> Belmonte in his paper seeks to refine the proposal
> of Spence in looking at the simultaneous transit
> of a pair of stars. One of the benefits of
> Belmonte’s proposal is that the Spence proposal
> brings forward the history of the Old Kingdom.
> To overcome the chronology problem, Belmonte
> proposes a solid alternative in the upper
> culmination of Phecda and Megfrez, which results
> in a determination for the Old Kingdom pyramids
> more in line with the accepted chronology of the
> Old Kingdom.
> Belmonte reviews and acknowledges prior proposals,
> including that of Piazzi Smyth and Proctor and
> Brusch that the pyramids were aligned to the pole
> star of the era. Thuban being the pole star of the
> era, which Belmonte notes is closest to the pole
> in 2787 BC. Belmonte acknowledges this as
> plausible but that it is out of line with the
> accepted chronology of the Old Kingdom.
> Rawlins and Pickering found a minor error in
> Spence’s calculations and propose an alternative
> approach leveraging 10 Draconis, which yields a
> date of 2638 BCE +/- 10 years. Spence in her
> reply, remains unconvinced by Rawlins and
> Pickering’s approach due to the faintness of 10
> Spence, Belmonte and Rawlins and Pickering
> proposals have each attempted to create a better
> fit to the accepted chronology of the Old Kingdom.
> Rawlins and Pickering briefly challenge the
> chronology by taking aim at the “rarely
> complete” kings list to support their earlier
> date of 2638 BCE.
> Puchkov puts forward an argument on pp 35-36 that
> the chronologies propose by Breasted, Shaw and
> Beckerath broadly align with the exception of the
> 9th and 10th Dynasties. Here, Breasted has
> accepted the king list and duration of Eusebius 23
> kings lasting 285 years whereas Shaw and Beckerath
> have allocated 35 years and 26 years total for
> these dynasties. Puchkov identifies that the
> majority of this discrepancy comes about due to
> the treatment of the 9th Dynasty.
> This duration for the 9th and 10th Dynasties has a
> flow-on impact to the dates for the Old Kingdom.
> Since there is room for debate on the duration in
> a chronology, an earlier Old Kingdom date should
> not be discounted. However, the next obstacle for
> an older Old Kingdom is the radiocarbon dates
> published in 2010.
> Puchkov writing on Hall of Maat, finds that prior
> to the 2010 paper of Ramsey et al the radiocarbon
> dates and chronologies were out of alignment.
> Puchkov provides a calibration of the radiocarbon
> data available for the Old Kingdom which shows a
> clear correlation with stellar dates for an older
> Old Kingdom (Figure 33). The same figure shows
> Spence and Belmonte’s proposals falling well
> outside of the expected range of calibrated data.
> Following review of Puchkov, we are left with two
> alternatives: continue to follow the chronologies
> of Shaw or Beckerath, or allow for an older Old
> Kingdom. Spence, Belmonte and [to a lesser extent]
> Rawlins and Pickering all sit in the later Old
> Kingdom dates. Each justify their proposals
> through proximity to the chronologists dates for
> the Old Kingdom.
> With the set of identifications I have made, the
> stories of the Westcar Papyrus are placed in
> December of the era. When combined with the
> assumption that the 15th day of the first month of
> Peret refers to the civil calendar which is known
> to wander, the dates proposed by Belmonte would
> drive an early October timeframe which does not
> fit the story lines of the Westcar Papyrus
> storylines. The date range proposed by Puchkov
> does and is supported by compelling evidence.
> Belmonte, J., On the Orientation of Old Kingdom
> Egyptian Pyramids, Archaeoastronomy, no 26, 2001
> Rawlins, D. and Pickering, K., Astronomical
> orientation of the pyramids, Nature, Vol 412, 16
> August 2001
> Puchkov, A., Egyptian Starry tales. Part I:
> “Stretching of the cord” ceremony for
> astronomical orientation of the Old Kingdom
> pyramids., accessed from academia.edu
> Puchkov, A., Hall of Maat discussion forum post,
> accessed from
Logically, there is an underlying assumption in all this, not by you but the astronomers who have studied this: That due north mattered. This is an assumption, nothing more. What if the aim was mskhtjw and in the process of aiming for it, a due north orientation was obtained. Belmonte pointed out that Alkaid began to dip below the horizon during the later 27th century especially in lower latitudes and so Alkaid, the presumed aim of Djoser's serdap, was no longer imperishable. That is the historical pretext for changing the aim. Spence proposed Kochab and Mizar, but Belmonte has the better model I think. The reason is that with Phecda and Megrez in the early 26th century BC, you get a transit delay of 2 arc-minutes which closely matches the Great Pyramid's rotation with respect to due north...without due north being in the cross hair!
And so the way I am putting this all together is that due north was never the aim, which also means that the Lightbody Thuban model does not apply. To build such an elaborate shaft just to be able to aim for Thuban's excursions doesn't make sense to me. The trial passages look architectural to me even if they were to lead to the northern stars in the pyramid. Something was being practiced on a small scale, perhaps an angle bisection.
Regardless, I think the aim was always mskhtjw and when Alkaid lost its imperishable attribute, Egyptian astronomers looked for an alternative within that same asterism due to its great religious significance. That alternative was the simultaneous transit of Phecda and Megrez which produces the uncanny orientation of the Great Pyramid's base in the early 26th century. This is the model you're up against. I have to sometime look at Puchkov's data to see if there are any problems with it. But I think you have everything in place for a decisive challenge of the current star-aiming model. May be Glen Dash had it right with the shadow method which makes this independent of the observational era. Really well done, Engbren.