[cletus]

I'm no physicist but I've asked myself this question. It's a bit like string theory. String theory is a mathematical answer that solves some (all?) of the inconsistencies between quantum theory and gravity but has some implications that have no experimental evidence (eg extra dimensions).

Dark matter always struck me as a kludge to explain the universe fit our model. There are many theories on it but no observed or experimental effects of dark matter to date.

We say that there are four fundamental forces in the universe: weak nuclear, strong nuclear, electromagnetism and gravity. The first three are pretty adequately explained by quantum mechanics (AFAICT). The last of course isn't but is described pretty darn well by relativity.

Thing is, what's always struck me as odd is the other forces, I believe, can both attract and repel. There is no observation or experimental evidence of "antigravity".

It has always made me wonder if we're not making an error by trying to fit gravity into the Standard Model. Perhaps it's not a force like the others are and simply the result of the nature of space-time.

Anyway, like I said: complete layman here. What I'm saying might be completely nonsensical to anyone with half a clue about physics.

I know the LHC has looked and is looking for any evidence at the edges of the Standard Model of some violation that will hint at something that might explain all this. I also know minds far brighter than mine have spent a lot of time thinking about this.

I'm still left wondering if dark matter/energy isn't simply another "string theory".

[tjradcliffe]

Dark matter is no more a kludge than phlogiston, or the lumineferous aether, or neutrinos. All of them were introduced as novel entities to explain experimental phenomena. The first two turn out not to exist, the latter does: http://www.tjradcliffe.com/?p=1801

Calling them kludges is to mistake the basic process of science for a hack.

There are any number of confirmatory observations that fit the dark matter model, just as there were any number of confirmatory observations that fit the neutrio model. It's just that we haven't observed any dark matter particle interactions directly, just as we hadn't observed any neutrino interactions directly before Reines' experiment.

It may be that dark matter turns out not to exist, and then we will know it was wrong. Until then it is perfectly ordinary science working in perfectly ordinary ways as it has been for over a century.

[deciplex]

> There are many theories on it but no observed or experimental effects of dark matter to date.

FTFA:

> And most spectacularly, you get an entirely new prediction: that when you get two clusters of galaxies colliding, the gas inside should heat up, slow down and emit X-rays (in pink, above), while the mass that we can see through gravitational lensing (in blue, above) should follow the dark matter, and be displaced from the X-rays. This new prediction has been borne out observationally and held up over the past decade, a spectacular indirect confirmation of dark matter.