IN RESPONSE TO MY EARLIER POST ON INTERSTELLAR TRAVEL, Frank Tipler emails:

In section N of the Appendix for Scientists in my book THE PHYSICS OF IMMORTALITY, entitled “Relativistic Spacecraft,” I point out that, in effect, those books you reference on interstellar travel were obsolete before they were written.

Human will NEVER engage in interstellar travel. Only human downloads and artificial intelligences. Carrying full size human bodies, active or frozen, is too inefficient.

In my more recent book, THE PHYSICS OF CHRISTIANITY, Chapter 11, I discuss the ultimate interstellar drive, the neutrino rocket powered by a Standard Model process that allows ordinary matter to be transformed into radiation like neutrinos. Think of the DeLorean car at the end of the movie Back to the Future. This is what this technology will look like. Power is supplied by converting garbage into energy and the propulsion system is a rocket exhaust that has no effect on the surroundings.

I point out in Chapter 11 of the latest book that we’ll have both the human download technology and the neutrino rocket within 50 years. You should not teach your students the the future will be based on obsolete physics.

Sounds more like Greg Egan’s Diaspora. But I’ll be sure to let my students know — and they’ll be amused to see that I’ve been chided for lack of imagination by a physicist of Tipler’s eminence.