[time-nuts] finding time astronomically.

Jim Lux jimlux at earthlink.net
Mon Jan 23 16:27:57 EST 2012

On 1/23/12 1:18 PM, Javier Herrero wrote:
> El 23/01/2012 21:43, Jim Lux escribió:
>> One is where you "lay the iphone on the table" in a fixed position.
>> One could use the internal accelerometers to determine "level", but I
>> don't think you could tell orientation, unless, perhaps, you can see
>> circumpolar stars? That is, by watching the movement of the
>> stars/planets through the field of view over some hours, could you
>> figure it out? Or is there some fundamental ambiguity.
> I don't know about the iPhone, but I've seen an HTC with a funny
> application that, when you point anywhere in the sky, it shows you the
> constellations that are there. Even if you point it to ground, it shows
> you the constellations in the other hemisphere :) I don't remember if
> the application is this http://www.google.com/mobile/skymap/ or
> something similar, but in any case, the phone knows its orientation
> quite good (well... also depends on the phone to have the right time, of
> course... :) )

yes, Pocket Universe (pUniverse) does this quite nicely (esp on the iPad)

But it uses the magnetic compass (and GPS) as well as orientation.

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