APOD: South Pole Star Trails (2012 Aug 02)

[Anthony Barreiro]

Thanks ta152h0 (how do you pronounce that?) and Neufer, this is very interesting. The various assertions and dismissals of this theory make me think that (1) human beings are very good at finding correlations and patterns; (2) it's hard to know what people who lived long ago and didn't leave any written documents may or may not have been thinking; and (3) it's a common mistake of lazy or disputatious thinking to conclude that because a hypothesis has not been proven it has therefore been disproven. One possibility not mentioned in the wikipedia article: perhaps an older late paleolithic culture built smaller monuments at these locations, and the later fourth dynasty Egyptians built the surviving pyramids and Sphinx on the same sites. One can speculate endlessly. I'll meditate wearing my pyramid hat this evening and let you all know what I discover.

[b][color=#0000FF]Detail Observed from 10 Feet away with Curiosity's ChemCam Image Credit: NASA/JPL-Caltech/LANL[/color][/b]

---

<<This image displays the type of detail discernible with the telescopic camera of the Chemistry and Camera (ChemCam) instrument on the Mars Science Laboratory mission's Curiosity rover. The instrument uses a telescope for spectroscopic analysis of chemical elements in targets such as rocks or soil. The same telescope serves the instrument's camera, called the remote microimager. For this image, the remote microimager photographed a dollar bill from 10 feet (3 meters) away.

ChemCam was conceived, designed and built by a U.S.-French team led by Los Alamos National Laboratory in Los Alamos, N. M.; NASA's Jet Propulsion Laboratory in Pasadena, Calif.; the Centre National d'Études Spatiales (the French government space agency); and the Centre d'Étude Spatiale des Rayonnements at the Observatoire Midi-Pyrénées, Toulouse, France. Researchers will use the tools on the rover to study whether the landing region has had environmental conditions favorable for supporting microbial life and favorable for preserving clues about whether life existed.>>

Thanks Neufer. Having watched the JPL live feed of the landing of Curiosity on Mars and seen the first pictures in a packed planetarium last night, I do believe that Providence has favored our endeavors, and that we may be entering a new age, perhaps marked from A.D. MCMLVII. Now if we could just start working toward "E Pluribus Unum" on a global scale ... .

[Michael112914]

Moderator's note: The following post contains pseudoscience but I was too late to clear it off before a discussion happened.

Pertinent to discussion here regarding Hancock, Bauval, and a few others, let me say this:
...
Astronomers Tony Fairall and Ed Krupp claim that, in 10,500 BC, the vernal equinox was in Virgo, and not in Leo (as claimed by Hancock and Bauval).

Wrong. In 10,500 BC, the vernal equinox was in Leo, by any meassure or interpretation. In that year, the vernal equinox's ecliptic longitude was west (to the right) of Denebola, the eastmost (leftmost) star in the sickle-&-right-triangle lion-asterism of Leo.

What's the explanation for Fairall's and Krupp's erroneous claim?

Well, the equatorial co-ordinates, (the 2000 Right-Ascension (RA) and declination) given by Fairall, for the vernal equinox in 10,500 are exactly what they'd be if he'd assumed that he precession rate has always had its current value (about 50.28 arcseconds per year, or 360 degrees per 25,772 years).

But that's known to be incorrect. The precession rate has been increasing, and was lower during all of the past 12,500 years.

About 10,500 years ago, it reached a minimum of only 49 arcseconts per year. Because that was a minimum, it spent some time around that value.

On its way between 49 and 50.28, its variation was pretty much linear. And, because it spent some time near its minimum value, then if we assume that its average value during that 12,500 years was the average of 49 and 50.28, then that average will be a bit high--The actual average precesion-rate is actually somewhat less, over that 12,500 years, than the average of 49 and 50.28 arcseconds per year.

Using that average, the average 49 and 50.28, over the 12,500 year interval, gives a vernal equinox position, for 10,500 BC, that is west (to the right) of Denebola, the east boundary of the sickle-&-right-triangle lion asterism. In other words, by ecliptic longitude, the vernal equinox of 10,500 was in Leo Proper.

(By "in Leo Proper", I mean within the ecliptic longitude range of the lion asterism, bounded by Denebola (Beta Leonis) and Epsilon Leonis (the tip of Leo's sickle).

