# Helium balloons falling down

**URL:** <https://boards.straightdope.com/t/helium-balloons-falling-down/51675>\
**Category:** Factual Questions\
**Created:** [January 25, 2001, 4:58am UTC](https://boards.straightdope.com/t/helium-balloons-falling-down/51675 "2001-01-25T04:58:48Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![spiffo](https://avatars.discourse-cdn.com/v4/letter/s/bb73d2/32.png) [@spiffo](https://boards.straightdope.com/u/spiffo)\
**Post date:** [January 25, 2001, 4:58am UTC](https://boards.straightdope.com/t/helium-balloons-falling-down/51675/1 "2001-01-25T04:58:48Z")

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Guys,

why do helium balloons eventually come down from the ceiling, as apposed to staying up there forever? Dr Beckril from 1st year Physics in the back of my mind is shouting osmosis, but I am not listening.

Spiffo

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**Author:** ![rpinrd](https://avatars.discourse-cdn.com/v4/letter/r/b3f665/32.png) [@rpinrd](https://boards.straightdope.com/u/rpinrd)\
**Post date:** [January 25, 2001, 5:17am UTC](https://boards.straightdope.com/t/helium-balloons-falling-down/51675/2 "2001-01-25T05:17:27Z")

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Leakage I’d guess. Perhaps including osmosis, but not necessarily limited to just that.

Your typical Pikachu Mylar helium balloon is not exactly a precision scientific instrument. I assume those seems, and the throat of the balloon, leak. Helium escapes, buoyancy lost, balloon comes down.

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**Author:** ![sethdallob](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@sethdallob](https://boards.straightdope.com/u/sethdallob)\
**Post date:** [January 25, 2001, 5:39am UTC](https://boards.straightdope.com/t/helium-balloons-falling-down/51675/3 "2001-01-25T05:39:43Z")

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> [@](#):
>
> \*Originally posted by rpinrd \*  
> **Your typical Pikachu Mylar helium balloon is not exactly a precision scientific instrument.**

_laugh_

Anyway, it is leakage through the neck (not osmosis).

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**Author:** ![spiffo](https://avatars.discourse-cdn.com/v4/letter/s/bb73d2/32.png) [@spiffo](https://boards.straightdope.com/u/spiffo)\
**Post date:** [January 25, 2001, 5:43am UTC](https://boards.straightdope.com/t/helium-balloons-falling-down/51675/4 "2001-01-25T05:43:13Z")

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OK OK, what about in cases where the balloon does not get much smaller?

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**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\
**Post date:** [January 25, 2001, 5:59am UTC](https://boards.straightdope.com/t/helium-balloons-falling-down/51675/5 "2001-01-25T05:59:24Z")

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There’s a good discussion of this topic in [this old GQ thread](http://boards.straightdope.com/sdmb/showthread.php?threadid=14309)

Arjuna34