Wednesday, December 29, 2010


What is the shape of a drop of water?
If you Google that question, you'll find a Wikipedia answer
with much more information than most people will ever need.
Farther down the search page, the same question is posed 
by a nine-year-old to Bob Trach of Argonne National Laboratories
in a series called, "Ask a Scientist."  His answer is more my speed.

Contrary to popular misconception
a free-falling raindrop is not shaped like a teardrop--
round on the bottom and pointy on the top.

If the falling drip is small enough, it is a perfect sphere.
A sphere is the geometrical shape that has
the smallest surface for its volume.
The drop takes this shape because water molecules
tend to stick to each other.  So, when not confined by a container,
and with nothing around it to distort its shape,
a very tiny water drop is perfectly round like a ball
because the water molecules are pulling inward toward each other.

If the drop is larger like a raindrop in free-fall,
it has a domed top and a semi-flattened bottom
because as it falls it must push the air out of it's way.

Photos taken recently through my window 
during a rare sunny day with temperatures above freezing.


Flea said...

Sweet! Thanks for the info on drops! Makes total sense.

Anairam said...

Well, I have learnt something now! Perhaps we think of it as a teardrop shape because as it detaches from an object, like from your icicle (is it an icicle?) on the left, it starts of as a teardrop shape for just that instant?
PS I am thinking of all those poor kiddies who are going to have to change their way of drawing rain. Hahaha, an entire shift is going to have to take place in art education!

Pearl said...

I love information like that.


Sarah said...

I knew this but only from recently. Until then I had thought they were raindrop shaped!

Linda Sue said...

Reluctant to acknowledge...WATER water everywhere. We have it sort of under control at the moment- wondering about the bridges in Australia, however. So - rain is ROUND! hmmmrumph.

TALON said...

I have to confess I noticed the unspherical shape of raindrops as a child...funny how we romanticize imagery, isn't it? And yet science is always there to remind us that certain things are actually physically impossible. Loved your drop shots...which is making me laugh as it sounds more like a basketball reference! :)

(and now I know where the sun's been hanging out! We haven't seen a trace of it in days!)

Maude Lynn said...

Cool shots!

Anonymous said...

Isn't it amazing what you can learn from reading blogs!! Happy New Year!!

Regina said...

Oh too much!! Lovely drops and free falling thoughts- Wishing you a warmer, cozy and especially fuzzy New Year my dear!!

kendalee said...

Fascinating and what gorgeous photographs! I wonder if drawings of raindrops are that shape just so that we don't mistake them for balls or tiny helmets?

Wishing you a very happy New Year and may it continue throughout 2011! With love and thanks for your company on the 2010 journey - it has made all the difference to me.