[digz]

I went to a conference* in 1994 in which Kip Thorne gave a talk on time travel. He made an offhand comment about evidence that backwards time-travel does not occur that was along similar lines. 2 points: 1) Not inconsistent for 'real' physicists to think about these issues. 2) I don't think this work is as novel in concept as the author thinks.

* Was for Carl Sagan's 60th birthday... was intended for serious audience of big time scientists but was intended to entertain.