Conference noted::sf

    There Will be Time by Poul Anderson

"By His Bootstraps" by Robert Heinlein

    Ah, this is easy!
    
    I've probably read between 100 and 1000 time-travel stories in my
    life.  Few of them can even measure up to H.G. Wells's standard.
    This inlcudes some of even the most celebrated authors.  John Varely's
    "Millenium" is a good example of a great author writing a lousy
    time-travel story.
    
    I have for some time been 'collecting' these stories in my head
    to see how they really stack up, because it is a VERY difficult
    type of story to do well, be original, and still be logical all
    at once.  Most resort to pandering off what is little more than
    metaphysical gobbledygook as rational scientific theory.
    
    Most amusing (and hypocritical) are the supposedly Hard science-fiction
    writers who write time-travle stroies without having made any apparent
    attempt to find out what the current physcail theories on the nature
    of time are.  Contrary to popular belief, theoretical physics DOES
    have some very definite things to say about the way that time probably
    works.
    
    But enough criticisms, let me answer your question.  The best "Hard"
    science-fiction time-travel novel is easily "Timescape" by Gregory
    Benford.  First, because it is the only novel that I know of that
    clearly is an extension of current scientific knowledge and not
    a cancellation of it.  Secondly, because by ANY standard this is
    a great book, irrespective of the fact that it is a time-travel
    story or even a science-fiction story.  It is an excellent exploration
    into the nature of the human character and our contemporary society.
    
    The best "Science-Fiction bordering on fantasy" time-travel story
    is almost certainly "The Anubis Gates" by Timothy Powers.  This
    is one of the wildest, funniest, most confusing, and yet thoroughly
    logical (the plot, not the premise) books I have ever read.  I found
    myself keeping a set of notes just so I could try to keep track
    of everything that was going on in different times, and the ways
    that would (might) affect other events.  It would take most people
    a lifetime to write a story this involved.
    
    I think that both of these stories are better appreciated if you
    have already read a fiar number of other time-travle stories to
    compare them against.  This is because one of the best qualities
    of both of these books is that they will start a situation very
    similar to a dozen other time-travel stoires, but instead of resolving
    it with the same old boring and illogical platitudes, they actually
    came up with fresh and original resolutions again and again.  I
    was pleasantly suprised with every new chapter of both of these
    books.
    
    --  Barry

    "The Technicolor Time Machine," by Harry Harrison.
    
    RE: .3
    
    > This inlcudes some of even the most celebrated authors.  John Varely's
    > "Millenium" is a good example of a great author writing a lousy
    > time-travel story.
    
    I agree Varley's *novel* "Millenium" isn't very good. However, it
    was an expansion of an excellent Varley short-story (written under
    the pseudonym "Herb Boehm"), "Air Raid," which is well worth the
    read. Incidentally, "Millenium" came to being because a Hollywood
    producer bought the rights to "Air Raid" and Varley was tapped to
    do the original storyline for the script. The deal apparently fell 
    through (at least I haven't heard any more about it in recent months), 
    and it appears that Varley decided to cut his losses and turn his
    movie storyline into the novel.
    
    Fred
    

  I'm with .2 -- "By His Bootstraps" may have been the best ever.  In that
  vein, there is also "All You Zombies" by the same author.

  A long time ago I was told that when "By His Bootstraps" was first published
  (in Astounding, I think), it blew the minds of the SF writing community
  to the extent that it was two years before another time travel story was
  published in this country...

  The following may be met with raucous laughter, but...  I think that one
  of the best time travel stories ever written was done by Andre Norton
  in "The Time Traders" and "Galactic Derelict."  If she had only stopped
  writing sequels after those books...

  JP

    Poul Anderson has written several novels and short stories about
    the Time Patrol, starting with "The Guardians of Time."  The Patrol
    guards a mutable history.  The logic of this is never made clear,
    but the human impact of such a thing is vividly painted.
    
    Fritz Leiber has written short stories and at least one short novel
    set in "The Big Time."  These involve a universal conflict between
    the "Spiders" and the "Snakes," two mysterious factions (mysterious
    even to their employees) contending for control of space and time.
    Time is mutable in this series, too, but with an explanation --
    there is a second temporal dimension, the Big Time, in which the
    history of the Little Time (ordinary time) can be altered.
    
    Isaac Asimov uses a similar technique, calling the extra dimension
    "physio-time," in "The End of Eternity," a single novel.
    
    Since .2 mentioned "By His Bootstraps," let me mention Heinlein's
    other tight-time-loop short story, "All You Zombies."
    
    Note 331 discusses the, as it were, technical aspects of time travel.
    
    Earl Wajenberg

    	When someone does list their favorite time travel stories, could
    you at least give a plot synopsis, with emphasis on how the time
    travel was done?  Thanks.
    
    	Larry
    

Re .7

Anderson's Time Patrol series has a variety of plots, of course, with the 
overarching theme being the protection of that history which produced the Time 
Patrol.  They time-travel using wheelless motercycle-like vehicles that fly as 
well as teleport through time.  No rationale for their mechanism is ever 
given.

The Spiders and Snakes of Leiber's stories (called the Change War series) 
time-travel by retreating to "Places" (cap-P) outside normal spacetime, where 
the Big Time flows, not the Little Time.  Once again, the devices that do this 
are just there, unanalyzed.

In "The End of Eternity," by Asimov, the time-travellers worked from their base 
in Eternity, an artificially created miniature spacetime with its own temporal 
dimension and four spatial dimensions, one of which coincides with the time 
dimension of the normal universe.  The plot deals with the inimical effect of 
too much control on human history and how that excess control is thrown off.

In Heinlein's "All You Zombies," the main character is a time traveler who 
creates himself.  The time machine is a thing the size of a briefcase.  You 
adjust the controls inside, throw a metallic mesh net over the cargo, and 
*ZAP* you're at the destination time.
    
Earl Wajenberg

    
    Piers Anthony's Bearing an Hourglass (2nd book of a series) has
    to be one of the most exasperating time-travel stories I've read.
    Basically, a man takes over the job of 'Father Time' so to speak,
    and lives backwards (reminds me of Merlin in Once and Future King).
    He also has the ability to stop time and reverse his own time flow
    so he can communicate with people living in 'regular' time.  It
    leads to some very interesting reading, but it can leave you 
    bewildered at times (N.P.I.).  Its not classic time-travel, but
    you should enjoy it regardless.
    
    One of my favorite time-travel scenes was in Roger Zelazny's 
    ROADMARKS.  It involves a road that stretches from ancient Babylonia
    to far in the future, with exits at many different times and places.
    Only a few people have discovered the road, and travel it frequently.
    One of the travelers made his living by burying artifacts in ancient
    locations, cruising up the road, and digging them up a few thousand
    years later, and selling them off.  What a racket!
    
    /Dan

    For a different kind of time manipulation, try "The Girl, the Gold
    Watch, and Everything," by the late John D. MacDonald.  In this
    novel, its relative time rate rather than time travel or backward
    time that is involved.
    
    Earl Wajenberg

    Another good book about time travel was Philip Jose' Farmer's 
    TIME'S LAST GIFT.  I Believe the title was something like that,
    it was awhile ago when I read it.
    It's kind of a spoiler to talk about it, so I'll insert a form feed.
    
    The book didn't deal too much with the time travel itself, but with
    the adventure of a crew on an expedition going back a million years
    BC.  But the most greatist discovery reading the book was that one
    of the men on the expedition pulled alot of string to be on it.
    The reason being that he was immortal and could not die of old age.  When
    the expedition was ready to return to the future, he said he was
    staying and told then to look somewhere special when they returned.
    When they arrived back to the future, they looked in the placed
    mentioned and found many gifts of time including things like 
    snap shot pictures of Christ.  As it turned out he was still alive
    after all those years, although I remember something about there
    being two of them since he would be there for his own birth.
    Mike_L

    Dan's mention of Zelazny in .9 brought to mind another great RZ
    story which I suppose technically could be called a time-travel
    tale.
    
    "Divine Madness" is about a man who (somehow. Sorry, Larry :-))
    reverses the flow of time in order to save his wife from a car
    accident. The intriguing thing about the story is that, expect for
    the final lines it is ...
    
    .written is line this way the to similar, backwards entirely told
    
    Fred

    
    !read to hard pretty been have must that, WOW
    
    /Dan (i refuse to spell my name backwards)

    
    "Oleander Morning," (maybe "Eliander Morning?") by ????
    
    (Anybody else ever heard of this one?)
    
    An excellent characterization. The time travel aspects are secondary
    to the character development.
    
    Ed E.

    re .10
    
    The Girl the Gold Watch and Everything is also one of the funniest
    books I've ever read. I still laugh out loud over parts of it and
    I've read it several times.
    
    re .7
    
    There Will Be Time by Anderson is about a man who is born with
    the ability to travel in time and how he meets other such travelers
    and eventually deals with a corrupt society of time travelers.

re: .12 (i think)

Another Zelazny play-on-time is in "Creatures of Light and Darkness",
which has two characters named Set (after the Egyptian god) and The
Prince Who Was a Thousand, each of whom is both the father and son of
the other due to a time travel paradox (never explained, needless to
say!).  At one point, before Set regains his memory and realizes that
The Prince is his father/son, the two have a cross-time/space battle
called a "temporal fugue".  I've always loved that term ever since.

