Four megalithic sundials: geometrical
The unexpected appearance of a novel "sundial" type of crop picture at Oliver's Castle on April 15, 2007 has stimulated much excitement and wonder around the world.
Charles Mallet and others have carefully investigated the flattening of fairly-thick plant stems there in oilseed rape; and have concluded that many of those plants were smoothly bent at a 90-degree angle to the ground, just above their roots (by unknown means), leaving them still alive yet growing horizontally.
Another "sundial" type of crop picture appeared next to Avebury Ring four years ago, on the night of the summer solstice June 21, 2003. A large crowd of people were celebrating nearby, yet no one noticed any human activity in the field where that picture was later found. One month later on July 20, 2003, yet another "sundial" (resembling Avebury) appeared at Hackpen Hill.
Then two years later at Avebury Ring on July 27, 2005, a "solar-lunar" type of crop picture appeared, which showed 19 small mini-circles in its very centre, evidently meant to symbolize the 19-year Metonic cycle of the Moon.
Could we be receiving messages today in Wiltshire fields, from a group of unknown crop artists who are more technologically advanced than ourselves? Or could all of these amazing crop pictures just be the work of clever human fakers?
In order to distinguish between those two hypotheses, I carried out careful geometrical analyses on all four solar-lunar crop pictures from 2003-2007. It seems that a deep astronomical code, based on megalithic astronomy from the ancient British Isles, was embedded carefully within all of them. Yet no one took any notice for the past four years, until a new picture at Oliver's Castle brought the subject more closely to our attention!
Over ten years ago in the 1990's, astronomer Gerald Hawkins likewise found a "hidden geometrical code" in many early (and much simpler) crop pictures. It involved five geometrical theorems which were demonstrably true, but which ancient experts such as Euclid had missed. Hawkins provided good evidence from that work for a paranormal origin of certain crop pictures, but still a slim possibility for human fakery remained. Now however, in light of this new work, the possibility for human fakery seems to have become almost negligible. Those "hidden astronomical codes" (which no one could decipher for the past four years) are more powerful and complex than the earlier codes found by Hawkins. They tell us the precise latitude North of the unknown artists who made such pictures, as well as (in one case) their approximate historical epoch.
How ancient people counted time by the Sun
Today most of us live in big cities such as London, Sydney or Los Angeles, and we live by "artificial time" kept on electronic clocks. We can hardly even see the stars, owing to light and/or chemical pollution in our air. By contrast, most ancient people lived very differently from us---far closer to Nature---and kept time by the Sun.
That is why hundreds of "stone circles" are still found in the countryside all across Britain or in other countries; because such stone circles were used by ancient people to count seasonal or even historical time. A typical yearly calendar based on carefully-placed standing stones is shown schematically below (from www.mythicalireland.com):
For high latitudes such as 50 degrees North as found in Britain, our Sun rises in the northeast on any summer solstice around June 21, but in the southeast on any winter solstice around December 22. Then at intermediate times of the year on March 20 (the spring equinox) or September 22 (the autumn equinox), it rises due east and sets due west. Now if a series of tall stones are placed carefully in the ground at proper locations, then one tall stone (the "gnomon") may cast a long shadow from the rising Sun on other stones some distance away, and thereby tell the "time of the year" accurately to one or two days.
One interesting feature of this kind of "stone clock" is that the rising Sun seems to "move" more rapidly from day to day, when it lies close to either equinox rather than close to a solstice. The precise angular location on any horizon where the Sun rises is called its "azimuth", and may be any of 45 degrees for due northeast (in the northern summer), 90 degrees for due east (fall or spring), or 135 degrees for due southeast (in the northern winter). Similarly, the Sun may set at 315 degrees due northwest (in the northern summer), 270 degrees due west (fall or spring), or 225 degrees due southwest (in the northern winter) (see aa.usno.navy.mil/data/docs/AltAz.html).
