New class of galaxy has been discovered, made almost entirely of dark matter

Re:New class of galaxy has been discovered, made almost enti... by sandworm101 on Friday August 26, 2016 @03:14PM (#12368593)

I would call 'dark matter' a description rather than an explanation. It seems to effect gravity. So it has mass. So it's 'matter'. But other than that it is unobserved, and so 'dark'. A+B = a very short but accurate description of an observation, rather than an explanation of why that observation happens.

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Re:New class of galaxy has been discovered, made almost enti... by mikeash on Friday August 26, 2016 @03:19PM (#12368649)

Well, it's a bit of both. It's an explanation in that it explains the observational discrepancies in terms of matter that's difficult to observe, rather than, say, different laws of physics or extra dimensions or whatever. But it's also just a description in that it just means some sort of matter with mass that's hard to see.

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