Not strictly "time travel" but there's also:
	- "Counter Clock World" by Philip K. Dick, where time starts
	  to run backwards and the dead burst out of their graves
	- "The Simulacra" (also by Dick) where time travel is the
	  "Von Lessinger effect" and an authoritarian U.S. government
	  uses it to try to cut a deal with the Third Reich
	- "The Crystal World" by J. G. Ballard, where a crystalline
	  growth that freezes time itself spreads over the world
	  from the jungles of Brazil

    re .16: "temporal fugue"
    
    Actually, I think it was the Prince and the Steel General who have the
    fugue.
    
    A "fugue" battle is fought by jumping back in time say 5 minutes
    so that there are "now" two of you, then four minutes later, both
    of you jump back 3 minutes, "now" there are 4 of you. In "...Light
    and Darkness" The two combatants build up quite large armies in
    this way straining the spacetime continuum to its limit. A masterful
    piece of writing.           
    
    "...Light and Darkness" is an amazing work as it takes place across
    the entire fabric of spacetime, it took me several readings to begin
    to get the "true" order of events sorted out.
                                                   
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    	In the novelization of THE TERMINATOR, the time machine used
    to send Terminator and Kyle Reese from 2029 to 1984 was called a
    "chronoporter", and the act of time traveling was called
    "chronoporting", both phrases which I personally like.
    
    	So as not to break my own "rule", neither the movie nor the
    book told how that particular time-traveling was done, except that
    nothing inorganic could go through, and Kyle said he saw a white
    light and felt pain, "like being born."
    
    	Larry
    

    re. "fugue battle" Poul Anderson also uses this idea in There Will
    Be Time

    "The Man Who Folded Himself," David Gerrold.
    
    Excellent, btw. Gerrold confronts almost every time-paradox ever
    imagined in the book. There is life after tribbles :-).
    
    Fred

    My two favourite time travel stories are:
    
    Time after Time - Jack the Ripper steals the Time Machine and H
    G Wells chases him into the (contemporary future).  It was also
    a great movie...
    
    Thrice upon a Time - by James Hogan.  Basically, using waves of
    Tau particles, communication takes place backward in time to warn
    the past of problems in the future.  It gets out of hand - recursively.
    Its got a clever plot and cute hardware (like a PDP-30!).
    
    
    BobW
    

  And how could we forget Groff Conklin's "Adventures in Time and Space"
  anthology...  This book has interesting subsections, one of which is
  time travel.  The stories were considered to be classics at the time
  (1945?) and most of them still are.

  JP

    Someone mentioned Poul Anderson - _There Will Be Time_
    
    My P.A. collection yeilded the following :
    
    Past Times  (anthology)
    
    The Dancer From Atlantis
    
    The Corridors Of Time
    
    The Guardians Of Time  (Time Patrol series)
    Time Patrolman
    
    The Man Who Came Early (short story - much anthologized)
    
    the last was a personal favorite
    
    good readin !     Dana

    	What about the book TIME TRAVELERS STRICTLY CASH?  What is the
    plot?  How do the time travelers in this novel move about?
    
    	Larry
    

    I believe this is the latest collection of short stories about
    Callahan's, a fictitious bar created by Spider Robinson.  Callahan's
    is located on contemporary Earth, but it somehow gets customers
    from all over, and I mean ALL over.  Some of them happen to be time
    travelers.  Others are from parallel universes, or other planets,
    or escaped from genetics labs, etc.  There are several anthologies
    of these stories.
    
    Earl Wajenberg

    ASFM had several short stories about a man whose time machine
    was a trash can. Have these been issued as a book? I no longer
    remember much about them except that they were funny.
    Bonnie

    re .11:  I'm reading T'sLG & finding it slow-going; not as quick
             as some of his other works.

    ADV IN T & S was Healy & McComas, in case anyone was going searching...
    
    'Tho time travel was used to go *big* game hunting, Gerrold's
    DEATHBEAST is kind of a prehistoric Jaws story and worth the read.
    In a similar (but quieter vein) is Chillson's THE SHORES OF KANSAS
    (great title!), about a man who supports his experiments by
    bringing back an occaisional artifact or two.
    
    One I thought was fun was the psuedo-time travel story THE GREAT
    TIME MCHINE HOAX, by Keith Laumer.

    The there's the classic THE MAN WHO MASTERED TIME, by Ray Cummings,
    and  Moorcock's BEHOLD THE MAN.
    
    				Don ICEMAN::Rudman

A fun one is a book called "The Ship that Sailed the Time Stream"
by <name left as an exercise for Jerry B>, about a sailing ship/floating
research lab that gets struck by lightning at an inopportune moment.

Its fun!
		Nigel

    	What happened to the research ship when it was struck by lightning?
    (Obviously I would like to know more than "It went through time").
    
    	Was there any explanation as to how lightning could have caused
    physical movement through time?
    
    	Larry
    

                           ,                 _
        re: .29  Was it Jose Mario Garry Ordonez Edmondson y Cotton?
    
        re: .30  Gee, Larry, don't you watch OUTLAWS?
    
    					Don

    	I know about OUTLAWS, but I haven't seen it yet.
    
    	But don't tell me they traveled through time after being hit
    by lightning?!
    
    	It isn't another schlocky SF TV series, is it?
                  
    	Larry
    

re: .30 :

L. Sprague deCamp's "Lest Darkness Fall" uses the idea of a direct lightning
strike in a historically active area ( ie. Rome ) as a means of letting the
protaganist "slip" back into time.

Maybe Heinlein's "Farnham's Freehold" time travel via direct nuclear strike is
by the EMP, which is just another lightning strike :-)  

kevin

    Re .32:
    
    The _Outlaws_ and one then-currently law-abiding ex-outlaw law officer
    traveled through time while or after lightning did something funny.  As
    far as I know (I only watched about three episodes), this is the only
    fantasy or science fiction part of the series; it was only a way of
    getting the old West characters to modern times.  From there on,
    conventional rules take over.
    
    
    				-- edp

    re .32 & .34 : ...but its still schlokky !

    All true.  But, like Crime Story, is nice to see some direct action
    once in a while.  Besides, these guys are practically buletproof!

    Speaking of FARNHAM'S FREEHOLD, leave us not forget THE DOOR INTO
    SUMMER.
    
    							Don

    	Finally saw OUTLAWS.
    
    	In my opinion, it's THE A-TEAM meets BACK TO THE FUTURE.
    
    	There's so little SF in it, it almost isn't worth putting the
    series in that category!  Lightning striking them and sending them
    into the future has got to be one of the most pathetically unrealistic
    ways of time travel I have ever seen!  It should have just fried
    the Outlaws (like it really would have) and spared us this bland
    excuse for another detective/adventure series!
    
    	Larry
    

    Tuesday night (3/10) 9pm.  CBS
    
    TV Guide recommends it. 
                                                   
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    re .38:
    
    The Boston Globe panned it.
    
    I didn't watch it, but taped it. Did anyone watch it? Is it worth
    it? 
                                                   
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	re .39

	I watched it and thought it was fair.  You should have been there
	to edit out the deluge of commercials but the story wasn't that
	bad.  Rather a welcome relief to the SF wasteland TV usually is.

		Bob L.

    re: Timestalkers

    I also thought it was o.k. 
    
    I have one complaint however that really relates to SF time travel
    stories in general:
    
    The earth is not standing still! How do all these time travels keep
    themselves from ending up in the middle of space when they travel
    years into the future?
    
    Do all these devices have a way of moving the person in space
    as well? If so, why do you have to be in the right location before
    time traveling?
    
    On Timestalkers, the bad guy gained access to a secure facility
    by going back to 1926 and getting "inside" and then returning to
    the present. Of course he had to make sure he was in the right spot
    before returning!
    
    Has anyone read any good SF that deals with this problem?
    
    David.
   

    re .40,.41:
    
    I think it is all H.G. Wells fault, remember how he got his time
    machine out of the Morlok's cave?
    
    I think the usual explantion has to do with being at the bottom
    of a gravity well, etc etc.
                                                   
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    H. G. Wells's time machine, the original, moved continuously through
    time, so you could see it flowing forward and backward around you,
    just as in the George Pal movie.  Obviously, it is just dragged
    along by the Earth the way the rest of us are.  WHY this should
    be so isn't clear, but there it is.
    
    In "The Technicolor Time Machine" by Harry Harrison, the inventor
    of the time machine makes an off-hand remark about making sure to
    get the spatial coordinates right for fear of winding up in deep
    space, but that's all anyone says about it.  Nobody notices that
    this probably means the time machine is also a teleporter -- e.g.
    move a nanosecond into the past and three hundred miles west.
    
    On "Dr. Who," we switch planets at least as freely as we shift times,
    and the Doctor is always muttering rather incoherently about
    "coordinates," so in that case they seem to be taking the movement
    of planets into account.
    
    Earl Wajenberg

    The film TIME AFTER TIME also has a time machine that includes
    spatial displacement at no extra charge. Herbert leaves Victorian
    London and ends up in present-day San Francisco.
    
    re: TIMESTALKERS
    
    Thumbs down from me. It was on the lower end of OK until the
    singing pc made its debut. That almost did me in. I also thought
    that Hutton and (especially) Kinski were terribly miscast.
    