The precise angular height above the horizon of the Sun at any time of day is called "altitude". At sunrise or sunset, its altitude always equals zero. During the middle of the day, its peak altitude (due south as seen from Britain) will depend on latitude north, and also the summer or winter season (high or low in the sky respectively). Modern hourly sundials often use "altitude" to the tell the time of day. But for the megalithic field sundials to be discussed here, which only measure the rising or setting Sun, we only need to concern ourselves with "azimuth", because "altitude" will generally be zero.
All yearly sundials keep time according to what is known as the "tropical year"---how long it takes for the Sun to return to an identical location in Earth's sky---rather than a "sidereal year"---how long it takes for the distant stars to return to an identical location in Earth's sky. The two kinds of year are almost but not quite identical, because the daily spin axis of our planet processes about due north once every 26,000 years ("precession of the equinoxes"). There are two other very slow changes of Earth's motion over historical time: (i) a slow change of its tilt angle relative to the Sun; and (ii) a slow precession of its elliptical orbit about the Sun, both of which become relevant when analyzing megalithic sundials, and will be discussed briefly below.
Fortunately, we do not need to worry too much about how to build a precise, yearly observatory for the Sun out of standing stones, because an enterprising professor of astronomy at the University of Massachusetts, namely Judith Young, has already done so in a field near her university! Her modern stone observatory is called the "Sun-wheel", and two vivid pictures of how it keeps yearly time are shown below (see www.umass.edu/sunwheel):
On the spring equinox of March 20-21, our Sun rises due east at azimuth 90 degrees. A second tall stone was placed just to the right of due east in the photograph above, so that the rising Sun would be "framed" between two nearby stones just after it rises and moves south (a similar two-stone portal was used at Stonehenge). Later on the winter solstice of December 22-23, our Sun rises in the southeast near 122 degrees at the latitude of Boston (42 N). So now we see how such ancient sundials would have worked; and why they still fill the rural landscape, all across the modern British Isles.
Sunrise geometries at Avebury 2003
But why should we need to learn today about megalithic sundials? Personally I took little interest in the subject, until a series of "sundial" pictures appeared in Wiltshire fields, the most recent being Oliver's Castle of April 2007. Earlier in 2004, 2005 and 2006, the crop artists had shown other motifs based on the ancient Mayan calendar or modern wormhole theory. First Mayan calendars, then wormholes, and now sundials! They certainly expect us to have a wide range of knowledge. Or could each of those three different themes be coming from three different groups, using the same communications device (say a buried wormhole) near Silbury Hill?
In any case, if we wish to understand more clearly the four "sundial" pictures mentioned above, we should start with the easiest and most straightforward, namely Avebury of June 21, 2003:
Avebury 2003 shows an ancient and well-accepted sundial design, that has also been found on a few stones near Knowth or Loughcrew in Ireland (see below). Its "gnomon" or tall-shadow-casting stone is represented by a small white circle near the bottom of the figure (labelled with a red square), that has been embedded within a green "teardrop" shape. The upward, counter-clockwise flow of that teardrop then represents a north-to-west motion of the Sun's shadow upon other nearby stones, as shown upper right to top centre (white circles "8" to "0"), when proceeding from sunrise on June 21 to sunrise on September 22.
That same, slow, 91-day solar motion will be repeated four times within any 365-day year; and it serves as the primary astronomical basis for an ancient "Irish megalithic calendar", which was in widespread use throughout the British Isles from 3500 BC to 1000 BC. Later however it fell into complete disuse. Today it is known mainly for to its resemblance to a modern Celtic calendar, and also due to its rediscovery by Alexander Thom in the 1960's, when he was surveying megalithic sites all across Britain.
For simplicity, let us choose to begin any megalithic year on March 20 with a spring equinox. Such a date will correspond to "0" or the large white circle at top, when looking at a picture of Avebury 2003. Next we may count downward to "8" as a tiny circle along the middle-right until we reach June 21 (the summer solstice). Then we may count upward again from "9" to 16", and so return to the large white circle at top on September 23 (the autumn equinox). Next we may count downward again, but this time on the left from "17" to 24" until we reach a tiny white circle along the middle-left on December 22 (the winter solstice). Finally, we may count upward again from "25" to "32", until we return for a third time to the large white circle at top on March 20 (the spring equinox). That was how the megalith builders counted time 5000 years ago.