Oh yes, another thing that Fairall and Krupp disregarded (in addition to the variation of the precession-rate) was the proper motion of the stars--Denebola in particular.

Denebola, in 10,500 BC, was noticibly farther east (leftward) than now. That means that Leo's right-triangle was noticibly longer than it is now. (But not enough to spoil Leo's lion-look).

Some say that the Egyptians didn't recognize Leo as a lion. But advocates of the Age of Leo construction of the Lion Statue aren't saying that it was built by Dynastic Egyptians. Fairall and Krupp don't know what the late Pleistocene people recognized as constellations. It doesn't matter--Leo looks like a lion in the upright resting position--the Sphinx's position. Look at a side-view of the Sphinx, and a diagram of Leo, side-by-side.

Some point out that it would be difficult to perceive Leo in the sky when the sun is in Leo, because it would be glared-out by the nearby sun. But it's long been of interest to many people what constellation the sun is in at a particular time. The fact that the constellation isn' visible when the sun is in it doesn't change the fact that the sun is in it, and that many have considered that interestng or significant.

Fairall and Krupp are astronomers. How likely is it that they don't know that the precession rate didn't always have its current value, and that assuming that it did would give an estimated 10,500 BC vernal equinox farther east than it acutally was? How likely is it that they don't know about stars' proper motion (the stars gradual movement in the sky, noticible over the millennia)?

So what are we talking about here? Honest error, or dishonesty? You be the judge.

Michael

[Nitpicker]

Pertinent to discussion here regarding Hancock, Bauval, and a few others, let me say this:
...
Astronomers Tony Fairall and Ed Krupp claim that, in 10,500 BC, the vernal equinox was in Virgo, and not in Leo (as claimed by Hancock and Bauval).

Wrong. In 10,500 BC, the vernal equinox was in Leo, by any meassure or interpretation. In that year, the vernal equinox's ecliptic longitude was west (to the right) of Denebola, the eastmost (leftmost) star in the sickle-&-right-triangle lion-asterism of Leo.

What's the explanation for Fairall's and Krupp's erroneous claim?

Well, the equatorial co-ordinates, (the 2000 Right-Ascension (RA) and declination) given by Fairall, for the vernal equinox in 10,500 are exactly what they'd be if he'd assumed that he precession rate has always had its current value (about 50.28 arcseconds per year, or 360 degrees per 25,772 years).

But that's known to be incorrect. The precession rate has been increasing, and was lower during all of the past 12,500 years.

About 10,500 years ago, it reached a minimum of only 49 arcseconts per year. Because that was a minimum, it spent some time around that value.

On its way between 49 and 50.28, its variation was pretty much linear. And, because it spent some time near its minimum value, then if we assume that its average value during that 12,500 years was the average of 49 and 50.28, then that average will be a bit high--The actual average precesion-rate is actually somewhat less, over that 12,500 years, than the average of 49 and 50.28 arcseconds per year.

Using that average, the average 49 and 50.28, over the 12,500 year interval, gives a vernal equinox position, for 10,500 BC, that is west (to the right) of Denebola, the east boundary of the sickle-&-right-triangle lion asterism. In other words, by ecliptic longitude, the vernal equinox of 10,500 was in Leo Proper.

(By "in Leo Proper", I mean within the ecliptic longitude range of the lion asterism, bounded by Denebola (Beta Leonis) and Epsilon Leonis (the tip of Leo's sickle).

Oh yes, another thing that Fairall and Krupp disregarded (in addition to the variation of the precession-rate) was the proper motion of the stars--Denebola in particular.

Denebola, in 10,500 BC, was noticibly farther east (leftward) than now. That means that Leo's right-triangle was noticibly longer than it is now. (But not enough to spoil Leo's lion-look).

Some say that the Egyptians didn't recognize Leo as a lion. But advocates of the Age of Leo construction of the Lion Statue aren't saying that it was built by Dynastic Egyptians. Fairall and Krupp don't know what the late Pleistocene people recognized as constellations. It doesn't matter--Leo looks like a lion in the upright resting position--the Sphinx's position. Look at a side-view of the Sphinx, and a diagram of Leo, side-by-side.

