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Hand held moon location detector
  [vote for,

I've long wanted a small hand-held sphere which would do nothing but always have a circle on it in the exact direction of the moon.

So if you're holding when the moon is overhead, you see a moon on the top of it. You turn it over, but the moon image remains on top, because that's where the moon is.

It would of course work by detecting the very subtle gravitational pull of the moon.

I imagine it about the size of a baseball, made of black glass, except of course for the brightly lit moon image.

Killelea, Sep 01 2009

Invisible Finger for pointing at the Moon Invisible_20Finger
[Dub, Sep 01 2009]


       [+] whimsy [ ] science.
FlyingToaster, Sep 01 2009

       In the 1970s there was (allegedly) a tiltmeter sensitive enough to detect tides in a cup of tea, so I imagine some application of that. [+]
coprocephalous, Sep 01 2009

       Nice idea [+]   

       This could be done with GPS. Knowing the date, time and position on the Earth's surface, it would be easy to use an ephemeris to locate the moon.   

       Now, some practicalities .....   

       A featureless black glass sphere would be reall neat, so you're going to need an induction charging cradle to get power into it.   

       If the mechanism uses the interior of the sphere as a bearing surface and has a heavy weight so that that part of the system always points "down", that will maintain the position of the "moon" dot no matter how the sphere is rotated,   

       Multiple steerable projection sources will probably be needed.   

       Make the sphere football sized and put the major starts and planets on it as well. Have an RF or IR remote control to allow selection of "highlighting".   

       This could be a great application for OLED technology.
8th of 7, Sep 01 2009

       //Now, some practicalities //
You *have* to go and spoil things, dontcha?
coprocephalous, Sep 01 2009

       Given that earth's gravitation is not felt the same everywhere i doubt it would be possible to detect the moon from gravitic measurements confined to one place and time. The GPS-solution looks valid, though, and would enable to use the device in an extended manner - "It's full of stars!"
loonquawl, Sep 01 2009

       Sure, it could probably be done using GPS and some induction charger for power, but that feels inelegant.   

       I looked up direct gravity detectors, and to be sensitive enough, it seems the detector would have to be about the size of a large refrigerator. But perhaps the technology will improve.   

       And sure, why not have a "planet mode" and "star mode"?
Killelea, Sep 01 2009

       The direction indicator should be an invisible finger
Dub, Sep 01 2009

       If you want an awesome sky-map application for a Windows Pocket PC, look up 'Leo's Void' (sorry I don't have a link). I use it heaps to find out what I'm looking at. It also has an insane amount of data attached to each star, planet and other objects.
neutrinos_shadow, Sep 01 2009

       // very bright object in the early morning sky //   

       Probably just [UB] bending over to pick up a penny out of the dirt .....
8th of 7, Sep 01 2009


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