# Every single breath we take, we get at least one atom from Julius Caesar's last breath? **URL:** \ **Category:** Factual Questions\ **Created:** [October 24, 2022, 3:26am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691 "2022-10-24T03:26:41Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![EmbarrassingDad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/embarrassingdad/32/5441_2.png) [@EmbarrassingDad](https://boards.straightdope.com/u/EmbarrassingDad)\ **Post date:** [October 24, 2022, 3:26am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/1 "2022-10-24T03:26:41Z")
I’ve heard this touted as a fact a few times. Is it true? ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [October 24, 2022, 3:38am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/2 "2022-10-24T03:38:24Z")
No way to know for sure but this article goes thorough the calculations. And now we know what The Police were _really_ singing about. > **[Estimations: Your Breath and Julius Caesar's](https://futurism.com/estimating-how-many-molecules-you-breathe-that-were-from-julius-caesars-last-breath)** > > Not all of physics consists of pin-point accurate mathematics. In certain situations, using assumptions and rough values to come to a workable value is very important. Other times, we may not have the time to run through a very precise set of... > So now we have two estimations: the volume of air in the entire atmosphere and the number of molecules in a single breath. Given that your breath and Caesar’s have the same volume, all we have to so is divide them out, giving us a figure of 6.4x10ˉ⁴. However, we’re not quite there yet; as this is the number of molecules in every cubic meter, so we must now divide this by the volume of a single breath (0.5 liters), and doing so our number comes out to be… _drum roll_ … 1.28 molecules! What does this mean? > > Every time you breathe, there’s a good chance that at least one of those molecules was exhaled by Julius Caesar in the throes of death. ---
**Author:** ![EmbarrassingDad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/embarrassingdad/32/5441_2.png) [@EmbarrassingDad](https://boards.straightdope.com/u/EmbarrassingDad)\ **Post date:** [October 24, 2022, 3:40am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/3 "2022-10-24T03:40:38Z")
Thank you! That is perfect. ETA: good joke, took me a minute ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 24, 2022, 3:59am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/4 "2022-10-24T03:59:54Z")
I was taught it as Galileo’s last breath. It is a favourite question to lead into the entire order of magnitude estimation techniques in science, but especially physics. When I did our equivalent of final year high school / university entrance exams, there was always a question of this nature in the physics paper. They were a lot of fun. Clearly there wasn’t an exact answer, but it was the opportunity to prove that you had a handle on the fundamentals rather than just rote learning. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [October 24, 2022, 4:28am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/5 "2022-10-24T04:28:02Z")
The link doesn’t work for me. Very often, the “answer” in articles like this fail to address an important point. Some do, but many don’t. Since the link is dead for me I can’t tell what this article does. The point is this: Many of the atoms in Caesar’s last breath are no longer in the air at all. Consider the oxygen atoms. You don’t just have to count the number of oxygen atoms in the air. You also have to count the number of oxygen atoms in the oceans. Various biological processes take oxygen and turn it into water. Other processes destroy water molecules and release oxygen. So many of the atoms breathed by Caesar are now part of the Indian Ocean. The question is sometimes phrased as “molecules” of Caesar’s last breath rather than atoms. This is almost certainly wrong. Probably none of the molecules still exist intact. ---
**Author:** ![EmbarrassingDad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/embarrassingdad/32/5441_2.png) [@EmbarrassingDad](https://boards.straightdope.com/u/EmbarrassingDad)\ **Post date:** [October 24, 2022, 4:50am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/6 "2022-10-24T04:50:26Z")
Good points. The link is still working for me, maybe try it again. ---
**Author:** ![FrenchDunadan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/frenchdunadan/32/5449_2.png) [@FrenchDunadan](https://boards.straightdope.com/u/FrenchDunadan)\ **Post date:** [October 24, 2022, 6:21am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/7 "2022-10-24T06:21:39Z")
Atoms react. So any “O” or “C” or even “N” in Julius’s last breath could now be in mineral, vegetate or animal molecules and not be breathable. But the point stands for realizing the huge numbers of atoms on Earth. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 24, 2022, 11:45am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/8 "2022-10-24T11:45:32Z")
The initial question was never framed to come up with a trivial pursuit like answer. It was always about the methodology. The numerical answer is near irrelevant. But the modern world, and Internet click-bait in particular, morphs these into stupid things that really don’t have much to do with the intent. A deeper answer that attempted to include metrics of the various metabolic and chemical cycles in the environment would make for an interesting question, but nobody would be expected to have numbers to hand without references. But the simple answer, just assuming simple mixing, should be answerable by anyone with high-school science and some scribble paper, without reference to any other source. That is the point of the question. Not that one possible answer is about 1. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [October 24, 2022, 12:11pm UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/9 "2022-10-24T12:11:19Z")
I sincerely doubt it! First of all, the amount of air he exhaled compared to the total volume of air around the earth is fantastically small. Secondly, we exhale CO2, much of which ends up inside of plant life and is no longer in a gaseous state. I do agree with this, however: “Every breath you take contains a molecule of history.” ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 24, 2022, 2:01pm UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/10 "2022-10-24T14:01:44Z")
