Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
At room temperature, the average air molecule travels at the speed of a rifle bullet.
55
Airports that are at higher altitudes require a longer airstrip due to lower air density.
39
Sound travels fifteen times faster through steel than through air.
134
Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
0
A cesium atom in an atomic clock beats over nine billion times a second.
43
Cold water weighs more than hot water.
93
Scientists aren't sure what color dinosaurs were.
312