Some corals lay down a thin growth ridge every day, with a rhythm that changes through the seasons. In 1963, palaeontologist John Wells counted about 400 ridges per year on corals around 380 million years old. Earth was spinning faster back then: a day lasted roughly 22 hours. Since then, lunar tides have slowly braked its rotation.
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.