Not as close as they appear

This evening’s sky. The beautifully  crescent Moon has passed south of Pollux and is about to come into a straight line with the two Twin stars.

The appulse – the moment of smallest apparent distance between Pollux and the center of the Moon, as viewed from Earth’s center – is May 12 23h by Universal Time, which is 4, 5, 6, 7 hours earlier by clocks on “daylight-shifting time” in North America’s Eastern, Central, Mountain, and Pacific time zones.

And the minimum separation between Pollux and the Moon’s center was 1.60°. But that, too, was geocentric – as if viewed from the Earth@s center, the way calculations have to be made. From our position on Earth’s northern hemisphere, the Moon is displace somewhat southward, so the separation is greater (the effect called parallax).

Much of this – what viewpoint you are talking about, whether you are talking about angular or linear distances between objects, the Moon’s sunlit shape and its solid shape –  is part of “The Apparent versus the Real,” a distinction so useful to keep in mind that we are making it the opening chapter in the new Astronomical Companion. Just now I’m trying to think up a sketch to illustrate it.

Maybe one of the many cartoons on the theme of “Objects in mirror are closer than they appear”?

__________

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” or ”Open image in new tab”, 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.

 

2 thoughts on “Not as close as they appear”

  1. I just stumbled upon your work. I very recently became enlightened and am currently… lost quite frankly. If trying to rediscover our… roots I guess. From looking up ancien games like ‘real’ tenez and 2eyed cat, to trying to find ‘homelands’ or themes through various written tex and ‘petrified’ relics. I keep confusing folk. I was trying to make a parrelel based on renaming ‘communism’ ‘columnism’ and then contasting it to ‘capitalism’ (renamed chapiterism, for laughs) and it gets mocked. Noone wants to debate schloastically, everyone claims my grammar or… well my rhetoric mainly, indicates my ideas as ‘sub’ or beneath them. Its ok thou, we all fear some other thing.

    Very niche question, do you put any credence to ‘Earths Chakras’, that is to say, Mt. Shasta, Lk. Titicaca, Uluru, Glastonbury/Shaftsberry, Pyr. Giza, Unknown (‘wandering based on aeon’ or X), and Mt. Kailash being energy vortexes? If so, based on aeon, where would you place it in the aeon, or [Solve for X] in mathspeak. If not, what do you think was ‘mistranslated’ to mislead folk?

    Thank you for your work, smart men think for 1, wise men think for all.

    Be well friend

    1. I’m worry to say I can’t answer these questions because I don’t understand them. I hope someone else can. But I wish you well, too. And I’m glad you posted your comment; some others have been having difficulty doing so.

Write a comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.