Some point out that it would be difficult to perceive Leo in the sky when the sun is in Leo, because it would be glared-out by the nearby sun. But it's long been of interest to many people what constellation the sun is in at a particular time. The fact that the constellation isn' visible when the sun is in it doesn't change the fact that the sun is in it, and that many have considered that interestng or significant.

Fairall and Krupp are astronomers. How likely is it that they don't know that the precession rate didn't always have its current value, and that assuming that it did would give an estimated 10,500 BC vernal equinox farther east than it acutally was? How likely is it that they don't know about stars' proper motion (the stars gradual movement in the sky, noticible over the millennia)?

So what are we talking about here? Honest error, or dishonesty? You be the judge.

Michael

See the following link (Stellarium bug report) for a good description of possible inaccuracies in precession calculations (especially going back as far as 10,500 BCE). You might have to make your case (rather than just state it) if you are going to convince anyone who cares:

https://bugs.launchpad.net/stellarium/+bug/1090215

Accuracy for most precession calculations is only between 4000BC and 8000AD, beyond that is uncertain.

The general formulae for precession of the equinoxes is subjected to long term errors as the behaviour of the motion is uncertain. One of the points often missed by most is that one cycle of 26,500 years does not return to the same place in the sky. Physically, this is caused by the torque (Q) of the Earth's rotation, and is not easy to determine its exact influence. (It is complicated to derive!)

Ultimately, this is because of the 'obliquity of the ecliptic' /epsilon/ as the Earth's axis is not fixed but can vary between 22 and 25 degrees. Its period is some 41,000 years. I.e. in 14000AD, the tilt is predicted as 22deg 38' 01.9". In 8000BC, it was 24 deg 13' 42,1". In 19466AD it will be exactly 23 degrees.

There should be roughly about 2 or 3 degrees difference in declination (+ve for the pole in northern hemisphere -ve in the pole south hemisphere) between the pole position 26000 years hence. Motion is actually a spiral not circular. (See attached figure) Worst this difference is a different amount each 26,000 years, cycling as a combination of both the 26,000 and 41,000 year. Biggest change expected about 210,000 year hence, smallest 830,000 years hence. (as Stellarium only moves 99,999 AD, these are not relevant. You only need to be right for about eight precessional cycles.)

The motion of the Earth is very complex group of physical processed. I.e. It included nutation, varying rotational velocity, change is Earth's eccentricity orbiting the sun, etc.

Recommend you read;
1) Laskar, J., "Accurate spin axes and solar system dynamics: Climatic variations for the Earth and Mars", A&A., 416, 799 (2004)
2) Simon et.al., "Precession Formulae and Mean Elements for Moon and Planets ", A&A., 282, 663 (1994)

Regards, Ari

Note: The statement by Fabien; "The Sun should be in the location in 25,722 years (or 25,920 if you go by older standards) from now. It is not -- it takes 26,500 years for that to manifest." is essentially wrong.

[Nitpicker]

Also, here is a screenshot of how Stellarium simulates the Northward Equinox in 10,500 BCE (which is probably not exact). Shown on the diagram is the equator (blue), the ecliptic (red), the ecliptic coordinate grid (olive coloured; current epoch shown, but you get the idea), and the modern IAU defintion of the constellation boundaries (dashed red). My opinion is there really isn't much meat to the argument, one way or another.

10,500 BCE

[Chris Peterson]

The main issue here is that Hancock and Bauval are pseudoscientific frauds, and simply bringing them up is enough to get one banned from the Asterisk.

[Nitpicker]

I didn't even bother looking up Hancock and Bauval. Regardless, it seems like the Northward Equinox was near the boundary of Virgo and Leo (based on either the modern or vague, ancient definition), circa 10,500 BCE. Edit: Of course, this date is roughly 10,000 years before the Babylonians first divided the ecliptic evenly into the 12 zodiacal signs.

[geckzilla]

Yeah, it slipped through because of Thanksgiving. Note that any further promotion of pseudoscience here will be subject to the usual moderator action which is especially harsh for first-time posters and/or guests.

[Michael112914]

First, if anyone wants to say that my previous post, or this one, contains “pseudoscience”, then I invite them to actually specify a statement in the post that is “pseudoscientific”, or demonstrably incorrect.

