# Are human beings donuts? **URL:** \ **Category:** Factual Questions\ **Created:** [December 14, 2005, 11:45pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665 "2005-12-14T23:45:14Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [December 15, 2005, 2:55pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/21 "2005-12-15T14:55:11Z")
> [@Liberal](#): > > Is a torus allowed to have a shut-off valve, so to speak? Or does the fact that the sphincter is elastic make it a non-issue? The sphincter is not a closed surface, topologically, so it’s technically a hole even if it puckers so tight you couldn’t drive an ice pick up there with a sledge hammer. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [December 15, 2005, 2:56pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/22 "2005-12-15T14:56:39Z")
When your head’s up your ass, does that make you a cruller? ---
**Author:** ![Malacandra](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@Malacandra](https://boards.straightdope.com/u/Malacandra)\ **Post date:** [December 15, 2005, 3:04pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/23 "2005-12-15T15:04:01Z")
Similarly, ISTR that the length/width/height dimensions quoted for Noah’s Ark are in roughly the same proportions as the human body (tho’ differently oriented). So not only are we ambulatory doughnuts, but we are roughly the same shape as Noah’s Ark. ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [December 15, 2005, 5:33pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/24 "2005-12-15T17:33:22Z")
For a really thorough count of the number of through-apertures on the human body, don’t forget to include piercings. ---
**Author:** ![bordelond](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bordelond/32/150_2.png) [@bordelond](https://boards.straightdope.com/u/bordelond)\ **Post date:** [December 15, 2005, 6:13pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/25 "2005-12-15T18:13:16Z")
> [@Hail Ants](#): > > Kennedy said he was! > > 😃 Nice! ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [December 15, 2005, 7:05pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/26 "2005-12-15T19:05:13Z")
> [@Liberal](#): > > Are human beings donuts? “MMMmmmm! Long pork!”~~Homer Simpson. ---
**Author:** ![jawdirk](https://avatars.discourse-cdn.com/v4/letter/j/df705f/32.png) [@jawdirk](https://boards.straightdope.com/u/jawdirk)\ **Post date:** [December 15, 2005, 8:07pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/27 "2005-12-15T20:07:32Z")
A Human is not a donut. Nostrils and ears connect to the throat. So a human has 5 distinct holes. And don’t forget piercings. You could also argue that each hair is a separate object topologically, but still part of the human. ---
**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\ **Post date:** [December 15, 2005, 9:07pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/28 "2005-12-15T21:07:59Z")
> [@Q.E.D.](#): > > Not quite. The bladder connects to the outside world via the urethra, and is filled through a pair of tubes, one from each kidney. The kidneys have no other connection to the outside–all the fluids and waste products cross over from the bloodstream via osmosis. I wouldn’t really count that. If stuff can get in, there’s at least one hole there. Actually, if you want to get really picky, humans are mostly empty space filled with a lot of electrons and nuclei. So no, we’re not donuts–we’re not even connected. ---
**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:** [December 15, 2005, 10:07pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/29 "2005-12-15T22:07:42Z")
> [@jawdirk](#): > > …ears connect to the throat. Only if the eardrum is perforated. The eustacian tubes run from the back of the throat to the middle ear, which is separated from the outside world by the normally airtight tympanum. > [@ultrafilter](#): > > Actually, if you want to get really picky, humans are mostly empty space filled with a lot of electrons and nuclei. So no, we’re not donuts–we’re not even connected. Ah ha! Here’s the real crux of the question: how does one define a “hole” in this context? I think we need a definition which excludes the spaces between atoms and molecules, since common sense dictates that we think of these as being contiguous, for our purposes. ---
**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\ **Post date:** [December 15, 2005, 10:14pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/30 "2005-12-15T22:14:05Z")
> [@Q.E.D.](#): > > Ah ha! Here’s the real crux of the question: how does one define a “hole” in this context? I think we need a definition which excludes the spaces between atoms and molecules, since common sense dictates that we think of these as being contiguous, for our purposes. The hole in your mouth is a wider space between molecules than elsewhere in your body. I guess you could set a minimum size, but if you’re getting into topology, it’s not fair to expect common sense to have any input. ---
