Once in a Blue Moon

Super Moon image from https://commons.wikimedia.org/wiki/File:Supermoon.jpg

Tonight we will have a Super Moon, as we will next month and the month after that. But the third one is special because it  will also be lined up for a lunar eclipse. But wait, that's not all that's special about the January 31, 2018 full moon. It falls under the designation of a Blue Moon -- at least in one sense. 

"Once in a blue moon." How often is that? about every 2 1/2 years, though whether you'd say 2.5 or 2.7  depends on which definition you use for blue moon, .

From the time I looked it up some years ago, I considered the blue moon to refer to the second full moon in a solar calendar month. (Obviously, lunar calendars are designed to have only a single full moon in a month). However, today I looked it up and found that it also had another meaning that is a bit more precise, though not as commonly used today.

From https://www.space.com/15455-blue-moon.html

The older meaning defines a Blue Moon as the third full moon in a season that has four full moons. Called a seasonal Blue Moon, this occurs about every 2.5 years, according to NASA. Why the third moon? There are roughly 29.5 days between full moons, making it unusual for two full moons to fit into a 30- or 31-day-long month. 

Accordingly, what fits a blue moon definition in one sense may not fit it another. The seasonal blue moon last occurred on May 21, 2016. But a blue moon measured by month rather than by season can only occur at the very end of the month, and that is said to occur about every 2.7 years.

Here's the infographic from: https://www.space.com/16776-blue-moon-explained-infographic.html

This particular terms has evolved into multiple meanings that deviate quite a bit from the strictly astronomical.  Space.com link brought me to : http://www.skyandtelescope.com/observing/once-in-a-blue-moon/, which traces the terms through various meanings, including some specific to songs. The earliest it finds is an expression of absurdity that then came to mean never:

like saying the Moon is made of green cheese. Both were obvious absurdities, about which there could be no doubt. "He would argue the Moon was blue" was taken by the average person of the 16th century as we take "He'd argue that black is white."

 The concept that a blue Moon was absurd (the first meaning) led eventually to a second meaning, that of "never." The statement "I'll marry you, m'lady, when the Moon is blue!" would not have been taken as a betrothal in the 18th century.

 Then there were times when the moon actually appeared blue, as a result of huge amounts of ash in the air from volcanoes or fires.

So, by the mid-19th century, it was clear that visibly blue Moons, though rare, did happen from time to time — whence the phrase "once in a blue Moon." It meant then exactly what it means today, a fairly infrequent event, not quite regular enough to pinpoint. That's meaning number four, and today it is still the main one.

However, from an astronomical point of view, the blue moon did come to mean something more specific, though the way we tend to use it today -- the definition I taught my own kids -- seems to find its roots only as far back as the 20th Century. 

One striking fact for those of us who are familiar with lunar calendars is how the frequency of blue moons dovetails with leap months, namely 7 times in every 19 year cycle. The Chinese calendar adds a leap month about once every 3 years, and the the Jewish calendar is set to haves 7 leaps years every 19 years.   

Halloween economics, or what your view of trick or treating says about you

This is uncommon for me because it is an  an argument in memes. I started out posting this on G+, but that platform is very bad for featuring pictures. So I decided to put it here.
Disclaimer: I don't do Halloween and find the threat implied in the whole trick or treating approach to emulate an extortion racket rather than a sustainable economic system of any kind.

A few years ago, I came across this cartoon:

 One on the same theme was this:

 This year someone posted one that tried to go the other way, namely that trickle down economics withhold candy:

That image is actually not nearly as effective as this one:

or even this one:

I'm not here to defend trickle-down economics as a system, but as I was thinking about the various memes, I had this epiphany: Socialism is the ultimate trickle-down economic system. You allow a single organization to take individual wealth in the form of high taxes and then distribute it as it sees fit. That is exactly the idea of this illustration:

In fact, what would happen is that while taking the candy that is supposedly to be redistributed, all the hands that pass it on drop some or deliberately transfer some to their own pockets. That is an inevitable cost of such systems of distribution. 

Of course, extreme positions are just that, and there are many Republicans who are not in favor of trickle-down economics, and many Democrats who don't embrace Socialism. Each side likes to show the most extreme form of the other while ignoring its own.

But anyone who presents the notion of fairness being that people do reap the fruits of their labors as a new-fangled Republican idea is ignoring literature that dates at least as far back as oh, 600 BCE or so, when Aesop's fables were composed. You can read The Ant and the Grasshoppper  online to understand how deeply rooted that sentiment is in culture. You can read also read  the 1918 version of The Little Red Hen online.

That story came up in one M. Sott Peck's books. He said that he had first considered it unChristian because it seemed to indicate a lack of charity, but he came to realize that the lesson of self-reliance, the obligation to do what one can  applies not just to material things.