[gore3000]

I once attended a fascinating lecture at the Smithsonian about how the Zeiss planetarium works. Totaly geocentric, and very accurate. Clockwork, only (!) about 200 gears, some are (a bit) elliptical.

I have been to more than one planetarium and I think they all were 'geocentric'. The machinery seems quite interesting too though I have not heard as good an explanation of it. I think they have been around for quite some time, certainly from before computers and it is quite amazing how they do so much.

[RadioAstronomer]

I have been to more than one planetarium and I think they all were 'geocentric'. The machinery seems quite interesting too though I have not heard as good an explanation of it. I think they have been around for quite some time, certainly from before computers and it is quite amazing how they do so much.

I agree! Whoohooo! Those are wonderful machines. It is so cool you like them also. :-)