Earth's axis slowly traces a circle across the sky, like a wobbling spinning top: this is precession, which takes about 26,000 years to complete. Today the axis points almost at Polaris. But some 4,700 years ago the pole star was Thuban, and in roughly 12,000 years it will be bright Vega, though less precisely aligned.
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.