If you represent the Earth's lifetime by a single year, say from January when it was made to December, the 21st-century would be a quarter of a second in June -- a tiny fraction of the year.
地球の一生を１月から12月までの １年としてたとえてみると 21世紀は６月のある４分の１秒 － １年のほんの一瞬にしかすぎません