December 20, 2014
How Do We Know How Old Everything Is?
Guide to Space Ep. 138
How Do We Know How Old Everything Is?
Airdate: 12/22/2014
Comments (2)
H
Helge Bjørkhaug · December 23, 2014
On average I'm 7 - 10 years old :-) Red blood cells are replaced every 120 days. Liver completely replaced every 400 days. Skeleton 10 years.
F
Fraser Cain · December 23, 2014
Is there any part that doesn't get completely replaced?