Here’s a recent graph, from astronomer Jaques Laskar, showing how the precession-rate has varied over the millennia.



In case the image doesn’t post, here’s a link to it:
http://mb-soft.com/public/preces01.gif


As I mentioned before, when Fairall told the equatorial co-ordinates (RA and declination) of the vernal equinox in 10,500 BC, the position that he gave was exactly what you’d get if you assumed that precession has always had its current rate.

Don’t take my word for that. Determine it for yourself.

In every regard, I interpreted Laskar’s graph in the way that’s least favourable to my claim.

Laskar shows several lines, graphing precession-rate as a function of time. The green line doesn’t have s low a minimum as the others, making it less favourable for my claim, and so it’s the one that I used.

The green line’s minimum around the time of interest is 49 arcseconds per Julian year.

The current rate is 50.28 arcseconds per Julian year.

I used the average of 49 and 50.28 arcseconds per Julian year. That implies approximating the curve with a straight line between now and 10,500 BC.

But, for one thing, the curve is upward-curving over that interval. That means that the straight-line approximation implies overly much precession during that interval. …something unfavourable to my claim that the equinox was farther east in 10,500 BC.

For another thing, as I mentioned before, the curve spends some time near its minimum of 49, something that isn’t reflected in my linear approximation of the rate.

Another way in which I interpreted Laskar’s graphs unfavorably for my claim is my use of the green curve. As I said, of the several curves in the figure, the green one is the only one with the higher minimum in that region. Additionally, the blue curve, with a lower minimum, is the one that only extends over a 20,000 year period, suggesting that it’s intended to be accuracy-optimized for that period, which covers the interval of interest.

The other thing that most planetarium software probably doesn’t consider is proper motion. The stars gradually move in the sky, with respect to eachother. Denebola, the east (left) apex of Leo’s right triangle, and the east boundary of “Leo Proper” (Leo’s sickle and right-triangle), is a fairly fast-moving star. During the past 12,500 years, Denebola has moved about 1.72 degrees, roughly westward.

Any accurate determination of which side of Denebola the vernal equinox was on in 10,500 BC must consider the varying precession-rate, and Denebola’s proper motion.

When those two things are considered, then you’ll find that, in 10,500 BC, the vernal equinox was about 2/3 of a degree west (rightward) of Denebola.

In other words, in 10,500 BC, the vernal equinox was about 2/3 degrees into Leo Proper.

In order for the vernal equinox to be to the east of Denebola, it would be necessary for my approximation of the precession during the interval, based on my linear approximation of the rate, to be too low. In fact it would have to be off by 42% as much as the constant 50.28 assumption is, over that interval.

I’ve told why my precession-estimate is high. But, in any case, looking at the graph, it’s obvious that the linear approximation can’t result in an integral 42% as far off as the one that results from the constant 50.28 assumption.

The precession over that interval is the time integral of the rate over that integral. You can do it by Simpson’s rule if you want to, but you’ll find that, as I said, my estimate for the accumulated precession over the interval is a high estimate…unfavourable to my claim. In other words, the equinox in 10,500 would actually have been a little farther west (farther into Leo Proper) than the 2/3 degree figure that I stated.

But a look at the graph shows that the constant 50.28 rate-assumption is humungously farther off than any error of my linear approximation could be.


Nitpicker:

You said:

See the following link (Stellarium bug report) for a good description of possible inaccuracies in precession calculations (especially going back as far as 10,500 BCE).

I didn’t use Stellarium.

You might have to make your case (rather than just state it) if you are going to convince anyone who cares

Sure, reporting what I determined doesn’t prove it.

But I hope you’re not asking for a complete demonstration of the determination here. If anyone is interested, then I invite them to determine it for themselves. If anyone isn’t interested enough to do the determination for themselves, then it remains, for them, my word vs someone else’s.

I’m merely stating what I determined, and telling the information that I used, and which two astronomers disregarded, when they concluded that the vernal equinox was within the boundaries of modern Virgo in 10,500.

If anyone would like to use software to make the determination, then I emphasize that it’s necessary to use software that accounts for the varying precession-rate, and for proper motion.

Also, here is a screenshot of how Stellarium simulates the Northward Equinox in 10,500 BCE (which is probably not exact).