    It had "series pilot" written all over it.
    
    --- jerry

        The controls on the time crystals were pretty dumb.  It only
        read days and years... I suppose the time of day was random (or
        hardwired to "high noon"... after all, it *was* leading up to
        cowboy era :-) ).  The controls were stupid, to be generous.
        Nice to be able to change it from 1986 to the exact day in 1886,
        in a couple of seconds, with only two buttons.
        
        The one thing I like about it was when Kinski snuck into
        the base by zapping back to 1926.  The typical implementation
        would be to just do it, saunter down into the valley, and
        show up safely in the present.  They had him very carefully
        studying the terrain with his range-finder monocular both
        before and after the time transfer to choose his exact spot.
        Not that there aren't problems even with this, but it's an
        improvement over the usual.
        
        There are *two* possible sequel (or series) threads in it...
        first, the woman asking if he minded if she called on him to
        help out now and then; and second, Kinski's lost time crystal
        being bashed down in the old-west mud under the wagon wheel.
        Sigh.
        
	It was borderline OK.  It'd be nice to say I haven't seen
        anything worse in a while, but, well... unfortunately, I
        have.
        
        	/dave

    A few years ago, there was a strange little movie called "The Final
    Countdown."  In it, the aircraft carrier USS Nimitz is on training
    manoeuvers near Hawaii when it gets sucked into a time warp.  (This
    is apparently a natural phenomenon, looking a bit like a small
    hurricane tipped on its side.)  With that infallible instinct that
    all time travelers have for arriving at crucial moments in history,
    the Nimitz & crew find they are still near Hawaii, but in 1942,
    just in time to try to prevent the attack on Pearl Harbor.
    
    After a lot of perfectly reasonable discussion about whether one
    can or should alter history, they decide they are at least duty-bound
    to try.  There is some amusing aeriel combat between modern jets
    and Japanese Zeros, all safely far out at sea where it could all
    have ahppened for all the effect it has on history.  Just as the
    Nimitz is getting into a good position to really change history
    (and presumablly BECAUSE they would beable to change history), the
    time warp comes looming up over the horizon and sucks them back
    to the present.
    
    Such a bald summary makes it sound kind of dumb, but the acting
    and the characters' appreciation of their peculiar situation actually
    made it very fair entertainment.  Anyone else ever see it?
    
    Earl Wajenberg

    Yes, Its been on HBO quite a lot in the past six weeks.

  I agree, Earl.  Not a bad flick.  And the special effects in this one
  remind me of another movie that hasn't been mentioned here -- "The
  Philadelphia Experiment."  Also not bad...

  JP

    There's one thing that I did NOT like about those movies.  Just
    as they got to the good part, time had to bring them back.
    
    It seemed a bit of a cop-out to me that, instead of dealing with
    some intriguing altered-history scenarios, the cop out with bringing
    them back against their will.
    
    "Back to the Future" was an exception to this in that something
    had to happen before a certain timeframe in order to get back home.
    
    I would just *love* to see a version of "The Final Countdown" where
    the storm was one-way only.  Just to see what they could come up
    with.

    	RE 446.47 -
    
    	Nit pick - they arrived on December 6, 1941, not 1942.
    
    	RE 446.50 -
    
    	I remember an audible "Awww!" throughout the audience when I
    first saw the movie when the NIMITZ crew was not going to fight
    the Japanese with their modern weapons.  Of course, I also remember
    some pre-Rambo types applauding and saying "Beautiful!" when the
    Japanese pilot was shot to death by some Leathernecks.
    
    	It would be interesting though if they HAD fought (and defeated)
    the Japanese attack force; would this have affected their history
    enough that they would have then ceased to exist, or what?  And
    how could the NIMITZ have been created in the first place if that
    historian had not existed previously from 1941 to build it?  Or
    is this another time-loop theory (see THE TERMINATOR Topic, #153)?
                                                                      
    	Larry
    

    It is worth seeing as light entertainment. It is on HBO
    now in the Boston area. 
    

    Re .51
    
    That's the sort of logical puzzle addressed in 331, among other
    places in this file.

    The return of the timestorm to bring the NIMITZ back to the
    present didn't bother me like it did some people. OK, so we
    get robbed of seeing the NIMITZ kick the living crap out of
    the Japanese fleet. I figure that the NIMITZ going back in
    time was destined to occur, not so that it could save Pearl
    Harbor (obviously, because it didn't), but to deposit the
    James Farrentino character back then so he could become the
    tycoon. Perhaps Nature caused the timestorm because it was
    the only way to resolve the paradox of the Farrentino character
    existing twice.
    
    My favorite bit in the whole movie was rationale the Captain
    (Kirk Douglas) had for trying to stop the invasion. Not for
    some misguided sense of ethics or anything like that, but
    simply because it was his duty as a Naval officer to protect
    the US from any enemies. Period. The singularity of the
    situation had no meaning for him. The US was in danger, and
    by god, he was going to do whatever was in his power to help.
    Rather simple-minded in a way (and most liberals would think
    rather fascist), but it rang true.
    
    --- jerry

    re .51 again:  An interesting supposition.  I'd gues the ending
    would be a time loop similar to THE TIME TRAVELERS:  The Nimitz
    stops the Japanese.  This changes the future so the Nimitz doesn't
    time warp and therefore cannot stop the attack.  This resets Reality
    to scenario one and the Nimitz shows up in '41 just in time to....
    
    For those who like stories of old war machines vs new try "Hawk
    Among the Sparrows", a story about a jet fighter warped back to
    WWI.
    
    						Don

    Re: NIMITZ vs Japanese fleet.
    
    	It also would have been interesting for the Japanese to find
    the Nimitz: CVN-68 would have been on the ocean floor!  It would
    have be a perfect example of low-tech out performing hi-tech.  The
    strike force from the Nimitz might have been able to inflict heavy
    damage on Yamamoto's task force, but through the vast number available,
    the Japanese could have overwelmed the Nimitz's air defenses.  The
    heat seeking air and surface to air missiles probably would not
    find a strong enough source to target.  And the scenes of the F-14s
    shooting down the Zeros was a laugh.  In a mass attack of Zeros,
    the best weapon a F-14 probably has is its jetwash since in a gun
    to gun fight, the Zero is better armed, can turn well inside the F-14,
    and presents a smaller target.
    
    As for the Nimitz, she relies to heavily on escorts to defeat submerged
    or surface level threats.  The torpedo planes would have sunk her!
    
    It was a cute movie, but not something to think about.  A definite
    movie when in the mood to have the brain in neutral.
    
    	Klaes
    
    (I know, pick, pick, pick!)
    

    re:.56
    
    Oh come now! Certainly the Japanese ships would've provide
    a sufficient infrared profile for heat-seeking missiles. I
    know this was a point mentioned in the alluded to story,
    "Hawk Among the Sparrows". The WWI German fighters weren't
    hot enough, so the supersonic jet used backwash and sonic
    booms to destroy them.
    
    --- jerry

    
    Did I say ships? No I said xxx-to-AIR missiles.  Anti-ship missiles
    don't care about heat.
    
    But I'd STILL like to see a modern carrier (by itself!) counter
    an attack by 50+ torpedo planes plus their fighter escort.
    
    One of these days I'll have to read "Hawk Among the Sparrows", sound
    like somebody was thinking when they wrote it.
    
    	Klaes
    

    Re .58:
    
    I read it some time ago.  The thing that made it work (somewhat)
    was that the fighter was modern enough to use kerosine (which was
    purified by being filtered through chamois).
    
    The story was cute and enjoyable.   It appeared in _Analog_.
    
    Steve Kallis, Jr.

    I dont think the Zero's would have done more than scratch the paint
    off the F-14's.  Today's planes fire MUCH more potent bullets than
    WWII's did.  Also, since the Jets are flying faster than the Japanese
    bullets, I think they would be pretty safe assuming they didnt run
    straight into a Zero.  
    
    Does anyone know whether modern carriers are better armored than
    WWII ones?
    
    /Dan

  Hmmm.  Not sure about that, Dan.  First of all, the Korean Conflict was
  the first in which planes had the capability to fly faster than bullets.
  I've read that there are documented cases of F-86s that shot themselves
  down by: 1) firing a burst, 2) entering a high-power shallow dive,
  and 3) pulling up into the stream of bullets.

  The skin on a fighter is pretty fragile.  If any kind of foreign object
  starts to tear it up, then the plane loses its aerodynamic integrity and
  arrives on the ground as a collection of nuts, bolts, and sheet metal.
  It may be that this only happens at high speed and that the F-14s would be
  traveling as slowly as possible in order to fight with the Zeros at all...
  Still, it's something to think about if you're a fighter jock who wants to 
  die of old age.

  JP

    re Zero's vs. F14's:
    
    Looks like time for FLIGHT.
    
    (i.e. the Flight simulator on the Vaxstation)
                                                   
                  /
                 (  ___
                  ) ///
                 /
    

    
    This is starting to get away from the topic, but...
    
