Alan Alda's own childhood experience provided the inspiration for a challenge he posed to scientists earlier this year: to describe a flame such that an 11-year-old child can understand what it is. Now, a new question drawn from more than 300 submissions asks scientists to describe what time is, the Associated Press reports.

Get the full story

This story is free
for registered users

Registering provides access to this and other free content.

Register now.

Already have an account?
Login Now.

In Nature this week: researchers classify pancreatic cancer into four subtypes using sequencing, and more.

Genotyping analysis of measles in Ontario indicates the strain there didn't originate from Disneyland or Europe.

The UK Medical Research Council says the proposed path of a new train line could affect research at the Francis Crick Institute.

The House of Lords in the UK approves a bill to allow mitochondrial donation.