Memory is an active process that is heavily dependent on what we already know. If we don’t keep the memory sharp, it will gradually atrophy.
Researchers have discovered a 40,000-year-old adhesive that Neanderthals used to repair their tools. An elephant's heart beats around 30 times per minute and weighs up to 21 kilograms. The moon landing marks a 50th anniversary of the first manned mission to the moon, which left the Earth's surface on July 20, 1969.