In a fraction of a second, lightning can heat the air around it to roughly 30,000 °C, about five times hotter than the surface of the Sun. That superheated air expands so violently that it produces a shock wave. What you hear next is thunder: the sound of that explosive expansion rolling across the sky.
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.