The Sun & The Moon

Posted by jns on April 7, 2006

I have a friend upon whom I can rely to send me, with some regularity, unbelievable photos and incredible stories, most of which turn out in the end to be fabricated photos and urban legends. Someplace in the forwarding of these things, someone will often add a wishy-washy “I don’t know if this is true, but….” and then carry on anyway.

Sure enough, the last photo I got from him was a beauty: an arctic landscape with a bright, tiny sun hovering on the horizon and, above it, an enormous crescent moon. It was quite a lovely image. The text with it said

This is the sunset at the North Pole with the moon at its closest point. And, you also see the sun below the moon. An amazing photo and not one easily duplicated. You may want to save this and pass on to others.

“…not easily duplicated” is correct! While the image is pretty, it’s a complete fabrication, and I’d like to think that should have been obvious to anyone seeing it. But then, I’d like to think a lot of things that turn out to have nothing to do with reality.

Happily, snopes.com says plainly that the photograph is a fabrication, created digitally by a German astrophysics student. (Follow the link for the details and to see the image.)

However, Snopes missed their chance to state the obvious: the photograph could not possibly be a real image of “sunset at the North Pole” for one simple reason that everyone should be able to spot — the image of the moon, compared to the image of the sun, is far, far too large.

But how could anyone be expected to know this^*, you ask? Well, I claim, nearly everyone knows the cause of total solar eclipses, even if they’ve never seen one: the moon passes between the Earth and the sun and exactly covers the disk of the sun for a short time.

The simple deduction, then, is that the apparent size of the moon, as seen from the Earth, is very nearly the same as the apparent size of the sun. Thus we know that this image, in which the moon is some 20 times the size of the sun, must be a fabrication.
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^* This is an interesting question, particularly since in films, night scenes are often created with a looming, full moon shot with a telephoto lens; the same is rarely done for the sun, unless it is near the horizon into which the movie’s heroes are riding. People often seem ready to accept that the apparent size of the moon is substantially larger than it is in reality, whereas they seem to imagine the apparent size of the sun to be rather smaller than it actually is. These mistaken notions are exploited in the north-pole “sunset” image.

Mystical Time

Posted by jns on April 4, 2006

Not to harp on the innumeracy thing (although — plug time! — it is part of the mission of Ars Hermeneutica), but I’m a little irritated.

You see, I keep seeing people for the last few days pointing out, in e-mail and on their blogs^*, that on 5 April something unusual is going to happen. Namely, the time and date at one moment in the wee hourse will be

01:02:03 04/05/06

“This will never happen again!” is trumpeted along with the observation.

Of course, this is incorrect for two contradictory reasons: 1) it isn’t really happening in the first place; and 2) it will happen again.

Dispensing with #2 first, a moment’s reflection quickly shows that because only the last two digits of the year are used in the mystical rendering, this “reading” will happen precisely every 100 years, give or take depending on leap seconds or other adjustments; we could say it will happen exactly every 100 nominal years.

Now, for #1. It should come as no surprise that I am always troubled by mystical malarky like this, but I find it more troubling when it is so arbitrary, depending as it does only on accidents of the way we count time and keep track of days.

For most Europeans, the revelation won’t make any sense because they tend to write the day number before the month, 05/04/06, so clocks won’t get all mystical for them until 4 May. But should the mystical power depend so critically on using only two digits for the date? Oh dear, but 04/05/2006^# just doesn’t do it, does it? All this without even mentioning the different calendars and years observed by different cultures (China, say, or Orthodox Christians or Jews). Also not to mention that it depends on the fact that we divide the day up into 24 hours, and each hour in 60 minutes of 60 seconds each — like that’s natural and deeply meaningful!

I am not, however, totally immune to these accidental coincidences of digits. For instance, I find it useful — as a mnemonic — that Ars Hermeneutica’s incorporation was recorded in the Maryland Department of State at 11:11 on 11 November. Surely that must mean something!

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^* For example, Shakespeare’s Sis mentions it here.

^# Update added barely one hour before the mystical event here in the Central-Daylight-Time timezone: I just realized with some excitement that if only we more generally used a 24-hour clock and wrote our dates euro-style, we could look forward, in just a couple of months, to 20:06 20/06/2006, which is guaranteed never to happen again with our current Gregorian calendar.