I know it because I have seen the evidence. I can't prove one shred of it you'll just have to take my word for it.

Small game out of convenience mostly.

but I am the best authority you have on the subject and I have a better understanding and grasp on the subject than the vast majority of researchers even the ones who are scientists. The only ones who know more are some governments and the are not interested in disclosure, mainly because of what I have outlined in this thread.