Artifact is Oldest Known Astronomical Instrument

[Swift]

From Laboratory Equipment magazine on-line

In 1977, archaeologists unearthed a great number of precious relics from the tomb of Xiahou Zao (?-165BCE), the 2nd Marquis of Ruyin of the Western Han dynasty. They named a piece of lacquerware "lacquerware of unknown name", for no one has been able to identify it. Divergent views also have been held over the possible function of a pair of overlapping lacquered disks from the same tomb.

After more than two years cooperative study with experts from the Anhui Museum and the Fuyang Municipal Museum, Shi Yunli, professor from the Department of the History of Science and Scientific Archaeology, Univ. of Science and Technology of China, has recently resolved the puzzles and found that the former is a special gnomon with template, while the latter parts of a equatorial device for the positional observation of celestial bodies. Both are the oldest astronomical measuring instruments with definite information of date that can still be seen in the world. The findings were published in the Studies in the History of Natural Sciences, the leading Chinese journal in the history of science.

The gnomon with template is a typical instrument used by ancient Chinese astronomer in determining the advent of different seasons with the gnomon shadows cast on the template by the midday sun. It consists of a vertical pole and a level template laid in south-north direction at the foot of the pole. The gnomon with template from the tomb of Xiahou Zao has two symmetric and foldable parts. As being fully set up in the south-north direction, the midday sun will cast the shadow of a vertical tablet in the northern half onto three fixed positions on the template respectively on the days of the Summer Solstice, the Vernal/Autumnal Equinoxes, and the Winter Solstice.

Maybe I should have posted this in the Astromonical Equipment forum.

I was a little unclear if the object pictured in the article is the actual historic piece (in which case it is in great condition or been restored) or a reproduction made from the original.

[profloater]

I think Stonehenge is a little older and was almost certainly used to predict eclipses by means of the Aubry circle. Nice gnomon however.

[HenrikOlsen]

I think Stonehenge is a little older and was almost certainly used to predict eclipses by means of the Aubry circle. Nice gnomon however.

"the oldest astronomical measuring instruments with definite information of date"

Stonehenge it likely older, but dating it is also less precise.

[geonuc]

When I read "with definite information of date", I think the writer meant to exclude objects that cannot definitely be said to be older, due to imprecise dating. Even if its age is uncertain, Stonehenge is definitely much older than this instrument. Perhaps the article authors were thinking 'oldest hand-held instrument.'

[Swift]

I'm not really interested in wordsmithing this, but I kind of think most people wouldn't consider Stonehenge an "instrument".

As I said in the OP, that is not the puzzling thing to me. The puzzling thing to me is that the instrument shown is remarkably well preserved, and it is unclear to me whether what is pictured is the as discovered original object, the original object after restoration, or a modern reproduction of the original object.

[profloater]

perhaps it was stored in a pyramid along with the knife sharpeners? How old was the beautiful but damaged brass astrolabe recovered from shallow waters near Greece?

[Perikles]

How old was the beautiful but damaged brass astrolabe recovered from shallow waters near Greece?

The antikythera thingy was around the end of the 2nd century BC. Have a look here.

[profloater]

The antikythera thingy was around the end of the 2nd century BC. Have a look here.

Thanks, now that was an instrument to wonder at!

[eburacum45]

I'm afraid I am somewhat skeptical of the Stonehenge claims; there is probably only one definite alignment (even that is in some doubt as to its exact nature; it is probably midwinter sunset, not, as usually claimed, midsummer sunrise).

Apart from that one alignment I supect that all the others are accidental, occuring simply because Stonehenge is constructed as a ring of regularly spaced stones, and this regularity allows a very wide range of geometric figures to be drawn, some of which coincide with other celestial directions. I supect that most, if not all, of these other alignments are spurious.

Why do I think the midwinter alignment is real? Well, it is seen in several other monuments of similar age, including Newgrange. Sure, Stonehenge could have been a calendar of sorts; but I think they would have used other, more convenient methods of marking the time. And as for predicting eclipses, that seems a bit of a stretch.

[profloater]

I'm afraid I am somewhat skeptical of the Stonehenge claims; there is probably only one definite alignment (even that is in some doubt as to its exact nature; it is probably midwinter sunset, not, as usually claimed, midsummer sunrise).

Apart from that one alignment I supect that all the others are accidental, occuring simply because Stonehenge is constructed as a ring of regularly spaced stones, and this regularity allows a very wide range of geometric figures to be drawn, some of which coincide with other celestial directions. I supect that most, if not all, of these other alignments are spurious.

Why do I think the midwinter alignment is real? Well, it is seen in several other monuments of similar age, including Newgrange. Sure, Stonehenge could have been a calendar of sorts; but I think they would have used other, more convenient methods of marking the time. And as for predicting eclipses, that seems a bit of a stretch.

I have a friend (Robin Heath) who regularly uses students to demonstrate the method at stonehenge,(and has published his method) using the outer ring of post holes I referred to You place a pole in the hole and move it round each day forming a vernier effect and it aligns with sun and moon eclipses. Stonehenge was constructed at the correct lattitude to project the ecliptic as a circle on the ground. I think it is highly likely it was designed as a calculator to predict eclipses and not just equinoxes. But by whom I often wonder.

