"ksana" is the Sanskrit word designating the smallest interval of time. It is the 90th part of a thought. When a man snaps his fingers, 63 ksanas have gone by – and within each passing ksana there are 900 instances of arising and ceasing.
To see a World in a Grain of Sand
And a Heaven in a Wild Flower,
Hold Infinity in the palm of your hand
And Eternity in an hour.
– William Blake