Not only are the many different stone locations shown at Avebury 2003 approximately correct; they are closely correct. For example, the large white circle "0" at top has been drawn much larger than either tiny circle "8" or "24" on left or right, because the spacing of solar azimuths becomes much larger within any one-eighth part of a quarter-year, when the Sun lies closer to an equinox than to a solstice.
In order to quantify that relationship, I measured angles of solar azimuth along the right-hand side of that picture (because the left-hand side had been distorted through perspective), and found predicted sunrise angles of 90, 73, 63, 56, 51, 48, 46, 44, 43 degrees when proceeding from "0" to "8". By way of comparison, true sunrise angles for latitude 58 N would be 90, 81, 73, 65, 57, 51, 45, 42, 40 degrees. Fairly close, but one would need a more precise measurement of those crop azimuth angles without any influence whatsoever of photographic perspective, to make an exact comparison.
In summary, the ancient Irish megalithic calendar divided any 365-day year into 32 equal parts of 11.4 days each, and that was the calendar shown at Avebury Ring on the summer solstice of 2003.
Avebury 2003 also appears in stone at two archaeological sites in Ireland
Strangely enough, a true megalithic sundial similar to Avebury 2003 was carved onto kerbstone K15 at Knowth in Ireland, sometime around 3500 to 2000 BC:
The stone-sundial shown there divides each quarter of any 365-day year into eight equal parts. In fact, a solid line was carved from its gnomon all the way to the left-hand edge of that rock, through an intermediate arc-triangle representing "8", to emphasize the fact. (I added a dashed line through another "8" on the right for purposes of clarity.)
Here we see a much more even spacing of azimuths than was shown at Avebury 2003, perhaps because it would be hard to carve an uneven spacing into hard rock. The total angle which any solstice sunrise "8" makes with the equinox "0" appears in this ancient sundial to be approximately 55 degrees, as compared with approximately 50 degrees as shown in Avebury 2003 (suggesting a slight increase of latitude to 60 N from 58 N).
A second stone-sundial, similar to the one shown above, has also been found at Loughcrew in Ireland.
Two broad spirals (one large, one small) which appear on the right-hand side of that Knowth rock are thought to represent a "large warm summer sun" or a "small cold winter sun" respectively. As if on cue, those two spiral symbols later appeared in crops at Fort Nelson on June 5, 2004, in the season that followed Avebury 2003.
Sunrise geometries at Oliver's Castle 2007
More recently on April 15, 2007, a second "sundial" type of crop picture appeared at Oliver's Castle north of Roundway. It was oriented precisely west-to-east in the high hilltop field where it was found. Several tall trees nearby cast their long shadows onto it late in the afternoon, to give the impression of a "gnomon". Everyone could see right away that it was meant to represent a sundial, but of what kind specifically?
That crop picture, when viewed from above, shows a simple and elegant construction using a series of eight overlapping circles and their intersections:
Yet this particular sundial seems harder to interpret than Avebury 2003, because it shows no fixed location for its gnomon. The precise location of any vertical-shadow-arm or gnomon depends sensitively on latitude. By trial and error, I found that placing a gnomon at position "10" in Oliver's Castle (red square) would yield satisfactory results, for the geographical location and field orientation where it was found.
Thus, by working from an accurately reconstructed model of that crop picture on graph paper (made using ruler and protractor), I found that placing a gnomon at position "10" would yield sunrise azimuth values of 50 or 130 degrees for the summer or winter solstices respectively; which are approximately correct for latitude 51 N, and the east-west field orientation of that crop picture as it was drawn. Actual values of sunrise azimuth at either solstice should equal 50 and 128 degrees for latitude 51 N (Avebury), or 48 and 130 degrees for latitude 53 N (Knowth). A slight change in the Earth's tilt over the past 5000 years may have shifted both values slightly further east today than in 3000 BC, but by only about one degree.
