There's a person named Cecil Adams who writes a column for the Chicago Reader called "The Straight Dope." The motto of his column is "Fighting Ignorance Since 1973."
I think fighting ignorance is a wonderful thing. It's one thing to disagree on facts, but to remain willfully ignorant when proofs stare you right in the face is downright wrong.
I'm currently engaged in a discussion with some folks on ChabadTalk.com. The discussion really got underway in this thread (note: the discussion was started in a different thread and then continued in this thread with post 50.
What's interesting is that my disputants are maintining their position in spite of the evidence that I've brought. One main point of contention seems to be the Rambam's description of the solar system in Hilchos Yisodei HaTorah, Chap. 3. He writes (sorry, I don't know how to encode the original Hebrew into HTML -- if anyone would be willing to drop me an email and let me know how, I'd be grateful!) in the first section:
There are nine gilgulim [which I'll translate as spheres for now, even though that may not be accurate]: The closest sphere [to the earth] is the sphere of the moon. The second, which is higher than that is that of the star called Cochav. The third, which is higher than that contains Nogah. The fourth sphere contains the Sun, the fifth sphere contains Ma'adim, the sixth sphere contains Cochav Tzedek, the seventh sphere contains Shabtai, the eighth sphere contains all the other stars that appear in the heavens, and the ninth sphere rotates every day from east to west.
It's fairly obvious that what the Rambam is describing here is an Ptolmaic system of the solar system. Indeed, you can easily pick out some of the planets names: Ma'adim = Mars (which is red), Nogah = Venus (as it shines brighter than any other star), Shabtai = Saturn. The Rambam didn't use the Roman mythological names for the planets, but it's pretty clear that he's describing the solar system as had been held for over a thousand years before his time.
One of the proofs that I brought to show that this model was incorrect was a photo taken from Mars showing Mercury passing in front of the Sun. Now, if Mercury is in an inner orbit from the Sun and Mars is in an outer orbit, then how could Mercury pass in front of the Sun (as seen from Mars). To use a heliocentric comparison, that's like Jupiter passing between the Earth and the Sun (can you imagine what that kind of an eclipse would look like!).
I also brought our experiences with astronomy and sending out other spacecraft as proof of the correctness of the heliocentric system.
I'm still waiting to hear back from my disputants, but I'm sure that they will respond. I don't think that they'll back out of an argument.
Using this information, I argued that the Rambam was (as most of us recognize) flat out wrong with regard to the solar system. If you are going to posit that there is a mesora which cannot be wrong, then you also must posit that the Rambam was writing from his scientific knowledge of the day, and not from the mesora.
I find it interesting that my disputants are stubbornly holding on to this idea (geocentrism) which is really not an ikkur of our emunah. It's not like I'm arguing against creation ex nihilo, or against Torah MiSinai or against Yetzias Mitzrayim. It's a simple scientific matter that is perfectly compatible with the Torah.
I'll continue my dispute over there as long as I can. Fighting ignorance is tough work.
(Note: If any of the ChabadTalk.com folks find their way here, feel free to comment on the post, but let's leave the actual scientific debate over there).