It isn’t. It shows the vernal equinox as being east (left) in ecliptic longitude, with respect to Denebola. That’s because Stellarium disregards variation of the precession-rate, or proper-motion, or both.

I’m not criticizing Stellarium. I like its realistic beauty. But it just isn’t intended for accuracy at times that are 12,500 years in the past or future.

My opinion is there really isn't much meat to the argument, one way or another.

Yes, the vernal equinox was quite close to Denebola in 10,500 BC. Most likely that’s what made 10,500 BC a time of interest for Hancock and others before him. Most likely, at some point, someone asked an astronomer when the vernal equinox entered Leo, or the “Leo Proper” sickle-and-right-triangle asterism’s range of ecliptic longitudes. The astronomer, according to that assumption answered “Around 10,500 BC”. If so, he didn’t disregard variable precession-rate or proper motion.

I didn't even bother looking up Hancock and Bauval. Regardless, it seems like the Northward Equinox was near the boundary of Virgo and Leo (based on either the modern or vague, ancient definition), circa 10,500 BCE.

Yes, and I suggest that its nearness to entering Leo Proper at that time was the thing that made the year 10,500 BC of interest—after someone found that out by asking an astronomer.

Edit: Of course, this date is roughly 10,000 years before the Babylonians first divided the ecliptic evenly into the 12 zodiacal signs.

Of course. But Leo’s sickle-and-right-triangle suggests a lion in the upright-rest position.

At this time of year, Leo rises early in the morning, before sunrise, so check it out for yourself.


Chris:

You said:

The main issue here is that Hancock and Bauval are pseudoscientific frauds

I clarified at the outset that I don’t subscribe to Hancock’s prehistoric super-civilization, or his “Orion correlation”.

My topic wasn’t Hancock. I said that in my initial post, quite clearly. My topic was the matter of which side of Denebola the vernal equinox was on, in 10,500 BC. It was about 2/3 of a degree west (rightward) of Denebola.

…about 2/3 of a degree into Leo Proper.


Michael112914

[Chris Peterson]

First, if anyone wants to say that my previous post, or this one, contains “pseudoscience”, then I invite them to actually specify a statement in the post that is “pseudoscientific”, or demonstrably incorrect.

If you want to discuss how we can determine where the NCP was in the distant past, that's one thing. But why start out with a reference to a pair of scientific frauds? It just gives the impression that your interest lies not in the science and math, but to supporting some sort of historical significance that doesn't exist.

[Michael112914]

If you want to discuss how we can determine where the NCP was in the distant past, that's one thing. But why start out with a reference to a pair of scientific frauds? It just gives the impression that your interest lies not in the science and math, but to supporting some sort of historical significance that doesn't exist.

My interest in this matter lies in factual astronomy. My purpose wasn't to support Hancock, but if the facts support him regarding the matter of where the vernal equinox was in 10,500 BC, that's ok, because my purpose isn't to support, or to not support, anyone.

That doesn't mean that I'm posting to support Hancock. I've clarified that I don't subscribe to Hancock's main theses--I don't believe his prehistoric super-civilization or his "Orion correlation".

Two astronomers published an incorrect statement, based on an obviously wrong assumption (the assumption that the precession-rate was always what it is today), and based on disregarding Denebola's proper motion. They did it to debunk pseudoscience. Debunking pseudoscience is a laudable and noble goal.

But there are other better ways to refute Hancock's prehistoric civilization (It would have left a lot of signs that aren't there). There's no need to use an incorrect astronomical statement to refute it.

Astronomers are professionals, who have the public trust. That carries a responsibility.

I have nothing against debunking what one feels is incorrect, but when incorrect information is used in the service of the debunking, then I emphatically say that the ends don't justify the means.

Michael112914




I was merely addressing an astronomical question.

[Nitpicker]

Actually, I think Stellarium does model the proper motion of Denebola and a few other bright, close stars. Less sure about whether Stellarium's rate of precession is constant, or not, because I don't care enough. The points are that:
1) the zodiac and the modern constellation boundaries were only defined some 10,000 years or more afterwards,
2) any date in ancient history has a considerable uncertainty,
3) precession has some uncertainty so far in the past,
4) there is little to suggest that what we call the asterism Leo was considered a lion by anyone 12,500 years ago,
5) the position of the Northward Equinox in 10,500 BCE was hardly the only evidence used to debunk the pseudoscience,
6) ignoring the above points, the Northward Equinox was very close to any reasonably definable boundary between Virgo and Leo in 10,500 BCE (which may or may not be related to the position of Denebola), such that if anyone nominated the "wrong" sign of the two, they wouldn't be wrong by much, and it wouldn't mean anything beyond that, then or now.

