Archaeoastronomy in the British Isles - The Stones and the Stars: Building Scotland's Newest Megalith - page 75

If, then, we have to accept that the megaliths record a program
of scientific observation, by any ordinary definition, how far did
the interpretation of those observations go? Thom believed that
the builders realized that the world was round and that either it
or the sky was very slowly precessing on its axis. As mentioned
above, the bright star Capella moved northward spectacularly dur-
ing the history of the megaliths. It rose and set well south of the
major-standstill (northerly) Moon even at the building of Stone-
henge I, but it had become circumpolar at the latitude of Mid
Clyth by 1760 b.c., never setting at all. All the other stars moved
with it, owing to precession, but Capella's behavior, crossing the
major-standstill markers, would be most conspicuous, and indeed
there are more markers for Capella in Thom's histogram of align-
ments than for anything else.
As for the world being round, as the builders moved north,
and the events on the horizon drew further apart, the astrono-
mers were in effect measuring the curvature of Earth's surface.
The significance of it might not have struck them had they not
reached Lund, on the extreme north of Unst, the most north-
erly of the Shetland Islands. There they erected a 13-foot high
stone, with a possible minor-standstill alignment to another
menhir nearby. At major standstill, in Neolithic times, allow-
ing for parallax and refraction, calculation shows that the Moon
itself would have been circumpolar for a day or two each month,
for the best part of a year - swinging around the sky without
setting. “This information must have been carried south and
would have had an effect on these people's philosophical reason-
ing,” Thom wrote in The Journal for the History of Astronomy .
“Could they have avoided the knowledge that the Earth was a
sphere? [ 13 ] ”
Game, set and match, to Thom? But before returning to the
Thom-Daniel debate, which has further ramifications - here is
an unprovable speculation from the Glasgow Parks Astronomy
Project, formulated by Gavin Roberts and the author. On natural
rocks near many megaliths, and sometimes even on the stones
themselves, there are carved mysterious “cup-and-ring” marks
that some think may have represented stars. Along with them
are found carved spirals, frequently in pairs, joined and coiling in
opposite directions (Fig. 4.20 ).