The equinox, when night becomes as long as day, will come on Wednesday September 22 (at 19h by Universal Time – 4 or more hours earlier by North American clocks that are still on Daylight Displaced Time). Tuesday evening will be a good time to contemplate the sky as the geometrical event called “equinox” is about to happen.
See the end note about enlarging illustrations.
In this wide view of the sky from east to west, geometries are interlaced!
The Sun (below the horizon) is at the point or “node” where its path, the ecliptic, crosses southward through the equator, the plane in which our planet rotates. The opposite node, 180° over in the east, is where the Sun will be six months later, at the March or northern “vernal” (spring) equinox.
Half way between is the December solstice point, where the Sun will be at its southernmost. Coinciding with that is the “antapex of Earth’s way,” away from which we are traveling; stands to reason, because it is 90° from the Sun.
And coinciding now with that other equinox point is the “anti-Sun.” You could call it Earth’s shadow; if the Moon happened to be at it, there would be a lunar eclipse.
To be there the Moon would have to be less than 25 hours back along its path – it was Full on Sep. 20 at 23:54 Universal Time. But even then it would miss the shadow, being in the half of its orbit that is south of the ecliptic.
Here is the spatial situation:
Shown are the planets’ paths in September. In yellow are sightlines to them from Earth at the date of the equinox. The Sun is exaggerated 4 times in size, the four inner planets 300 times.
It isn’t really the Sun that is arriving at the autumn equinox point; it is Earth that arrives at the vernal equinox direction – the dashed line with ram’s-horns symbol – and sees the Sun in the opposite direction.
Down to Earth Department
Anthony Barreiro has sent me a link to a San Francisco Chronicle article: “California’s recall system is an undemocratic mess. ‘Approval voting’ can help fix it.” Of approval voting, as you may remember, I’m a long-time advocate.
The article compares four electoral systems used in the US: plurality (the commonest), top-two, ranked choice, and approval voting -which lacks the disadvantages of the other three. It is the least used, so far, but is catching on: it’s been adopted by the cities of Fargo and St. Louis, with popular results. If California were to adopt it, it would be on its way!
A thing I didn’t know is that the correct term for the field of election science is “social choice.” The professional association in that field, the Society for Social Choice and Welfare, uses approval voting in its own elections, and “Several other science societies have followed the experts and adopted approval voting.”
You might also be fascinated to see the evidence, based on abundant polls, that the 2016 Republican nomination race would have ended differently if it had been conducted by approval voting. Trump, throughout that that time, never had the highest numbers of Republican voters who approved him, but there were 15 contenders, and they split the anti-Trump vote, in the way that plurality voting so often does.
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ILLUSTRATIONS in these posts are made with precision but have to be inserted in another format. You may be able to enlarge them on your monitor. One way: right-click, and choose “View image”, then enlarge. Or choose “Copy image”, then put it on your desktop, then open it. On an iPad or phone, use the finger gesture that enlarges (spreading with two fingers, or tapping and dragging with three fingers). Other methods have been suggested, such as dragging the image to the desktop and opening it in other ways.
Sometimes I make improvements or corrections to a post after publishing it. If you click on the title, rather than on ‘Read more’, I think you are sure to see the latest version.
This weblog maintains its right to be about astronomy or anything under the sun.
A late equinox being on the 22nd I’m glad that I read that as I’d assumed it was on the 21st and planned to visit the Star Disk at Scarborough, Yorkshire, England on the equinox….still will but a day out now! Suppose to be the largest Star Disk which is a map of the northern hemisphere skies in Europe if not the whole planet.
Is the December solstice point the antapex of the Earth’s way, or the apex of the Earth’s way? If you confirm that we really are heading away from that point, I’m going to have to turn my mental picture of the Earth’s orbit around the Sun inside out.
Do you know if approval voting has every been applied to policy questions?
Here in California we have lots of ballot initiatives in every election, and occasional referenda. These ballot measures are often deceptively worded to get people to vote for some emotionally compelling value while concealing the fine print which will benefit the wealthy special interests who paid to get the measure on the ballot. Voters only have the choice of voting yes or no. I have adopted a strategy of presumptively voting no on every initiative and yes on every referendum, until I have read the pro and con arguments with an open mind. The burden of proof is on the sponsor of the initiative or referendum to get me to vote their way.
I’m imagining a different system, where a particular problem is identified, there’s some formal brainstorming process to generate a range of potential solutions, and all the reasonable solutions are put on a ballot. Voters get to decide whether they would support each solution on its own merits. Then our elected representatives would try to craft a plan that integrates all the solutions that got widespread support.
The system you imagine would be an application of approval voting.
I don’t understand the difference between “ballot initiatives” and “referenda” and why you “presumptively vot[e] no on every initiative and yes on every referendum”.
An initiative proposes a new law (usually an amendment to California’s already ridiculously long Constitution, so it could only be amended by another vote of the general electorate). A referendum seeks to abolish an existing law. I start by assuming that I’m going to vote to keep things the way they are. Then I read the arguments pro and con, and consider which interest groups are supporting and opposing each measure, and change my mind only if I am affirmatively convinced to do so. There are a lot of initiatives that look very appealing on the surface, but when you get down into the fine print they’re either intentionally misleading, or well-intentioned but not well crafted.
Do you know of any real world examples of approval voting being used to set policy, or has it only been used to elect representatives?
By the way, I got my mental image of the Earth’s orbit around the Sun turned right way round again. That really is the antapex of the Earth’s way, where we see the waxing quarter Moon.
I don’t know of such examples. I would like to know, and I suggest you ask the Center for Election Science, which campaigns for AV, and draw their attention to the San Francisco article in case they don’t know of it. I hope this address works, if not google the CES:
aaronhamlin@electology.org
Your query about the direction of the antapex suggested to me that I build an indication of it into my 3D diagrams, which I will do when time allows.
Apparently “referendum” and “initiative” are defined differently in different places.
In California, a referendum is “A vote by the people to _approve_ or reject an existing law,” according to https://my.lwv.org/california/los-angeles/voting/ca-initiative-and-referendum-systems (So not exactly what Anthony said.) An initiative is “A brand new law or constitutional amendment and voted on by the people.”
But according to http://www.ncid.us/initiative_referendum “Referendum – The legislature refers a piece of legislation to the people to either approve or reject it by vote,” and “Referendum – The legislature refers a piece of legislation to the people to either approve or reject it by vote.” I believe that’s the definition that applies in Colorado, for example.
Regarding approval voting for policy issues, “Colorado law provides that in the event that two conflicting measures are approved, the measure with the most affirmative votes supersedes the other on any points of conflict. However, the other measure is not wholly superseded.” (https://ballotpedia.org/Laws_governing_the_initiative_process_in_Colorado) So that’s approval voting, approximately. I think it’s that way in most jurisdictions.
Here in California, in practice, a referendum is placed on the ballot by somebody who wants to repeal an existing law. A yes vote means you want to keep the law, a no vote means you want to repeal it.