Why? If dark matter is 90+% of the mass of 'everything', then surely many more anomalies would occur without us having to be hit by a chunk of dark matter.
Well, if the dark matter is ~90% of the mass of everything, that doesn't necessarily mean that 90% of the mass of every thing is dark matter. As far as I understand it, we see the effects of the large amount of extra matter but we don't really know where it is or how it's distributed. That could mean that there isn't any dark matter clustered in large enough quantities close by for us to detect.
Assuming it's not near us, why would that be? Our star isn't much affected by it. We can't see nearby stars being pulled willy-nilly.
Well, a really spread out distribution across the universe would explain that.
And if it's a weird non-localised 'blanket' that can't hit you in the foot, then it'd be great to have some guesses as to the structure so we can test for it.
Well we have a prediction for what the particle would look like (/act like). That's what the detector is there for. Well, not just dark matter. Think neutrinos and Cherenkov radiation.
As far as the other questions go, I'm not sure enough to answer and I'm pretty sure that some of those questions are open.
I asked mostly for the conversation value, I certainly am not sure of anything myself!
Well, a really spread out distribution across the universe would explain that.
It would, but then there's the 'why' it's spread out. Maybe that's answered in the particle predictions but something is keeping it apart, but doesn't affect visible matter in the same way. It's obviously spread out just enough to not be clumpy, but not so much that it can't pull a galaxy together. If it were everywhere it wouldn't have the effect we think we see.
Ordinary matter forms dense clumps like planets and stars because it's sticky. Atoms may be attracted to one another by gravity, but in order to get them to actually stick together into dust grains, planets, stars et cetera, you need them to collide inelastically, and that requires the electromagnetic force.
Two dark-matter particles in the void will be attracted to each other (slightly) by gravity, but when they meet they'll just sail straight on through one another without colliding. This prevents the formation of small-scale (ie sub-galactic scale) dark matter clumps.
Well, if the dark matter is ~90% of the mass of everything, that doesn't necessarily mean that 90% of the mass of every thing is dark matter. As far as I understand it, we see the effects of the large amount of extra matter but we don't really know where it is or how it's distributed. That could mean that there isn't any dark matter clustered in large enough quantities close by for us to detect.
Assuming it's not near us, why would that be? Our star isn't much affected by it. We can't see nearby stars being pulled willy-nilly.
Well, a really spread out distribution across the universe would explain that.
And if it's a weird non-localised 'blanket' that can't hit you in the foot, then it'd be great to have some guesses as to the structure so we can test for it.
Well we have a prediction for what the particle would look like (/act like). That's what the detector is there for. Well, not just dark matter. Think neutrinos and Cherenkov radiation.
As far as the other questions go, I'm not sure enough to answer and I'm pretty sure that some of those questions are open.