# What are we made of. **URL:** \ **Category:** Factual Questions\ **Created:** [February 21, 2003, 11:39pm UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668 "2003-02-21T23:39:27Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [February 21, 2003, 11:39pm UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/1 "2003-02-21T23:39:27Z")
Sugar and spice and everything nice. (Blanks?) and snails and puppy dog tails. Other than _that_, I mean. šŸ˜‰ The [shit](http://boards.straightdope.com/sdmb/showthread.php?threadid=164733) thread made me think of this (again), so Iā€™ll ask what is very possibly a silly question. What _are_ living things made of? Trees, us, whatever? A tree canā€™t possibly be made from the earth it grows in, there just isnā€™t enough. Does it get all that mass from carbon in the air? Do we? Please be gentle with the chemistry stuff, ok? Peace, mangeorge ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [February 21, 2003, 11:51pm UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/2 "2003-02-21T23:51:23Z")
[Carl Sagan] We are all made of star stuff. [/Carl Sagan] Yes, trees get most of their mass from the atmosphere. I donā€™t recall the details, but a couple hundred years ago, a scientist tested this, but meticulously weigh a growing young tree periodically by digging it up and knocking all the soil from its roots before taking a measurement. He concluded that the tree was gaining mass not from the soil and water, but from the air. Since animals (for the most part) either eith plants or eat animals that eat p;lants, they get their mass from the air too, mostly. ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [February 21, 2003, 11:53pm UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/3 "2003-02-21T23:53:54Z")
We are mostly water. 80-90%, IIRC. ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [February 21, 2003, 11:56pm UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/4 "2003-02-21T23:56:38Z")
Oops, forgot to add: I think the next biggest bit would be the calcium in our bones. Iā€™m guessing thatā€™s around the 10% area. ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [February 22, 2003, 12:01am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/5 "2003-02-22T00:01:27Z")
No, Helmont actually concluded that the treeā€™s mass came from water. I donā€™t know of an experiment which actually showed, in this fashion, that air was the source. ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [February 22, 2003, 12:07am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/6 "2003-02-22T00:07:47Z")
Nametag wrote: > [@](#): > > No, Helmont actually concluded that the treeā€™s mass came from water. I think youā€™re mistaken (unless you can come up with an awfully good cite). Water is hydrogen and oxygen. The bulk of a tree is carbon in one form or another. You know, that process where it eats the carbon dioxide out of the air anp poops out free oxygen for us to breathe. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [February 22, 2003, 12:29am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/7 "2003-02-22T00:29:35Z")
But thereā€™s so little CO[sub]2[/sub] in the air; 78.095% nitrogen, 20.938% oxygen, 0.033 noble gases and **0.031% carbon dioxide**. Something like that, šŸ˜‰ ---
**Author:** ![Dogface](https://avatars.discourse-cdn.com/v4/letter/d/9d8465/32.png) [@Dogface](https://boards.straightdope.com/u/Dogface)\ **Post date:** [February 22, 2003, 12:30am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/8 "2003-02-22T00:30:07Z")
He could be both wrong and right. Helmont could have concluded that the mass came entirely from water. This experiment was done before plant respiration was understood in the least. ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [February 22, 2003, 1:00am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/9 "2003-02-22T01:00:57Z")
mangeorge wrote: > [@](#): > > But thereā€™s so little CO2 in the air I think itā€™s actually a tad bit higher than .031%. But youā€™re right it isnā€™t a very high percentage. But in actual terms there are some gillion billions of tons of CO2 floating around. How much CO2 does the world add to the atmosphere every year? I think itā€™s on the order of billions of tons. Yet the increase in CO2 is only going up slowly. It seems to me that your argument is sort of like saying there isnā€™t enough food available for all the animals on earth because the food makes up only .000000001% of the weight of the earth. Nope, water is hydrogen and water. Trees are virtually all carbon. Wellā€¦maybe virtually is a tad high, letā€™s call it mostly. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [February 22, 2003, 1:12am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/10 "2003-02-22T01:12:57Z")