A time-dependent spacing of sunrise azimuths was likewise measured from my reconstructed model as 90, 79, 72, 67, 63, 59, 55, 52, 50 degrees, when proceeding from outer-edge location "0" (either equinox) to outer-edge locations "8" or "24" (either solstice). Actual values should equal 90, 83, 76, 68, 62, 57, 53, 51, 50 degrees at latitude 51 N. Such model-dependent angular measurements need to be further quantified, before we can draw any detailed conclusions.
In summary, Oliver's Castle appears to show a very general kind of sundial, since the precise location of its gnomon was not specified. For example, moving its currently-placed gnomon (red square) from "10" to "11" would give suitable values of sunrise azimuth for 48 N latitude, while moving it to "12" would give suitable values for 42 N latitude
Hackpen Hill 2003 shows a megalithic sundial with three different gnomons
Now as we begin to analyze this third sundial, matters will become even more complex, and we will truly begin to appreciate the high intelligence of those crop artists! One month after the first crop picture described above appeared at Avebury Ring, another crop picture of a similar kind appeared at Hackpen Hill on July 20, 2003:
When looking at this new picture, again we can see the same "small white circle" and "teardrop" shape as shown at Avebury 2003; but now there are three separate gnomons called G1 (red), G2 (blue) and G3 (yellow), all located within the same sundial. Each teardrop describes the slow seasonal motion of daily sunrise from any solstice to an equinox, as viewed along the horizon at altitude zero. The outermost part of Hackpen Hill likewise shows 32 separate "white circles", which would be expected for counting yearly time by an Irish megalithic calendar.
Still, this particular sundial shows no well-defined east, west, south or north. How are we supposed to interpret it? Its three gnomons G1, G2 and G3 lie at 120-degree angles to one another, and also at different radii from the centre. The entire picture would have been hopeless to interpret, had not those always-clever crop artists given us an essential clue. Thus, certain white balls along its outer perimeter were drawn with slightly-smaller diameters than the others; and it is to those "small balls" that we need to "connect the arrows", from any gnomon to its two azimuths at the summer or winter solstice.
Having found that essential clue, I connected G1 (red) to outer positions 8 and 24; G2 (blue) to outer positions 13 and 27; and G3 (yellow) to outer positions 3 and 17. A few of these assignments remain ambiguous, owing to occasional inaccuracies of drawing "small balls", but this scheme should be approximately correct as a whole. Next, having connected the arrows, I measured differences of solstice azimuth away from due east as 57 degrees for G1, 55 degrees for G2, or 60 degrees for G3; and could thereby deduce a narrow range of latitudes from 60 N to 62 N where this particular sundial would be functional. All of those latitudes lie too lie far north for anywhere within the British Isles; but could correspond to southern Greenland (unlikely), or more probably southern Norway (see below). More accurate measurements would again be useful without any photographic perspective.
A slight offset of gnomon G1 from due east at Hackpen Hill resembles a similar offset of the eastern passage at Knowth
Given the extreme care with which that Hackpen Hill crop picture was drawn, I found it remarkable that gnomon G1 (red) was placed intentionally with a slight offset from both outer positions "16" and "17", so as to lie essentially between them. What could this mean? The total angular interval between "16" and "17" equals (360 / 32) = 11.3 degrees, and so the observed offset would amount to 5 or 6 degrees away from the equinox (due east).
Of possible relevance here, both the eastern and western passages at Knowth were also built with a slight offset from due east or west, with azimuths of 85 or 259 degrees respectively. The highly advanced builders of Knowth could hardly have included such a big offset by chance:
The Knowth site as a whole shows fairly accurate alignments of its sunrise or sunset azimuths away from due east by 40 to 45 degrees at either solstice, consistent with a latitude of 53 N. Why then should its eastern and western passages have been built with an offset from due east or west by 5 or 11 degrees? In practical terms, sunrise enters that eastern passage 6 days after any spring equinox, while sunset enters the western passage 18.5 days before any spring equinox.
