The Cosmic Calendar

This mind-blower is from Carl Sagan's The Dragons of Eden. My PowerPoint rendition packs even more punch. Pack the duration of the universe into a 365-day year, and the time from the Middle Ages to the present lasts but a second.

Imagine the fifteen-billion-year lifetime of the universe compressed into the span of a single year.  Then every billion years of Earth history would correspond to about 24 days of our cosmic year and one second to 475 revolutions of Earth around the sun.

All of recorded history occupies the last ten seconds of December 31.  And the time from the waning of the Middle Ages to the present occupies little more than one second.

Few writers can equal the late Carl Sagan's ability to describe science in lay terms. On his darker side, he sued Apple for naming a protoype computer the "Sagan." Apple rechristened it the "BHA" -- an acronym for butt-head astronomer.

After his PBS show Cosmos, a new unit of measurement was named for him.

1 sagan = billions and billions