# Drink a glass of water, how much is dinosaur pee? **URL:** \ **Category:** Factual Questions\ **Created:** [September 8, 2013, 9:01am UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319 "2013-09-08T09:01:31Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![grude](https://avatars.discourse-cdn.com/v4/letter/g/e47774/32.png) [@grude](https://boards.straightdope.com/u/grude)\ **Post date:** [September 8, 2013, 9:01am UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/1 "2013-09-08T09:01:31Z")
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. Who was right?šŸ˜› ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [September 8, 2013, 9:31am UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/2 "2013-09-08T09:31:46Z")
Water isnā€™t recycled. All that oxygen that plants ā€œproduceā€ comes from water that has been torn apart. Because surface ocean water gets cycled through plants faster than deep ocean water, I suspect thereā€™s a pretty good chance that thereā€™s not even a single molecule of urine in there. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [September 8, 2013, 10:22am UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/3 "2013-09-08T10:22:41Z")
But plenty of the oxygen molecules you breathe were once dino piss. ---
**Author:** ![don\_t\_ask](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@don\_t\_ask](https://boards.straightdope.com/u/don_t_ask)\ **Post date:** [September 8, 2013, 10:28am UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/4 "2013-09-08T10:28:41Z")
Well I use a Brita filter but apparently it may not [help.](http://www.metacafe.com/watch/1090487/will_a_brita_filter_urine/) ---
**Author:** ![Arkcon](https://avatars.discourse-cdn.com/v4/letter/a/96bed5/32.png) [@Arkcon](https://boards.straightdope.com/u/Arkcon)\ **Post date:** [September 8, 2013, 12:51pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/5 "2013-09-08T12:51:39Z")
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 ā€œurineā€ better for your question ā€“ all of that has been metabolized by other organisms a thousand-fold since then. This is a derivation of the old chestnut ā€“ How many people are descended from Genghis Khan or Julius Cesar. And yes, I know Julius Cesar had no biological children ā€“ 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 donā€™t produce urine ā€“ defined (by me, since you didnā€™t) as a water solution of urea. Instead they excrete uric acid as a paste mixed with their fecal matter. So the ā€œwaterā€ in dinosaur ā€œpeeā€ is like Julius Cesarā€™s ā€œdescendents.ā€ Close, but not exactly the same. Unless I miss my guess on dinosaur biology ā€“ any coprolite that definitively prove otherwise? ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [September 8, 2013, 1:35pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/6 "2013-09-08T13:35:34Z")
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 letā€™s say 10^26 oxygen atoms. Each cubic meter of air at the surface of the Earth contains about 10^25 oxygen atoms. Letā€™s say that the entire atmosphere is equivalent to a box ten miles high, 25,000 miles long, and 8,000 miles wide. Thatā€™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. Letā€™s say that over the entire history of dinosaurs there were a hundred billion of them. Letā€™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. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [September 8, 2013, 2:15pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/7 "2013-09-08T14:15:39Z")
to add more complexity water is also a solid (not water ice) as part of a crystal or hydrate. ---
**Author:** ![heathen\_earthling](https://avatars.discourse-cdn.com/v4/letter/h/13edae/32.png) [@heathen\_earthling](https://boards.straightdope.com/u/heathen_earthling)\ **Post date:** [September 8, 2013, 2:31pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/8 "2013-09-08T14:31:24Z")
> [@Wendell\_Wagner](#): > > Letā€™s say that over the entire history of dinosaurs there were a hundred billion of them. This feels like an extreme underestimate, since it works out to only about 600 dinosaurs born per year. ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [September 8, 2013, 4:07pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/9 "2013-09-08T16:07:35Z")
There are many places in the world where dinosaur piss is the least thing you have to worry about being in the water, Iā€™ll clue ya. ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [September 8, 2013, 4:39pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/10 "2013-09-08T16:39:02Z")
