Senmut and Phaeton: Supplementary Notes MICHAEL READE D.S.C, for many years a marine navigator, now a confectionery technologist consultant to industry. The author's paper in our last issue concluded that the astronomical ceiling in the tomb of Senmut records the event remembered by the Greeks as the "Fall of Phaeton", involving the passage of the comet Venus and an inversion of the poles. Some further thoughts are appended here. 1. The Crocodiles on the Egyptian Monuments The two crocodiles (sometimes more) which appear on the astronomical ceilings appear to represent the constellations Serpens Caput and Serpens Cauda. The one which climbs up the back and peeps over the head of the hippopotamus (identified as Boötes) presents very little difficulty; a star globe marked with stars down to the 4th. magnitude makes it obvious that it must be Serpens Caput, especially if the globe is set for an upside-down earth (i.e. poles interchanged). Serpens Cauda presents much more difficulty, yet it appears that this must be the correct identification of the crocodile which is usually shown just below Leo. Serpens Cauda is nowhere near Leo in the sky and the explanation lies in the three temporally separate incidents which are run together on the Senmut ceiling. Stage 1 of the action shows the bull near Scorpius, with a cometary tail stretching towards Boötes; Leo has no place in this scene but Serpens Cauda has. Unfortunately, however, Boötes is shown to the right of the bull and Serpens Cauda to the left; if the positions of the two are interchanged, every requirement is satisfied (except in so far as a rather higher position in the sky for the crocodile would be better and it is also aesthetically disappointing that Boötes must always keep his back turned towards Serpens Cauda). Stage 2 of the action shows the bull between Leo and Boötes. Both Boötes and Leo are now correctly placed, but Serpens Cauda has no place in this scene (it would be some distance behind Boötes). The writer considers that these monuments were designed on the basis of very ancient documentary (more likely masonry) records, probably deriving from about 1500 years before Senmut's time. The records evidently included some items which were not at all clear to the ceiling designers, and the position and activity of Serpens Cauda will probably have been one of them. This resulted in some strange interpretations on some of the monuments, such as depiction of the lion with a crocodile's tail. If the identification of Serpens Caput and Serpens Cauda is correct, the small figure between them will be Ophiucus, who is also known as "the serpent bearer". It may also be noted that some authorities see Serpens Caput and Serpens Cauda as simply the head and the tail of a single celestial serpent which winds its way either through or around Ophiucus. Senmut seems to have seen the serpent as divided into either four or five sub-sections stretching up almost as far as Scorpius (as is quite plausible), each of them represented by a separate crocodile. 2. Mars and the Egyptian Underworld The supposition that the Egyptian Gods of the Underworld will represent stars which had disappeared from the sky at some time should be capable of verification (e.g. the 4 stars of the Southern Cross might well be amongst them; the eye which was lost by Horus in combat with Seth could also be traceable). If the ancient claim that the sun has changed its direction of travel four times is correct, the Egyptians would certainly have cause to treat the Gods of the Underworld with respect, for they would always be liable to resurrection and resumption of their former activity in the sky. It is conceivable that the history of Mars on the astronomical ceilings is a real life example of the perils which faced man in those Pantheistic days. Dr Velikovsky has indicated that Mars was known but was generally regarded as inoffensive prior to about 750 BC. Senmut constructing an astronomical monument in 940 BC could well have deemed it wise to ignore Mars, lest his undue exaltation should offend the more powerful Gods. Seti and Rameses II (and their successors), however, would have been well aware that one disregarded Mars at one's peril. They probably saw the earlier disregard of Mars as a dreadful mistake on the part of their ancestors, for which they had been punished a hundredfold. (Cf.: " . . . for I the Lord thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation . . ." - Exodus 20, v 5.) They would probably have instituted a thorough search of the old records to establish just what Mars had being doing at the time of the Phaeton episode, going on to construct new and better monuments on which Mars was suitably honoured, at the same time also taking great care to make sure that nobody else had been inadvertently omitted or not been given his proper place in the hierarchy. These suggestions are offered in the hope that they may help Egyptologists to pick up confirmatory evidence from the old texts. 