Snow: Seven questions, seven answers about snow
Winter in the country. And with snow this time! Fun to play in, to make snowballs and to bite at the falling snowflakes. But, how is snow actually formed and why is snow white? Is snow as pure as it looks? Are all snow crystals the same shape and are they all identical? Is snow cold or warm? Who is the Snowflake Man? Learn about snow and snow crystals in 7 questions and 7 answers.
Why is snow white?
When snow melts, all that’s left is water. Water is translucent, so why does snow look white? Because snow consists not only of frozen water, but also of tiny air bubbles. The rays of light that fall into the snow are scattered by the thousands of squares of the crystals, making the snowflakes appear white, although they don’t actually have their own color.
Are all snow crystals equal?
No, all snow crystals are not the same in shape, but they do have one thing in common: they all have six arms or leaves. Ice crystals that form between -4 and -6 ° C always have a hexagonal symmetrical shape. The growth is greatest on those six arms due to new freezing water droplets.
How does snow form?
Small dust particles form the basis
Without dust in the air, we wouldn’t have snow. Dust should not really be taken literally, it can also be salt, sand, clay or volcanic ash. An ice crystal grows around those microscopic dust particles, which are called grafts (or freezing core or crystallization core).
Ice crystals become snowflakes
Ice crystals are always hexagonal. This ice crystal, together with hundreds of other crystals, forms a snowflake, because the crystals stick together. There are about 4000 crystals in a snowflake of 4 cm. The snowflake grows until it becomes so heavy that it swirls down. Snowflakes fall at a speed of 3 to 5 kilometers per hour. Sometimes they stay in the air for hours before they hit the ground. In their fall, the snowflakes still carry dust particles with them.
So snow is actually an air purifier. There is a saying that says snow is the poor farmer’s dung. People who enjoy eating or snapping snow are therefore warned. Snow is not at all as pure as it looks!
What shapes do snow crystals have?
Snow experts distinguish seven important basic shapes of snow crystals. The ideal temperature for their development is -12 to -15 ° C.
- the prism measure: a column that can be hollow or full
- the picture: this is a flat hexagon
- the needle: a kind of straw
- the asterisk: a very simple hexagonal shape, without too many decorations, with thin arms
- the dentrietje or tree: the most known and drawn form of ice crystal. The hexagon with beautiful arms
- the sector image: a full hexagon without too many decorations, with thicker arms
- the irregular shape: chunks that are not actually connected to each other
Who took the first picture of a snow crystal?
An American farmer from Jericho, Vermont, named Wilson A. Bentley (1865-1931). He put together a microscope annex camera and took the very first photo with it in 1885. After that, he made no less than 5,000 micro-images of snow crystals in 40 years. He is therefore called the Snowflake Man. The Snowflake Man claimed that no two were the same snow crystals, but that theory has since been refuted by scientists who have seen two identical snow crystals under their microscope.
Is snow cold or warm?
Snow is quite warm. That’s because there is a lot of air in snow. You can compare it a bit with a down blanket. This is how the cold from above the snow does not penetrate into the ground. Animals underground, such as mice, worms and moles, for example, can continue to live under the protective snow carpet. Also roots, bulbs and tubers of plants do not freeze. Everything under the ground continues to grow and bloom slowly.
Why does snow creak when you walk on it?
Above – 10 ° C, snow does not crack. Below – 10 ° C the snow will crack when you walk over it, because you then kick the ice crystals to pieces. And that gives a crackling sound.
And just this: dirty snow melts faster than clean snow. So quickly get out your camera and quickly take a few snapshots before all that beauty gets dirty and disappears again!