dragon's head and tail

[Themis]

this is a question that i've posted among other comments time ago. i'm still seeking for the anwser. could anybody tell me when the ancient talked about the 'dragon's head (tail)', were they using the true or mean measure? for example, in Tetrabiblos, the dragon head is "mean" or "true"? could Ptolemy already calculated the mean Nodes movement? thanks is anybody could comment on this question.

[rahu]

the true node was only included in the early 70 when neil michelson of para research began including the true node in their emphemeri.i don't think the ancients had the math necessary for true node measurement.but i am not sure of this conclusion.maybe a moderator can clarify.
rahu

[sskohli]

hey rahu
i don't know about ptolmey, but the ancients of india have been using true nodes since ages.. as in your name, Rahu and Ketu are true nodes.

sandeep

[rahu]

hey sandeep
i didn't realize that vedic emphemerii described the retrogade and direct motions of the node ,i thought they just gave the average 3'/day retrograde motion.
rahu