Gravity powered lamp

“A Virginia Tech student has created a floor lamp powered by gravity.”

“The electricity is generated by the slow fall of a mass that spins a rotor. The resulting energy powers 10 high-output LEDs that fire into the acrylic lens, creating a diffuse light. The operation is silent and the housing is elegant and cord free – completely independent of electrical infrastructure.”

So obvious when seen, and yet it’s taken 130 years since the invention of the light bulb for anyone to think of powering a lamp with a falling weight.