Humans¿ìè¶ÌÊÓÆµâ€™s guide to the 21 best ideas of the 21st century A quarter of a century in, this is our definitive pick of the ideas in science and technology that are already transforming the world Features
HealthFalling asleep isn’t a gradual process – it happens all of a sudden Brain activity from more than 1000 people shows a rapid transition from being awake to being asleep, rather than a slow transition between the two states ¿ìè¶ÌÊÓÆµ