Sky Power Blog Post #9 — “Top o’ the Year” to You & Yours

Perihelion appearing on Lachine lakeshore in mid winter with snow and ice by the lighthouse, Quebec, Canada. Image by GIass and Nature
Perihelion appearing on Lachine lakeshore in mid-winter with snow and ice by the lighthouse, Quebec, Canada. Image by Glass and Nature.

Here’s to a great transition for you at this end + beginning of old / new trips around the sun …

“party fact” of note:

TODAY, January 2, 2024 (as I write this), we’re actually at our CLOSEST to the sun for the whole year . . . in fact, more than 3 million! miles closer than when we’re farthest away, in the first week of July! (Go figure! — The Earth’s seasons are an axis-tilt thing, rather than distance.) This point, at the closest-to-sun “end” of our annual slightly-elliptical orbit around the sun, is called “PERIHELION“. [ Our average distance from the sun is about 93 million miles, though — so the yearly variation is only a few percent. … + By the way, we are now moving around the sun at > 20 miles per SECOND. (frequent-flyer miles!) *** ]

blessed winter (summer-down-under), to us all ***

In the icy photo of spectacular scenery above — posted here at PERIhelion –we have two examples, left & right of the sun along that dawn horizon, of PARhelia (plural of “parhelion” = “BY-the-sun”) — a.k.a. “sun-dogs“:  They’re always at the same angle up in the sky as the sun (or along a horizontal line with the sun) — so they “dog” the sun! They, like the other two atmospheric-optical phenomena gracing this scene (more on those, below), are effects from the sun’s light rays interacting with (being “scattered” by) myriad tiny salt-grain-sized hexagonal ice crystals floating in the air. Each of the sun-dogs (parhelia) is 22 degrees to either side of the sun, as that’s the angle at which light refracts (or bends) through these 6-sided flat-plate ice crystals. The crystals whose scattered light makes up the sun-dogs, are oriented horizontally as they float & fall — with their flat faces facing straight up & straight down (and their thin edges firing bright colors of light in our direction!). … + why falling ice crystals don’t flutter ? : … Read on ! ***

That preferred horizontal-plane orientation results from the maximizing of aerodynamic stability as these crystals fall. Here’s a little home “flight experiment” to try: Just hold a credit card in the horizontal plane, with clean dry fingers, and then let it go: You may be surprised!, as I was, by what happens and what doesn’t, as it falls!) ***

The vertical shaft of light in the photo above is a “sun pillar“, created by reflections of the sunlight off the bottom horizontal flat-face surfaces of
the countless crystals that happen to be in the right place for you to see their glint. It’s an upside-down analogue to the path of setting-sun / moon reflection we’ve all seen on the top surface of the ocean or a lake — (that “highway of light” stretching across the waves from you toward the sun or moon).  

Finally, the “halo” (big circle in the sky) in the photo is again from that same kind of ice crystals — but randomly oriented, so their refracted light is not limited to those two special directions down where sun-dogs howl (astride the sun).

This is the year (a LEAP-year, too! — so I have one extra day to get it done!) for my science / art “Skyhenge” “year-clock” sculpture to finally be built & deployed at various latitudes on this planet. 

But for right now, this picture offers what I see as a different kind of “year-clock”:  At present we’re at the TOP (o’ the year to you & yours) — if we take northern-hemisphere winter solstice to be the top; and then those two sun-dogs mark both of the equinoxes.  

We’re all now beginning, yet again, a “re-cycling” in time***

 — Chronologically yours,
                                      Joe J.


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