On Sun, Oct 05, 2008 at 04:28:26PM -0400, Shane Mage wrote: > >I see that astronomers can "see" planets circling far away stars by > >observing the wobble of the star cause by the planet's gravity... > > That is a deduction which will or will not stand up to a modest > increase in the resolving power of our telescopes. But if a > sufficient increase in telescopic resolution shows no planet, leaving > that "wobble" unexplained, what should one think of an astronomer who > reacted by saying "that planet is really there, all right--we just > don't see it because it is made of dark matter?"
Dark matter has absolutely nothing to do with extra-solar planets and the reasons they can't be seen with optical telescopes. Dark matter is the non-radiating stuff that is operating on orders of magnitude larger objects, like galactic clusters. Galaxies and clusters are behaving in gravitational ways that indicate there is probably a lot of mass there, but none of it seems to be emitting any radiation. This is different than the normal (baryonic) matter which does emit radiation, but we simply are too far or it is too faint to see (such as brown dwarf stars and extra-solar planets). That matter is virtually irrelevant when considering the large gravitational structure in galaxies and clusters. Matt -- GnuPG Key ID: 0xC33BD882 aim: beyondzero123 http://blogdayafternoon.com yahoo msg: beyondzero123 Life is pain, Highness. Anyone who says differently is selling something. -Westley _______________________________________________ pen-l mailing list [email protected] https://lists.csuchico.edu/mailman/listinfo/pen-l