Some experts believe that those offset passages were meant to measure monthly cycles of the Moon, as well as yearly cycles of the Sun. Thus, when sunrise in 3000 BC entered that eastern passage at an azimuth of 85 degrees, it would take another three lunar months precisely of 29.5 days before the Sun would reach its summer solstice. In other words, it would take another (3 x 29.5) = 88.5 days when counting by the Moon, or (94 - 6) = 88 days when counting by the Sun. Similar calculations may be made concerning the western passage. Quite a few other aspects of Knowth likewise suggest that it may have been used as a lunar observatory as well as a solar.
Now here is the interesting part: in 3000 BC, it took 94 days to go from any spring equinox to a summer solstice, whereas today it takes 92 days. The reason is because Earth's slightly elliptical orbit has precessed around the Sun by 70 degrees since then, and so any spring-summer interval was located slightly further from the Sun then versus now.
Therefore, if Hackpen Hill was designed with the same broad logic as Knowth (it even looks like Knowth: see above), then the slight offset of its gnomon G1 from "16" towards "17" would suggest a general date of astronomical relevance between 3000 and 1000 BC, when spring seasons on Earth were still 94 days long. By looking very carefully, one can also see that gnomon G2 at Hackpen Hill lies offset between "4" and "5", while gnomon G3 lies offset between "25" and "26". Do you think they are trying to tell us something?
Avebury 2005 showed both solar and lunar azimuths to illustrate a 19-year astronomical cycle of the Moon
Lastly, we may close our analysis with the straightforward case of Avebury 2005, which appeared on July 27, 2005. It showed a four-armed Celtic cross, and included 19 secondary mini-circles within its centre most part (close to the "red square") that were apparently meant to symbolize a 19-year astronomical cycle of the Moon:
We can interpret this particular crop picture with ease, because an inspired professor of astronomy at the University of Massachusetts, Judith Young, has recently created a very similar "Sun-wheel" observatory in a field near her university (www.umass.edu/sunwheel). A schematic version of her modern standing-stone observatory is shown below:
Some standing stones (coloured in black) were placed to indicate where the Sun rises and sets, while other standing stones (coloured in red) were placed to indicate where the Moon rises and sets. Two kinds of stone are necessary, because our Moon rises and sets in general with a slightly different azimuth from our Sun. That happens for two reasons. First, when measured relative to Earth's equator, our Sun varies rather slowly in "declination" from +23.5 to -23.5 degrees each year, whereas our Moon varies more rapidly in declination by a similar amount each month. Secondly, our Moon may vary in declination every month from +28 to -28 degrees maximally, or else from +18 to -18 degrees minimally.
How long does it take to switch from one kind of variation to the other? It turns out that, once every 19 years, our Moon varies in declination by a maximal amount of +28 to -28 degrees; whereas halfway or 9.5 years between those two periods, it varies in declination by a minimal amount of +18 to -18 degrees. The precise number of years required to switch lies close to 19 when measured relative to the Sun, or 18.6 when measured relative to the distant stars.
This is called the "Metonic cycle" of the Moon, after the Greek astronomer Meton who supposedly discovered it Each period of maximal (+28 to -28 degrees) or minimal (+18 to -18 degrees) declination is then called a "lunar standstill". Any standstill is termed "major" if the Moon rises as far as possible outside of the Sun (28 degrees) relative to due east; or "minor" if the Moon rises as far as possible inside of the Sun (18 degrees). Our Moon reached its last major standstill in 2005-2006, beginning around June 2005 and continuing until June 2006. It will reach its next minor standstill in 2015. The Avebury crop picture of July 2005 was evidently meant to illustrate the onset of that last major standstill, beginning on a full moon only one month earlier.
Now having explained some basic astronomy, we will change our terminology back to "azimuths" from "declinations", because azimuths tell where the Sun or Moon will rise or set relative to any local horizon (and depend on latitude). In Judith Young's Sun-wheel, the maximal deviation of solar azimuths from east or west amounts to only 32 degrees at either solstice, because Boston lies at a relatively low latitude of 42 N relative to Avebury (51 N) or Knowth (53 N). Likewise, the maximal difference between azimuths for the Sun and Moon near Boston never exceeds 9 degrees at either standstill, owing to the low latitude there.
