Drink a glass of water, how much is dinosaur pee?

Here’s more information on the subject. These experiments were some of the first to use isotopic tracers in biology. It’s now standard methodology.

p.s. That creek is completely dried up as I write this. I live in the upper Midwest, which is in the midst of a horrific drought. :frowning:

Never mind “Once breathed by Caesar”. Consider Caesar’s last breath. John Allen Paulos calculated that there is a 98% chance that your last breath contains at least one molecule from Caesar’s last breath. http://econ161.berkeley.edu/movable_type/archives/001392.html

Admittedly the author assumes that only a trivial share of molecules were vented to outer space or sea or the Earth.

Decent username/post combo right here.