Deflating Claims That ESA Craft Has Spotted Dark Matter

Yesterday, we posted news that data from the European Space Agency's XMM-Newton spacecraft had been interpreted as a possible sign of dark matter; researchers noted that a spike in X-ray emissions from two different celestial objects, the Andromeda galaxy and the Perseus galaxy cluster, matched just what they "were expecting with dark matter — that is, concentrated and intense in the center of objects and weaker and diffuse on the edges." StartsWithABang writes with a skeptical rejoinder: There seems to be a formula for this very specific extraordinary claim: point your high-energy telescope at the center of a galaxy or cluster of galaxies, discover an X-ray or gamma ray signal that you can't account for through conventional, known astrophysics, and claim you've detected dark matter! Only, these results never pan out; they've turned out either to be due to conventional sources or simply non-detections every time. There's a claim going around the news based on this paper recently that we've really done it this time, and yet that's not even physically possible, as our astrophysical constraints already rule out a particle with this property as being the dark matter!

Comments

Re: Dark matter and the sniff test

[Anonymous Coward]

You're already been given one clear proven kind of "dark matter"; the neutrino. This is incredibly difficult to spot; interacts very little; is almost absent from normal ("small scale") physics and yet it's existence is clear and well evidenced. It's really not that big a stretch that there is something else.

The thing is that if there isn't someone has to come up with really clever expansions for a whole load of other stuff. This would not be nearly the first time a physicist was wrong. In fact a truly dedicated physicist should try took be wrong several times a day. However strange and contrary to instinct would rule out relativity and quantum physics; in fact most of what we know to be true about the world. You have to find something more than gut instinct to oppose this with.

Re:Dark matter and the sniff test

[wonkey_monkey]

I'm just a lowly engineer, but for me "dark matter" has never passed the sniff test.

And yet it seems like most physicists - of whom I am not one - seem to think it is the simplest explanation for what we see.

The quote in the summary sums up, for me, the somewhat churlish attitude some people adopt when faced with dark matter:

There seems to be a formula for this very specific extraordinary claim: point your high-energy telescope at the center of a galaxy or cluster of galaxies, discover an X-ray or gamma ray signal that you can't account for through conventional, known astrophysics, and claim you've detected dark matter! Only, these results never pan out;

Of course they have never panned out - so far. If one of them had panned out, we would have stopped looking. Your keys are always in the last place you look.

Photons started out their theoretical life as a kludge factor to solve the ultraviolet catastrophe (great band), and people were appalled by the idea.