8 Seriously Bizarre Scientific Theories From History

5. Spontaneous Generation

Aristotle was a smart bloke, but he believed some weird stuff.

He believed that living things could arise from inanimate materials such as mud when exposed to "air and heat", forming from a "frothy bubble" (whoa there with the technical terms).

His theory, unlike the barnacle goose debacle, was based on some real world observations. He saw that maggots would apparently spontaneously bloom from a carcass, or a grain store would suddenly seem to generate mice or the hull of a ship would slowly sprout barnacles.

He basically saw it as the same as great plants sprouting from tiny seeds.

To be fair, his theory is not all that dissimilar to the idea that life arose from non-living matter in the primordial soup. However, to go from single-celled organisms to full mouse is a bit of a leap.