D Can you believe it, astronauts become taller by as much as 3cm when they go into space!

This is because astronauts experience weightless in space due to low gravitational force, so there is no stress on their spine which leads to spine-lengthening. But they return to their original height once they are back on Earth.

D The tallest man who was every reliably measured and recorded was Robert Wadlow of Alton, Illinois. At the age of 22, 1940, he was measured by doctors to be 8ft 11.1in (274cm) tall. But 18 days after this he died.

Wadlow was born a normal sized baby, but he suffered from a disorder of his pituitary gland which caused him to continue growing all his life. By the time he was 13 he was already 7ft 4in tall.