Tue, Jun. 24th, 2008, 10:13 am
Stars above, wine-dark sea below

This interesting article discusses new research results which pinpoint the date of Odysseus's return to Ithaca based on astronomical clues in the Odyssey.  But the article has a glaring, obvious, silly astronomical mistake in it.  I'm sure it's the journalist's fault, not the researchers'.

Five bonus points to the first person who replies to this post identifying the error.  I'll be very disappointed if the winner isn't an alumnus of one of my Astronomology classes.
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Tue, Jun. 24th, 2008 05:35 pm (UTC)
[info]baal_kriah

Well, there's an error of fact in "about noon on April 16, 1178 B.C., and would have coincided roughly a decade before the most often cited estimate for the sack of Troy — about 1190 B.C." because 1178 B.C. is roughly a decade after 1190 B.C. However, this hardly seems like what you would refer to as an astronomical mistake. I'm not astronomer enough to spot it. Is it somewhere in "Odysseus is told to watch the Pleiades and late-setting Boötes and keep the Great Bear to his left"?
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Tue, Jun. 24th, 2008 05:38 pm (UTC)
[info]isomeme

Good spotting on the first one, but that's not what I was looking for. Calendar errors go in a different category. :) And nope, the latter isn't what I'm looking for, either.
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Tue, Jun. 24th, 2008 05:47 pm (UTC)
[info]mendaxveritas

The first weird error I notice is that the writer seems to think that 1178 BC was before 1190 BC -- though the odd use of the word "coincided" in that sentence makes me suspect a copy-editing error.

Then there's the problem that new moons are typically seen at daytime, not at night, since the reason the moon appears "new" is that we're looking at its dark side, i.e. it's between us and the sun.

The explanation of Mercury going retrograde is a bit vague but not exactly wrong.

The most serious problem with the piece is the improbability that oral tradition accurately preserved for centuries all the exact astronomical details so that the date of the return to Ithaca could be calculated by future astronomers -- assuming, that is, that the story isn't fictional in the first place.
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Tue, Jun. 24th, 2008 05:55 pm (UTC)
[info]isomeme

There's certainly a lot of distortion throughout the article; like you, I suspect the journalist or the editor messed things up.

The new moon does figure into the one flat-out, unambiguous astronomical error in the piece, but not in the way you mention; new moons are typically seen after sundown, in the western twilight. Before sunset the brilliance of the sun makes them effectively invisible to the unaided eye.
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Tue, Jun. 24th, 2008 05:48 pm (UTC)
[info]omegabaphomet

The day of the slaughter is, as Homer writes more than once, also a new moon (something that's also a prerequisite for a total eclipse).

Should say "full" there! I'd love to attend and be an alumni, but you live too far from Texas! [Or, I live too far from CA?? ;-P ]
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Tue, Jun. 24th, 2008 05:50 pm (UTC)
[info]mendaxveritas

Really? How could there be a total solar eclipse during a full moon? Note that a solar eclipse involves the moon being between the sun and the earth, and a full moon involves the earth being between the moon and the sun.
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Tue, Jun. 24th, 2008 05:51 pm (UTC)
[info]isomeme

You're tantalizingly close, but no, actually solar eclipses happen near the new moon, not the full.
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Tue, Jun. 24th, 2008 11:55 pm (UTC)
[info]omegabaphomet

Oops, I was thinking lunar eclipse.
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Tue, Jun. 24th, 2008 06:02 pm (UTC)
[info]azael93

I can't figure it out. Yer killing me.
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Tue, Jun. 24th, 2008 08:44 pm (UTC)
[info]isomeme

See below...[info]takwish got it.
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Tue, Jun. 24th, 2008 08:59 pm (UTC)
[info]azael93

Yeah, I, um knew that, I was just testing ya'll.
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Tue, Jun. 24th, 2008 07:39 pm (UTC)
[info]takwish

The Pleiades ain't a "constellation."
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Tue, Jun. 24th, 2008 07:45 pm (UTC)
[info]isomeme

I'll give you partial credit on that one, since that is an astronomical mistake. But what I'm after isn't a matter of terminology, but of physical (im)possibility.
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Tue, Jun. 24th, 2008 08:10 pm (UTC)
[info]takwish

OK, next: if the moon were actually new at sundown the night before the eclipse, then it would have had roughly 18 hours of waxing time by noon the next day. Can't a total solar eclipse only occur when the moon is actually new?
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Tue, Jun. 24th, 2008 08:15 pm (UTC)
[info]isomeme

Bingbingbing!! We have a winner. A visible new moon is one that has passed the Sun and is waxing, while an eclipse can only occur during the passage itself. If you can see the new moon in the evening twilight, the next solar eclipse possibility is a month in the future.

You are now an honorary graduate of Astronomology. Use your power wisely. :)
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Tue, Jun. 24th, 2008 08:20 pm (UTC)
[info]takwish

Yaay!
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Wed, Jun. 25th, 2008 12:24 am (UTC)
[info]omegabaphomet

I think the version of this story I read didn't have that issue, it says: "The day of the slaughter is, as Homer writes more than once, also a new moon (something that's also a prerequisite for a total eclipse)." That sounds correct, right?

http://www.sciencedaily.com/releases/2008/06/080623175435.htm
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Wed, Jun. 25th, 2008 12:54 am (UTC)
[info]isomeme

Yep, that phrasing is fine, though it's worth noting the distinction between the astronomical new moon (which occurs at the moment of conjunction, which is when an eclipse can happen if moon is at one of its ecliptic nodes) and the visible new moon, which typically occurs at least half a day later. When Homer talks about a new moon, he almost certainly means a visible one. So the sequence would be eclipse followed by new moon.
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Wed, Jun. 25th, 2008 12:57 am (UTC)
[info]omegabaphomet

I throw star petals at your astomological feat! Hey, if you put it on DVD then I could project your lectures on the wall at SWL. Larger than life!
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Wed, Jun. 25th, 2008 01:51 am (UTC)
[info]kath8562

Pish... somebody got it before I did!! New moon the night before-hah! I groaned over that one...
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