We seem to be near the limit already. While sprinter Usain Bolt has travelled a 100-metre stretch in just 9.58 seconds, biologist Mark Denny predicts that in the future a human could bring that down to a maximum 9.48 seconds. That’s equivalent to 23.4mph.
“Humans are able to tolerate a force of 5 g before they lose consciousness,” explains Gregg Kai Nishi, surgeon at the Khalili Center for Bariatric Care in Los Angeles. “Transferred to a body, which must counteract the force of gravity, that’s equivalent to a body weight of 53st 7lb.
Our brain is like a super-calculator: it consists of around a billion cells which each build around 1,000 connections to other cells. This dense network possesses a storage capability of 2.5 million gigabytes – in theory we could remember everything.
When the lava hits the water, it hisses and roars like a startled predator. Thick plumes of smoke are pushed against the smooth black cliff face by the wind. It looks like the water is on fire. Pedro Oliva, who is battling the surf in a kayak, feels the embers hit his face.
At 8ft 11in Robert Wadlow holds the record for the tallest human ever to have lived. His height was due to hyperplasia of his pituitary gland, which resulted in an abnormally high level of human growth hormone.
A professional martial artist could actually go head to head with a polar bear, the biggest predatory land mammal on Earth. This extraordinary scenario was discovered by biomedical engineers at Wayne State University, after Olympic boxers fought against a dummy.
“Our brainpower is subject to psychological limits. It is limited by the speed at which information bits – in the form of electrically charged particles – can get from A to B,” says Simon Laughlin, neurobiologist at Cambridge University.
A tetrachromat is an organism with a distinctive super sense: it sees 99 million shades of colour. Normally a person perceives only 500,000 true colour sensations. But as a result of a genetic defect, the eyes of some people have four types of colour receptors instead of three.