Biologist/mathematician J.B.S. Haldane’s 1926 essay “On Being the Right Size” puts the kibosh on giants. Such legendary behemoths as Gargantua and Pantagruel, Paul Bunyan, and the giant encountered by Jack at the top of the magic beanstalk, explains Haldane, would have all fallen victim to gravity: Their bones, unable to support their weight, would have shattered the minute they took a step.

The point of the Haldane essay is that all species have size limits. Animals, grown too big, can’t function. A hummingbird the size of a turkey, for example, wouldn’t be able to hover; and a grasshopper the size of a pony wouldn’t be able to hop. The Blob of horror sci-fi movie fame—basically a giant amoeboid lump of jelly—would