5 truths about dark matter that no scientist can deny

Every so often, advocates of a fringe theory — one that doesn’t fit the evidence as well as the mainstream theory — do what they can to breathe life back into it. 

Sometimes fresh data emerges that challenges the dominant idea and forces alternatives to be reconsidered. Often, a new set of observations fits a once-discredited idea, restoring it to popularity.

At times, a false narrative is the cause, as false views that have been fairly rejected by mainstream pros gain traction among a new generation of unskilled people.

Here are five truths that, once you know them, can help you see through the false equivalencies presented by those who would sow undue doubt about one of cosmology’s biggest puzzles.

The total amount of normal matter in the Universe is unambiguously known.

You cannot explain either the cosmic microwave background or the large-scale structure of the Universe without dark matter.

Dark matter behaves as a particle, and that’s fundamentally special compared to something that behaves as a field.

Very real small-scale physics effects, like dynamical heating, star-formation and feedback, and nonlinear effects must be worked out.

You must explain the full suite of cosmological evidence, or you’re cherry-picking, not doing legitimate science.