When wind stretches tiny drops of very runny lava, they freeze into strands of volcanic glass as fine as a human hair, sometimes tens of centimetres long. In Hawaii they are called 'Pele's hair', after the goddess of volcanoes. Light enough to drift on the breeze, they are best handled with care: they cut like broken glass.
On 27 August 1883, the eruption of the Indonesian volcano Krakatoa was heard as far away as Rodrigues Island, nearly 4,800 km away. Its pressure wave was picked up by barometers worldwide and circled the globe several times. The tsunamis that followed killed more than 36,000 people.
The deepest known point in the ocean, Challenger Deep, lies roughly 10,900 m below the Pacific surface. Drop Everest in and its summit would still sit about 2 km underwater. Down there, the pressure is more than 1,000 times what you feel at sea level, roughly a tonne pressing on every square centimetre.