Manual of Life - Things You Didn't Consider Till You Did #32

When you pee during really cold weather (near-freezing or below), why does it steam on impact?

Sure, there's a difference of 35C difference or more between the fluid from within your body and the surface it falls on, but water (which makes up 96% of urine) evaporates at 100c. So why can you still see vapours?

Bonus question:
Is water the only thing being evaporated?

I had a couple more India posts, and I'd hoped to wrap them up in January, so we could return to regular programming this month. But I obviously don't draft them when I should, and then tinker too much with them when I should post, so here we are.


Anonymous said...

Is it the urine steaming? Or is it a condensation of moisture in the air along the hot stream, sort of like contrails?

km said...

I am guessing it is condensation, as the anonymous commenter pointed out.

Shyam said...

On impact with what? And also, is this a boys-only post? :)

??! said...

Impact on the surface you're peeing on, baba. And please, we're an equal-opportunities blog.

This is a good point. One shall have to conduct experiment more closely (the things we do for science...)

Shyam said...

But see, if it was below freezing, us ladies would most likely not be anywhere outside peeing into anything that steams :) That's what I meant by "boys-only" :D