It would make sense for me, if I were to make measurements, to measure the synodal year. The sun will come up....there!
So, just some added bits of info for me to store here:
So...the importance of the lunar eclipse was as a measuring the device. Or is that the theory? If someone were calculating the next lunar eclipse, the question "why"? would be answered if they were using it as a checking device for, say, precession (all these terms I'm learning...)
I've also found the 8/99 link.
On the other hand, in arithmetical lunisolar calendars, an integral number of synodic months is fitted into some integral number of years by a fixed rule. To construct such a calendar, the average length of the tropical year is divided by the average length of the synodic month, which gives the number of average synodic months in a year as:
12.368266... Continued fractions of this decimal value give optimal approximations for this value. So in the list below, after the number of synodic months listed in the numerator, an integer number of tropical years as listed in the denominator have been completed:
12 / 1 = 12 (error = -0.368266... synodic months/year) 25 / 2 = 12.5 (error = 0.131734... synodic months/year) 37 / 3 = 12.333333... (error = 0.034933... synodic months/year) 99 / 8 = 12.375 (error = 0.006734... synodic months/year) 136 / 11 = 12.363636... (error = -0.004630... synodic months/year) 235 / 19 = 12.368421... (error = 0.000155... synodic months/year) 4131 / 334 = 12.368263... (error = -0.000003... synodic months/year) The 8-year cycle (99 synodic months, including 3 embolismic months) was used in the ancient Athenian calendar. The 8-year cycle was also used in early third-century Easter calculations (or old Computus) in Rome and Alexandria.
http://en.wikipedia.org/wiki/Lunisolar_calendar
...but I don't know how this relates to Buddha's enlightenment or Venus. The eight year cycle was a form of regulating calendar (I feel I'm re-typing--only worse--migeru's diary on the subject of calendars; worse because I'm probably getting it all wrong and am in a cloud of oh-so-very unknowing....;)
So: the transit of Venus across the sun? Some other special astronomical event? I don't know how I'd work out which one it is because I don't know of many.
Another question about the tzolkin. I'd understood it to be for planting maize (among other things), so it started not when mars and venus conjoined, but at one of the sun's zeniths (I type that as if I knew what it meant.) So as the "long" tzolkin worked out, there would be a new one each year, whose start date was calculated by a synodal event?
I'm baffled now as to why anyone would want to invent the "sidereal" time period. The synodal one (it's back where it started) marks a pure cycle. The sidereal relates to the "background of stars", the zodiac, the constellations, against which we are running anti-clockwise (? to the left? I still don't have a good mental map of the earth in relation to the celestial sphere...I'm trying to find a good site to help me fix a picture, so I can get the rough layout of the major stars clear in my noggin...)
But, yes, the background "fixed" stars were used for..what, navigation? So for navigators it would be important to know if each year was slightly slowed relative to previous years, otherwise a ten year off-shoot might mean missing the island...something like that?
So the lunar eclipse was a calibration device?
And I still don't know what fifty nine bells refer to, or how the alchemical metals relate to the eight year lunisolar calendar; and I don't have it clear in my head how the sun and the moon interact--there's some shift, I suppose...we can count off cycles of the moon (new - full - gone - new etc...) and roughly twelve cycles makes a year, but not quite, so they had to "refix" the year by letting one have thirteen lunar cycles, and after eight years (and three additions) it was more or less okay, with a give or take--always forward? Always backward? One or t'other?
But this doesn't seem to get me any closer to answering the puzzle which has, no?, to do with Venus?
So...using Venus to calculate the year...Venus has a synodal cycle of 584 days. The synodal solar cycle is about 365 days? 120 days difference, or maybe it's closer to 118? (I remember that number), which is twic fifty nine...but I'm buggered if I know if that all links up in some way, and I would have the first idea how they'd be measuring this in the sky--they'd be using moon events as a tick tock and at certain points either re-set their clocks, or check where certain planets and/or stars were in the sky?
Finally (I'm still looking forward to seeing how this all ties up), I thought this was amusing.
