Mars had an oxygen-rich atmosphere around 4 billion years ago
13
The word 'mile' is derived from the Latin word for 1,000 - the number of paces it took the average Roman!
6
30 years ago, you could buy a lifetime, unlimited first-class travel pass with American Airlines for $250,000.
14
In 2012, as phone booths become increasingly obsolete because of mobile phones, a Japanese artist has turned several booths in Osaka into aquariums.
7
Not swinging your arms when you walk increases the effort of walking by 12%, the equivalent of walking 20% faster or carrying a 10 kg backpack.
12