The Baghdad Battery
A 2,000-year-old clay jar from Iraq, found in 1936, suggests ancient electrical knowledge that historians never suspected existed. The Parthian-era artifact consists of a copper tube and iron rod sealed with asphalt. When filled with vinegar, experiments show it could generate half a volt of electricity. This would be enough to electroplate metal objects with gold. Some researchers maintain it was simply a storage vessel, while others see it as evidence of early electrical experimentation.
