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Old 09-29-2019, 11:58 PM
guizot is offline
Join Date: Mar 2005
Location: An East Hollywood dingbat
Posts: 8,818
Originally Posted by am77494 View Post
So imagine air to be tennis balls and water vapor to be marbles. Imagine you have a container with 100 tennis balls. Now imagine that you add the marbles to fill up the space between the tennis balls.

As you probably understand, the space between the tennis balls expands when the temperature goes up, so you can fit more marbles at a higher temperature..
Why do you make the bolded assumption? That's where your explanation loses your grandmother. Sorry.

A lot of the explanations here have statements like this which make assumptions or take things for granted, and thereby make the explanations fail.
". . . it measures how much moisture the air can hold relative to the current temperature. So 90% humidity when it's hot out is a lot more water than 90% humidity when it's cold out . . ."
What is that supposed to mean? How much it can hold? Or does hold? And if it's more water, then why have the same measurement? What's the point?
" . . .the amount of water vapor in air, relative to (usually as a percentage of) the amount of water vapor that would barely start to condense out of air, given a flat water surface to condense on . . ."
Water condensing on a "flat water surface"? What is that supposed to mean? How do you differentiate between the the water forming the surface itself and the water condensing? How does water condense on water? And why do we want to measure that?

This is not to say the explanations are wrong--just rhetorically faulty.

Last edited by guizot; 09-30-2019 at 12:00 AM.