geocentric system : show trace of planets around the earth ?

Fadabe · Post #1by **Fadabe** » 12.05.2006, 18:32

Hello

I??ve got a little presentation on the ptolemaic system coming up and
have been searching a while now for any good graphical representation of it.
It seems to be really hard to find one .

Well and then I stumbled upon Celestial . I just found it today and have played around with it a little bit . By now I ve gotten to center-view the earth and let all the other objects move around it.
(Which is admittedly not very hard to do)

My problem now is that I want to show the traces of these objects .

When I turn on the orbits I see the traces but only in regard of the movement around the sun which is rather useless for my purpose.
I hope you know what I mean

Do you know any solution for this problem?

Oh and I tried to split the screen to show on the one side a heliocentric view with the orbits of the planets around the sun and
on the other a geocentrical one .
Is it possible to show the sun -centered with orbit view and the earth -centered with trace of the planets view at the same time?

TIA
Fadabe

buggs_moran · Post #2by **buggs_moran** » 12.05.2006, 19:42

If all of your items are defined as planets you just need to turn orbits on. You might want to look here at the work that is already being done... http://www.shatters.net/forum/viewtopic.php?t=9369

Look at the liks in that post for more references on Ptolemaic systems as well.

Fadabe · Post #3by **Fadabe** » 13.05.2006, 02:59

Hi buggs
sorry I don't really understand what you mean by defining all items as planets.Could you please describe the procedure in detail? (I just installed Celestial today and am still wrestling the basics till now.)

I also see that perhaps my description of the problem was perhaps not entirely understandable. So here a new try:
I want Celestial to show the movements of the planets circling around the earth as seen from the earth like in this little animation :
http://www.edumedia.fr/a228_l2-epicycles-theory.html
Unfortunately this one is not freeware .

Fadabe

P.S.: I also P.M.d Andrea and asked her if she would mind to send me a copy of the ptolemaic system you are creating. She meant that it would probably be a little to high for me as a newbie in this early development phase . I wish you two good luck in it . I think that it will be appreciated by not only me but a great many othery as I didn't find many really usable ptolemaic models on the internet .

buggs_moran · Post #4by **buggs_moran** » 13.05.2006, 12:33

First off Andrea is a he :wink:

... Secondly, I misread your post. Defining things as planets would not have helped you. And no, there is not a "trace" function in Celestia that I am aware of which would perform what that little animation does. Did you create your own SSC file to make the planets orbit Earth? Celestia can be a tricky creature at times. It is still very young as far as software goes. The main people that work on it do it as a hobby, even the original programmer, Chris. As far as getting a trace funtion, you could put it in the wishlist forum, but there are a lot of people ahead of you. I am sorry I couldn't be more help. Here are a few animations I know of you might be able to get permission to use.

http://www.csit.fsu.edu/~dduke/models
http://www.astro.utoronto.ca/~zhu/ast210/geocentric.html

Fadabe · Post #5by **Fadabe** » 13.05.2006, 13:13

UUUUPS
when he told me that he is from Italy I should have been gotten suspicious.

Sorry about that Andrea if you read it . But I guess that's just globalization.
I'm from Germany where Andrea is very definitely a female name.

Anyway thanks for your help . The canadian link is one I haven't found until now. It looks interesting.

I'm sorry you misunderstood my problem at first sight . I found it rather hard to describe it . Just my English I guess.

Fadabe