    Armor? What's armor on a modern carrier?  One might also ask, what
    are air defenses?  Two or three missile launchers and Phalanx systems
    do not a solid air defense make (read what happens to the Nimitz
    in 'Red Storm Rising' (is that sf?)).
    
    As for aircraft weapons: The F-14 carries 1 20mm cannon, the Zero
    had 2 20mm and 2 7.7mm guns.  Airplane skins are thin, so even the
    slower guns on the Zero would do plenty of damage.  Besides, all
    if takes is one slug in the turbin and the engine will probably
    shred itself (if bad enough it will even take out the other engine).
    
    
    But lets get this back to time travel, I don't think the space/time
    can take much more of this.
    
    	Klaes
    
    P.s. Once FLIGHT V1.4 is out, if somebody can come up with decent
    versions of the planes, I'll be glad to meet them over Tulukia Atoll.
    

    This mythology that todays fighter jets and carriers would have
    a tough time against yesterdays fighter planes and carriers is just
    do much bunk.
    
    First of all, fighter jets a perfectly capable of flying and fighting
    at subsonic speeds (thus little holes would only shred the jet of a
    dumb pilot).  Secondly, almost all of them are armed with an array
    of anti-personell weapons that can devastate armored cars, light
    tanks, and people, as well as fighter planes in a pinch.  Most of
    these jets (circa this films time) are carrying some form of the
    legendary "Vulcan" cannon, a gun that can throw out so much lead
    a second that overuse often results in the bullets melting in the
    barrels.  Fighter planes would be turned into confetti in the face
    of one of these.
    
    Most air-to-air rocketry comes in several forms, heat-seeking, computer
    targeted, and "other" (don't ask).  Only the heat-seekers would
    have any trouble with fighter planes (arguable), and most experienced
    pilots know how to use these against 'black' targets.  The other
    rockets can be launched towards targets from literally miles away,
    hard to defend against in a Zero.
    
    Another over-looked factor is visibility and manuevability.  Modern jets
    can manuover and fight with no problem in cloud banks, smoke, and
    total darkness.  And just because they are fast does not mean that
    they can't do complex and tight aerobatics.  And lets not forget,
    they ARE fast.
    
    As for the carriers themselves, they are guarded by a complex of
    systems that far exceeds their escorts alone.  Let me mention just
    one of them.  I have had the (dubious?) distinction of working on
    the AEGIS systems that are part of the defenses of the Nimitz class
    carriers.  These systems were designed to shoot Super-Entenard (sp?)
    type missles out of the air with bullets!  SE missles can be launched
    from over 12 miles away, reach speeds well over mach 2 and approach
    thier target by skimming a few feet above the water line, they are
    not easy to stop.  When properly armed an AEGIS system can easily
    destroy any combination of things moving towards it that is smaller
    of slower than a fighter jet.  This includes missles, planes, small
    boats, torpedoes, large waves, dolphins and flying fish!  Japanese
    Zeroes would be lucky to get within 500 feet of the Nimitz.
    
    Now lets talk about movement and recon, only three of the different
    kinds of aircraft shown in this film where fighters (by my count)
    almost all the rest where reconnosance (sp?) planes, of varying
    natures.  One was a radar plane that can pinpoint ships and aircraft
    over a hundred miles away, the Japanese did not have ANY radar and
    were limited to line of sight.  Modern aircraft carriers are much
    faster than their WWII counterparts, and thus with their superior
    recon would have no trouble keeping the Japanese fleet totally ignorant
    of their location.
    
    In truth all of this only scratches the surface of the advantages
    that a modern force would have over a 40 year old one, even if
    seriously outnumbered.
    
    --  Barry

    Well friends having been in the Navy myself and being and electronics
    tech who worked on the F-14 also, and served aboard the Enterprise
    herself I can safely say that the Japanese fleet/aircraft would
    have been obliterated.  The aircraft could have been downed without
    firing a shot. How? Simple.  Take 12 F-14's doing Mach 2+ spread
    them out and have them fly through the formations of Zeros.  The
    jet wash and shock waves would send the planes tumbling uncontrollably.
    Those that weren't destroyed would have no time to even react before
    the F-14's would be out of sight.  Do this a couple of times and
    the fight is over.  
    
    The M61A1 Vulcan Cannon on the F-14 has two firing rates: 4000 and
    6000 round per minute.  The gun is usually set at 50 round bursts
    so as not to use up the entire magazine with one trigger pull. The
    Zero in the movie should have been turned into match sticks.  The
    Sidewinder(heat seeker) missile would have no trouble locking onto
    the engine heat of a Zero. If they wanted too one Phoenix missile
    with a nuclear warhead would take care of the entire flight of Zeros.

    Steve

    Also the stories of jet shooting themsleves down with there own
    gun fire is totally untrue.  Remember the bullets are moving with
    the speed of the the jet plus their own speed. so your talking 
    approximately MACH 2. This is much faster that the firing aircraft.
    Most guns are used in a dog fight situation anyway and this is always
    done at subsonic speeds. Supersonic speeds are used for getting
    to and away from a fight.
    
    Now interestingly enough if the F-14's are used like I said in .65
    if a ZERO did get off a few rounds they would not work because the
    jets would be moving faster than the bullets and would out run them.
    In fact they would probably be out of range before the pilot squeezed
    the trigger.
    
    Steve

    1)	Regarding the possibility of an aircraft shooting itself down,
    this actually happened in the 1960's.  The aircraft in question
    was a Navy  Tiger (F11F, I think).  The pilot fired a burst from
    his 20 mm. and then put the plane into a moderately steep dive at
    full engine thrust.  Net result was that he dove through the descending
    trajectory of his cannon burst.  It ain't easy, but it can be done!
    
    2)  The Mitsubishi Zero had another peculiarity that no one has
    mentioned yet.  Its impressive performance was assisted in part
    by a total lack of armor and the extensive use of magnesium.
    As a result, hitting a Zero and destroying a zero were nearly the
    same thing.
    

    Regarding the speed of bullets relative to the speed of the aircraft
    firing them - yes, it's true that initially the bullets' speed is
    the sum of the muzzle velocity and the aircraft velocity, but there
    is this thing called drag, and bullets, despite their very high
    ballistic coefficient (which characterizes the relative magnitude
    of inertial and drag forces on an object), do slow down, and unpowered,
    they will eventually slow down to a velocity lower than that of
    the (powered) aircraft that fired them.  Whether or not in practice
    this occurs quickly enough for an aircraft to "shoot itself down"
    is not obvious, but some reasonable assumptions and a little
    calculating should be able to demonstrate the plausibility or
    implausibility of this.
    
    Note also that independent of their horizontal velocity, bullets
    fall with the acceleration of gravity just like anything else. 
    There is some lift due to their horizontal velocity, but my guess
    is that it would be negligible relative to their mass.
    
    len.
    

    Re last several:
    
    Backk in the Neolithic age, when I was in college (we had great
    courses in how to polish flint spearheads ...), there was an actual
    news report about a jet fighter that had shot itself down.  However:
    
    1: the jet was flying subsonic.
    
    2. the airctraft was in a climb attitude when the guns were triggered.
    
    3. after firing, the aircraft went into a dive such that it intercepted
       its downward-arcing bullets.
    
    That particular maneuver wasn't very bright.
    
    Steve Kallis, Jr
    

    RE .69
    Yes that would be about the only way that a plane could shoot itself
    down.  
    
    RE .68
    
    A bullet when fired in a horizontal direction would be completely
    impossible to catch up to in any mode (diving,supersonic or what
    ever).  If you want an example just go out and fire a gun level
    with the ground and and the same time drop another bullet from the
    same level as the barrel.  At the same instant that the dropped
    bullet hits the ground so does the bullet that was fired. Simple
    straight forward physics.  Therefore any aircraft firing bullets
    in any attitude  under a 45 degree up angle would not be able
    to catch up with it's own slugs. And even so I think it would be
    difficult.  Even .69's news item must have had some pretty high
    odds against it. But then again Murphys Law does rule all.
    
    Steve 8^)

    re .70;
    
    Your model does not take into account the fact that the aircraft
    can a) accelerate after firing and b) accelerate downward at more
    than 1g.

    Re .71:
    
    Well, I suppose if someone reallyu wanted to have the company pay
    off on his or her life insurance policy, the maneuver you mentioned
    might be made, but ...
    
    
    Steve Kallis, Jr.
    

RE: .*

The best defence of a carrier by far is it's one complement of planes.  They
far out weigh any other type of defence.

"Japanese Zeroes would be lucky to get within 500 feet of the Nimitz."

I don't think the Zero's ever need to get that close! :-)

Jim.

    
    Re: Zeros close to the Nimitz.
    
    If I were on the Nimitz under such an attack, I wouldn't be worried
    about the Zeros, I'd be worried about the Vals and Kates.  While
    the Zeros were busy keeping the air defenses busy, the torpedo planes
    would make swiss cheese of the carrier's hull.  Aegis may (I repeat
    MAY) work on air attacks, but Sea Sparrows and Phalanx systems don't
    track underwater targets.
    
    	Klaes
    
    P.s.  Would someone PLEASE bring up something to get this topic
    back on track.  I'm sorry I started this.
    

