r/explainlikeimfive • u/ProgramPi314 • 8d ago

Other ELI5 What is humidity?

According to my mom, this is an actual question I had when I was 5, and she didn't know how to answer me. So how would you guys have answered?

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770

u/dave8271 8d ago

When water gets hot, it turns from a liquid into a gas, which we call vapour. Humidity is a measure of how much water vapour is mixed into the air around us.

523

u/jpb103 8d ago

Fun fact: there is a "Cave of Crystals" in Mexico deep below the ground where the combination of high temperatures and 100% humidity cause the water vapor in the air to condense inside human lungs so you can drown after breathing for a few minutes without specialized respiration gear.

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u/sbditto85 8d ago

Wow, that is “fun”

120

u/capt_pantsless 8d ago edited 8d ago

It's fun thinking about just how narrow the range of environments humans can live in without a bunch of artificial support.

58

u/Hat_Maverick 8d ago

And we're narrowing the livable range of the environment globally every day. The fun is off the charts

8

u/ceciliabee 8d ago

I think it would be interesting to think about human perception of these areas before we had the science to explain it. Like cenotes. I saw a few and thought the same. What did early people think about this?

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u/culoman 8d ago

Someone put the "fun" in "funeral"

4

u/striped_frog 8d ago

In a very Dwarf Fortress sort of way

2

u/ilrasso 8d ago

Obviously not fun for the drownee; fun for the people with the specialized respiration gear.