Finding Black Holes

I was reading an article about scientists finding "10 Monster Black Holes." Things like that catch my eye fairly often. A couple of things bothered me. You cannot see black holes so they could not have been spotted with any telescope of any kind. You infer them... from the effects they cause (I should say "theoretically cause" because that is more accurate). They might not be actually black either. We don't know, we have not seen one. It is surmised that they are so dense and create so much gravity that nothing can escape from them (except something does), not even light. Ironically, it is light which helps us know they exist. As things are pulled into them, especially gases, the friction creates heat and light and it is behind this heat and light that they theoretically exist. The light obscures them.

How did we find out about them, you ask?  Back in 1962, scientists came across a glow of  X-rays out there and were unable to figure the source. Apparently, X-rays can escape from these things. Gamma rays apparently also. More on that later, I hope. But maybe not, maybe the X-rays emanated from the stuff being pulled in when it was just outside the pull of the gravity the black hole is supposed to produce. Anyway, these X-rays were a puzzle, seemingly having no source. A collapsing star could produce them and that may have been the theoretical answer at the time. Actually, black holes were posited years before that... all the way back into the 1700's but technology, math, and theory took a couple of centuries to catch up and allow science to understand them properly.

My problem is that I do not have the knowledge to properly understand them. And so I can only provide a vague explanation for you.

I see black holes all the time. They are caused by cars at night without their lights on. They are only theoretical also... until they get close.