George Jones said:
In the video, Morrison has presented correctly the wormhole results contained in:
1) the paper "Wormholes, Time Machines, and the Weak Energy Condition" (Physical Review Letters, Volume 61, Number 13) by Morris, Thorne, and Yurtsever;
2) the research monograph "Lorentian Wormholes" by Matt Visser.I think that professional relativists like Kip Thorne and Matt Visser know the difference between timelike and spacelike dimensions.
For my own (unreadable) take on this, see
http://groups.google.ca/group/sci.physics.research/msg/ca7fd4ed9d282afb?hl=en&dmode=source.
Not unreadable at all, I can read every word! It's just with all the math at first glance it's a bit incomprehensible is all, but perfectly readable.

To go through it will take me more time. For the record, how do I access Physical Review Letters? Is there a separate subscription or do I need to subscribe to Physical Reviews? I am a physician by training (though I got my BS in P. Chem at university of chicago, enrico fermi institute in '67, 42 yrs ago--sigh--) and can access medical data bases like Medlar, but not all science data bases. At this time I would like broaden my horizons a bit and get back to some hard science. It's time, so to speak, to try swimming a few laps in the deep end.
In any case, for now, let's try it with words. In your andromeda example: I hop into my trusty aafal (almost as fast as light) starship and crank the velocity to the point that the 2.5 M LY trip to andromeda takes 4 hrs on my watch, so I make the 5M LY round trip in 8 hrs. Under "normal" relativistic conditions, the home I return to is 5M years older, in actual fact there may not even be a home to come back to since there is a rumor that less than 10,000 years after I leave, standard Earth time, the planet Earth is razed to make room for a full service assisted-living condominium for the aging population of Betelgeuse 4 named
New Methusela, but I digress. To solve this problem it seems I have opened a "lorentian (?) wormhole" between my ship and the couch in my living room. From your description, it appears that each of the wormhole's 2 portals exist in lock step with the space time coordinates in which it was opened and that the time it takes to enter one portal and exit the other, transit the wormhole, is independent of any ensuing relative motion of the portals during its lifetime but remains a function only of the
original physical distance between the two. If not consider the following. I shlep my portal a distance of 5M light years to Andromeda and back, yet I can just hop through on my return and be back in my living room in time for my afternoon tea with my wife. However, when I look outside my star ship on my return 5M yrs later, I see nothing resembling my home which was destroyed ages ago even without the interference of extraterrestrial construction companies. Even if I actually return to the exact coordinates of my garage on Earth 5M years later, this point is no longer a short hop to my living room because the Earth is not where it was at the start of the trip. Ignoring both the Earth's solar and sun's galactic orbits, the galaxy itself has drifted some 10,000 light years towards the constellation Hydra in those 5M yrs. So the worm hole is now stretched at least 10K LY. Can I just step through to my living room where my wife is nervously wringing her hands as she waits for the answer? If, on the other hand I return to the point in space where the Earth actually was was when I embarked, assuming I can locate that point since all reference points have also shifted, I find myself either drifting in interstellar space or worse find myself in the vicinity if not inside, some large stellar object, the gravitational effect of which might just "darn" --close-- my wormhole, possibly with me in it thereby making my subsequent appearance on "Discovery TV" difficult. Poor me!

If the wormhole is not destroyed there is a fair chance it might be distorted to the point transit is difficult if not impossible. All of this seems a bit risky. How are these problems resolved?
I'm sure this objection and others like it are easily answered. If you would be so kind as to take the time, it would help me further understand the phenomenon you are speaking about. Meanwhile I will attempt to work through the math on your website. I didn't see anything that was beyond my pay grade, it's just that the most complicated math I do these days, other than trying to understand the federal deficit is computing half-lives of various medications in the body during conditions of compromised liver function or kidney excretion, which thankfully do not as yet contain lorentian transformations

so I am a bit rusty. All the best, David Katzin.