The idea of the atom was first introduced by Leucippus of Miletus around 450 B.C.. Leucippus and his pupil, Democritus, theorized that all matter was composed of atoms, or bits of matter too small to be seen. The word "atom" comes from a Greek word, "atomos", meaning uncuttable, because Leucippus believed that atoms were the building blocks of all materials and therefore could not be broken down any further.
Convection, the transfer of heat through a liquid by circulation of currents, is very apparent in lava lamps. When the wax is heated it becomes less dense than its surroundings and rises. As the wax travels up through the water it begins to cool, by dissipating heat into its surroundings, and by the time it reaches top it begins to sink again.
In 2004, on the island of Flores in Indonesia, a team of Australian and Indonesian researchers discovered the remains of a hobbit-sized human, one that stood no more than a meter tall. Remarkable, these researchers determined that this new species of human lived as recently as 13,000 years ago, shattering the long-held belief that Homo sapiens have had the planet to themselves for the past 25,000 years.