# How fast is an acoustic wave on a fat woman's buttocks during doggy-style sex? **URL:** \ **Category:** Factual Questions\ **Created:** [November 7, 2013, 5:32pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342 "2013-11-07T17:32:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [November 7, 2013, 5:32pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/1 "2013-11-07T17:32:51Z")
Thought of it while disinterestedly watching porn on the Net. (That sentence is a good one for for any number of reasons…) Besides intrinsic interest, it would be good for a nerd “your Mama’s so fat…” joke. ::Off to find a strap-on dynamometer.:: ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [November 7, 2013, 5:45pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/2 "2013-11-07T17:45:35Z")
> [@Leo\_Bloom](#): > > Thought of it while disinterestedly watching porn on the Net. (That sentence is a good one for for any number of reasons…) Besides intrinsic interest, it would be good for a nerd “your Mama’s so fat…” joke. > > ::Off to find a strap-on dynamometer.:: I don’t know the direct answer, but I’ve seen high-speed videos on YouTube of all sorts of things, including acoustic waves on a woman’s buttocks. It wasn’t during sex, but the cause is probably irrelevant. You could make calculations based on what you see. ---
**Author:** ![Lukeinva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lukeinva/32/17872_2.png) [@Lukeinva](https://boards.straightdope.com/u/Lukeinva)\ **Post date:** [November 7, 2013, 5:49pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/3 "2013-11-07T17:49:51Z")
To save you the trouble of clicking [this link](http://en.wikipedia.org/wiki/Acoustic_wave) I have cut & pasted the equations below. * * * Moderator Note - copied/pasted material removed * * * ---
**Author:** ![drachillix](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@drachillix](https://boards.straightdope.com/u/drachillix)\ **Post date:** [November 7, 2013, 6:35pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/4 "2013-11-07T18:35:49Z")
The same speed as on a skinny woman, just does not have as far to travel 😃 ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [November 7, 2013, 6:44pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/5 "2013-11-07T18:44:42Z")
I thought the speed (and height) of waves depended on how deep the water - I assume the same applies to bodies - the speed and visibility of waves on a female anatomy are proportional to the depth of the fat layer through which they propagate. ---
**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:** [November 7, 2013, 7:13pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/6 "2013-11-07T19:13:59Z")
I doubt that the OP is actually asking about acoustic waves. Acoustic waves in a mostly-water medium would travel at thousands of miles per hour, and would not be visible in anything but an extreme high-speed video. Probably what the OP is actually wondering about is the transverse waves which can be seen rippling across the surface. ---
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [November 7, 2013, 7:20pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/7 "2013-11-07T19:20:36Z")
They’re moving at the speed of love. ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [November 7, 2013, 7:24pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/8 "2013-11-07T19:24:50Z")
And so, boys and girls, we can see that engineers are not like you and me. Regards, Shodan ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [November 7, 2013, 7:28pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/9 "2013-11-07T19:28:51Z")
while having sex there is no application of the ideal gas law. ---
**Author:** ![SandyHook](https://avatars.discourse-cdn.com/v4/letter/s/dec6dc/32.png) [@SandyHook](https://boards.straightdope.com/u/SandyHook)\ **Post date:** [November 7, 2013, 7:29pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/10 "2013-11-07T19:29:51Z")
Damn I love the dope. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [November 7, 2013, 7:36pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/11 "2013-11-07T19:36:13Z")