(precession)
[...]
claims have been made that precession was known in Ancient Egypt prior to the time of Hipparchus. Some buildings in the Karnak temple complex, for instance, were allegedly oriented towards the point on the horizon where certain stars rose or set at key times of the year. A few centuries later, when precession made the orientations obsolete, the temples would be rebuilt. Note however that the observation that a stellar alignment has grown wrong does not necessarily mean that the Egyptians understood that the stars moved across the sky at the rate of about one degree per 72 years. Nonetheless, they kept accurate calendars and if they recorded the date of the temple reconstructions it would be a fairly simple matter to plot the rough precession rate. The Dendera Zodiac, a star-map from the Hathor temple at Dendera from a late (Ptolemaic) age, supposedly records precession of the equinoxes (Tompkins 1971). In any case, if the ancient Egyptians knew of precession, their knowledge is not recorded in surviving astronomical texts.
I don't know why I enjoyed the image of the egyptians knocking down their temple and rebuilding it pointing...a couple of degrees to the west (or east...I is so confused!) Maybe it was the idea that they didn't know why their buildings were off. "Bloody hell, we got it wrong again! Right! Knock it down." Don't fight forces, use them R. Buckminster Fuller.
But it can be confusing if you don't give yourself time to put it together.
You have stumbled into sidereal periods. I have been trying to avoid them--there is nothing wrong with them--just, I have been hoping to keep down complications.
I like eclipses for other reasons, but yes, until you have modern high-precision instruments, eclipses are absolutely the cleanest and most accurate way of astronomical measurement. Very useful, technically.
The passage you found on 8/99 is good: The heart of comparing the Moon against the year. A LOT of information is implicit in that passage. Of all those ratios, the only one that connects to Venus though, is 99/8.
99 months is 8 years is ____ rounds of Venus. Once you fill in the blank you are home.
So: the transit of Venus across the sun? Some other special astronomical event?
Yes, though this wasn't part of my puzzle. Very important in modern science: It was the basis for deducing planetary distances (such as that the Earth is 93 million miles--I forget how many kilometers--from the Sun) which was a major problem of the 18th century. Telescopes and filters are needed to make the observations. Not ancient.
I'm baffled now as to why anyone would want to invent the "sidereal" time
Yes. I feel that one doesn't do it until one has to. This too is modern. It takes time to explain. Fortunately for the ancients, they didn't need it.
But, yes, the background "fixed" stars were used for..what, navigation?
Yes, but this too lies outside my puzzle. It is a whole study. Maybe a semester course to become proficient. I never learned this.
Yes, in ancient times and modern. Right into the 20th century it was the only way to do many things.
That piece on the Egyptian temples was a find. I had no idea about that.
Maybe it was the idea that they didn't know why their buildings were off. "Bloody hell, we got it wrong again! Right! Knock it down."
:D It seems strange, for sure.
Meanwhile, go back and look at the synodic month: This is the month as we mean it in common usage--new Moon to new Moon. How many days?
The pieces are all nearly there.
Putting together the Babylonian planetary hours may entail more than I thought. Maybe we pause for breath first. We'll see. The Fates are kind.
So: eight years is the same as ninety nine lunar cycles is the same as five Venus cycles
Not sure about the dragon. I couldn't find any pages about it--I'll have to keep looking.
And I don't know how the seven days fit in. I asked my friend last night; he didn't know. Why seven days? And how does it fit?
So...
A - 59 B - Venus and Mars meet every 9 tzolkins, but I don't know how that relates to the year/moon C - ? D - 8/99 see above E - Something to do with lunar eclipses? But I don't know how eclipses fit in to Venus / eight year....
Am I getting warmer? Don't fight forces, use them R. Buckminster Fuller.
A - 59 Still don't know! Don't fight forces, use them R. Buckminster Fuller.
Why do this? They just wanted a whole number--no fractions.
More later. The Fates are kind.
