from the Earth. They are even able to measure the amount of electricity in the ground by tapping their legs.
This works because at any given time on Earth, there are 40,000 thunderstorms going on, which create around 100 volts for every meter above the ground. When the itsy-bitsy spiders climb up a wall, they are not trying to catch a nice breeze, as birds do, but to use the extra negative charge around the vertical object to fly even higher. Their silk tendrils have a similar effect, as they are also negatively charged.
That doesn't mean that wind conditions don't play a role: Moonsung Cho observed that before every electric take-off, spiders assess the wind and the breeze around them by lifting their front legs -- probably because, like humans, they prefer not to fly when tornados are close by. So... why should you care about what spiders do?
If you are a CBR reader, there's a chance that some of your favorite comic book authors have already used it for a handful of heroes. Weirdly enough, Spider-Man is not one of them; of course, his famed "web wings" have allowed him to glide at times, but only to a limited degree. Peter Parker's future counterpart, Miguel O'Hara can fly, but that's thanks to the material that comprises his suit and is not based on his power set. But there is a spider hero who does have the ability of flight: Spider-Woman.
Now, ignoring the fact that she was afforded the power of flight when she was actually the Skrull queen during the events of Secret Invasion, the real Spider-Woman (Jessica Drew) has shown that she can at very least glide through the air. She has been shown to do this by deploying her webs when she jumps in an extremely similar to the way that we now know spiders do, before lifting off into the air.
There are of course other, non-spider superheroes (and villains) who can tap into the electric field to fly, like Black Lightning, who charges his lower body with electric energy and is capable of flying at the speed of light. There's also fan-favorite Storm, whose flight has been explained by her control of air currents and winds. And let's not forget Guardian, the leader of the Canadian team Alpha Flight, who has "the ability to lock himself relative to the Earth's electromagnetic field." This means that his powers counteract the Earth's rotation, allowing him to move westward at the same speed that the Earth rotates. We'd of course me remiss in not mentioning the Master of Magnetism himself, Magneto, who has used his powers in a dizzying array of ways to affect self-propelled flight.
Whether this will all lead to art imitating life in a Spider-Magneto mash-up remains to be seen, but we can only hope that such an abomination will not truly manifest in nature. If it does... well, CBR for one welcomes its new flying arachnid overlords.