Amazing fact about Candle flame, Tick of a Watch, Taste of salt, One drop of perfume, Wing of a bee.

You can see a candle flame from 50 Kilometers on a clear, dark night. You can hear the tick of a watch from 6 meters in very quiet conditions. You can taste one gram of salt in 500 liters of water (.0001M). You can detect one drop of perfume diffused throughout a three-room apartment. You can detect the wing of a bee falling on your cheek from a height of one centimeter.