Physics
Sound travels four times faster in water
Water molecules sit closer together than air molecules, so vibrations pass along faster — about 1,480 m/s versus 343 m/s.
More in Physics
Sunlight you see is 8 minutes old
Light needs about 8 minutes and 20 seconds to cross 150 million kilometres, so you always see the Sun as it was, never as it is.
Lightning is five times hotter than the Sun
A bolt of lightning heats the air around it to about 30,000°C — roughly five times hotter than the surface of the Sun. That sudden heat is what makes the thunderclap.
Glass is not a slow-flowing liquid
Old cathedral windows are thicker at the bottom because of how they were made, not because glass flows. At room temperature glass is a solid.
Glass is not a liquid
Old window panes are thick at the bottom because of how they were made, not because glass flows. Glass is an amorphous solid.