Next I measured precise values of azimuth from that Avebury 2005 crop picture as 52 and 132 degrees for the Sun (at either solstice); versus 39 and 145 degrees for the Moon at its major standstill (in the years 2005 and 2006), or 66 and 118 degrees for the Moon at its minor standstill (in the year 2015). By comparison, known values of solar azimuth are 50 and 128 degrees at Avebury (51 N), or 48 and 130 degrees at Knowth (53 N). Likewise, known values of lunar azimuth for a major standstill are 36 and 148 degrees at Knowth (53 N), or 25 and 162 degrees at Callanish (58 N).
Both solar and lunar azimuths would therefore seem to place Avebury 2005 within a narrow range of latitudes from 52 to 53 N. The Sun deviates there from due east by approximately 40 degrees on either solstice; while the maximal difference between azimuths there for the Sun and Moon is typically 13 degrees. More accurate measurements may allow us to refine those estimates in the near future. Finally, the precise sizes of "balls" (large-solar or small-lunar) in Avebury 2005 were used to specify a certain latitude of 52-53 N; but those ball diameters could easily be changed to indicate other latitudes, so long so the angular spacing of its four arms were likewise changed in tandem.
Alexander Thom, Martin Brennan and N.L. Thomas
We did not "invent" most of the ideas presented here. Instead, it should be noted that three scholars in particular: Alexander Thom, Martin Brennan, and N.L. Thomas, worked out most of the basic ideas concerning megalithic astronomy in the British Isles some years ago.
Alexander Thom was a professor of engineering at Oxford. He first surveyed megalithic sites all through Britain, and published his early results in Journal of the Royal Statistical Society (1955). Then he published two more articles in 1962 and 1964 which addressed megalithic units of length:
Next he went on to discover precise solar alignments at many stone circles, which led him to argue for a prehistoric solar calendar of 16 months (half of 32). His proposed 16-month year contained four months of 22 days, eleven of 23, and one of 24. He explored that topic further in Megalithic sites in Britain (1967), Megalithic lunar observatories (1971), and Megalithic Remains in Britain and Brittany (1978).
Martin Brennan discovered that "intensive sun-dialling" was practiced in ancient Ireland, with techniques both scientific and advanced. "Those were the oldest sundials in the world, and predate all others by thousands of years." He also explained how lunar theory was developed in the Boyne Valley, and emphasized that they were not just a people who understood the Sun. Later he wrote The Stones of Time: Calendars, Sundials and Stone Chambers of Ancient Ireland (1984):
More recently, Brennan has found that early Celtic explorers even made their way to western North America 2000 years ago, where they carved Ogham or Gaelic characters onto the rocks to mark a spring equinox (see "Martin Brennan at Anubis Cave equinox" on video.google.com/videoplay?docid=-1856547827596216006). .
N.L. Thomas has carefully interpreted many different stone inscriptions from Knowth or other megalithic sites, as described in his 1989 book, Irish symbols of 3500 BC. .
Finally, as an important addendum to such previous work, C. Knight and R. Lomas in their book Uriel's Machine (1999) argue that the ancient Book of Enoch was written somewhere in the British Isles just before the Flood (ca. 3100 BC). It describes a large megalithic observatory similar to the ones described above, except where each quarter of the year (91 days) had been divided into three parts rather than four or eight. Thus, every full year of 365 days would have contained 12 months rather than 16 or 32.
Some people believe that the ancient British Isles could have been a remote outpost of a more advanced Sumerian civilization. For example, "Shamsiel" in Enoch taught "signs of the Sun", while "Shamash" in Sumeria was a "god of the Sun". Furthermore, certain recovered cylinder seals from ancient Sumeria show star-like symbols which suggest that two kinds of calendar, using either 12 or 16 months, may have been in use at the time (see "Shamash" or "Annunaki" on Wikipedia).
Might some of those modern crop pictures be coming from the megalith builders themselves?
In light of these new geometrical and astronomical analyses, it has become clear that the four crop pictures discussed above: Avebury 2003, Oliver's Castle 2007, Hackpen Hill 2003 and Avebury 2005, could not plausibly have been made by local human fakers.
