Durin's Day

In The Hobbit, it defines Durin's Day as "the first day of the last moon of autumn, when the sun and the moon are in teh sky together." Something like that, please correct me if I'm wrong. Anyway, there's this 1974 Tolkien calender lying around the house, and in one scene it has Tolkien's depiction of the death of Smaug. It is a rough draft, with Tolkien's notes to himself on it. Near the moon, it says "the moon should be a crescent, it was <unreadable> after the New Moon on 'Durin's Day'.
If Durin's Day is a new moon, how are you supposed to tell if the sun and the moon are in the sky together. You can't SEE a new moon. Or am I getting my phases mixed up?

The new moon can be a waxing crescent. Poetically: the old moon in the arms of the new.

Tolkien also referred to a chasm so deep that you could see a star twinkling in the daytime sky. This is from an old idea that if you dug a deep narrow well, you could see stars looking up from the bottom.

This is wrong. The only possible way this could work would be in a mountain range where the top of the chasm was so high, that there was little atmosphere, and no light to speak of refracted through the thicker air at the bottom. I know of no such place on earth. Maybe Frodo and Sam walked in such a place in Middle-earth.

A crescent moon is a crescent moon. Not a new moon. Perhaps Tolkien meant a waxing crescent moon leading the sun through the day, and setting first. This would indeed be a few days after the new moon following Durin's Day.

What I find fascinating is that in Rivendell, when it is said that it was beyond their ability these days to predict when Durin's Day would next be, Gandalf disagreed.

Surely the Elves who had watched the sky since before the Sun and the Moon, knew much. In Gondor, too, founded by a seafaring race, celestial observation would not be unknown. The Dwarves, chased from their caverns, may have lost this lore, but Gandalf clearly knew of it, and perhaps that very night, looked at charts in Elrond's house, and calculated that Durin's Day would indeed fall late enough so that the Doorstep could be found and sat upon in time.

I think you're right that the Elves and Numenoreans must certainly have known enough about astronomy that they could have calculated such an event... Certainly if you consider Elrond's pedigree, you'd think he'd know about such things. But there's a sense in which The Hobbit is not entirely in Middle-earth. It's certainly set there, but when Tolkien started out, it wasn't set in Middle-earth... The story of The Hobbit was drawn into Middle-earth. When TH was written, Tolkien had not written about the Third Age, perhaps he'd not written about the Second Age, yet, I can't remember now. So there are inconsistancies between TH and other writings about ME.

The New Moon is the phase of the moon when it is between the Earth and the Sun its' disk being invisible _or also_ the first visible (or waxing) crescent.

Occassionally, on the New Moon, you might find yourself in its shadow. This is an eclipse.

Tolkien makes a point about the vessels of the Sun and the Moon and of their deliberate origin. All of the legends and mythologies of Creation, make a point of this.

I think it is beyond coincidence that we stand on the surface of the Earth, gazing at the New Moon, a quarter of a million miles away, as it perfectly eclipses the Sun, ninety-three million miles away. Two celestial objects of such immensely different size and distance, and yet they look the same size from here...

How fantastic!

Yes!! I have often wondered at that.....wondered at, mind you. What are the chances?

Good golly, Moses!

Who could say?

I once posed a disturbing question to the ASK THE SPACE SCIENTIST website maintained by NASA.

You see, the Leonid Meteor Shower each Nov. 17 occurs because we cross the path of Comet Temple Tuttle, which has a 32 year orbit. Seems to me there's a chance we could come mighty close one November! I looked at a Japanese astronomer's site www.astroarts.com/cgi-bin/jump?comets/1998/0055P.html
that geometrically plotted the comet's location on given dates. To the best resolution of this display it predicted a couple of close approaches in the next three centuries. Too close to call! So I asked NASA.

Like Thorin, they said, it lies beyond our ability to say when that day will come...

image.gsfc.nasa.gov/poetry/ask/a11773.html

Basically, they must run a huge integral computation to account for the changing gravitational perturbation of the orbits and positions of every object in the Solar System acting upon every other body over many decades to answer the question. Theoretically, it could be done. Perhaps it should be done, even if you have to devote a real year of supercomputer time to calculate it!

I think my question caught them off guard! I was surprised they didn't have even rough answers to this one. All they can say is that it will be in our ballpark with everything that comes with it...

Perhaps they could give you an estimate on the distribution of perfect eclipses, presumably distributed evenly throughout Creation.

image.gsfc.nasa.gov/poetry/ask/askmag.html

You would have to divide that astronomically small number by what may be an astronomically small number of life bearing planets to arrive at anything approaching a reasonable estimate of the odds against us seeing our perfect eclipses.

This is one of those things that makes you go: Hmmmmmmm...


P.S. I really was just planning to post so I could check out the new post picture I'm fooling with on my day off!

Ugh! I don't know if I would want them to try to figure out when a meteor would hit the planet.....at least, I wouldn't want to know about it, that's for sure! Remember when they predicted a strike a couple of years ago? Someone I think had a decimal point wrong or something......whew!

Yeah, he had two observation times, extremely close together. Not enough for an astronomically precise calculation. (Maybe he needed a woman with sense on the team to hold him back from his impetuous announcement!)

The Jet Propulsion Laboratory back calculated the objects orbit and looked to see if they had a picture of it already, taken years before, and just hadn't noticed. Sure enough they did, and were able to more accurately calculate the orbit.

Which tells me that they ought to have a ballpark on Temple-Tuttle...

(The little hobbit shivers, and vows to dig his next hole a little deeper!)

Scientifically "New Moon" means a totally dark lunar disc, unobservable except by noting stars that don't appear because hidden behind it.

But in popular usage, as Tar Elenion has already noted, it refers to the thin crescent moon seen for a few days after the scientific new moon phase, particulary the slim crescent seen the first day after.

In historical documents that is normally what is meant, the first observable moon in a new lunar cycle.

Check almost any dictionary for both usages.

I'm surprised the Dwarves did any astronomy at all.....

Sure! Lots of those ancient Races did astronomy. There's a Quenya word for 'astronomer', you know, meneldur, 'devoted to the heavens'.

Easterlinge is right though. The Dwarves were more "earthy". I have a little trouble picturing them studying the stars :/

That's true.