[sonnyblarney]

"In seriousness, we can observe the effect, and even map the distribution of the stuff."

No, we can measure the dissonance between our best theories and reality. And make a conjecture about 'stuff'.

[gbrown]

I'm not a physicist, but my basic understanding of the state of the science tells me you're simply incorrect. We can observe the effect of dark matter via gravitational lensing, and folks much smarter than me have devised studies to exclude differential behavior of gravity at classical and galactic scales.

Give me a recent and well supported study indicating that dark matter may be something other than matter, and I'll happily read it.

My understanding is that the existence of dark matter is uncontroversial among physicists, and that the best bet is some sort of WIMP.

[reitanqild]

As a non-physicist I assume the physicists have thought really hard about this.

But it feels very strange to accept something that:

- is a particle

- doesn't interact with other normal particles (except through gravitation)

- doesn't interact with particles of its own kind

[roywiggins]

Neutrinos are almost as strange. They interact a tiny bit via the weak force, and they interact via gravity like everything else, but that's it. We know they exist because of the weak interaction.

Maybe dark matter interacts with things via the weak force, but even less than neutrinos- not quite zero, but just small enough that we can't measure it, or can't measure it yet. Hopefully, they do interact a little bit by some other mechanism otherwise they'll be very hard to detect- I believe this is what current attempts to find dark matter are relying on.

[tylerjwilk00]

This assumes that we are 100% certain that our understanding of gravitational lensing is accurate _AND_ that only mass affects gravitational lensing.

[gbrown]

Nothing in science is assumed with 100% certainty. I would argue that working from our best available theories (while always looking for ways to falsify them) is perfectly reasonable.