This comes off a debate I had with my dad a long time ago.
My position:All water on Earth is continually recycled through evaporation and such, meaning there are at least a few molecules of former urine in that refreshing drink.
His position:There is so MUCH water on Earth the chances of having even one water molecule of former urine is small.
Water isn’t recycled. All that oxygen that plants “produce” comes from water that has been torn apart. Because surface ocean water gets cycled through plants faster than deep ocean water, I suspect there’s a pretty good chance that there’s not even a single molecule of urine in there.
Earth has had a statistically insignificant input of material between the time of the dinosaurs and our time. So all atoms of the biosphere are constantly recycled.
You have to define “urine” better for your question – all of that has been metabolized by other organisms a thousand-fold since then. This is a derivation of the old chestnut – How many people are descended from Genghis Khan or Julius Cesar. And yes, I know Julius Cesar had no biological children – which brings me to my next point.
Since dinosaurs were related to, more or less, reptiles and birds, they may have shared biological traits with them. Specifically, those animals don’t produce urine – defined (by me, since you didn’t) as a water solution of urea. Instead they excrete uric acid as a paste mixed with their fecal matter. So the “water” in dinosaur “pee” is like Julius Cesar’s “descendents.” Close, but not exactly the same. Unless I miss my guess on dinosaur biology – any coprolite that definitively prove otherwise?
There are 5.352 times 10^23 oxygen atoms in one gram of water. One pint equals 473. 176 grams. So one pint equals 2.532 times 10^26 oxygen atoms. This is all approximate, and a glass is usually considered to be something smaller than a pint, so let’s say 10^26 oxygen atoms. Each cubic meter of air at the surface of the Earth contains about 10^25 oxygen atoms. Let’s say that the entire atmosphere is equivalent to a box ten miles high, 25,000 miles long, and 8,000 miles wide. That’s a box of 4,000,000 cubic miles, which is about 1.67 times 10^16 cubic meters. Only a fourth of the atoms in that box are oxygen, so the atmosphere is contains about 4 times 10^40 oxygen atoms.
Let’s say that over the entire history of dinosaurs there were a hundred billion of them. Let’s say that each of them had 10^27 oxygen atoms in them that were released at death. So 10^41 oxygen atoms were released at death (in decomposition) to the atmosphere by the dinosaurs in total. Surely many of these atoms passed through many dinosaurs. All these numbers are very approximate. At the very least, we can say that probably a large percentage of all oxygen atoms currently in the atmosphere passed through at least one dinosaur. The oxygen atoms in your glass have been in the atmosphere in the past few years. Many of them, and probably most of them, passed through dinosaurs.
Yeah, you’re right. I was trying to work fast. Let’s say that there were 10 quadrillion dinosaurs. Then a total of 10^46 oxygen atoms were released into the atmosphere. Clearly many of the 4 times 10^40 oxygen atoms in the atmosphere were used many times in dinosaurs.
I thought it came from carbon dioxide that the plants tore apart.
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Upon further reading, it appears photosynthesis involves water and CO2 being combined to produce sugar, with oxygen as the lefover. So who gave up their oxygen - the CO2, or the H2O? Hard to say.
That is some awesome science right there. I would not have guessed the question could be answered, but damn, somebody figured out a way! I’m not sure what the utility of that is (other than answering ponderous questions on an internet discussion site 70 years later), but it’s still cool.
I live in an apartment complex that’s beside a small creek. One day, three kids who were of grade-school age stopped by while I was out on my patio reading a book, and one of them told me that she learned in school that tap water is recycled sewage. The kids all went “EWWWWW!” and I said, “All the water on earth has been reused many times. I bet dinosaurs drank some of the water in the creek.”
I told this story on another board, and someone else did bring up the “dinosaur pee” thing.