Is Michio Kaku right?

The theoretical physicist one sees on nearly every science show may have changed  his views  on UFOs.   Should we?

I’ve always regarded UFOs as real but unexplained.   I’ve had a handful of experiences with odd lights in the sky, but I felt there was a rational explanation for them,  especially a large airplane flying high in the night sky which made no noise and its lights suddenly disappeared.   It has become increasingly harder to figure out the objects airborne military gun cameras keep capturing.

What say you?