Is Dark Matter real, in the sense that it is some type of "matter" aka a particle that will in the future be studied as part of Particle Physics.
Resolves yes if the particle is identified, no if it is accepted that it does not exist, such as it is now accepted that the Ether does not exist.
I might bet since this is not expected to be controversial once resolved (eg ether, atomic theory)
On the one hand I agree that this won’t be controversial once resolved, on the other hand it has to be clear that it has indeed been resolved. It may take a while for full consensus to form.
Imagine that it is agreed that modified gravitational interactions are the solution (à la MOND) in certain scenarios (e.g. they are the only way to predict the Tully-Fisher relation) but later on we still find some new particles that in certain cases act as dark matter. Or vice-versa, some new particles are found, they explain part of the anomaly but not all of it, so that some modified gravity is still necessary. The debate could go on forever and it might even seem resolved for a while. Perhaps defining objective metrics to pin down what the consensus is at any given time would help. For instance something like consensus on DM = at least two reviews appearing in ARA&A acknowledge that a dark matter particle has been conclusively found.
@mariopasquato While I agree it's unlikely to become a real issue, I don't want to commit to ARA&A still being in existence when this question is resolved. I think for a question such as this the correct approach is to simply delay resolution as long as there is reputable dissent.