NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Hypothetical Exercise - Abduced By Aliens
From: Mike Burkes
Date: 2008 Jun 20, 19:31 -0700
From: Mike Burkes
Date: 2008 Jun 20, 19:31 -0700
Hi folks great problem! I also used the small scale "azimuthal equidistant proejction" from an atlas, plotted the stars' substellar points, and circles of position but had 3 intersections one was 25d N, 150.5d W and this one was the basis for the iterations. The real long intercepts yielded an initial fix of 23d 43m N, 157d 25m W enabling me to further iterate a fix of 23d 17.5m N, 157d 17.3m W pretty close to you folks' results. Mike Burkes On Jun 15, 10:18�pm, "Greg R."wrote: > [The basis for this hypothetical celnav problem has been discussed (at least in theory) on the list before, so let's try it with a "for real" exercise] > > After recovering from being unceremoniously dumped on an unknown shore in his/her last adventure (not to mention draining the sailing budget with salvaging the boat and the boatyard repair bills), our intrepid navigator decides that a several-weeks long cruise to somewhere in the distant islands would be just the ticket. Several days into this idyllic voyage a definite feeling of relaxation starts to set in - ah, now this is the life. > > But of course, it was not to continue... after toasting yet another glorious sunset at sea, our intrepid navigator suddenly finds his/her reverie broken by a group of very bright lights moving rapidly through the sky. After passing close abeam, the lights abruptly change course and hover directly over the boat, illuminating it with what can only be a several-billion candlepower searchlight. To his/her horror, the navigator suddenly finds the entire boat being lifted out of the water and into the open doors of what appears to be some sort of alien spacecraft. Then just as suddenly as they appeared, the armada of alien spacecraft abruptly depart for an uncharted (at least to us) part of the galaxy. > > Luckily for our intrepid navigator, the aliens are only curious and do him/her no harm. After a couple hours of poking and prodding (and having a good laugh over the primitive Earthling navigation equipment), they realize that the human lifeform is so vastly inferior to their own that nothing further would be gained from holding him/her any longer and they decide to return their captive back to Earth. > > In an instant (at least in Earth time) they're once again hovering over the navigator's home planet, gently place the boat back in the water, and disappear once again before the navigator has a chance to fully comprehend exactly what just happened. > > But there's no time to dwell on this latest adventure... like a good navigator s/he realizes that the most pressing problem right now is to figure out where the boat is now located (at least it seems to be on an ocean, which is a good thing...), but notes with some dismay that all of the onboard electronic navigation/computer gear was apparently zapped by being transported to the outer reaches of the galaxy. > > However, all of the celnav gear (sextant, books, plotting tools, chronometer, etc.) is still intact and onboard, evening twilight is approaching, and with an ironic sense of deja vu the navigator takes these sights: > > � 05:46:40Z �Vega �Hs = 16�38.8' > � 05:52:18Z �Spica �Hs = 54�43.4' > � 05:54:26Z �Pollux �Hs = 21�02.6' > > Height of eye on the boat = 8 feet, index error = 0.0', and assume standard atmospheric conditions (the salvage/repair/refit budget didn't allow for purchasing a new barometer and thermometer). Last known Earth date was June 14, 2008 - you can ignore any dilution of time factors (or other effects of trans-space travel). > > Where are we? And where is the nearest civilization? > > Discussion item: How would you go about solving this particular navigation problem? > > -- > GregR --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---