DIRD (Defense Intelligence Reference Documents)

Paul Sizz's physics textbooks from the 1990s-2000s contain detailed descriptions of advanced propulsion technologies that were actually already developed or in development by classified military programs. The speaker notes that Sizz (along with Hal Puthoff and Eric Davis) is cited as a source in DIRD (Defense Intelligence Reference Documents), suggesting his 'academic' work was actually documenting classified capabilities. The fact that Sizz's predictions match observed UAP technology suggests his textbooks were describing real classified systems.