ds1 (7) would like to know why snow, when it piles up on top of say a fence post, does so in a symmetrical yet curved manner....

[popsycal]

Any one oblige with an explanation?

It should be a square shape with sharp edges but maybe the edges fall off and become curves??? Ds knows that the edges collapse in on each other, falling off the sides.

wind?

there are sharp edges but curved

I cant explain
guess i oght to take a photo

you see I think there is some scientific explanation (eg some sort of static force....)

Maybe I am overthinking it

yes wind or creative squirrels

It's the wind, in't it?

The wind.

ds1 asks: but what if it isnt windy. Wold it be flat then?

Maybe it's because the temperature in the edges is slightly warmer then the temperature inside the snow itself. The structure of the inside stays fuller as the low temp maintains lots of space between the snowflakes whereas, the snow on the edges is slighly more compact because the air is slightly warmer, creating a curved appearance???

There is always some kind of air movement, if only slight.

This is what happens to sand in the desert.

Surface tension of water?

Miniscule drops of water are between the pieces of ice forming the snow, acting like a glue.

Then, the molecules are attracted to each other, so they naturally form the shape which minimises the number of them that are not surrounded by others.

Hence, the Curved shape at the top of the pile.

But, obviously, there is a limit to how wide the curve can hold on top of a narrow fence top, therefore the sides of the curve (or imagine a ball stuck on a fence!!) fall off, leaving the straight edges.

Going bac to the whole surface tension ball stuck on fence thing, this is why it is curved, yet symetrical, as the fence is a certain width and the curve can only hold the same amount on each side, if that make ANY sense at all??

That is my TOTALLY uneducated guess, and I am probably wrong, but hey, I tried!!!

get him to do his own experiment

If it was the wind it wouldnt be symetrical? Cause the wind is only coming from one direction?

The wind blows in many directions.

Ok ignore my straight edges thing, as I read wrong and though FENCE , not post, so hmm, but sphere theory and surface tension idea still holds, I think?? Natural tendancy due to the polarity of H2O to form a sphere??

Hang n I will ask DH, he is the nerdy one!!

BTW, this is gonna bug me now until someone comes up with the right answer!!