# Every Atom in Your Body Is Replaced every 5 Years

**URL:** <https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147>\
**Category:** Factual Questions\
**Created:** [December 5, 2023, 8:43pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147 "2023-12-05T20:43:21Z")\
**Posts on this page:** 1\
**Showing post:** 26

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**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\
**Post date:** [December 7, 2023, 3:35pm UTC](https://boards.straightdope.com/t/every-atom-in-your-body-is-replaced-every-5-years/994147/26 "2023-12-07T15:35:30Z")

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> [@Water Molecules and Christopher Columbus](https://boards.straightdope.com/t/water-molecules-and-christopher-columbus/452307/1):
>
> cup of water taken from any ocean today would have at least 250 molecules from the original cup of water Columbus dumped

It’s not hard to do some calculations like this. I looked up the volume of the Pacific ocean, and the volume of one water molecule, multiplied and took the square root. This gives a geometric mean of 4.6 ml, which is quite close to a teaspoon.  
Thus, there are as many molecules in a teaspoon of water as there are teaspoons of water in the Pacific Ocean. If somebody dumped a teaspoon of water into the Pacific, and we waited long enough for it to be well mixed, the average number of those original molecules in a newly sampled teaspoon would be one.

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