# If you can't hear sound in a vacuum... **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [June 27, 2002, 2:06am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151 "2002-06-27T02:06:56Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Dr.Strangemind](https://avatars.discourse-cdn.com/v4/letter/d/dbc845/32.png) [@Dr.Strangemind](https://boards.straightdope.com/u/Dr.Strangemind)\ **Post date:** [June 27, 2002, 2:06am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/1 "2002-06-27T02:06:56Z")
why are vacuum cleaners so darn noisy? 😃 I had to ask. Dr. Strangemind ---
**Author:** ![Reeder](https://avatars.discourse-cdn.com/v4/letter/r/c6cbf5/32.png) [@Reeder](https://boards.straightdope.com/u/Reeder)\ **Post date:** [June 27, 2002, 2:09am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/2 "2002-06-27T02:09:40Z")
4-3-2-1… ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [June 27, 2002, 2:22am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/3 "2002-06-27T02:22:45Z")
If it’s dirty, it’s not a true vacumn, chowderhead. ---
**Author:** ![Junchbailey](https://avatars.discourse-cdn.com/v4/letter/j/ea666f/32.png) [@Junchbailey](https://boards.straightdope.com/u/Junchbailey)\ **Post date:** [June 27, 2002, 4:05am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/4 "2002-06-27T04:05:10Z")
“why are vacuum cleaners so darn noisy?” That’s exactly what I thought when I clicked on this thread. Good minds think alike I guess. ---
**Author:** ![Happy\_Lendervedder](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/happy_lendervedder/32/8488_2.png) [@Happy\_Lendervedder](https://boards.straightdope.com/u/Happy_Lendervedder)\ **Post date:** [June 27, 2002, 4:24am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/5 "2002-06-27T04:24:00Z")
> [@](#): > > why are vacuum cleaners so darn noisy? Does this really need to be answered? It’s the motor. Happy ---
**Author:** ![heresiarch](https://avatars.discourse-cdn.com/v4/letter/h/278dde/32.png) [@heresiarch](https://boards.straightdope.com/u/heresiarch)\ **Post date:** [June 27, 2002, 7:15am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/6 "2002-06-27T07:15:06Z")
You weren’t actually IN the vacuum, now were you? duh. ---
**Author:** ![BrandonR](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@BrandonR](https://boards.straightdope.com/u/BrandonR)\ **Post date:** [June 27, 2002, 7:23am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/7 "2002-06-27T07:23:56Z")
What’s sadder, the question or the people who take the question seriously? I choose the latter. 🙂 ---
**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:** [June 27, 2002, 11:58am UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/8 "2002-06-27T11:58:37Z")
**In Space, No One Can Hear You Clean** ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 27, 2002, 12:04pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/9 "2002-06-27T12:04:09Z")
I took my vacuum cleaner back to the shop in disgust; when I opened the box there was clearly a great deal of matter in there. ---
**Author:** ![Big\_Sam](https://avatars.discourse-cdn.com/v4/letter/b/df788c/32.png) [@Big\_Sam](https://boards.straightdope.com/u/Big_Sam)\ **Post date:** [June 27, 2002, 12:25pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/10 "2002-06-27T12:25:49Z")
It’s because you were using it to clean your carpet. Vacuum cleaners should be used to clean vacuums only! ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 27, 2002, 12:36pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/11 "2002-06-27T12:36:42Z")
How does a vacuum get dirty, anyway? ---
**Author:** ![femtosecond](https://avatars.discourse-cdn.com/v4/letter/f/f08c70/32.png) [@femtosecond](https://boards.straightdope.com/u/femtosecond)\ **Post date:** [June 27, 2002, 12:57pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/12 "2002-06-27T12:57:48Z")
Interstellar dust. Duh. ---
**Author:** ![Delta-9](https://avatars.discourse-cdn.com/v4/letter/d/3be4f8/32.png) [@Delta-9](https://boards.straightdope.com/u/Delta-9)\ **Post date:** [June 27, 2002, 1:02pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/13 "2002-06-27T13:02:47Z")
> [@](#): > > \*Originally posted by heresiarch \* > \*\*You weren’t actually IN the vacuum, now were you? duh. \*\* Reminds me of an old Steve Martin routine. . . ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 27, 2002, 1:17pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/14 "2002-06-27T13:17:31Z")
I fancy doing it the old-fashioned way; where can I buy an interstellar duster? ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [June 27, 2002, 1:50pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/15 "2002-06-27T13:50:15Z")
Why? Because they suck. They suck. If they didn’t suck, they’d blow. ---
**Author:** ![cornflakes](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@cornflakes](https://boards.straightdope.com/u/cornflakes)\ **Post date:** [June 27, 2002, 2:06pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/16 "2002-06-27T14:06:15Z")
I’m just torr up over whether I should post a serious answer to this thread. Since a few physicists have already posted, I think I’ll pass. Cal? ---
**Author:** ![femtosecond](https://avatars.discourse-cdn.com/v4/letter/f/f08c70/32.png) [@femtosecond](https://boards.straightdope.com/u/femtosecond)\ **Post date:** [June 27, 2002, 2:41pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/17 "2002-06-27T14:41:23Z")
> [@](#): > > I fancy doing it the old-fashioned way; where can I buy an interstellar duster? You’re right. You still would need something to reach between the ribs of the cosmic microwave background radiator… > **[Why is a table saw quiet but a circular saw loud?](https://home.howstuffworks.com/question338.htm)** > > Circular saws can be so loud that a person may have to wear hearing protectors whenever using it. Vacuum cleaners are also as loud as a jet engine. How can a 30-inch table saw be so much quieter than a circular saw? So. Now somebody close this thread! ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [June 27, 2002, 11:09pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/18 "2002-06-27T23:09:57Z")
GQ is for questions you actually want a serious answer to. Jokes go in MPSIMS. This thread is closed. bibliophage moderator GQ ---
**Author:** ![TubaDiva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tubadiva/32/507_2.png) [@TubaDiva](https://boards.straightdope.com/u/TubaDiva)\ **Post date:** [July 8, 2002, 6:19pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/19 "2002-07-08T18:19:14Z")
Oh, what the heck, let’s move this to MPSIMS and see where it takes us. “Space, the final frontier – of cleaning.” your humble TubaDiva Administrator Fighting valiantly not to make the standard Uranus joke. ---
**Author:** ![Hoopy\_Frood](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hoopy_frood/32/8452_2.png) [@Hoopy\_Frood](https://boards.straightdope.com/u/Hoopy_Frood)\ **Post date:** [July 8, 2002, 9:08pm UTC](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151/20 "2002-07-08T21:08:29Z")
Simple. See, the reason a vacuum consists of essentially nothing is because the cleaner has come along and taken everything out of it. All the noise that would exist in the vacuum has been transferred to the cleaner. What you hear from the cleaner is what you would here in the vacuum if the cleaner hadn’t gotten there first. Problem is, due to the funny way quantum mechanics works, it is impossible to actually find a vaccuum before the vacuum cleaner gets to it, therefore, the cleaner has already done its work. By the time you reach the vaccuum, it all seems eerily silent, and the cleaner seems noisy. I would show the calculations involved that determine the point at which a cleaner shows up after a vaccuum is created, but they’d be way to complex for you to understand. [Next page](https://boards.straightdope.com/t/if-you-cant-hear-sound-in-a-vacuum/116151.md?page=2)