[Donald Schneider]

Dear Paul,

Thank you for reading my essay and for your response. It is most appreciated.

If we cannot accept certain points as valid, then there is no point in my addressing other points you made. If we cannot, for example, agree that you and I would not be here today had it not for been for the reproductive acts of our respective parents, then I suggest this entire forum degenerates into a theater of the absurd and is pointless of and in itself.. No matter how we term the concept of cause and effect, it obviously and irrefutably exists The reproductive act referred to was external to the future existence of the conceived children.

A cause must precede its effect or it cannot, by definition, be termed the effect's cause. Quite simply, one's twin sister cannot also be one's mother.

You attempt to undercut the entire thrust of my argument in a manner that I anticipated and refute right in the essay; points which you did not address in your attempted rebuttal.

The letter from Einstein that I refer to is cited within Paul Davies’s About Time. Additionally, I cite a personal email exchange that I had with a very prominent and respected contemporary physicist whose answer leaves no doubt that my understanding of the “block universe” (or "multiverse") is his as well. So at the very least, there seems to be one professional in the field who would not attempt to undercut my basic premise along the lines you have here.

Additionally, if the past, present and future do not all exist simultaneously, then why do so many physicists even speculate if time travel is possible? (Many believe it is.) What would be the point in doing so if that were not the case?

Before one can travel anywhere, the destination must exist. It is true that Einstein did not believe time travel (at least into the past) was possible; but not because he didn’t believe that the past still existed, but rather because he believed the violation of causality would render such impossible. That is, the dreaded “Grandfather Paradox.” (The advent of the “Many-Worlds Interpretation” of quantum mechanics seems to nicely address this problem.)

--Don