# Questionable claim on "Manswers": Sperm speed **URL:** \ **Category:** Factual Questions\ **Created:** [September 27, 2009, 3:22am UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719 "2009-09-27T03:22:43Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Superhal](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Superhal](https://boards.straightdope.com/u/Superhal)\ **Post date:** [September 27, 2009, 3:22am UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/1 "2009-09-27T03:22:43Z")
I was watching Spike TV’s Manswers the other day, and one bit of trivia I couldn’t understand because of the way they phrased it. The way they set it up was that if sperm were human sized, for example, the distance they have to swim would be like a human swimming across the Pacific Ocean. Then, they said sperm travels at 30 mph (I’m assuming here that they continued the whole “if it was human sized” thing,) but I wasn’t sure if they swam at this speed or were ejaculated out at this speed. Also, they compared sperm speed to Usain Bolt, but this doesn’t make sense either as sperm are swimming. So what is the relative speed of sperm, not including ejaculation? ---
**Author:** ![Dervorin](https://avatars.discourse-cdn.com/v4/letter/d/eb8c5e/32.png) [@Dervorin](https://boards.straightdope.com/u/Dervorin)\ **Post date:** [September 27, 2009, 8:54am UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/2 "2009-09-27T08:54:26Z")
A couple of millimetres per minute, apparently: [Speed of a Sperm Cell - The Physics Factbook](http://hypertextbook.com/facts/2000/EugeneKogan.shtml) Claims of it being equivalent to swimming the Pacific are wildly exaggerated. Average sperm size is about 25 micrometers; scaling that up to human size (let’s call it 2m for simplicity) is a factor of about 80000. The length that a sperm cell has to swim is of the order of 20cm, or 0.2m. 0.2m \* 80000 = 16,000m - 16km or 10 miles. Not really Pacific-sized. However, it must be noted that sperm are swimming through a far more viscous medium than water, which I have no idea how to account for. But even if it’s a factor of 10 difference, it would still be only like swimming 100 miles, rather than the thousands of the Pacific. ---
**Author:** ![Argent\_Towers](https://avatars.discourse-cdn.com/v4/letter/a/e8c25b/32.png) [@Argent\_Towers](https://boards.straightdope.com/u/Argent_Towers)\ **Post date:** [September 27, 2009, 9:01am UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/3 "2009-09-27T09:01:17Z")
The only way to test this is to get a Pacific Ocean-sized space, fill it with semen, and have someone swim across it. Now seeking volunteers. Come one, come all. ---
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [September 27, 2009, 9:05am UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/4 "2009-09-27T09:05:30Z")
I’m pretty sure the Japanese have done this, but not for scientific reasons. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [September 27, 2009, 1:42pm UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/5 "2009-09-27T13:42:22Z")
> [@Argent\_Towers](#): > > The only way to test this is to get a Pacific Ocean-sized space, fill it with semen, and have someone swim across it. Now seeking volunteers. Come one, come all. Wait, volunteers for swimming or for filling? ETA: Actually, either way, no. ---
**Author:** ![runcible\_spoon](https://avatars.discourse-cdn.com/v4/letter/r/9fc29f/32.png) [@runcible\_spoon](https://boards.straightdope.com/u/runcible_spoon)\ **Post date:** [September 27, 2009, 5:52pm UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/6 "2009-09-27T17:52:06Z")
> [@Argent\_Towers](#): > > The only way to test this is to get a Pacific Ocean-sized space, fill it with semen, and have someone swim across it. Now seeking volunteers. Come one, come all. What if we got a bunch of Insta-Semen (just add water!) and dumped it in the Pacific? 'Course, then we need volunteers to stir until mixed… ---
**Author:** ![Alex\_Dubinsky](https://avatars.discourse-cdn.com/v4/letter/a/dbc845/32.png) [@Alex\_Dubinsky](https://boards.straightdope.com/u/Alex_Dubinsky)\ **Post date:** [September 27, 2009, 8:48pm UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/7 "2009-09-27T20:48:00Z")
> [@Dervorin](#): > > However, it must be noted that sperm are swimming through a far more viscous medium than water, which I have no idea how to account for. Mythbusters did it! The viscosity slows you do down by the same factor that it makes it easier to push forward. But, considering their 80,000x smaller size (measuring linearly!), they don’t swim as we know it. Btw, sperm don’t have to swim 20cm. They just have to cross the cervix. ---
**Author:** ![Superhal](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Superhal](https://boards.straightdope.com/u/Superhal)\ **Post date:** [September 27, 2009, 11:12pm UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/8 "2009-09-27T23:12:34Z")
I have no doubts about the **stamina** of sperm, but I’m more interested if they flubbed the **speed** of sperm vs the force of ejaculation. ---
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [September 28, 2009, 2:05am UTC](https://boards.straightdope.com/t/questionable-claim-on-manswers-sperm-speed/511719/9 "2009-09-28T02:05:06Z")
> [@Alex\_Dubinsky](#): > > Btw, sperm don’t have to swim 20cm. They just have to cross the cervix. I think they need to get to the [fallopian tubes](http://www.wisegeek.com/what-are-fallopian-tubes.htm) not just cross the cervix