3. The Distance off of Phaeton The Senmut ceiling gives at least some indication of the apparent size of Phaeton as it was coming in towards its closest approach which, according to the hour angle diagram already published, occurred very shortly before Phaeton was struck by Zeus/Jupiter (or the celestial bull was struck by Horus, should the reader prefer Egyptological to Graeco-Roman nomenclature). The great circle distance between Leo and Bootes is close to 33° of arc (that is, the space between adjacent faces of each, rather than the distance from centre to centre). Scaling off the northern panel of the Senmut ceiling, the length of the body of the bull is fully two-thirds of this angular distance but the greatest "thickness" of the body of the bull is only about a quarter of it. The thickness of the bull's body is more likely than its length to be representative of the apparent diameter of the comet, which would appear elongated in shape, probably also rather greater in "thickness" than the true diameter of its core or nucleus. A first approximation might therefore be that Venus appeared to subtend an angle of about 8° at the eye of an observer on the earth's surface when the action was nearing its height. The diameter of Venus is presently estimated at about 99% of the diameter of the earth. The angle it would subtend at the eye of an observer on the earth's surface when it was at distances of 4 to 50 earth diameters (measured centre to centre) is shown in the table below, which is calculated from the equations presented on the accompanying diagram. Establishing Distance of Venus by Angle Subtended Establishing Distance of Venus by Angle Subtended Angle a = height of centre of Venus above observer's horizon Angle q = angle subtended by Venus at eye of terrestrial observer Approximate distance from observer to centre of Venus = (N x D) - (D/2 x sin a). NOTE: The term (D/2 x sin a) is an approximation; the true distance is very marginally greater than that given by this over-simple formula. sin q/2 = (0.495 x D) / (N x D) - (D/2 x sin a) = N - 0.5 sin a The diagram is drawn for the condition: N = 4; a = 30°; q = 15° Values of N (Distance off of Venus in earth diameters, measured centre to centre) Angle subtended at observer if angle a = 20° (Venus low in sky) if angle a = 65° (Venus high in sky) 4 15.0° 16.0° 6 9.8° 10.2° 8 7.3° 7.5° 10 5.8° 5.9° 20 2.9° 2.9° 50 1.14° 1.14° This table would seem to suggest that it is unlikely that Phaeton approached more closely than about 6 to 8 earth diameters. A cross check is obtainable by another method. We know from the Phaeton story that Phaeton was mistaken for the sun, at least during the early stages of the action. The angle subtended by the sun at the earth's surface currently varies between a minimum of about 31.5 minutes in July and a maximum of about 32.6 minutes in January. For Venus to subtend an angle of 32 minutes (= 0.53°), the same calculation as above indicates that its distance off would have to be about 107 earth diameters. This clearly favours a greater distance off than that suggested above; even if the confusion with the sun occurred 5 or more hours before the closest approach, the distance off at this time would hardly be likely to exceed, say, 25-40 earth diameters if the closest approach was going to be to 8-10 diameters. There are, of course, legends that the sun appeared larger in ancient days than it does to-day; naturally, also, the ancients could have seen Phaeton as rather larger in apparent diameter than the sun without substantially affecting their initial assessment that it was actually the sun in charge of a new and inexperienced charioteer but these calculations do suggest that the hitherto common assessment of a closest approach of 4 diameters is likely to be appreciably too close. 10 diameters for the closest approach looks nearer the minimum allowable, more being easily conceivable, but it must be conceded that this is still a very crude estimate. For comparison, the distance from the earth to the moon is about 30 earth diameters. What the ancients would actually have seen would be the "sun" climbing much too high in the sky at the start of the day, followed by an over-correction and a swoop down to the much too low level at which it ultimately set the world on fire. The first impression of a high "sun" would have been given by the bearing and altitude of Phaeton at or near the proper time of dawn; the second would have been given by the later very marked increase in the visible diameter of Phaeton, much beyond the normal apparent diameter of the sun, making it appear to come quite exceptionally close. _________________________________________________________________ \cdrom\pubs\journals\review\v0202\41senmt.htm