Peter Sturrock is an emeritus professor of applied physics at Stanford University and one of the very few scientists who has publicly expressed a great deal of interest in UFOs and acted on that interest by twice surveying colleagues on the subject which resulted in some very surprising findings. He is also unambiguous on one particular category of UFO evidence which he happens to know a little bit about . . . . radar reports.
"Yes - radar is physical evidence," Sturrock stated in an email exchange he was generous enough to grant me.