Originally Posted by
Stefan
We know of the effects. We don't know much of what composes dark matter or dark energy, but we do observe the effects of these phenomena. This is how much of physics works. Kepler and Newton didn't know what gravity was, but they were able to describe how it worked. Later, our understanding of gravity was refined with Einstein. Currently, physicists are trying to reconcile quantum gravity. The same applies here. Just because we don't know what something is composed of, nor do we observe it directly, does not mean there is reason to question its empirical existence. Theories are never finished, they are always applied to scrutiny and refinement. That is the nature of science. Just because there is a problem, one mustn't assume it is because the basis of what we do know is wrong. If that were the case, then there would be no use in any form of science, which seems odd considering the massive amount of practical applications we've gained from modern science.