In 1912, meteorologist Alfred Wegener proposed that continents move, citing how coastlines fit together and identical fossils on opposite sides of oceans. Most geologists rejected the idea because he could not explain what force would push them. Wegener died in 1930 on an expedition in Greenland. Only in the 1960s did plate tectonics prove him right.
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.