NavList:

Hanno, you wrote:
"I cannot imagine there being still a technical reason for using CelNav."

Certainly true for manual celestial navigation, but there is a window for automated celestial navigation, especially if you can get above a good bit of the atmosphere to make the observations (though that has its own problems).

And you also wrote:
"No serious modern seafarer or pilot would use it to travel the Earth"

Absolutely right. And they don't... But they do occasionally stay in practice, partly because some (probably mis-guided) regulations recommend it. Of course, manual celestial stands only as a backup... to the backup... to the backup. When I teach celestial, I try to ask students at an early point "what's the best backup to your GPS"? And a few usually guess from the preamble to the question that the answer I'm looking for is "another GPS". While an onboard GPS "system" with its charting and plotting built-in may get fried, there' no excuse for not having a good robust GPS receiver that can at least output lat and lon for manual plotting on a chart. You would be amazed, though, how many people simply do not think of this sort of thing. If that fails or if the whole GPS signalling system is suspect (spoofing or jamming, in other words), then a navigator might be forced to dig out the sextant. But manual celestial is a very inferior substitute to GPS (I really should be writing the more "GNSS" to cover other systems like Glonass, but I'm sure you get what I mean). GPS is a nearly all-weather, continuous-plot form of position finding, while traditional celestial provides a fix at most only a few times per day with DR required in between. And with mediocre weather, it may be days between celestial fixes. There is a great gulf between the capabilities of a simple GPS receiver and the capabilities of manual celestial navigation.

You again:
"CelNav is an avocation, a hobby if you will."

Except, again, in automated systems --celestial navigation "robots". Such systems do exist, and they are becoming rapidly easier to construct and also they should be cheap enough even for yacht navigation in the near future. Such systems would completely bypass and circumvent nearly all of the tools of the trade of traditional celestial navigation. They would be unlikely to use anything remotely resembling sextants, relying instead on digital camera arrays. And of course, relevant to this specific discussion, they would have no use for anything like the traditional Nautical Almanac, instead taking their data from any number of electronic databases. Her Majesty's Nautical Almanac Office cannot survive by selling almanacs to robots.

And you wrote:
"And actually, that adds to its beauty. It is an elegant entry to astronomy,
it allows virtually anyone to fathom his location in the Universe, it introduces you to the strange world of Non-Euklidean Geometry, it will demonstrate the fantastic concepts of planetary movements, it allows you to retrace the journeys of the great explorers.... I could find many more reasons why people still do CelNav - no, why they are still deeply fascinated by it."

I agree with all of this, but at the same time, it's important to recognize that this is equivalent to an epitaph. All of these "meta" applications are real and valuable, and of course, the historical element is permanent; history exists forever. But as far as current practice goes, we might as well just say, "hey, it's a helluva lot of fun!" (which it is, for the right kind of person), and leave it at that!

A week ago when Robin Stuart and I were shooting sights of the Sun around noon at Beavertail Point, our activities drew lots of questions, of course, but the biggest crowd gathered when I had my laptop out to experiment with taking video through a makeshift mounting on a sextant. It was the modern technology juxtaposed with the "weird old sextants" that got folks interested. And it was interesting to see two teenage girls genuinely excited about looking through the sextant and understanding how the zenith distance gave us our distance from the sub-solar point. They were genuinely enthusiastic about the concept. It confirms two things that Bruce Pennino also said in his follow-up post: "I think people are interested in seeing people doing "real" things." and "Kids are interested in geometry." This idea of doing "real" things can and should be a major "selling point" for the subject today. As people begin to realize that the 21st century is a world of illusion, urban legends, spoofing, un-real "reality" entertainment, and fantasy worlds, doing "real" things has a growing appeal. There is a possibility that this is merely a temporary "backlash" against technology, but I think it will be relatively long-lasting. In an era of illusion, sell "reality".

-FER

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