# Why are tennis balls sold in hermetically sealed cans?

**URL:** <https://boards.straightdope.com/t/why-are-tennis-balls-sold-in-hermetically-sealed-cans/491410>\
**Category:** Factual Questions\
**Created:** [March 31, 2009, 12:13pm UTC](https://boards.straightdope.com/t/why-are-tennis-balls-sold-in-hermetically-sealed-cans/491410 "2009-03-31T12:13:06Z")\
**Posts on this page:** 1\
**Page:** 2

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**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\
**Post date:** [April 1, 2009, 11:02am UTC](https://boards.straightdope.com/t/why-are-tennis-balls-sold-in-hermetically-sealed-cans/491410/21 "2009-04-01T11:02:23Z")

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> [@CookingWithGas](#):
>
> I mean “pop off” like a champagne cork.  
> I mean “pop off” like the lid of a sealed Tupperware container in the microwave.  
> I mean “pop off” like the top of a botulism-infected can of Campbell’s.
> 
> I would at least expect a big “whoosh” of air coming out.

There IS a whoosh of air coming out. It’s just not as big a whoosh as perhaps you are thinking, given that the pressures aren’t so great. More like a “pssssst” really. 😛

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