As you stretch a rubber band, it heats up. But as it cools down it actually loses some of the energy it stored when it was stretched. That means the longer a slingshot is left loaded, the less powerful it becomes. Unless you're Joerg Sprave, the internet's resident master of slingshot design, who discovered that simply reheating a stretched elastic band can restore up to 40 per cent of its original powuh.
His newest rubber band weapon, the Entropy Slayer 2000, packs a built-in heater that brings the sling's deadly elastic up to about 20C warmer than the ambient temperature. It basically features a miniature oven powered by a 3300mAh battery to heat the elastic.
The slingshot can stay cocked for as long as you need, but minutes before you need to fire it a simple flick of a switch brings the heater to life, re-energising the elastic. I like seeing a little science being brought into the mix when it comes to slingshot design — and I particularly like that there's a giant ocean separating me from Joerg's crazy creations. [YouTube via SlashGear]