Hey @BTE, "sigmas of evidence" is a bit of an odd framing. If it turns out dark matter isn't real, then some high-powered experiment would fail to find strong evidence for it.

To find strong evidence against it, you'd need dark matter to make some specific prediction and for data to be at odds with that prediction. Whilst that might happen, it's not usually the way experiments are set up.

Particularly for dark matter, it's hard for the theory to make a specific predictions since the amount of dark matter in a given galaxy or whatever is not something we have an independent prediction of, it's a free parameter.

@chrisjbillington It's just a free money market with a risk of resolving N/A. There's not really any need to worry about dark matter not being real.

@HarrisonNathan yes I know!

@chrisjbillington I understand. So better to say will the research that won the 2019 Nobel is falsified? Or maybe Can you help me write a better version of this question? Or am I just swimming completely out of my depth and I should move on?

@chrisjbillington Thanks for the comment btw! It’s been awhile!

@BTE Hm, maybe "falsification" is OK, though normally that would be framed in terms of some amount of conflicting evidence as well, whereas dark matter may be discarded as a theory because it sort of "fails to reproduce" rather than being "falsified" (not that I expect either).

Maybe something like:

Resolves YES on either a 5-sigma falsification of dark matter, or a high-powered experiment failing to reproduce its predictions, to a degree sufficient to produce scientific consensus that dark matter does not exist.

"Dark matter" for the purposes of this question refers to as of yet unidentified dark matter currently thought to explain galactic rotation curves etc, and excludes the currently known abundance of e.g. neutrinos and black holes, which technically are dark matter, but are not sufficient to explain observations attributed to dark matter"

You might disclaim that the market could be extended if consensus is in a state of flux due to recent peer-reviewed evidence available at market close (at your discretion - not going to extend on crackpottery nobody is taking seriously, even if they manage to get into a peer-reviewed journal)

@chrisjbillington something like "5 sigma evidence for something else explaining all the observations currently ascribed to dark matter (not necessarily the same thing for all such observations)"?

@ArmandodiMatteo (but we'd have to decide how narrowly to interpret "matter" -- I'd go with "anything whose stress-energy tensor can be approximated (at least on Galactic scale) by diag(rho, p, p, p) with p << rho, whether or not it's made of particles")