We've all heard it said before that no two snow flakes are alike.
I have always had trouble believing this entirely. Sure, it could be true, but I do not think there's anyway we could ever prove this, and therefore, I think we must consider that it just might be incorrect.
In order to prove that no two snowflakes are alike, we'd have to have some kind of database like Afis that has cataloged in it every snow flake that was ever generated. Obviously not possible since every snow flake I've encountered is in some other form right now, be it water or vapor.
According to WikiAnswers, a typical snowstorm can produce anywhere from 20 to 300 trillion flakes of snow, depending on the intensity of the storm. To give you some idea of the magnitude of 20 to 300 trillion, in 2008 there were 6.69 billion people on earth. That means each person on earth could have 44.8 thousand snowflakes to themselves. I might be wrong, my math skills were never very good...
I'm finding a lot of conflicting information in my quick little Google research project on the number of snow flakes per storm and such, so I'm just going to pretend my numbers are perfect from here, and say also that we're only talking about one storm.
Look, there are a lot of snowflakes! There's no possible way to prove that they are all completely unique, so I call shenanigans on this "fact". If you can prove me wrong, I'll gladly bow to you. Until then, I say it's BS.