Thanks everyone for the interesting comments. Just thought I should clarify something: Dr. Farrell's research is very much outside of the scientific mainstream, so most people are not going to put much stock in it. I believe, as does Dr. Farrell and many others, that the Great Pyramid at Giza is far older than mainstream science suggests, and that it was not a tomb, but a machine of some type, built by a highly advanced culture that inhabited the planet at the time. The physics involved was very close to what scientists such as Tesla were developing. This physics, based on the idea that "space" is not a vacuum, but is filled with a subatomic substrate (used to be called the "ether") degenerated into myth...and is encoded in various ancient myths of subsequent legacy cultures.
One of the things Farrell and others point out is that Maxwell's original equations were altered, which led modern physics down a very different path (at least the public version of modern physics). Another PhD who has deeply researched along similar lines is Paul La Violette:
http://www.etheric.com/
Again, for anyone who adheres completely to the mainstream scientific paradigm, Farrell and others like him will just seem nuts...but if you're open to questioning the prevailing dogmas of science and history, you may find his research compelling.