Electronic Billboard

There is a popular science lesson that every high school physics or chemistry teacher must perform. It involves using foods to power a small light bulb, along with some nails and wire.

Citrus fruits, for example, are acidic and their juice helps to conduct electricity. It would appear that if you had enough oranges, you could power something big, like a billboard.

Fortunately, Tropicana has plenty of oranges, and what better promotion for their orange juice than this? Thousands of oranges have been used, and it took 3 months of testing before it worked, which also uses thousands of copper and zinc spikes to make it work.