Thursday, January 29, 2009

Feather Light & Steel Strong

It's hard to imagine just how strong spider silk really is. Although a strand of silk long enough to circle the Earth would only weigh 12 ounces, with similar density, it would be five times stronger than steel. Spider silk, also called gossamer, is a fiber made of protein and spun by the spider in its own body with spinnerettes. Mostly the spiders use it to construct webs to catch prey, or to protect their offspring. The silk can stretch 40% of its length without breaking, which allows some small spiders go "ballooning" by spinning several threads into the air and letting themselves be carried along by the wind. Although they don't sail terribly far, some theorize this is how spiders made their way to islands, in addition to hitching rides on ships.

In past times, spider silk was used for the crosshairs in scientific instruments such as telescopes. Scientists have long been interested in duplicating the spinning process, as spiders use water as a solvent, operate at room temperature and use renewable resources, all very desireable. It hasn't been practical to keep masses of spiders for spinning (some have a tendency to eat each other) and so far attempts to mass produce spider silk have been unsuccessful.

The next time you knock down a web with a broom, consider what a remarkable construction it really is.

Thanks to Jon Sullivan at for sharing such a beautiful photograph.


High Desert Diva said...

Spider webs are beautiful creations...when they're outside.

vicki archer said...

Absolutely fascinating post - I can't wait to have a closer look next time I come across a spider's web, xv.

Ann said...

I always love to see those droplets of water on the spider web. Just like a delicate lace work.