no

It's not an external cause. It boils on its own, because the molecules don't want to be close together.

You should be an astronaut

I'd still say it's spontaneous because when you reduce pressure you're removing a factor rather than adding one. It's like saying "when you compress a spring and then remove the compression force, it will spontaneously return to its previous length." Water vapor can be seen as water's "natural" state when thero no pressure forcing it to be a liquid. Also saying "simple thermo" to an astronaut is definitely mansplaining, because it implies the other person doesn't know that simple thermo. Maybe it's just pedantry, but in that case damn that's some terrible phrasing.

This post isn't showcasing mansplaining. It's showcasing pedantry.

Just like this comment!

“Spontaneous” is actually the correct word to use here, using its definition in statistical mechanics.

Here’s an example: https://principlesofchemistryopencourse.pressbooks.tru.ca/chapter/5-6/

While you are technically correct, you also misunderstand who the target audience is and what language is required to actually make people understand.

When speaking to a normal person you don’t want to slap random jargon and care too much about precise definitions. So in that context spontaneous is a great word to describe what is happening. People without deep backgrounds in the field will not understand technical jargon and it will only make them not pay attention.

Spontaneous doesn't mean "happens suddenly without explanation" what are you on about?

Everything has a cause.

I agree, it really is showcasing pedantry. That man is just an asshole, not a misogynistic asshole. To me, this thread is full of confirmation bias. People who want to see what they personally believe, not objective reality.

Hahaha, under that definition not spontaneous can ever occur