@cindyment You don’t have any problem with any of those concepts, because you bend over to Authority.
You have never seen a black hole, never seen an object made of just Neutron stars (a theoretical object that violates all known laws of physics), never seen String Theory (or it’s 10 other dimensions), never sensed Black matter (Or have an iota of evidence that it exists)......
I have not seen air either .... though technically I have seen atoms under an electron microscope.
Black holes and neutron stars violate all known laws of physics? Which ones in particular? Surely you know off the top of your head, .... or .... are you just stating that because you read it somewhere and choose to believe it? I tend to question eveverything myself, but unlike you, I equipment myself with the tools to question things ... and to ask the right questions.
One of those recognized laws of physics is the Chandrasekhar Limit. Do you know what that limit allows? ... black holes and neutron stars, so how can they violate every law of physics when there is one that sort of explicitly states they can occur? Inquiring minds want to know.
I will assume you don't know who those scientists are. I at least provided one example. That was one more than you did.