Sound travels about 4 times faster in water than in air.
408
Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
In zero gravity, a candle's flame is round and blue.
16
It takes a photon 170,000 years to travel from the core of the Sun to the surface, but only 8 minutes to travel the rest of the way to Earth.
6
Your brain is 80% water.
525
The most expensive material on the planet is antimatter - worth $62.5 trillion per gram.
18
Rafflesia Arnoldii is the largest flower in the world and can grow as big as an umbrella.
42