NavList:

Brad Morris wrote:

So Dr. Kolbe, that'd be my entry.  Now I look forward to yours!  Will you wrap your problem up?

I would like to thank everyone who contributed to this little problem and I would like apologise for my delay in replying. The fact is that a storm blew through this region some ten days ago and the area was littered with trees and branches that had been brought down in the wind. One branch just managed to reach out to my telephone line as it came down and I have been without phone or broadband connection until yesterday, when the repair men finally worked their way through their list to my line.

I should explain by way of background that I am writing a fictional novel (a sequel to the Kindle book 'War Gold') in which a soldier, deep in the Sahara desert during WWII, came across a lost Egyptian temple. He sent some artefacts that he had discovered there for dating to several friends of his, who were experts in archaeology. But he refused to disclose the precise whereabouts of the lost temple as it was his intention to return to the site after the war to excavate it and he did not want other people getting there first. However, our soldier had been a yachtie before the war and so was facile in celestial navigation. And so, by way of insurance, along with the artefact which he sent to each of his friends, he also sends a photograph which at first sight looked like a general scene of the site where he had been doing some preliminary surveying. Now, our soldier got killed during the war so he never got back to his lost temple, but our modern day hero suspects that the identical photos sent to all the recipients of the artefacts some seventy years ago contains a clue to narrow down the search for the location of the lost temple.

I should say that I don't really have a really clever solution to the problem and I was hoping that one of the luminaries on this list could come up with something cunning, particularly something that did not require a clock in the photo but instead depended upon some special celestial phenomenon which would narrow down the time to a few seconds. That goal seems illusive though. Getting local time to within a few seconds in a photograph is relatively easy. Getting ephemeris time in one guise or another is a lot more difficult.

I would like to comment that despite the stated qualification that this was a site on land, many of you proposed a solution that depended on a horizon. Assuming that the sensible horizon can be linked to the observed horizon in the same (or, indeed, some other) way on land as it can at sea is never a good idea. There is invariably a gentle slope up or down even in the flattest looking deserts. The only places where you could reasonably expect the land to be 'flat' is in a playa, or fossilized lake bed. Even then, a 'short dip' solution would usually be required.

Thanks again to everybody for their efforts.

Geoffrey