Bob Lazar doesn't believe in Zero Point Energy. As in, he doesn't think it can be extracted for use in gravity propulsion. I presume this is why he was thinking element 115 might be a fuel source. It makes sense since Lazar would have come from a conventional physics education where space is empty. In such a situation you would need an exotic fuel source. My source is highly reliable and the information comes from Lazar himself. I respect Bob and would love to talk to him one day. I doubt I'd be in this position had he not come out in the 90s. That being said I gotta disagree about element 115, I'm convinced the fuel source for UFOs is the zero point fluctuations of spacetime. Possibly in the form of cold fusion.