Natural Philosophy – Page 2 – The Celestial Monochord

The Revolution Will Not Be Heavenly

Today, I bought a copy of Nicolaus Copernicus’ book, On the Revolutions of the Heavenly Spheres, in an edition edited by Stephen Hawking. The original 1543 book helped inspire people to give up the idea that the Earth was the center of the Universe, and that the Earth circles the Sun, not visa versa.

As I understand it, the change was such a shock and so deeply altered the way people saw the hierarchy of things, in both the heavens and on Earth, that for centuries, whenever people talked about similar upheavals, they would call them another Revolutions, meaning Copernicus’ book. After a while, the association of the term with the book got forgotten — hence the word “revolution”.

Trouble is, in the original title, De revolutionibus orbium colestium, the word means “spinning around and around in circles,” as in, “the going around of the celestial orbs.” So the root word of “revolution” is not “revolt,” it’s “revolve” — to wind up exactly where you started and have to do it all over again.

And all too often, that’s how revolutions have gone, at least outside of science. You wind up with the same cast of characters, at best, and you have to stage another revolution, over and over and over.

I swear, the fact that this is Tax Day is PURE COINCIDENCE!

World’s Largest Banjo?

I know what you’ve been thinking: “When is he gunna tell me about the world’s biggest banjo?”

Well, unreliable sources claim that an object in Branson, Missouri is the World’s Largest Banjo, but I doubt it’s a real banjo. To qualify as a true banjo, you need vibrating strings and you need these vibrations to be transmitted to a membrane via a bridge for the purpose of amplification. A website describing Branson’s disturbing monstrosity makes me suspect that what they have there is a mere sculpture of a banjo:

“The neck holding five fiber optic strings is 47-feet long. A true replica of a collectible Gibson banjo, the huge fiberglass shell has a sturdy frame of over 3,000 pounds of steel.”

Perhaps Gibson’s factory in the Opry Mills Mall in Nashville (top) holds the record instead. The search continues … By the way, see Cecilia Conway’s book for an extensive analytical treatment of the features that constitute the essence of a banjo.

Sundogs and Sweet Angles

Sundogs (and Sun)

Astronomy has always been my first love, so people sometimes ask me what causes sundogs, rings around the sun or moon, light pillars, etc. I used to say, “Uh, it’s ice crystals.” That seemed to satisfy most people. But when I read the book “Rainbows, Halos, and Glories,” I learned what it really meant — how, exactly, ice crystals cause the various spots, arcs and rings you see in the sky from time to time. Suddenly the whole sky really came alive for me all over again.

Sundogs are the colorful spots you sometimes see on either side of the sun:

Sundog Sun Sundog

* O *
______________________________________ horizon

They’re caused by ice crystals shaped like hexagonal plates — like thick-ish stop signs, miniaturized. These little hex plates fall through the air with their faces parallel to the ground. So, picture billions of tiny quarters made of ice, all falling either “heads” or “tails”, not standing on the edge.

As they fall, the sun reflects off their faces and edges, and also passes through them making prismic colors (or not), depending on the angle of the sun and the angle from which you view them. There’s one particular angle that’s really sweet — an angle at which the sunlight passes horizontally right into the edge, along the plate’s face, and with the plate rotated “just so”. At that angle, the ice crystal passes a nice rainbow through itself.

Towards a certain direction in the sky, all the crystals that happen to be in this orientation “light up” that part of the sky. The direction works out to be about 22 degrees to the left and right of the sun:

* 22deg O 22deg *
_______________________________________

It turns out that various other angles are also “sweet” for different reasons. And ice crystals can have different shapes — for example, hexagonal cylinders, like pencils — which, in turn, creates a huge variety of wild arcs and rings and spots, which you can see if you are both lucky and alert.

Visit Les Crowley’s beautiful site on Atmospheric Optics or read “Rainbows, Halos, and Glories.”