Roy , I'm looking forward to the seeing the evidence for the orientations (and markings ), which must be based on the internal relations of the othostats and capstone as there is nothing external that is the usual stuff of archaeastronomy i.e. foresights etc . The possible number of internal relations is immense and likleihood of finding something apparently significant is consequently high . The orientations are predicated on the the structure being exactly as the builders left it .If there has been any movement or change , apart from the obvious case of the backstone then the argument for intentional alignments like that stone ,collapses .Worse , 50%of Portal Tombs have a surviving cairn and those that don't , as is the case at Trevethy have evidence of one .The surrounding cairn was the feature that at least allowed for erection of the capstone whilst supporting the orthostats .
Any surrounding cairn would diminish the number of possible plays of light except for the hole in the capstone which may not even be contemporaneous with the build , a masons view on this would be helpful i.e. to see what the tooloing may have been .
We do know about orientations of Portal tombs in relation to water courses and valleys and despite some attempts there has been nothing convincing in relation to astronomy .
Despite that it's great to see some time being spent on one monument we are sure to learn to something .[/quote]

Yes, the orientations are 'internal' and this is one of the reasons that we believe there has been no significant movement since it was erected.
If stone 7 were to be re-erected, we believe it would provide further evidence as to accuracy and intentionality of positioning and alignment.

We have indeed already observed an immense number of such internal relations and the complexity of 3 dimensional movements of light and shadow make it extremely difficult and time consuming to determine their significance - we have a lot of work to do!

We have yet to be presented with any evidence of there having been any surrounding or covering mound or cairn. Indeed our findings so far seem to indicate that this structure was more likely intended to be experienced as an open and dynamic device, not covered up as some 'Portal Tombs' appear to have been. Just because we cannot, as yet, determine how such huge slabs of granite could have been placed in position does not predicate the assumption that there must have been some other sort of mound or cairn to enable it. Some things are still a complete mystery to us, even with the technology we have available to us today, so we should not allow logical assumptions to become limiting factors in open enquiry.

As you so rightly said, we are sure to learn something here, and we look forward to continuing this amazing voyage of discovery. Thank you again for your valued contributions :)

What you say is vital. I cannot disagree.
We started (12 years ago!) with the 'usual astroarcheological stuff' but it rapidly got left behind by the internal light/shade aspects, which have their problems as you rightly point out. But as the years, and especially the last two, went by, the way the light and shadows it casts upon itself, throughout the day, and the year, play upon the worked stones became simply too astonishing to be dismissed as happenstance or co-incidence. It is like a giant sundial, a Solar Construct of great sophistication in its calendrical accuracy.
We make bold claims, but the evidence is compelling.
The time has come to abandon the "Anachronistic Archeological Paradigm"; the idea that the people who built and used this thing were witless savages.
And just to tickle the fancy, we have found a possible 'carving' that bears a remarkable resemblance to the Sumerian symbol for 60.
I am grateful for your interest.
David Kane.