    What was the topic?  I think I lost it 10 replies ago :^)

    Just went back & read .0.  Is that what this topic is about?

    Well, one time-travel story that's been neglected is the original,
    "The Time Machine" by H. G. Wells.  The George Pal movie was a fairly
    good reflection of it, in that both present a leisurely sort of
    travelogue of the future, but many details are different.
    
    In the book, the Eloi, the beautiful but degenerate people of the
    future, are like children, and the nameless time-traveler's affection
    for Weena is paternal in tone, not romantic.  (Very Victorian!)
    Also, the Eloi era is just his FIRST stop, albeit his longest. 
    He then goes on to see a rapid succession of future geological ages,
    all the way to the death of the Earth.
    
    Does anyone know of a time-travel story that pre-dates Wells?  I
    think he invented the genre.  I wonder what inspired him?
    
    Earl Wajenberg

    Sorry to get off the subject again, but I just have to reply to
    .70.  I noted that a fired bullet falls with the acceleration of
    gravity, but I fail to see what that has to do with its horizontal
    deceleration due to drag or the ability of a nondecelerating aircraft
    to catch up with it.  If the aircraft in question is at any reasonable
    altitude, it will take the bullets quite a while to fall.  Of course,
    the pursuing aircraft will have to dive in order to "fall" along
    with the bullets; is that what you meant?  That seemed so obvious
    as to not be worth mentioning.
    
    OK, now back to time travel.
    
    len.
    

    	Well, this is time travel of a sort - LOOKING BACKWARDS by Edward
    Bellamy.
    
    	A man is put into suspended animation in 1887 and is revived
    in Boston in the year 2000.  Interesting Victorian view of Bostonian
    society in the future.
    
    	Larry
                                                

    Larry Niven gave a speech long ago at an SF con on "The Theory and
    Practice of Time Travel."  This formed the basis for a written essay
    that has been anthologized.  It discusses all the technical aspects
    of the subject, with examples from fiction.  It's fun reading. 
    It forms a companion piece to "The Theory and Practice of
    Teleportation."
    
    Earl Wajenberg 

re: .77
Urk...did Wm. H. Hodgson's "The House on the Borderland" precede or
follow Wells's "The Time Machine"?

    re:.81
    
    Hodgson's book was published in 1908, 13 years after Well's
    story.
    
    --- jerry

    
      The short story Twilight (I think it's by Asimov) is pretty
    good. It starts with a bunch of the boys, sitting around the general
    store and shooting the sh*t. One of them starts in about the Strange
    hitchhiker he picked up. Seems the guy didn't know what year it
    was. He then proceeds to tell the hitchiker's story. The stranger
    got sucked into some sort of field, and ended up in the distant
    future. The story gets into the progress of man, both technilogicaly
    and socialy. A very good story that leaves you something to think
    about.
    
     I also remember reading a short story years ago in high school. I think
    the name was something like "The Sound Of Distant Thunder". It's
    about people taking vacations in the past to do some BIG game hunting,
    namely dinosaurs. It had a very good ending (I could be wrong, I
    was young and impressionable and also enjoyed drinking 'till my
    brain fell out). If anyone can find it, give it a read. How bad
    can it be?

    
                                               
    ike 

    
    I liked 'The Sound of Distant Thunder', and it brings up an interesting
    question in dealing with time travel.  Assuming that we've gotten
    around all the paradoxes and technical problems of time travel,
    what is the smallest change that a traveler can make and make a
    noticable change in the time stream?
    
    In the above mentioned story it was the killing of a butterfly,
    but is the size required of the change constant or is it inversely
    related to the distant back traveled?  Obviously if I go back far
    enough and accidentally kill the first living cells on the planet,
    life might develope, but will it take the same course?  Could not
    the very act of my breathing or even physical presence be enough
    to cause major changes in future?
    
    Or do we use Hogan's infinite parallel time streams and simply say
    that I have created yet another version?
    
    	Klaes
    

    	Nit-pick - 
    
    	The title of the story is "A Sound of Thunder", written by Ray
    Bradbury in 1955. 
    
    	In regards to your concept, there is the theory that every action
    we take creates in infinite amount of spacetime realities, ranging
    from the one we are in, to ones where we might have done something
    just slightly different, to radical action possibilities, to realities
    where we and the Universe we know do not exist at all!
    
    	Larry
    

    re .83:
    
    "Twilight" was written by John W. Campbell. (he may have used his
    pseudonym Don A. Stuart for the story).  It was one of the first
    SF stories that dealt with "feelings" rather than rays and rockets.
    
    I agree, a good story.
           
    					andrew

    Re .83, .86:
    
    John Campbell was the author, and he did indeed use the "Don. A.
    Stuart" pseudonym (Donna Stuart was his mother's maiden name, for
    the trivia buffs).  He wrote a sequel, "Night," years later.
    
    Steve Kallis, Jr.

    re ? - how small a change can you get away with - I recall
    reading someplace the notion that the "timestream" "heals itself"
    for relatively small changes; there's a sort of temporal inertia
    that damps out small perturbations, and only really big changes
    affect things enough to make "permanent" changes.
    
    Anybody know whose idea this was?
    
    len.
    

    Re .88 and others
    
    Roughly speaking, authors of time-travel stories use three different
    models of temporal dynamics.
    
    The simplest one is a completely rigid past.  You can't change it.
    If you try, you fail.  Sometimes, you fail just because circumstances
    always twist around to make you fail.  Sometimes, time-travelers
    find they are impalpable phantoms while they are in the past.  These
    stories are the sf equivalent of folktales about a protagonist battling
    Fate.
    
    Next is the one where "the timestream heals itself."  In this system,
    time travelers can wander about in the past harmlessly, for the
    most part.  They have to try hard and buck the current of the time
    stream.  If they try hard enough, it snaps into an alternate history.
    This format is lots of fun for time-war stories, in which the Time
    Patrol battles evil revisionists to preserve history.  Obviously,
    history can preserve itself in the first format.  In the third,
    history is unpreservable.
    
    The third form is the for-want-of-a-nail-the-shoe-was-lost kind,
    in which ANY alteration of the past can propagate into a complete
    new history.  Such a rapidly shifting setting makes an on-going
    series difficult to do, so most of these stories are one-shots based
    on the irony of the giant effect springing from the tiny cause.
    
    All three are widely used.  All three can be entertaining.  Only
    the first one is at all self-consistent, without a lot of handwaving.
    
    Earl Wajenberg

Physics is starting to deal with these things in the study of chaotic
systems and catastrophe theory. These are systems with several
different modes.  If you start out in one set of states, small
perturbations remain small.  You either return to the initial state or
orbit around it, like a frictionless pendulum swinging after a small
push.  In other states, however, perturbations get amplified
endlessly.  The onset of turbulence in a smooth stream is like this.
As soon as some of the streamlines start to snarl, they tangle up
others until the whole flow is a mess. 

Studying chaos sounds like a contradiction in terms, but you can 
still learn some useful things about it, such as where the boundary 
is between chaotic and orderly behavior, and what the dimension of the
fractal behaviors are.  Just as quantum mechanics tamed the 
fundamental randomness of subatomic particles, these theories might
help us with randomness of macroscopic systems.

Which kind of system is human history?  Impossible to say, since we 
don't even know how the micro-dynamics of history, namely the 
interactions between individuals, works.  Things get tough enough in simple
matters like incompressible fluids.  Still, if we can tame the chaos 
in systems like the weather, there might be hope for a science of 
psycho-history after all.

/jlr

    Sounds like Asimov's "The End of Infinity" .

    Re .88:
    
    There were a lot of such stories and speculations.  Besides an essay
    by Arthur C. Clarke, Fritz Leiber had whole stories on it.
    
    Re .99:
    
    That's _End of Eternity_; I don't think the notion was original
    with Isaac, though.
    
    Steve Kallis, Jr.

Another very good time travel story is "The Proteus Operation" by James 
P. Hogan, written in 1985. From the jacket:

       "By 1974... the iron heel of Fascism has subjugated Europe, Asia 
   and South America, and Africa has been devastated by a genocidal 
   war. Only in North America and Australia does freedom survive, and 
   the threat of war is imminent.
   
       "Democracy has only one last, desperate hope- Operation Proteus: 
   a top-secret project to send a team of experts back in time to an 
   era when freedom was still possible, to alter the outcome of 
   history. Yet when they arrive in the U.S. in 1939, their mission 
   seems all but hopeless. Europe is blind to the Nazi threat, and 
   America is lost in economic depression and isolationism.
   
       "In the face of daunting odds, the Proteus team commences its 
   mission. A delegation of diplomats travel to London to contact the 
   one man they believe might rouse England to action: an aging, 
   semiretired M.P. named Winston Churchill...

Hogan writes a good story with well-delineated characters, and pays 
more than the usual amount of attention to "real science".

- Richard

	 A long  time  ago  I read a novel by Philip K Dick which was pretty
	 good.   Can't  remember  much, except that is was rather funny - it
	 was  about this guy who cruised around all through history and kept
	 running  into himself.  It dealt with the usual paradoxes in a very
	 interesting manner.

	 Can anyone help me with the name?

	 -- POL

    I'm not an expert of Dick's work, but is it possibly
    DR. FUTURITY?
    