Instead, it seems increasingly plausible that the modern crop artists come from a culture which is more technologically sophisticated than our own, yet still have close links with a long-forgotten race of Irish megalith builders known as the Tuatha de' Danaan. Their name means literally "People of Anu" or "People of the Star-Sky". The Latin words "deus" and "dea" for "god" and "goddess" derive from them. The English words "Danube River" and "Denmark" also derive from them.
Most of what we know today about the Tuatha de' Danaan comes from studying megalthic sites, or from reading ancient legends such as those complied in the Lebor Gabala Erren (Leinster,1150 AD): "The Tuatha de' Danann came to Ireland in dark clouds. They landed on the mountains of Conmaicne Rein in Connacht, and brought a darkness over the sun for three days. Then they demanded kingship from the Fir Bolg. A battle was fought (the first battle of Mag Tuired) in which a hundred thousand Fir Bolg died. Thereafter the Tuatha de' Danaan took kingship of Ireland. Gods were their men of arts, and non-gods their husbandmen".
Now according to that same legend, the tall, fair-haired Tuatha de' Danaan were themselves defeated in battle just 200 years later by a dark-haired haired group of invaders from northern Spain known as "Milesians". And as if in confirmation of the legend, modern genetic research has shown that the inhabitants of western Ireland today near Connacht show certain rare DNA polymorphisms within their Y chromosomal DNA, shared by no other European people apart from the Basques.
Eachaid Ua Flainn, a poet from 985 AD, wrote: "The Tuatha de' Danaan had no vessels. No one knew whether it was out of the heavens, or out of the earth, that they came. Were they even men?" According to tradition, they had lived originally in a place called "Achaia" (possibly northern Greece), before they spent some years in "Lochlonn" (probably modern Norway). There they lived in "four great cities to the north" called Falias, Gorias, Finias or Murias, and taught science or other useful skills to the locals. Eventually they migrated to Scotland and Ireland around 2000 BC.
Some of the astronomical crop pictures discussed above seem refer to latitudes near 51-53 N, where Avebury and Knowth are located; whereas others seem to refer to a more northern range of 60-62 N, which might correspond to southern Norway. Likewise, Hackpen Hill seems to refer to a distant time in the past around 3000 to 2000 BC, when Knowth was first being built.
One long-time student of the Tuatha de' Danaan, a retired geologist called Tim O'Brien, has argued that the legendary term "Achaia" might refer to "Accad" in northern Sumeria (www.goldenageproject.org.uk/whodunit.html) where a group of advanced scientists once lived. After the collapse of that city in 2100 BC, did those scientists migrate elsewhere?
Just after the Flood (ca. 3100 BC), a frantic period of mound building began in low-lying areas all around the world, so that people would have somewhere safe to go if the flood waters returned. Silbury Hill was built for example during that period. By legend, Ireland was swept clear of any inhabitants for 300 years. Only by 2800 AD did a series of "invaders" once again begin to inhabit Ireland, as documented in the Lebor Gabala Erren. The Tuatha de' Danaan ("People of Anu") were supposedly the fourth of these, sometime around 2000 BC. Having left Accad in Sumeria after its fall (or perhaps Achaia in Greece), they would have had to travel first over land to Norway, and then later across the sea to Scotland and Ireland. It may have seemed logical for them to migrate to a relative place of safety such as the ancient British Isles, since their own ancestors ("Uriel" and "Shamsiel") seem to have had bulit megalithic sites there, one thousand years earlier.
Now the Tuatha de' Danaan who emigated to Ireland were reportedly tall, fair-skinned blondes or redheads with blue or green eyes. They dramatically upgraded the local Irish gene pool by interbreeding, so as to create the Celtic-Gaelic race we see today. St. Patrick recorded how one of their pure-bred women married an Irish king in 400 AD. They made the golden torc, and could move heavy stones with ease. But where did they come from originally? How did they reach Ireland by air? What kinds of technology might they have brought with them? And why do so many modern crop pictures appear near their ancient sites of settlement, often showing Celtic or even sundial-type astronomical motifs?
A table of solar solstice azimuths
A table of lunar standstill azimuths