[profloater]

I copied this from the book but the diagram does not copy. Just for interest:
Eclipse Prediction
Anyone who has ever tried to make a model of how the Sun and Moon move around the Zodiac will end up, most simply, with a circle of 28 markers around a central earth. Moving a 'Moon-marker' one position per day and a 'Sun-marker' once every 13 days, provides a calendar accurate to 98%. (Figure 3.3, Sun, Moon & Stonehenge, page 52)



Every year, for about 34 days, the full and new moons occur near the Sun's path (the ecliptic) and eclipses result. These two times, which are 173 days apart, move backwards around the calendar taking 18.6 years to complete a revolution. The precise two points where the moon crosses the apparent path of the sun through the zodiac ( the ecliptic) are called the lunar nodes.

By doubling the sun-moon calendar to 56 markers, we can obtain an accuracy of 99.8%, and meet the handy convenience that 18.6 x 3 is almost the same as 28 x 2. Now a 3:2 ratio enables eclipses to be predicted to high accuracy, as the picture shows. (Figure 3.6, Sun, Moon & Stonehenge, page 58)

[geonuc]

As I said in the OP, that is not the puzzling thing to me. The puzzling thing to me is that the instrument shown is remarkably well preserved, and it is unclear to me whether what is pictured is the as discovered original object, the original object after restoration, or a modern reproduction of the original object.

It's not clear to me, either. I looked around a bit, as I imagine you did, and found nothing useful in that regard.

[eburacum45]

From what I've read, Robin Heath is very ingenious. He is probably wrong about some, many, most, or all of his conclusions; I don't know which ones, and to be honest, neither does he.

Archaeoastronomist are sometimes tempted into much too much speculation; this can all too easily remove their conclusions from science into pseudoscience.

[Swift]

I'm afraid I am somewhat skeptical of the Stonehenge claims; there is probably only one definite alignment (even that is in some doubt as to its exact nature; it is probably midwinter sunset, not, as usually claimed, midsummer sunrise).

Apart from that one alignment I supect that all the others are accidental, occuring simply because Stonehenge is constructed as a ring of regularly spaced stones, and this regularity allows a very wide range of geometric figures to be drawn, some of which coincide with other celestial directions. I supect that most, if not all, of these other alignments are spurious.

Why do I think the midwinter alignment is real? Well, it is seen in several other monuments of similar age, including Newgrange. Sure, Stonehenge could have been a calendar of sorts; but I think they would have used other, more convenient methods of marking the time. And as for predicting eclipses, that seems a bit of a stretch.

From what I've read, Robin Heath is very ingenious. He is probably wrong about some, many, most, or all of his conclusions; I don't know which ones, and to be honest, neither does he.

Archaeoastronomist are sometimes tempted into much too much speculation; this can all too easily remove their conclusions from science into pseudoscience.

I had an archaeoastronomy course in college (given through the history department) back in 1980 (!), and obviously Stonehenge and other neolithic sites were part of that course, and I have read other information about it over the years, but I am far from an expert. We've also had other threads about it.

It seems reasonable to me that at least a few of the alignments in Stonehenge are legit and not accidental; I would think the solstice and equinoxes are likely. As you say, there are enough other similar sites that this seems reasonable. I too agree that eclipse prediction is at stretch (probably more than a bit, IMO).

One theory I remember reading years ago, to explain why Stonehenge isn't as good an "instrument" as it should be, is that what has actually survived to the present isn't the original observatory, but almost a recreation of the original (still neolithic), and even this has been manipulated since ancient times. All of those changes over the years probably have distorted some of the original alignments.

But, as you say, it is hard, from the available information, to know all the intents of the builders.

Edit - Here are links to two (of several) previous threads on Stonehenge, with some of this same discussion
Thread 1
Thread 2

[NEOWatcher]

It seems reasonable to me that at least a few of the alignments in Stonehenge are legit and not accidental; I would think the solstice and equinoxes are likely. As you say, there are enough other similar sites that this seems reasonable. I too agree that eclipse prediction is at stretch (probably more than a bit, IMO).

Ditto that.
It may show the cycles, and indicate when the moon and sun pass but that doesn't mean it predicts eclipses.
Unless there is something in Stonehenge that shows these in respect to the moon's orbital plane tilt, then I see no evidence to extend the idea to an eclipse.

[Ivan Viehoff]

I was a little unclear if the object pictured in the article is the actual historic piece (in which case it is in great condition or been restored) or a reproduction made from the original.

The link indicates the actual article is available to read for free on-line, though since even the index pages of the journal are in Chinese only you may need assistance to find it and read it.

Lacquerware can remain in remarkably good condition for very long periods of time, though it should obtain a "patina" with time. Nevertheless the item illustrated is complete and looks without patina. I suspect if the item found had been complete it would not have been so difficult to identify it. I therefore suspect what is shown is a modern reconstruction.

[TrAI]

From Laboratory Equipment magazine on-line

Maybe I should have posted this in the Astromonical Equipment forum.

I was a little unclear if the object pictured in the article is the actual historic piece (in which case it is in great condition or been restored) or a reproduction made from the original.

According to this news article on the University of Science and Technology of China the pictured objects are replicas, so I expect the originals look a bit older.