RE: Detecting nuggets of dark matter
As I was reading this reply a question struck me:
direct dark matter detection rely on the measurement of the visible recoil induced by a dark matter particle reaching Earth and hitting one of the detector constituents.
How can a dark matter particle hit the detector if it interacts only gravitationally?
As far as I understand, when regular objects (such as balls) hit one another it is mediated by molecular forces of elecromagnetic nature. And neutrino detectors rely on the weak force. If "hitting" means gravitational interaction, wouldn't it be too weak to be detected? But otherwise, it seems that dark matter would go through regular matter completely unnoticed as the most parts of neutrinos do. There will be no hitting. Am I missing something?
In this case, it can't and the way that is currently followed to detect dark matter is bounded to fail. There are good hopes that dark matter gets extra interaction on top of the gravitational ones (from early universe considerations). But again, this is an assumption.
Not necessarily the weak force for dark matter as dark matter may possess its own interactions (that are different from any interaction we know). The magnitude of these interactions has to be weakish (as we didn't detect dark matter so far), but on the other hand, we have models in which dark matter is strongly interaction (like in this post).
Yes, I mentioned the weak force only as an example to show that there should be some fundamental force that "performs the hitting". Thank you for your answer! It is now clearer to me.
BTW, what do you think about negative mass particles as dark matter (and dark energy) candidates? Is it a viable idea?
For the moment, I don't think anything about this idea... because I didn't read the paper yet. I will do that later today or tomorrow and then comment your post.