The Baghdad Battery

The Baghdad Battery is a clay jar containing a copper cylinder and iron rod. When filled with acidic liquid, it generates about 1.1 volts. Dating to around 250 BCE, it predates Alessandro Volta's battery by 2,000 years.

The challenge is determining its purpose. Some researchers suggest electroplating - using electricity to coat objects with thin layers of gold. We have gilded objects from that period that could have been electroplated rather than gold-leafed.

But it could also be a storage vessel for scrolls. The alternative explanation is simpler - we might be seeing technology where there's just coincidental design. Extraordinary claims need extraordinary proof.

Whether it was intentionally a battery or not, the fact that it CAN generate electricity shows ancient peoples could have stumbled into electrical phenomena. If one person discovered it accidentally, others might have developed it deliberately.