Between roughly 11,000 and 5,000 years ago, subtle shifts in Earth's orbit strengthened the African monsoon. The Sahara became a savanna dotted with lakes, home to hippos, crocodiles and elephants. Rock paintings even show people swimming in what is now desert. Then the climate flipped, and the sand reclaimed the land.
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.