On 12/08/2016 03:45 PM, Steve Allen wrote:
Except that Morrison and Stephenson and Hohenkerk only show the past. NASA polynomials attempt to predict the future, but (as seen in the data of this new publication) to their peril.
Yes, the Stephenson et al. paper is newer and presumably more authoritative and 'Theory' cites it first. I assume Espenak will update the other page eventually, and in the meantime it's an entertaining set of estimates. The 'Theory' file cites these two sources only to support the statement that we don't know historical solar time to more than about one-hour accuracy, a statement that I hope is vague enough to pass muster. If we wanted to get picky, we'd have to determine what's "historical": back to 3200 BC? or back to the earliest reliable astronomical records? if the former, we don't have even one-hour accuracy; if the latter, it depends on one's definition of "reliable". Still, the statement is in the right ballpark, which is all that's needed there.