About the night sky...

[plastik]

I just saw a sci-fi movie called Timeline, in which some scientists try to create a teleportation machine but whatever they put in it disappears and re-appears later. So they put in a camera and when it comes back it has pictures of a forest. Then they point the camera up and take a picture of the night sky, at which point they realize that it is a place in France called Castlegard on April 4th 1356 or something like that (the point is it's an exact date). And here is where my question arises. I can understand being able to deduce the date by looking at the night sky, but can we really deduce the point on the earth from which the picture of the sky is taken which such accuracy that you can say it's this or that village? <br />Was that science or fiction?

 

[heyscottie]

I would guess we would have to get year by looking at proper motions of stars -- maybe the camera caught Bernard's Star in Ophiucus which has a very high proper motion. (It is extrememly dim, however -- maybe it was a super-camera). You could probably get within a few years by seeing that.<br /><br />We could then pin down the date far closer by seeing any planets in the frame. This could get us within a couple of days or so if we are lucky.<br /><br />We can then figure out time and longitude if we happened to catch the moon in the picture by using the lunar distance method.<br /><br />Lastly, getting latitude is quite simple, especially if the camera caught the North Star.<br /><br />So it is theoretically POSSIBLE to get all this from a picture of the sky, but you'd have to be lucky and get a lot in the shot, and you'd have to have a really good camera, and you'd probably also want to know the orientation of the camera as it took the shot.<br /><br />Scott

 

[CalliArcale]

In fact, you'd probably have to plan out the shot in advance, which would mean knowing a great deal about what's in the sky -- which you'd predict based on knowing date, time, and location, making the whole exercise kind of recursive. Maybe if you put it on a robotic platform and programmed it to pan around a lot? <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[plastik]

So i suppose a lot of coincidences are necessary for something like that to happen. At least it sounds like it *could* happen, which makes the movie a bit more credible, at least on that point. Thank you very much for your replies.