For a while I lived on Long Island, which is essentially a suburb of New York. (It was awful, but that is not my point). Between everything, including a shopping mall, the night sky was so bright with glare that the only celestial objects were the brightest three planets, the Moon, Arcturus (in Bootes), Spica (in Virgo), Vega (in Lyra), Antares (in Scorpio, and the seven brightest stars of Orion. NOTHING else was visible.
That was my starting point for learning the sky. A little sparce! ;)
Later, I would make trips to better skies and then compare what I had seen with a star map that I had. The Fates are kind.
I'm seeing this (well, I'm a fraction of a degree to the west and south.)
http://www.fourmilab.ch/cgi-bin/Yourhorizon?lat=51.5000&ns=North&lon=0.000&ew=West&f ov=45.000&azimuth=270.000&z=2&elements=
It's a fascinating beast of a problem trying to capture a model which makes the realities (the various cycles) link together so that when I stare at that crescent moon...I know that it is being lit by the sun, but...I'm still stuck at the concept of the ecliptic: It is the path of the Sun against the background stars, yes. But when we look at the Sun, we don't see the stars behind it. We see the stars when we swing round and away from the Sun...where the Sun isn't. So I find the concept of the movement of the Sun against the (inivisible) stars behind it...hard to visualise...
Re: 59. So the 50 silver bells are the daily phases of the moon over two lunar cycles? (And a lunar cycle means: the moon is back in the same place in the sky? So, in 59 days, if I look out of the same window at the same time I'll see the moon in the same place and with the same size crescent of light?
Like I said, though, I need to get a...mental handle...on what I'm looking at. Really, I want to find a way to sense my movement relative to the sky. I want to get that sense of being on the panoramic deck of a huge ship, moving...(but in which direction relative to the celestial objects?)...and then, when I can sense that I am moving, really get that sense, then I think I'll be able to get how the celestial objects are also moving, relative to me and relative to each other.
But I'm still stuck in that mind set of: "Here I am, sitting here, not moving, and there are those obbjects...moving and changing...there's no dynamic, no motion...
I remember hitting that motion point once, looking down into the sky, the objects far below me...you know the sensation, when you involuntarily grab some grass to stop from slipping or falling into space.
As I also said, I can't find any references for the dragon. But I need to re-read what you wrote, coz I think you stated it in a side comment which I didn't read properly.
Anyway, Venus and the moon are at my window. I'll see if and how far they move between now and...later this evening, relative to my viewing space (they are framed...'twill be easy to see if they move more than a few of my centimetres. The moon is four fingers below the top window frame; Venus is four fingers below the moon...
...Gaianne, I have to thank yez! Don't fight forces, use them R. Buckminster Fuller.
Yes.
That's what it's for.
Really, I want to find a way to sense my movement relative to the sky.
One spring I walked every night up a local hill just after sunset. I was lucky to have a stretch of clear weather. Each night the stars sank lower into the Sun. (This was NOT on Long Island). After a month the sky had sunk one entire zodiac sign. The constellation of Gemini has a couple of bright stars (also, Procyon in Canis Minor is nearby) and their movement from roughly overhead down toward the Sun was very obvious. After a while I could begin to feel it.
Dope helps ;) The Fates are kind.
But the thing is, I realised as the moon went down...see, I'd be wondering how we could ever see Venus, as it's closer to the Sun than us, to look at it we have to look towards the sun. But then I realised that we must be looking acrossVenus, that it is moving away because I am spinning away from it. And I realised I was looking in the rear-view mirror, that the moon and Venus were moving away into the distance. I want to see the stars I'm moving towards, I'll have to check it out. My "east" looks out over the town, so there'll be a lorra light down below bleeding out a lot of stars above. I'll have to go see.
And the puzzle. I need more clues or pointing back towards the right track. Venus and the moon. I saw them this evening, a very elegant relationship, relative to my window. I thought of Islam and the crescent moon with its single star.
So, the moon. It's cycles. Then there are lunar eclipses, used to reset time systems. And there is Venus...and there was Mars in B. So Mars, too. Something about their conjunction and how it relates to lunar eclipses? ?????? I still can't get my head around the ecliptic. Don't fight forces, use them R. Buckminster Fuller.
