If you were eating a soup from a bowl with 500ml of soup taking 25ml spoonfuls, and the rain replaced the volume that you ate at the same rate as you ate it, how many spoon fulls would it take for the soup to be completely replaced with water? Also, when that happens, would it still be the same soup?
If you assume it gets thoroghly mixed between spoonfuls:
(All maths done while in the bathroom, should be checked before used for soup science) At spoonful 14 you’ll have less than 50% soup in your rainwater.
At 45 you’ll be down to a 10% soup contamination of your delicious bowl of rainwater.
At just over 100 spoonfuls you’ll be down to less than 0.5%.
Just like when you’re shaving the pubes of a bear you’ll have to draw the line somewhere.
At one point you only have 1 molecule of “soup” left, and a 50/50 chance of getting it so statistically you might never.
My soup I’ve got for lunch today is guesstimated at 40-60% water pre-rain. So it could very well be indistinguishable from rain water long before a one molecule scenario.
I feel seen.
You get the upvote for shaving the pubes of a bear