> [@Jasmine](#): > > the amount of air he exhaled compared to the total volume of air around the earth is fantastically small. That bit is, to some extent, the point of the question when posed in a useful context. Yes the volume of air is tiny in comparison, but the number of molecules in a breath is fantastically large. So much so that to a good approximation they cancel out. Avogadro’s number is silly big. 6.02 \times 10^{23} ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 24, 2022, 9:39pm UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/11 "2022-10-24T21:39:59Z")
> [@Jasmine](#): > > Secondly, we exhale CO2, much of which ends up inside of plant life and is no longer in a gaseous state. Mostly not. Mostly what we exhale is just the same air that we inhaled, with only a slight decrease in the oxygen and corresponding increase in the carbon dioxide (and no change at all in the nitrogen, which is most abundant). That said, the statement in the thread title is certainly too strong. If the average number of et-tu atoms in a breath is 1.28, then it will surely be fairly common to have a breath with no such atoms at all (as well as breaths with 2, 3, 4, or more such atoms). ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [October 24, 2022, 9:48pm UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/12 "2022-10-24T21:48:02Z")
> [@Chronos](#): > > > [@Jasmine](#): > > > > Secondly, we exhale CO2, much of which ends up inside of plant life and is no longer in a gaseous state. > > Mostly not. Mostly what we exhale is just the same air that we inhaled, with only a slight decrease in the oxygen and corresponding increase in the carbon dioxide (and no change at all in the nitrogen, which is most abundant). This is not a comparison of air inhaled vs air exhaled. It is a reference to the fate of most CO2 in the atmosphere: incorporation into a carbohydrate by a plant. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [October 24, 2022, 11:05pm UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/13 "2022-10-24T23:05:59Z")
But only temporarily. The plant will eventually be eaten, or die and rot away, and the hydrocarbons will turn into CO2 again. As I said above, not the _same_ CO2 molecules. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 25, 2022, 12:31am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/14 "2022-10-25T00:31:35Z")
We could easily ignore both oxygen and carbon dioxide in the question. 79% of the air is nitrogen, plus another 1% argon. It goes in and out unchanged each breath. Moreover nitrogen is very stable in the atmosphere, taking significant effort to make it react. Most of the oxygen we inhale is exhaled again as well. The idea we inhale oxygen and when we exhale it is all replaced with carbon dioxide is far from true (otherwise CPR would not work). Only 3.9% of exhaled breath is carbon dioxide. Even if all the oxygen and carbon dioxide in the exhaled breath was reworked and wiped from consideration, that 80% of stable nitrogen and argon leave the basic approximation answer correct. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [October 25, 2022, 10:31am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/15 "2022-10-25T10:31:53Z")
I don’t think that’s correct. As far as I understand, atmospheric nitrogen is taken by bacteria in the soil, which convert it to nitrates. Plants absorb the nitrates and make proteins. This enters the food chain. It passes from plant to animal to other animal. When an organism dies it rots, and releases nitrogen back into the atmosphere. Not so stable. > **[Nitrogen cycle](https://en.wikipedia.org/wiki/Nitrogen_cycle)** > > The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmospheric, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmospheric nitrogen, making it the largest source of nitrogen. Howe T... ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [October 25, 2022, 11:01am UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/16 "2022-10-25T11:01:55Z")
> [@Peter\_Morris](#): > > atmospheric nitrogen is taken by bacteria in the soil, which convert it to nitrates. Plants absorb the nitrates and make proteins This is true, but it is very slow. The rate of uptake from atmospheric nitrogen is tiny, within the scope of the question it is probably not going to be significant. Going by the cites, about 700 million tons of nitrogen a year is fixed. So 7 \times 10^{11} kg. The mass of the atmosphere is 5.15 \times 10^{18} kg. We are of the order of one ten millionth of the nitrogen being fixed in a year. Even over say 2000 years since Caesar, we are fixing well less than a thousandth of the atmospheric nitrogen. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [October 25, 2022, 3:02pm UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/17 "2022-10-25T15:02:04Z")
> [@running\_coach](#): > > … and doing so our number comes out to be… _drum roll_ … 1.28 molecules! What does this mean? > > Every time you breathe, there’s a good chance that at least one of those molecules was exhaled by Julius Caesar in the throes of death. There’s a big difference between “there’s a good chance” and the thread title, which states “every single breath”. When someone says “every single”, unequivocally, that is clearly an exaggeration. If I’d say, “Ten average breaths will usually contain about 13 molecules,” that would be much more accurate. Some breaths will have none, and some could have five. ---
**Author:** ![Bamdad10](https://avatars.discourse-cdn.com/v4/letter/b/a88e57/32.png) [@Bamdad10](https://boards.straightdope.com/u/Bamdad10)\ **Post date:** [June 28, 2023, 6:43pm UTC](https://boards.straightdope.com/t/every-single-breath-we-take-we-get-at-least-one-atom-from-julius-caesars-last-breath/973691/18 "2023-06-28T18:43:17Z")
Wow, I hope someone can back me on this but the calculations on this Futurism article are very wrong, to point out the easiest they say 6.4x10^-4 represents the number of molecules in a cubic meter which is hilarious, they go on and divide it by 0.5 x 10^-3 cubic meters and say they get 1.28 molecules, but that would only get you 1.28 molecules/ m^6 because the units do not cancel out