**Author:** ![jawdirk](https://avatars.discourse-cdn.com/v4/letter/j/df705f/32.png) [@jawdirk](https://boards.straightdope.com/u/jawdirk)\ **Post date:** [December 15, 2005, 11:18pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/31 "2005-12-15T23:18:21Z")
> [@Q.E.D.](#): > > Only if the eardrum is perforated. The eustacian tubes run from the back of the throat to the middle ear, which is separated from the outside world by the normally airtight tympanum. I don’t know about you, but if I plug my nose and close my mouth, I can blow a very small amount of air out of my ears. I can depressurize my ears in an airplane with my nose and mouth closed. So I think ears are only airtight in the same way that your mouth is airtight when it is closed. > [@Ultrafilter](#): > > Actually, if you want to get really picky, humans are mostly empty space filled with a lot of electrons and nuclei. So no, we’re not donuts–we’re not even connected. Or maybe we are all just wrinkles on a contiguous 13-dimensional M-brane? ---
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [December 15, 2005, 11:22pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/32 "2005-12-15T23:22:51Z")
> [@Johnny L.A.](#): > > Interesting factoid: > > If an average-sized man were to face north, and the intestines on the right side of his body were cut and stretched outside of his body as far as they would go to the east, and the intestines on the left side of his body were cut and stretched outside of his body as far as they would reach to the west… > > He’d die. But how much salt would it take to cover him? ---
**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:** [December 15, 2005, 11:28pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/33 "2005-12-15T23:28:05Z")
> [@jawdirk](#): > > I don’t know about you, but if I plug my nose and close my mouth, I can blow a very small amount of air out of my ears. I used to be able to, after one of my eardrums was ruptured in a fight, but once that healed up it was sealed. However, I just thought of another set of holes we’ve overlooked: At the bottom of each eye is a tear drainage tube called the nasolacrimal duct. These connect to the nasal passages, and are therefore connected to the mouth and throat. ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [December 16, 2005, 1:05am UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/34 "2005-12-16T01:05:25Z")
> [@ultrafilter](#): > > if you’re getting into topology, it’s not fair to expect common sense to have any input Do you get into a lot of fistfights at math conferences? 😉 ---
**Author:** ![Bob\_Scene](https://avatars.discourse-cdn.com/v4/letter/b/e19adc/32.png) [@Bob\_Scene](https://boards.straightdope.com/u/Bob_Scene)\ **Post date:** [December 16, 2005, 6:36am UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/35 "2005-12-16T06:36:12Z")
> [@picunurse](#): > > Once the zygote begins dividing, it forms a tube ([neural tube](http://www.uoguelph.ca/zoology/devobio/210labs/brainchart.html)) Everything else is window dressing. I think you’re talking about gastrulation, which happens pretty early in embryonic development and forms the archenteron, which becomes the digestive tract. The neural tube forms later in a completely different process. ---
**Author:** ![Trunk](https://avatars.discourse-cdn.com/v4/letter/t/87869e/32.png) [@Trunk](https://boards.straightdope.com/u/Trunk)\ **Post date:** [December 16, 2005, 3:56pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/36 "2005-12-16T15:56:58Z")
> [@Bryan Ekers](#): > > When your head’s up your ass, does that make you a cruller? It makes you a Klein Bottle. HA HA HA HA HA!!! ---
**Author:** ![Dr.Rieux](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@Dr.Rieux](https://boards.straightdope.com/u/Dr.Rieux)\ **Post date:** [December 16, 2005, 4:06pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/37 "2005-12-16T16:06:41Z")
> [@Bryan Ekers](#): > > When your head’s up your ass, does that make you a cruller? Or a Klein Bottle. ---
**Author:** ![Dr.Rieux](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@Dr.Rieux](https://boards.straightdope.com/u/Dr.Rieux)\ **Post date:** [December 16, 2005, 4:08pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/38 "2005-12-16T16:08:18Z")
Much like me… :smack: ---
**Author:** ![Trunk](https://avatars.discourse-cdn.com/v4/letter/t/87869e/32.png) [@Trunk](https://boards.straightdope.com/u/Trunk)\ **Post date:** [December 16, 2005, 4:12pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/39 "2005-12-16T16:12:37Z")
> [@Dr. Rieux](#): > > Much like me… > :smack: Interesting how no one posted that joke for 24 hours, and then two of us did it within ten minutes. I’m still laughing, by the way. ---
**Author:** ![SentientMeat](https://avatars.discourse-cdn.com/v4/letter/s/43a26b/32.png) [@SentientMeat](https://boards.straightdope.com/u/SentientMeat)\ **Post date:** [December 16, 2005, 4:59pm UTC](https://boards.straightdope.com/t/are-human-beings-donuts/335665/40 "2005-12-16T16:59:26Z")
Since the mouth attaches to two other exits (nasal and anal), we are donuts with a sidehole, topologically speaking (or more sideholes if we consider the tear ducts). True genus 2 donuts would require extra separate holes. I suppose stigmata could make you genus 5! [Previous page](https://boards.straightdope.com/t/are-human-beings-donuts/335665.md?page=1) [Next page](https://boards.straightdope.com/t/are-human-beings-donuts/335665.md?page=3)