    --- jerry

    OK.  Why did it take until .91 to start mentioning kind, genial
    Dr. A's first Eternity book, and that there are at least two more
    on the subject of Eternity by Ike (one is rather recent, and is
    busy trying to convince us that, in reality, he _has_ been writing
    one cohesive Future History all along -- and you thought he was
    jealous of poor Gordy Dickson...)
      One more.  Remember H. Beam Piper?  It may have been a bit
    simplistic in trying to limit the alternate realities, but doesn't
    _Lord_Kalvan_of_Otherwhen_ count?
    

    (Ahem.) *I* mentioned "The End of Eternity" all the way back in
    .6, as one of the few cases of a rational model for a changable
    past.  However, I didn't know there were two other Eternity books.
    I had heard Eternity was mentioned in passing in the more recent
    Foundation and Robot books.  What are the titles?
    
    Earl Wajenberg

    re:.96
    
    I wouldn't suggest calling Asimov "Ike" to his face. He doesn't
    like that name.
    
    re:.97
    
    Indeed, Asimov ties THE END OF ETERNITY in with the Robots/Foundation
    future history in recent books, but there isn't any book that's
    actually about the Eternals other than THE END OF ETERNITY.
    
    --- jerry

    I once read a collection of short stories by Pierre Boulle (who
    wrote _Planet_of_the_Apes_).  I don't remember the name of the
    collection or the story in question, unfortunately.  All of the
    stories were awful except the first, which was about time travel
    and was the best time travel short story I've ever read (but then
    I don't read many short stories).  Basically, the plot is this:
    
    	A man is sitting in a cafe in Paris a few years after the end
    	of WWI.  He sees another man in rather strange garb wandering
    	about.  Finally the strange man stops at the frenchman's table
    	and says, "Excuse me, but what year is this?"  The frenchman
    	is a little startled by this question, and the stranger explains
    	that he is from a highly technological civilization 20,000 years
    	in the past and he was going to travel to visit a civilization
    	he knew of 40,000 years after his time (20,000 after ours),
    	but the jump was too long to make in one hop so he was making
    	two.
    
    	While talking, a man comes over to their table, and says, "I've
    	been listening to your conversation and by and amazing coincedence,
    	I am from 20,000 years ahead of this time and going 40,000 years
    	before my time in two hops just like you!"  Well, the three
    	of them talk for a while about the amazing coincedence, then
    	the man from the past says he must go.  Before he leaves he
    	draws the frenchman aside and says, "I think the other man is
    	a spy sent to precede an attack on our civilization by the future
    	civilization.  I am going to go to the future and foil his plans."
    
    	Well, the story goes on of how these two men keep popping back
    	and forward in time, each plotting against the other, then
    	counter-plotting when the plots are discovered, etc.  The time
    	streams get VERY confused as they cross and re-cross and meet
    	each other before/after in relative and absolute time, etc.
    	It is an excellent story with a marvelous ending.  I wish I
    	could be of more help with the title, but if you can find it
    	it is certainly worth reading.
    
    Andy Humphrey

Newsgroups: rec.arts.sf-lovers,rec.arts.startrek
Path: decwrl!labrea!rutgers!att!lzaz!lznh!mmb
Subject: Time travel
Posted: 28 Nov 88 17:34:40 GMT
Organization: AT&T
Xref: decwrl rec.arts.sf-lovers:21007 rec.arts.startrek:18527
  
    The following is an excerpt from a New York Times article Nov. 22 Pg. C1
 
	3 Scientists Say Travel in Time Isn't So Far Out
 
			By Malcolm W. Browne
 
    Could Some advanced civilization devise a tunnel that would open
shortcuts through space between distant regions of the universe or
through time into the past? 

    The traditional reaction of most scientists to such notions is to
dismiss them as naive science fiction. But three theoretical
astrophysicists have published a suggestion that the laws of physics
might not prohibit such "wormhole" travel through space in time. 

    Dr. Kip S. Throne and Dr. Ulvi Yustsever of the California
Institute of Technology and Dr. Michael S. Morris of the University of
Wisconsin presented their startling conclusion in a recent paper in
Physical Review Letters. This prestigious scientific journal is an
official publication of the American Physical Society, and it accepts
scientific papers for publication only after they have been rigorously
reviewed by independent experts. 

    Dr. Thorne and his colleagues stopped short of predicting that
anyone will ever travel through cosmic "wormholes". It has yet to be
proved whether such travel is or is not theoretically possible, they
contend. But such travel cannot now be ruled out, they say, although
it will probably be possible to settle the issue one way or the other
on theoretical grounds. Science would profit from a concerted effort
to resolve the question, they said. 

    If travel into the past could be shown to be at least
theoretically possible, the mere possibility would have profound
philosophical and scientific consequences. Since a time traveler might
theoretically be able to change events that occurred in the past,
including his or her own birth, the rules of causality on which
science is based would be thrown into confusion. 

    "The future's here right now, if you're willing to pay the price."

Newsgroups: rec.arts.sf-lovers
Path: decwrl!ucbvax!hoptoad!tim
Subject: Re: Time travel
Posted: 29 Nov 88 01:10:30 GMT
Organization: Eclectic Software, San Francisco
 
    Yes, the Stanford idea is to take a submicroscopic wormhole and
expand it through some process only physicists understand (i.e., I
don't) until macroscopic objects can pass through.  It may or may not
be possible, but as Maurice Burns pointed out, it can't be ruled out. 
 
    Unfortunately, this is one of those time machines that only works
as far back as the time it's switched on.  That is, if we build one
in 2050, then it can never go back any farther than 2050.  This may
not be as serious a limitation as it sounds, though.  Presumably other
civilizations much older somewhere in the universe have already
constructed such things, and we would eventually find one at least
40,000 years old.  Then we would just go back to 2050 to tell them
about it, so it would appear that as soon as we switched the first one
on we could go all the way back past the start of human history. 

    I know of at least four time travel possibilities under current
physical theories.  The Stanford wormhole stretcher is one.  The Kerr
metric warp is another one that can take you up to the point where it
was switched on and no further.  It's a torus of rotating ultra-dense
matter spinning at near the speed of light; when you go through, it
puts you into a hyperspace with some funky properties.  Then there's
the old rotating cylinder of infinite length, which I don't think has
the time-switched-on limit -- unfortunately, no one's quite sure
whether it's possible to fake the infinite length bit yet.  Finally,
there are trajectories through black holes, between the inner and
outer event horizon, that will spit a ship back out, apparently
intact, at some other point in spacetime that we can't so far predict.
 
    There are obvious and not-so-obvious problems with each of these;
no one really knows whether any of them can be built.  How would you
stabilize a Kerr warp and keep it from imploding?  Can you stretch
wormholes to macroscopic size?  Would the mass of a spaceship passing
through disrupt the balance between the event horizons of a black
hole?  Can you flare the ends of a finite cylinder and get the same
effect?  But the mere presence of four such loopholes is fascinating;
it suggests that there are more waiting to be discovered, and that at
least one will prove to be feasible within the lifetime of the human
species.  In short, it makes time travel science fiction rather than
fantasy, and maybe not even far-future science fiction. 

    Tim Maroney, Consultant, Eclectic Software, sun!hoptoad!tim

    "Cling to the past and you'll be left behind." - Y & T

    "Considering the marvelous complexity of the Universe...its clockwork 
  perfection, its balances of this against that, matter, energy, 
  gravitation, time, dimension...I believe that our existence must be 
  more than either of these philosophies...that what we are goes beyond 
  Euclidean or other practical measuring systems, and that out existence 
  is part of a reality beyond what we understand now as reality." 

            - Captain Picard, "Where Silence has Lease", ST:TNG
                                       

         Speaking of time travel in a strictly science fiction sense, 
    there is a new book out on the subject entitled THE COMPLETE TIME 
    TRAVELER: A TOURIST'S GUIDE TO THE FOURTH DIMENSION, by Howard 
    Blumenthal, Dorothy F. Curley, and Brad Williams.

         It is a clever book designed as a tongue-in-cheek guide for
    tourists who are as interested in visiting *when* as they are
    *where*.  For example, the copyright date says both 1988 and 2038, 
    and the authors have books credited to them which won't be written 
    for another forty years or so.  The Foreword is by H. G. Wells.

         TCTT tells you what are the best modes for time travel (time 
    belts, time cars, etc.), what are the best places to visit, what 
    diseases to be inoculated against (Black Plagues and all that, you 
    know), what to wear, what rules must be obeyed, and even how to bring 
    children along.

         The authors obviously had a lot of fun writing this book, and
    they know their SF:  A bibliography on books, films, and television
    series dealing with time travel (some which have yet to exist in our
    time period) is located in the back.  In fact I cannot go into
    enough detail to tell you how well this book was written and made.

         TCTT is produced by Ten Speed Press, P.O. Box 7123, Berkeley, 
    California 94707, USA, ISBN 0-89815-284-4 (Hardcover).  I highly 
    recommend it, in fact it may become useful soon, what with these
    scientists supporting wormhole time travel and all. :^)

         Larry Klaes

    Hard to believe, an entire file on time-travel with no mention of
    the Dr. Who methodolgy of stepping "outside" the domain and re-emerging
    at a different time. In a machine with different physical dimentions
    in both spheres, and frozen in one of the most bizzare shapes possible.
    
