The launch of the fourth Spiderman film on July 3rd marks the perfect time to contemplate --ahem -- spiders. AKA: arachnids, derived from the Greek word meaning "get this creepy thing outta here." Just kidding; it's actually from Arachne, a mythological Greek weaver who was turned into a spider.
The alter ego of Spiderman, Peter Parker, became a superhero when he was bitten by an irradiated spider that injected radioactive chemicals into his body, giving him superhuman strength and agility, the ability to cling to most surfaces and thus run up walls, and a spider-sense that warns him of danger.
We were curious: How do Spiderman's abilities stack up against those of a real spider?
Strength and Agility: Spiderman is famed for his web-suspended swings from building to building over city streets. You can find examples of equally amazing leaps and bounds among real arachnids if you take a look at the jumping spiders. In a single leap a jumping spider can cover as much as 50 times its own length. It does so by using a powerful internal muscle that blasts fluids from the body into the legs, flinging the spider through the air (if the current holder of the world record for the long jump, Norwegian Arne Tvervaag, could make a comparable leap, he'd cover about 300 feet from a standing start; instead his record, set in 1968, is 12 feet 2 inches).
Walking Up Walls: Thanks to a stick-to-almost-anything skin, Spiderman can walk up walls. So can most spiders (if you're a tarantula, do not try this at home — you're too big and meant for burrowing). Each leg of a spider capable of climbing walls ends in a brushy covering of hair, and the end of each hair is in turn covered with microscopic organs that can take hold of small bumps in most surfaces, allowing the spider to go up walls and even across ceilings. This ability may be defeated by very smooth surfaces, such as that of a bathroom sink.
Spider Sense: Spiderman is able to sense danger lurking near, the warning signal coming as a pain in his head that varies with the intensity of the threat. Spiders can detect danger coming their way with an early-warning system called eyes. But that's not all: their most important source of information about the world and its hazards comes from highly sensitive hairs that cover the bodies of most spiders. These hairs perceive even low-level vibrations coming through whatever surface a spider is standing on. Many species also bear hairs that sense vibrations in the air, including sound.
Webs: Spiderman can fire strands of web from his wrists. Early in his career, he invented devices for doing this, but in later incarnations he developed biological adaptations that allowed him to make webs naturally. He can capture villains with the sticky stuff and use it like ropes for swinging from building to building. Real spiders produce several types of webs — some that are not sticky but serve as a superstructure for webs, some that are sticky and capture prey, some used for wrapping up prey in neat little packages (which, in some species, are given as gifts by males to females while courting; whether Spiderman has super gift-giving powers remains unrecorded). Some smaller spiders producer gossamer web, used as a sort of sail that catches the wind and can carry a spider far and wide, which probably explains in part why spiders are found almost everywhere in the world.
Spider silk comes from glands on the arachnid's posterior, with different silks produced by different types of glands. Some silks are comparable in strength to high-grade alloy steel and can stretch up to four times their relaxed length without breaking. Made basically of protein and water, the silk is extremely light weight once it dries. A single strand long enough to encircle the globe would weigh about 1 pound 2 ounces!
Still curious about the creepy-crawlers? Check out How Stuff Works.