[Chris Peterson]

Actually, I think Stellarium does model the proper motion of Denebola and a few other bright, close stars. Less sure about whether Stellarium's rate of precession is constant, or not, because I don't care enough.

Modern precession calculation algorithms (polynomials combined with periodic elements) derived from numerical integration models produce values that are accurate to a few arcseconds over historical periods (~10,000 y) and to a few arcminutes over 100,000 y or more. Code is readily available for anyone who wants to play around with long intervals. Most programs like Stellarium don't use such methods because they are computationally intensive and are rarely of any use for the intended audience.

[Michael112914]

Nitpicker, you're picking nits that aren't there. Fairall said that, in 10,500 BC, the vernal equinox was in the modern constellation-boundaries of Virgo. Period. That false statement, for which Ed Krupp, as well, is quoted, is what I was answering. Is a point 2/3 of a degree of ecliptic longitude degree into Leo Proper (2/3 of a degree of ecliptic longitude west of Denebola) within the modern boundaries of Virgo?

I anwered a simple astronomical claim. My answer is that, in 10,500 BC, the vernal equinx was not within the modern constellation-boundaries of Virgo.

As for the possible significance, to the people of that time, of the vernal equinox's position 2/3 of a degree of ecliptic longitude into Leo Proper--I'd be glad to discuss that as well. But please lunderstand that, if we discuss that, we're departing from the topic of astronomy, and we could then be accused of being off-topic. Besides, the reason why my post was, at first, designated as "pseudoscience", was precisely because I mentioned the context and background of the astronomical issue. So, the charge of "pseudoscience" could again be made, if we discuss those other considerations regarding the relevance of the astronomical fact. ...instead of just the astronomical question itself.

Nitpicker said:

I think Stellarium does model the proper motion of Denebola and a few other bright, close stars. Less sure about whether Stellarium's rate of precession is constant, or not, because I don't care enough.

You don't need to, because you don't use Stellarium for such distant times. There's rarely a need to.

Nitpicker said:

The points are that:

1) the zodiac and the modern constellation boundaries were only defined some 10,000 years or more afterwards,

Quite so, which is why I wondered about the relevance of Fairall's statement that in 10,500 BC the vernal equinox was in the modern constellation boulndaries of Virgo.

However, our modern constellation boundaries are entirely irrelevant when we're referring to a point that's within Leo Proper, the lion-asterism consisting of Leo's sickle and right-triangle.

(About your objection that pre-Babylonian people might not have seen a lion in Leo, I'll answer that when I get to it below)

2) any date in ancient history has a considerable uncertainty.

...Not quite sure what you mean, or how it's relevant.

At the risk of talking "pseudoscience", I readily agree that not all facts about ancient or prehistoric matters are known, including the exact dates of events, such as the dates at which some un-inscribed statues were built. I'm guessing that that's what you were referring to. If so, then I quite agree. But that isn't an astronomical issue.

3) precession has some uncertainty so far in the past

Maybe that's why Laskar's precession-rate graph, which I recently posted here, has 3 or 4 precession-rate curves, instead of just one.

I repeat that, among Laskar's precession-rate curves, I chose the one that is least favorable to my claim.

Or maybe you'r doubting that the precession over the relevant 12,500 years is similar to any of the curves in that graph. Then let me re-word my statement: By the only long-term precession-rate information that (or you?) can find, the vernal equinox in 10,500 BC was not in the modern constellation-boundaries of Virgo.

Certainly, if you have another precession-rate curve, and if it's from someone as distinguished and respected as Jaques Laskar, then by all means share it with us.

...But until you do, Laskar's graph is all we have.

Uncertain? But when Fairall and Krupp said that the vernal equinox in 10,500 was within the modern constellation-boundaries of Virgo, they expressed it as a certainty, a fact. If the matter is sufficiently uncertain, then maybe you're saying that they shouldn't have made that statement of fact.

