I never believed that all of them could be different.
Considering that each individual snowflake is made of billions, or even tens of billions, of atoms, the fact that they are not identical is not all that surprising. There are so many different ways you can arrange 10,000,000,000 atoms that you could make the entire earth out of snowflakes and still never have any duplicates.
do people really sit around, pondering whether or not there are two snowflakes that are identicle?
Yes--because it has huge implications for physics, material science, and even things like electronics.
A water molecule is very simple, and contains only three atoms--one oxygen and two hydrogen. It forms crystals according to very simple rules--the hydrogens of each molecule want to be close to the oxygen of the neighboring molecules while at the same time being as far as possible away from the hydrogen of neighboring molecules.
That very, very simple rule has significant real-life consequences--it means that water crystals will always have six sides (that's how many water molecules can form together in a group before the hydrogens become too close to each other). But it ALSO means that there are literally trillions of ways to arrange those six-sided crystals.
Many, many things in the real world, from computer chips (which are made from crystals of extremely pure silicon) to the lasers in a DVD player (which are made from crystals that contain tiny "voids" in them just barely big enough for an electron to fit into--when an electron falls into one of the spaces in the crystal, it releases a photon of light, and that is how the laser works) rely on understanding the ways that materials operate when they form crystals, and rely on understanding how the same materials can form crystals with different shapes and different properties.
Water is one of the simplest of all molecules, and obeys incredibly simple rules for forming crystals, yet the way those rules work together, it's possible to form trillions of crystals with different shapes. This can give you insight into how difficult it can be to predict and control the crystalline structure of materials even when the rules that govern the crystals are very simple. Because so much modern technology relies on understanding and controlling the way crystals of very pure material form, and being able to predict and control the structure of the crystal right down to the level of individual atoms, the way snowflakes are made is very important to a great many people.