    How about the idea that simply writing and posting a VAXnote causes
    an alteration of time and reality, and that the fact that you can
    read and respond to "old" notes is, in fact, causing a time-travel
    through the net? Maybe the people in the past can read the current
    responses? (Remember the Hypernet concept of alternate realities?)
    
    Getting serious now; I don't remember the name of the story, but
    I remember a short story about a guy who could travel in time. But
    everytime he went into the past (for ANY reason) time "re-strung"
    itself differently because of the alteration. The result was that
    there was no real relationship between the past and present because
    everythime he returned to the future, it was very different.
    
    I also remember a story about a guy that could time travel, and
    everytime he did he had to leave notes describing who he was and
    what has occurred, so that when he returned, he could "act" on his
    previous memories before they changed.
    
    he had no real past/present

    re .102:
    
    I think I just read that story!  I was reading an old issue of Analog
    recently, and in it was a story about someone who had come back
    in time to avert the world's destruction.  Just before each key
    event that he caused, he would write a note or leave a recording
    telling him his name, etc.  The next morning he would wake up like
    an amnesiac and begin with the message.  
    
    Darn it, can't remember the title!
    
    BW

This month's issue of "Discover" magazine has an interesting article in it 
about the theoretical possibility of time travel.

Carl Sagan recently wrote a science fiction novel ("Contact") about our first 
encounter with aliens.  As part of the story, he wanted a form of hyperdrive 
that would be reasonably respectable, scientifically.  He asked Thorne (of 
Misner, Thorne & Wheeler, the general-relativity gurus) if a stable wormhole 
was at all physically feasible.  Thorne looked the problem over and said that 
it was.  Exit Sagan.

Thorne went on looking at discovered that, if you take one end of the wormhole 
and send it on a round trip near the speed of light, you get a time-gate.  
Traffic through the wormhole slides backward and forward through time by an 
amount equal to the difference on two clocks tied to the two ends of the hole.

Thorne is now worrying about causal paradoxes and refusing calls from 
reporters.

Earl Wajenberg

    Many years ago I read a short story with the title "Vintage Season" but
    I forgot who was the author.  It was a time travel story.  The premise
    was that "time tourists" go to historic events (the Great Plague was
    the setting of the story) and experience it first-hand.
    
    The following news article reminded me of the story.
    
Hong Kong takes '97 reservations

The Sunday San Jose Mercury News, Travel section. Janaury 27, 1990.

Not everyone is fleeing Great Britain's last great Asian colony, Hong Kong.  By
treaty, on June 30, 1997, ownership of Hong Kong reverts back to the People's
Republic of China, a move that has caused a certain amount of panic in the
highly capitalist colony.

Some Hong Kong businesses are planning to cash in on the moment, however.  The
Excelsior Hotel (Causeway Bay; telephone 894-8888) is offering a two-day,
one-night package, with a guarantee rate of 1997 Hong Kong dollars - about $225
- single or double, and a champagne party to toast the end of British rule. 
The hotel overlooks Victoria Harbor.

The more central Hong Kong Hilton (2 Queen's Road; 523-3111) has accepted 67
reservations for the transfer date for rooms with a view of Statue Square and
Government House, where, old Asia hands are betting, the ceremony will take
place.

    Speaking of time travel, there's Isaac Asimov's "The End of Eternity."
    I read the longer and later version first, and then the original
    version in "The Alternate Asimovs."  TEoE was mentioned a little in
    previous replies.
    
    Eternity, or the Eternals, tinkered with Realities.  They would make a
    change here, a change there, to Reality, according to their computa-
    tions of what is good for humankind.  Of course what they didn't
    realize was that in doing so, they created a Reality where humankind
    did not develop interstellar travel until it was too late, about 15
    million years hence.
    
    I read TEoE the first time before the Challenger disaster five years
    ago today.  I'm not sure if the thought came to me at that time or
    later, but if there were Eternals and they made that one small quantum
    change (as it was called in the original TEoE) to make the O-ring fail,
    the end result would be (as we know) that the Space Shuttle got put
    back by years, and who knows what the eventual effect on space travel
    that one event in 1986 had?  Of course, I can't think of any particular
    beneficial side effect the Challenger disaster could have caused.
    
    --Simon
    

re: .105

I think "Vintage Season" was by C. L. Moore (forget if it was with or
without her hubby Henry Kuttner as co-author).
								paul

    Vintage Season is contained in one of the Volumes of "The Science
    Fiction Hall of Fame."
    
    					andrew

    Last September, while on vacation I picked up, cheap, three volumes of
    "Time Police" by Warren Norwood.  They were subtitled "Vanished,"
    "Trapped!" and "Stranded" respectively.  (Actually the third was
    co-authored with Mel Odom.)  When I got to the end of "Stranded,"
    I left the protagonist stranded.  If I should come across the fourth
    volume, "Refugee," I don't think I'd bother.
    
    I haven't come across "Time Police" since coming back to the US, but
    all of a sudden today I saw it twice, on a "pre-read" shelf, and in
    a place called the Books Warehouse.  (This was in Kittery, Maine.)
    
    --Simon
    

    The Adventures of Conrad Stargard (series name)
    Book One: The Cross-Time Engineer
    (four vols available)
    Ballantine pb.
    
    An accident places a 20th Century Pole in 13th Century Poland.
    He becomes a knight and an industrialist.  He also realizes that Poland
    is defenseless against the Mongol invasions to come in a few years and
    needs to transform 13th Century Poland.  His coping with the people of
    the 13th Century and his need to create a industrial ecomony in the
    nick of time make this an interesting time-travel series.
    

The current issue of "Discover" magazine (April 1992) features an article on 
time travel with two distinct mechanisms for achieving the effect.  And 
neither of them is the flying-wormhole method discovered by Kip Thorne and 
reported in their June 1989 issue.  (See .104.)

The first method, proposed by Yakir Aharonov of the University of California 
at Berkeley, uses bubbles.  According to general relativity, time inside a 
massive expanding shell would slow down, while time in a contracting one would 
speed up.  (The return of the bobble!  See topic 484.)  Using some very 
ill-explained quantum-fluctuation effects, Aharonov can amplify the otherwise 
miniscule effects to the degree that time slow-down actually becomes a 
time-reversal and the contents of the expanding balloon ages backwards.  
Aharonov airily admits that he hasn't worked out the consequences of reversing 
the timeflow of a passenger to a date earlier than the passenger's birth.  
(For that matter, how about a date earlier than entry into the bubble?)

The second method, made a little clearer, comes from J. Richard Gott of 
Princeton.  It involves flying a spaceship in a tight loop around two cosmic 
strings that are passing each other at very nearly the speed of light.
Cosmic strings have a density of about 2 x 10**16 tons per cm, and the speed 
required is .99999999992 c.

Neither of these methods, of course, is very practical in terms of technology, 
but we now have three methods (counting Thorne's) of physically doing 
something often dismissed as a logical absurdity.  So it's at least 
theoretically interesting.  So far, my impression is that the physicists have 
been concentrating on getting the minus sign in front of the T, and have not 
yet devoted much thought to the standard conundrums of time travel paradox.
                                                      
Earl Wajenberg

Article: 7712
From: [email protected] (Jon Nowak)
Newsgroups: news.config,sci.misc,sci.news,soc.history,alt.folklore.science
Subject: PROPOSAL: Time travel newsgroup
Date: Thu, 10 Dec 92 00:29:02 -0500
Sender: [email protected]
Organization: Modem Madness BBS    1+516-295-9435
 
>From: [email protected] (Javier Garcia-Torres)
>Subject: PROPOSAL: time travel newsgroup
>Message-ID: <[email protected]>
>Date: 6 Dec 92 01:42:31 GMT
 
>       I have this idea for a newsgroup.  I don't really know how to
>create a newsgroup, but I've heard that alt.* newsgroups don't require
>getting votes.  At any rate, it is more important, IMHO, to discuss the
>concept of the newsgroup before I get to the technical aspects of "read
>news".
>
>       I propose the creation of a newsgroup based on the premise that
>someday time travel is going to be possible, and therefore it is useful to
>discuss what would or wouldn't be appropriate in time travel.  For
>instance, would it be all right to assasinate Hitler, and, if so, at which
>point in history?  I would rather not use the newsgroup for discussion of
>the scientific aspects of time travel or validity of the entire concept,
>although the metaphysical implications of time travel would be okay.
 
		Well, rather than a new-group, I suggest a mailing list.
	And it has already been done.   IF you would like to join this
	mailing list, on the topic of Time Travel as mentioned above,
	send E-MAIL to [email protected]    The first line of the
	message should read:
 
		JOIN Time-Travel
 
	You will receive the welcome file, which contains the charter and
	posting instructions.   Spread the word, and join the fun.
 
-- 
--------------------------------|-----------------------------------
[email protected]               BBS: 516-295-9435 - Voice: 295-1627      
--------------------------------|----------------------------------
     Believe It If You Need It, If You Don't, Just Pass It On
--------------------------------|----------------------------------

Article: 59789
From: [email protected] (SCOTT I CHASE)
Newsgroups: sci.space
Subject: Re: Time Machine!?
Date: 26 Mar 1993 11:19 PST
Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
 
In article <[email protected]>,
[email protected] (Dave Jones) writes... 

