The hair of an adult man or woman can stretch 25 percent of its length without breaking.
116
Forensic scientists can determine a person's sex, age, and race by examining a single strand of hair.
101
Indoor pollution is 10 times more toxic than outdoor pollution.
62
The gas that gives rotten eggs their distinctive foul smell may slow ageing and block damaging chemical reactions inside cells, according to scientists in China.
5
Iron weighs more after it rusts.
68
Nearly 50% of the world's scientists are assigned to military projects.
71
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