4) there is little to suggest that what we call the asterism Leo was considered a lion by anyone 12,500 years ago,

...and so...?

That statement, too, doesn't bear on the correctness of my answer to Fairall and Krupp. What anyone considered Leo Proper to look like during the late Pleistocene epoch wasn't part of my specific answer to Fairall and Krupp.

Anyway, if we can discuss it, even when, in my initial post (in which I spoke of topics that got the post labeled as "pseudoscience"), I never said that it was a certainty that people of 10,500 BC regarded Leo Proper as looking like a lion. If you'll re-read my initial post, I spoke of an intriguing possibility. If you think that I claimed a certainty about how people, then, perceived Leo, then please quote that passage in that initial post.

That being said, your objection above has an answer that was in my initial post:

Leo Proper looks like a lion. The curve of the sickle resembles the lion's mane. The right triangle resembles the haunches of a lion in the upright-rest position--the position of the Giza Lion Statue. As I said, look at a side-view of that statue, and a diagram of Leo Proper, side by side.

As I also said, Leo rises early, visible in the sky some time before sunrise, at this time of year. Looking at it for yourself is the only way for you to judge, for yoursel, whether or not its appearance suggests a lion.

5) the position of the Northward Equinox in 10,500 BCE was hardly the only evidence used to debunk the pseudoscience,

Entirely irrelevant. I made it clear, in my initial post here, and several times since, that I don't subscribe to Hancock's theories about a prehistoric super-civilization, or his Orion-correlation.

In fact, I myself said, here, what you just said, above. I pointed out that, because there are other criticisms of the prehistoric super-civilization (the signs that it would have left aren't there), and his Orion-correlation, then therefore there's no need to use false facts based on incorrect evidence, in order to criticize those theories. In fact, I criticized the use of false facts in the service of debunking. We we quite agree on that. Thank you.

6) ignoring the above points, the Northward Equinox was very close to any reasonably definable boundary between Virgo and Leo in 10,500 BCE

No argument there. So what?

The vernal equinox was 2/3 of a degree of ecliptic longitude into Leo Proper. That means that it was not/u] within the boundaries of modern Virgo.

If you're speculating about Pleistocene constellation-peceptions, then I'll answer that, if the vernal equinox is clearly within Leo Proper, then there'd be no perception of ambiguity regarding whether or not that equinox was closer to something else than to Leo Proper (I mean, because it was in Leo proper.

And no, 2/3 of a degree isn't too close to say which side it's on.

(which may or may not be related to the position of Denebola)

Incorrect. I haven't heard of anyone saying that Leo would look like a lion without the structure of which Denebola is a part. So, if we're talking about the lion-looking asterism (the one in modern Leo), then we're talking about something that includes Denebola, as its east (left) boundary.

, such that if anyone nominated the "wrong" sign of the two, they wouldn't be wrong by much

On the contrary, if they said that the vernal equinox in10,500 was within the modern constellation-boundaries of Virgo, when actually it was within the ecliptic-longitude range of Leo Proper, they'd be completely wrong about a plain Yes/No matter.

And if they just said that it would be debatable which asterism the equinox was closer to--when it was inside the ecliptic longitude range of one of them, they'd be unambiguously wrong about that as well.

, and it wouldn't mean anything beyond that, then or now.

Again, not entirely sure of your meaning. Anyway, I wasn't talking about the meaning of where the vernal equinox was. I was talking about the fact of where it was. That's what the two above-named astronomers made a statement about, and said it as an objectively certain fact. Fairall and Krupp said that in 10,500 BC, the vernal equinox was within the modern constellation-boundaries of Virgo. It wasn't. Simple as that.

Michael112914

[Nitpicker]

I have no idea which definition of boundaries anyone was discussing or quoting with any certainty. I haven't researched deeply into any claims by anyone as it is just not important enough. But I shall repeat my point (again): if anyone has made a mistake on the location of the Northward Equinox in 10,500 BCE, it seems to be a rather small mistake, with no great consequence. I make bigger mistakes for breakfast. (As for the motivation of the person making the mistake, perhaps you should ask them, if you don't consider it too rude.)

[geckzilla]

Find something else to discuss.