>Its all been theory.  There were claims that certain situations, which 
>weren't necessarily practical to engineer, would result in 'timelike world 
>lines' which is jargon for going into your own past.  The latest one to 
 
You mean "Closed Timelike Curves".
 
>appear suggests that one method, involving wormholes connected together and
>move around each other at high speed, would fail because (if memory serves) 
>the quantum effects resulting from bringing them back together would destroy 
>the setup, in the same way that black holes are supposed to evaporate over
>time.
 
Here is what the sci.physics FAQ says on the subject:
 
TIME TRAVEL - FACT OR FICTION?                  updated 23-MAR-1993
------------------------------                  original by Jon J. Thaler
 
	We define time travel to mean departure from a certain place and
time followed (from the traveller's point of view) by arrival at the same
place at an earlier (from the sedentary observer's point of view) time.
Time travel paradoxes arise from the fact that departure occurs after
arrival according to one observer and before arrival according to another. 
In the terminology of special relativity time travel implies that the
timelike ordering of events is not invariant.  This violates our intuitive
notions of causality.  However, intuition is not an infallible guide, so we
must be careful.  Is time travel really impossible, or is it merely another
phenomenon where "impossible" means "nature is weirder than we think?"  The
answer is more interesting than you might think. 
 
THE SCIENCE FICTION PARADIGM:
 
	The B-movie image of the intrepid chrononaut climbing into his time
machine and watching the clock outside spin backwards while those outside
the time machine watch the him revert to callow youth is, according to
current theory, impossible.  In current theory, the arrow of time flows in
only one direction at any particular place.  If this were not true, then
one could not impose a 4-dimensional coordinate system on space-time, and
many nasty consequences would result. Nevertheless, there is a scenario
which is not ruled out by present knowledge.  This usually requires an 
unusual spacetime topology (due to wormholes or strings in general 
relativity) which has not not yet seen, but which may be possible.  In 
this scenario the universe is well behaved in every local region; only by 
exploring the global properties does one discover time travel. 
 
CONSERVATION LAWS:
 
	It is sometimes argued that time travel violates conservation laws.
For example, sending mass back in time increases the amount of energy that
exists at that time.  Doesn't this violate conservation of energy?  This
argument uses the concept of a global conservation law, whereas
relativistically invariant formulations of the equations of physics only
imply local conservation.  A local conservation law tells us that the
amount of stuff inside a small volume changes only when stuff flows in or
out through the surface.  A global conservation law is derived from this by
integrating over all space and assuming that there is no flow in or out at
infinity.  If this integral cannot be performed, then global conservation
does not follow.  So, sending mass back in time might be alright, but it
implies that something strange is happening.  (Why shouldn't we be able to
do the integral?) 
 
GENERAL RELATIVITY:
 
	One case where global conservation breaks down is in general
relativity. It is well known that global conservation of energy does not
make sense in an expanding universe.  For example, the universe cools as it
expands; where does the energy go?  See FAQ article #1 - Energy
Conservation in Cosmology, for details. 
 
	It is interesting to note that the possibility of time travel in GR
has been known at least since 1949 (by Kurt Godel, discussed in [1], page
168). The GR spacetime found by Godel has what are now called "closed
timelike curves" (CTCs).  A CTC is a worldline that a particle or a person
can follow which ends at the same spacetime point (the same position and
time) as it started.   A solution to GR which contains CTCs cannot have a
spacelike embedding - space must have "holes" (as in donut holes, not holes
punched in a sheet of paper).  A would-be time traveller must go around or
through the holes in a clever way. 
 
	The Godel solution is a curiosity, not useful for constructing a
time machine.  Two recent proposals, one by Morris, et al. [2] and one by
Gott [3], have the possibility of actually leading to practical devices (if
you believe this, I have a bridge to sell you).   As with Godel, in these
schemes nothing is locally strange; time travel results from the unusual
topology of spacetime.  The first uses a wormhole (the inner part of a
black hole, see fig. 1 of [2]) which is held open and manipulated by
electromagnetic forces.  The second uses the conical geometry generated by
an infinitely long string of mass.  If two strings pass by each other, a
clever person can go into the past by traveling a figure-eight path around
the strings.  In this scenario, if the string has non-zero diameter and
finite mass density, there is a CTC without any unusual topology.
 
GRANDFATHER PARADOXES:
 
	With the demonstration that general relativity contains CTCs,
people began studying the problem of self-consistency.  Basically, the
problem is that of the "grandfather paradox:"  What happens if our time
traveller kills her grandmother before her mother was born?  In more
readily analyzable terms, one can ask what are the implications of the
quantum mechanical interference of the particle with its future self.
Boulware [5] shows that there is a problem - unitarity is violated. This is
related to the question of when one can do the global conservation integral
discussed above.  It is an example of the "Cauchy problem" [1, chapter 7]. 
 
OTHER PROBLEMS (and an escape hatch?):
 
	How does one avoid the paradox that a simple solution to GR has
CTCs which QM does not like?  This is not a matter of applying a theory in
a domain where it is expected to fail.  One relevant issue is the
construction of the time machine.  After all, infinite strings aren't
easily obtained.  In fact, it has been shown [4] that Gott's scenario
implies that the total 4-momentum of spacetime must be spacelike.  This
seems to imply that one cannot build a time machine from any collection of
non-tachyonic objects, whose 4-momentum must be timelike.  There are 
implementation problems with the wormhole method as well.
 
TACHYONS:
 
Finally, a diversion on a possibly related topic.
 
	If tachyons exist as physical objects, causality is no longer
invariant. Different observers will see different causal sequences.  This
effect requires only special relativity (not GR), and follows from the fact
that for any spacelike trajectory, reference frames can be found in which
the particle moves backward or forward in time.  This is illustrated by the
pair of spacetime diagrams below.  One must be careful about what is
actually observed; a particle moving backward in time is observed to be a
forward moving anti-particle, so no observer interprets this as time travel. 
 
                t
One reference   |                    Events A and C are at the same
frame:          |                    place.  C occurs first.
                |
                |                    Event B lies outside the causal
                |          B         domain of events A and C.
     -----------A----------- x       (The intervals are spacelike).
                |
                C                    In this frame, tachyon signals
                |                    travel from A-->B and from C-->B.
                |                    That is, A and C are possible causes
                                     of event B.
 
Another         t
reference       |                    Events A and C are not at the same
frame:          |                    place.  C occurs first.
                |
                |                    Event B lies outside the causal
     -----------A----------- x       domain of events A and C. (The
                |                    intervals are spacelike)
                |
                |   C                In this frame, signals travel from
                |                    B-->A and from B-->C.  B is the cause
                |             B      of both of the other two events.
 
	The unusual situation here arises because conventional causality
assumes no superluminal motion.  This tachyon example is presented to
demonstrate that our intuitive notion of causality may be flawed, so one
must be careful when appealing to common sense.  See FAQ article # 6 -
Tachyons, for more about these weird hypothetical particles. 
 
CONCLUSION:
 
	The possible existence of time machines remains an open question. 
None of the papers criticizing the two proposals are willing to
categorically rule out the possibility.  Nevertheless, the notion of time
machines seems to carry with it a serious set of problems. 
 
REFERENCES:
 
1: S.W. Hawking, and G.F.R. Ellis, "The Large Scale Structure of Space-Time,"
   Cambridge University Press, 1973.

2: M.S. Morris, K.S. Thorne, and U. Yurtsever, PRL, v.61, p.1446 (1989).
   --> How wormholes can act as time machines.

3: J.R. Gott, III, PRL, v.66, p.1126 (1991).
   --> How pairs of cosmic strings can act as time machines.

4: S. Deser, R. Jackiw, and G. 't Hooft, PRL, v.66, p.267 (1992).
   --> A critique of Gott.  You can't construct his machine.

5: D.G. Boulware, University of Washington preprint UW/PT-92-04.
   Available on the [email protected] bulletin board: item number 9207054.
   --> Unitarity problems in QM with closed timelike curves.
 
-Scott
--------------------
Scott I. Chase			"It is not a simple life to be a single cell,
[email protected]		 although I have no right to say so, having
				 been a single cell so long ago myself that I 
				 have no memory at all of that stage of my 
				 life." - Lewis Thomas


Article: 59794
Newsgroups: sci.space
From: [email protected] (THE ARTSTONE COLLECTIVE)
Subject: Time Travel --Great Book--
Sender: [email protected]
Organization: [via International Space University]
Date: Fri, 26 Mar 1993 18:43:12 GMT
 
For those of you interested in Time Travel, I think you should read
this book:
 
"The Montauk Project"
Experiments in Time
by Preston Nichols with Peter Moon.
 
ISBN   0-9631889-0-9 
 
I got my copy from:

Adventures Unlimited Press
Box 74
Kempton, Illinois  60946-0074
 
They have a very interesting catalog.
 
Harry G. Osoff
Science & Technology Editor
Access News Network
 

    re .*
    
    "Child of Time" (Silverberg & Asimov) - although time travel itself isn't
    a major plot element.