Astonishment more than arguement, actually. šŸ™‚ Ever seen the giant redwoods in California? I realize they take centuries to grow, and contact a _lot_ of air in that time, but _golly_. So anyway, are we made largely (minus the H[sub]2[/sub]O) of carbon from the air? I say ā€œyesā€, but it is a little hard to grasp. I like the ā€œstar stuffā€ idea. ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [February 22, 2003, 1:12am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/11 "2003-02-22T01:12:57Z")
After removing my head from my ass I determined that a trip to google was called for. Turns out [Helmont](http://helmont1.tripod.com/HelmontABT91.htm) did conclude that trees were essentially water. The expirement took place in the early 1600ā€™s. But Iā€™m still going with: We are made of mostly water and calcium. Trees are mostly carbon. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [February 22, 2003, 1:19am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/12 "2003-02-22T01:19:19Z")
No, **SandyHook** , I know from _Star Trek_ that we are indeed carbon-based life forms. ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [February 22, 2003, 1:22am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/13 "2003-02-22T01:22:22Z")
Well, canā€™t argue with that. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [February 22, 2003, 1:42am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/14 "2003-02-22T01:42:58Z")
From an elemental point of view: By mass: oxygen (61%), carbon (23%), hydrogen (10%), nitrogen (1%)ā€¦ By number of atoms: hydrogen, oxygen, carbon, nitrogenā€¦ [Here is a complete list, down to radon.](http://www.foresight.org/Nanomedicine/Ch03_1.html#Tab0301) From a chemical compound point of view: By mass: water (65%), proteins (20%), lipids (12%)ā€¦ [Cite](http://www.foresight.org/Nanomedicine/Ch03_1.html#Tab0302). ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [February 22, 2003, 5:12am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/15 "2003-02-22T05:12:42Z")
[carbon-based](http://www.world-builders.org/lessons/less/les4/Vles4na.html) That includes us. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [February 22, 2003, 5:32am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/16 "2003-02-22T05:32:21Z")
SPONCH - sulfur, phosphorus, oxygen, nitrogen, carbon, hydrogen. Top 6 atoms in our bodies, in no particular order. ---
**Author:** ![MonkeyMensch](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@MonkeyMensch](https://boards.straightdope.com/u/MonkeyMensch)\ **Post date:** [February 22, 2003, 5:48am UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/17 "2003-02-22T05:48:14Z")
[homer] Aggghhhā€¦ Carbon-based life-formsā€¦ aggghhh [/homer] Seriously, though. _QED_ forget to mention the tag line to Carl Saganā€™s famous lineā€¦ ā€œand we longed to returnā€ ---
**Author:** ![Urban\_Ranger](https://avatars.discourse-cdn.com/v4/letter/u/e9c0ed/32.png) [@Urban\_Ranger](https://boards.straightdope.com/u/Urban_Ranger)\ **Post date:** [February 22, 2003, 4:28pm UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/18 "2003-02-22T16:28:50Z")
A lot of neutrons, protons, and electrons. šŸ˜ƒ ---
**Author:** ![jsb5048](https://avatars.discourse-cdn.com/v4/letter/j/a6a055/32.png) [@jsb5048](https://boards.straightdope.com/u/jsb5048)\ **Post date:** [February 22, 2003, 5:40pm UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/19 "2003-02-22T17:40:39Z")
Taco Bell BTW if I am like 80%-90% H2O why is it such a big feat to swim the English Channel? I mean you are only moving 10%-20% of your body. ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [February 24, 2003, 3:35pm UTC](https://boards.straightdope.com/t/what-are-we-made-of/156668/20 "2003-02-24T15:35:54Z")
> [@](#): > > \*Originally posted by jsb5048 \* > \*\*Taco Bell > > BTW if I am like 80%-90% H2O why is it such a big feat to swim the English Channel? I mean you are only moving 10%-20% of your body. \*\* First of all, water makes up about 65% of your body (see above). Second of all, you are moving 100% of your body, including the water (which is intimately a part of you down to the cellular level). One could of course remove all of the water first from the body in question, decreasing its mass, but one would find it somewhat difficult to reconstitute the resulting dessicated corpse. ā˜¹ A ship with a mass of 100,000 metric tons must have engines sufficiently powerful to accelerate this mass. It doesnā€™t matter whether the mass contained within the shipā€™s hold is seawater, crude oil, or chicken feathers. [Next page](https://boards.straightdope.com/t/what-are-we-made-of/156668.md?page=2)