Yeah, youā€™re right. I was trying to work fast. Letā€™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. ---
**Author:** ![sylmar](https://avatars.discourse-cdn.com/v4/letter/s/b782af/32.png) [@sylmar](https://boards.straightdope.com/u/sylmar)\ **Post date:** [September 8, 2013, 9:10pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/11 "2013-09-08T21:10:30Z")
ā€¦ ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [September 8, 2013, 9:17pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/12 "2013-09-08T21:17:15Z")
> [@Alessan](#): > > But plenty of the oxygen molecules you breathe were once dino piss. I recall an article by Isaac Asimov in which he calculated how many billion oxygen atoms once breathed by Julius Caesar were in each breath you take. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [September 8, 2013, 10:01pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/13 "2013-09-08T22:01:40Z")
> [@don\_t\_ask](#): > > Well I use a Brita filter but apparently it may not [help.](http://www.metacafe.com/watch/1090487/will_a_brita_filter_urine/) I wonā€™t be satisfied until I can see the guy pee out in the open. šŸ˜‰ ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 9, 2013, 11:27am UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/14 "2013-09-09T11:27:15Z")
> [@Blake](#): > > Water isnā€™t recycled. All that oxygen that plants ā€œproduceā€ comes from water that has been torn apart. I thought it came from carbon dioxide that the plants tore apart. ā€¦ 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. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [September 9, 2013, 2:44pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/15 "2013-09-09T14:44:02Z")
> [@Machine\_Elf](#): > > 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. The O2 comes from the water, as determined by experiments with labeled isotopes in the 1940s. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [September 9, 2013, 3:27pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/16 "2013-09-09T15:27:35Z")
> [@Colibri](#): > > The O2 comes from the water, as determined by experiments with labeled isotopes in the 1940s. That is some awesome science right there. I would not have guessed the question could be answered, but damn, somebody figured out a way! Iā€™m not sure what the utility of that is (other than answering ponderous questions on an internet discussion site 70 years later), but itā€™s still cool. ---
**Author:** ![nearwildheaven](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@nearwildheaven](https://boards.straightdope.com/u/nearwildheaven)\ **Post date:** [September 9, 2013, 3:31pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/17 "2013-09-09T15:31:13Z")
I live in an apartment complex thatā€™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 ā€œEWWWWW!ā€ and I said, ā€œAll the water on earth has been reused many times. I bet dinosaurs drank some of the water in the creek.ā€ I told this story on another board, and someone else did bring up the ā€œdinosaur peeā€ thing. Also trilobite pee, dodo bird pee, etc. ---
**Author:** ![aNewLeaf](https://avatars.discourse-cdn.com/v4/letter/a/ac91a4/32.png) [@aNewLeaf](https://boards.straightdope.com/u/aNewLeaf)\ **Post date:** [September 9, 2013, 3:42pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/18 "2013-09-09T15:42:35Z")
Ok, so how much dinosaur pee (or poop) is in a gallon of gasoline? ---
**Author:** ![Amblydoper](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@Amblydoper](https://boards.straightdope.com/u/Amblydoper)\ **Post date:** [September 9, 2013, 3:49pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/19 "2013-09-09T15:49:04Z")
> [@don\_t\_ask](#): > > Well I use a Brita filter but apparently it may not [help.](http://www.metacafe.com/watch/1090487/will_a_brita_filter_urine/) Activated charcoal does not filter out ammonia. You would be better off peeing in a fish tank. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [September 9, 2013, 3:53pm UTC](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319/20 "2013-09-09T15:53:31Z")
> [@Amblydoper](#): > > Activated charcoal does not filter out ammonia. You would be better off peeing in a fish tank. But the fish would probably not be better off. And I really donā€™t recommend drinking the fishtank water, either before or after ā€œcontributing to it.ā€ Do you know what fish do in that stuff? Youā€™re better off filtering your water through [aging casks along with significant amounts of yeast pee.](http://en.wikipedia.org/wiki/Scotch_whisky) [Next page](https://boards.straightdope.com/t/drink-a-glass-of-water-how-much-is-dinosaur-pee/668319.md?page=2)