Water vortex ties itself in a knot

Tying a smoke ring in a knot sounds impossible - but University of Chicago physicists have done something similar by creating a vortex knot for the first time, in a container of fluid.

Animals focus smell as well as vision

Animals can focus their sense of smell in much the same way as humans focus their eyes, helping them detect predators and search out food.

Why you can walk on water (mixed with cornstarch)

There's a well-known experiment in which cornstarch is added to water, turning it into a rather odd substance known as oobleck.

Humans evolved from ancient sharks

Human beings - along with all jawed vertebrates on Earth - are descended from a fossil fish that looks a lot like today's sharks.

Social status affects immune system

A change in the social position of a rhesus macaque can affect the expression of nearly 1,000 genes, perhaps partly explaining why poorer people tend to have worse health outcomes.

Moon 'wasn't created by giant collision'

A new chemical analysis of lunar material collected by Apollo astronauts in the 1970s appears to disprove theories that the moon was created through a massive collision between Earth and a Mars-sized object 4.5 billion years ago.

Language is necessary to understand numbers, study finds

Numbers above three are incomprehensible to people who don't speak a language that uses symbols for counting, say researchers at the University of Chicago.