[eipipuz]

Assume have an equation like `Energy = 0`, where `Energy = Mass + Photons`. It works great for almost everything, we can get the curvature of space by `f(Energy)` where `f(Photons) = 0`.

However there's this one experiment that says the answer is `Energy = 42`. `f(x)` is still useful, everything else works.

We can just amend the equation to be: `Energy = Mass + Photons + DarkMatter` where `DarkMatter = -42` and `f(DarkMatter) = 0`.

Or we can keep the E=M+P but change the way f works to be: `f(Photons, X) = Y` where for almost any value `f(Photons, X') = 0` and in this one case `f(Photons, X") = 42`.

To me it's clear that the first approach is less complicated. The first approach raises one question, "why -42?" The second approach raises "why does X?" exist and "why 42?"

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By the way, you are mistaken, we do interact with Dark Matter, that's how we detected it (Bullet Cluster). Gravity does interact with it.