Optical illusions occur when what the eyes see conflicts with what the brain expects.
75
A single cup of gasoline, when ignited, has the same explosive power as five sticks of dynamite.
57
Scientists are learning from the 1700-year-old Lycurgus Cup, which changes colour thanks to nano particles.
0
Scientists have revived a flowering plant from a fruit stored away in permafrost by Arctic ground squirrel 32,000 years ago.
16
One 75-watt bulb gives more light than three 25-watt bulbs.
57