[time-nuts] Canada's 5,000 year old calendar

[Lux, James P]

On 1/29/09 5:13 PM, "Magnus Danielson" <magnus at rubidium.dyndns.org> wrote:

> M. Warner Losh skrev:
>> In message: <25630a120901291622l5cc165ecna06e01cc3de52a39 at mail.gmail.com>
>>             michael taylor <mctylr at gmail.com> writes:
>> : An academic maverick is challenging conventional wisdom on Canada's
>> : prehistory by claiming an archeological site in southern Alberta is
>> : really a vast, open-air sun temple with a precise 5,000-year-old
>> : calendar predating England's Stonehenge and Egypt's pyramids.
>> ...
>> : Since we had some discussion about historic calendars earlier this
>> : year, I thought it might of interest here.
>>
>> I wonder if he has accounted for the progression in the earth's wobble
>> over the past 5k years to make his claims...
>
> Hmm... never check a story too closely... :)
>
> I think to recall that that kind of people use software that can fairly
> accurately re-play sky-events back in time... considering various of
> long-term drift effects. Would love to fool around with that kind of
> stuff... but it is probably unobtainables for mere mortals like me.

I haven't read the article yet (I'm going to though)

I wouldn't count on them having a fancy sky simulator.  For all you know,
they've got something that just has a "good enough" approximation to do
right now, and they plugged in a date for 5000 years ago.  There's
applications that do this sort of thing for Palm Pilots and iPhones for
instance.

I have a little Celestron SkyScout (a very nifty device) and it has a GPS
receiver and magnetic sensor, so you can punch in what planet you want to
look at, and it figures out where to point, presumably by using some sort of
programmed ephemeris.  However, the accuracy of that ephemeris probably
significantly degrades if you were to somehow enter a date (normally picked
up from GPS) 200 years ago or in the future.

Ditto for the "go to" telescopes.

There ARE very accurate planetary ephemerides available for free. Check out
CCMATLAB (not free, but cheap) for an interface to the JPL Ephemerides
algorithms.  These are basically numerically integrated differential
equations used for predicting the motions of heavenly bodies for doing,
among other things, spacecraft navigation.

http://ssd.jpl.nasa.gov/horizons.cgi
http://ssd.jpl.nasa.gov/?ephemerides

You can download them all from various JPL sites.

Jim