i must've been asleep when we were given definitive proof of dark matters existance interesting to see the distributions of what is possibly dark matter though, but just because a sillhouette looks like something, it doesn't always mean it is that something. is that my dark matter? it goes HURRRGGGHHHH! that's not my dark matter!
I'm still not buying the dark matter theory 100%. Still too much of 'creating a solution that fits the problem' sort of scenario, AFAIK. Plus, looking as far back in time as they are for their gravitational lensing, and then saying that they 'statistically' know what those galaxies are supposed to look like is weak. The structure of galaxies all those billions of years ago might have been completely different. I'm not saying they're flat out wrong, but the whole dark matter gig still smacks of round peg, square hole physics to me. I've got the same issues with it as a lot of other physicists do with String Theory.
But dark matter fits one of the traditional methodologies of "inventing" a theory to fit astrophysical data. I'm not convinced by it either, but at least there have been several models for an explanation discussed, and more importantly I get the feeling that most of the scientific community isn't convinced by it either. String theory however wasn't necessary, and IMO has done more harm than good to research in the last 30 years. If you like it's trying to get a round peg into a square hole whose location is unknown.... Maybe in 100 years time both Strings and DM will be just one offshoot of a UT..
String theory has some interesting facets to it- the biggest of which is that it independently yields a quantum theory of gravity, which is one of the really sticky points in modern physics. The problem is that the math gets too sticky even for computers pretty fast, and like Dark Matter, there is no way to verify the results experimentally. I suspect the path of modern physicists is much like the varying flavors of martial arts out there: they all grasp certain fundamental truths without seeing the whole, and while the paths are different, they will eventually find the same summit of the same mountaint they've been climbing all along.
I'd say that's its only worthwhile facet, and there are other "theories", at least as valid at this stage, which result in quantised gravity which deserve more respect than they've received. My problem is that string theory has taken 90% of the quantum gravity scientists in the last three decades, and it's now got to the point where young researchers are severely limited in their career path because of the obsessive string community. Considering classical physics seems to be least attainable from string theory , I think this is unjustified. But either years of maths and physics are wrong in their previously established theories for the universe as a whole and in particular galaxies, or some new theory (eg. DM) is required. Usually either we fill a need for a modified description of the world to accommodate observational evidence by inventing a new theory, or, am application for a nice theory/skill in pure maths is found in physics. I don't see where strings fit in. Other GQ theories at least use new mathematical tools on framework and fundamentals of CG.
I think at present we're able to describe pieces of the whole pretty accurately, but not the way these pieces fit into a unified framework. For example, newtonian mechanics describes a LOT about how the universe works at the macro scale, while quantum mechanics does the same at the submolecular level. The problem is getting the two married up, along with other stuff. My biggest gripe with string theory, which I find elegant in many ways, is that when things don't match their solution is to start adding dimensions to the framework. To me that's no different than postulating the existence of dark matter to explain why the universe is missing so much mass that they think it should have. Could be there's no missing mass and we simply have misinterpreted what we think we know. Anyhow, I think we're barking up the same tree here.
One other thing to consider is that all our observations take place from one spot in the universe, which is affected by conditions we can't change. (Local gravity, local ambient background radiation, etc.) If we could fly the Enterprise-D about 2000 LY from here and take a look from deep space, we might find out that our current theories are warped on any number of levels. No pun intended.
I've thought this very same thing for quite sometime now... Our knowledge is bottlenecked through one perspective so to speak.
