# Stupid (?) question: How do planes really fly?

**URL:** <https://boards.straightdope.com/t/stupid-question-how-do-planes-really-fly/1029890>\
**Category:** Factual Questions\
**Created:** [May 7, 2026, 2:37pm UTC](https://boards.straightdope.com/t/stupid-question-how-do-planes-really-fly/1029890 "2026-05-07T14:37:34Z")\
**Posts on this page:** 1\
**Showing post:** 68

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**Author:** ![Humbagger](https://avatars.discourse-cdn.com/v4/letter/h/db5fbb/32.png) [@Humbagger](https://boards.straightdope.com/u/Humbagger)\
**Post date:** [May 20, 2026, 8:49pm UTC](https://boards.straightdope.com/t/stupid-question-how-do-planes-really-fly/1029890/68 "2026-05-20T20:49:21Z")

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> [@Raza](#):
>
> air “doesn’t care” and has no incentive to flow faster.

> [@DesertDog](#):
>
> what motive the top-side air had to accelerate so it wound up even with the bottom-side, shorter path air again.

> [@how airplanes fly.](https://boards.straightdope.com/t/how-airplanes-fly/847658/24):
>
> If the molecules that take the longer path didn’t catch up to those that took the shorter path, you’d end up with a mass imbalance.

Not only does the top side air play catch up, for reasons explained in this thread, it can easily overtake the bottom side air:

[https://youtu.be/UqBmdZ-BNig?si=Phk82263zxGNh7am](https://youtu.be/UqBmdZ-BNig?si=Phk82263zxGNh7am)

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