**Moderator Note** I have removed the copied and pasted text from Lukeinva’s post (post #3) as it copied most of an entire wikipedia article. That goes a bit beyond fair use. The link to the article is still in Lukeinva’s post. ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [November 7, 2013, 7:45pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/12 "2013-11-07T19:45:11Z")
> [@Hypno-Toad](#): > > They’re moving at the speed of love. Well, depends on your technique. > **[Love wave](https://en.wikipedia.org/wiki/Love_wave)** > > In elastodynamics, Love waves, named after Augustus Edward Hough Love, are horizontally polarized surface waves. The Love wave is a result of the interference of many shear waves (S-waves) guided by an elastic layer, which is welded to an elastic half space on one side while bordering a vacuum on the other side. In seismology, Love waves (also known as Q waves (Quer: German for lateral)) are surface seismic waves that cause horizontal shifting of the Earth during an earthquake. Augustus Edward Ho... I agree with Chronos. The OP probably wants the speed of a Rayleigh wave which is somewhat complicated. It’s significantly less fast than a pressure wave though. Probably less than 10% of it. ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [November 7, 2013, 8:02pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/13 "2013-11-07T20:02:00Z")
You know, it is not really necessary to do all these calculations - most people just think about baseball to keep going. Regards, Shodan ---
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [November 7, 2013, 8:23pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/14 "2013-11-07T20:23:35Z")
For pigs, this velocity is about 3 m/s._[1-Hz surface waves in the skin propagate primarily as Rayleigh waves with a wavelength and velocity of approximately 3 m and 3.0 m/s, respectively](http://www.ncbi.nlm.nih.gov/pubmed/15568953)_ You can do similar calculations for human skin - the data is all [here](http://biophotonics.illinois.edu/pubs/biophotonics_current/IEEE%20TBME%20-%20InVivoSkin%20OCE.pdf). Damn, if I do these calcs. Or you can undertake research (funded by NIH of course), recruit Volunteers!! and publish the results. Oh - and “Double Blind” 😉 studies are mandatory in this case. ---
**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:** [November 7, 2013, 9:13pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/15 "2013-11-07T21:13:31Z")
> [@](#): > > Oh - and “Double Blind” studies are mandatory in this case. So, you keep doing that, and then you keep doing it again? 😉 ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [November 7, 2013, 9:47pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/16 "2013-11-07T21:47:33Z")
> [@Snarky\_Kong](#): > > Well, depends on your technique. > > [Love wave - Wikipedia](http://en.wikipedia.org/wiki/Love_wave) > > I agree with Chronos. The OP probably wants the speed of a Rayleigh wave which is somewhat complicated. It’s significantly less fast than a pressure wave though. Probably less than 10% of it. Raleigh wave or seismic wave? He did specify “fat”… It wouldn’t be a soliton in this case. 😃 ---
**Author:** ![Snarky\_Kong](https://avatars.discourse-cdn.com/v4/letter/s/a183cd/32.png) [@Snarky\_Kong](https://boards.straightdope.com/u/Snarky_Kong)\ **Post date:** [November 7, 2013, 9:49pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/17 "2013-11-07T21:49:11Z")
> [@md2000](#): > > Raleigh wave or seismic wave? He did specify “fat”… So? ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [November 7, 2013, 10:38pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/18 "2013-11-07T22:38:04Z")
> [@engineer\_comp\_geek](#): > > **Moderator Note** > > I have removed the copied and pasted text from Lukeinva’s post (post #3) as it copied most of an entire wikipedia article. That goes a bit beyond fair use. Copying Wikipedia text is [specifically allowed](http://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_License): > [@Wikipedia's Creative Commons Attribution-ShareAlike License](#): > > You are free: > > to Share—to copy, distribute and transmit the work, and Back on topic: > [@Leo Bloom](#): > > Besides intrinsic interest, it would be good for a nerd “your Mama’s so fat…” joke. How about a comparison to [Dark matter sound waves](http://www.newscientist.com/article/dn24536-eavesdropping-on-dark-sound-shrinks-the-shadow-universe.html)? That would be pretty damn nerdy… ---
**Author:** ![Fubaya](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@Fubaya](https://boards.straightdope.com/u/Fubaya)\ **Post date:** [November 7, 2013, 11:13pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/19 "2013-11-07T23:13:39Z")
Somebody’s gotta find a video of a girl with a two big ass zits and measure the time between their respective bounces as the wave passes. I tried to find one but got distracted, now I’m not really interested and kind of need a nap, but I can try again in a couple hours. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [November 7, 2013, 11:22pm UTC](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342/20 "2013-11-07T23:22:12Z")
> [@Leo\_Bloom](#): > > Thought of it while disinterestedly watching porn on the Net. (That sentence is a good one for for any number of reasons…) Considering that it does not even have a subject, no it isn’t.\ [Next page](https://boards.straightdope.com/t/how-fast-is-an-acoustic-wave-on-a-fat-womans-buttocks-during-doggy-style-sex/673342.md?page=2)