Question

On a cosmic calendar, in which the history of the universe is compressed into one year, how long is the average human life span?.

Answer 1

If one were to use 5 billion years as the age of the universe and 75 years as the average human life span then

T = 75 / 5 E9 = 1.5E-8

The number of seconds in a year is 3600 * 24 * 365 = 3.2E7

If t = N * T seconds in a year * fraction of human life span

t = 1.5E-8 * 3.2E7 = .48

A human life span is about 1/2 second compared to the life of the universe if the universe were compressed to a single year