Talk at the OUSFG Discussion Meeting
of 11th October 2006.
Based on previous talks in
How to Build a Time Machine
Before I start, I want to make it clear that this is a
discussion and not a speaker meeting. While I might start things off,
I will be disappointed if someone doesn't interrupt me to disagree with what I say.
Please don't be intimidated by the fact that
I've built my own time machine in the attic.
You still shouldn't be shy about interrupting me and telling me
I'm talking bollocks.
As an aside, let me tell you how useful a time machine is.
I've given this talk before, a few years ago. The first time I didn't really know what
to say, so I checked the attic, and there was a completed talk sitting
in the time machine. I had to remove some references to books that hadn't
been written yet, and to the Great Hilda's Armadillo Invasion of 20-ahem.
If, no when, I give the talk again and don't have any anachronism fixes
to make, I'll know it's time to send it back in the time machine.
The cool bit is that I generated
a talk out of a paradox without ever having to write a word.
It's even just what I would have written if I could be arsed.
I'll start off by
making a few general and controversial statements. It's then up to you to
disagree with me.
I believe that a time travel story isn't really a time
travel store unless it involves travel into the past.
We all travel forward in time at a rate of 24 hours every day, and there's
nothing really special about speeding up that rate. Whenever
you fall asleep, perhaps. You can achieve a longer leap forward
with cryonic suspension. There's a film called Forever
Young, where Mel Gibson, frozen in 1939, is accidentally resuscitated
in 1992 and has to learn about answerphones. As a decent chap, as of course
everyone was in 1939, Jamie Lee Curtis falls for him, and it all gets very
If you want to get really ambitious, you can use the time dilation effect,
either by travelling close to the speed of light, or passing through an
intense gravitational field, such as close to a black hole.
This is used to great effect in Joe Haldeman's The Forever War
(and various sequels),
where the dislocation felt by soldiers returning to earth centuries
after they left is used as an allegory for the dislocation felt
by returning Vietnam veterans.
Poul Anderson's Tau Zero takes this to extremes: after an
accident, a spaceship is forced to accelerate continuously, allowing
it to outlive the Big Crunch and another Big Bang.
But none of these are proper Time Travel stories. Jumping into the future
offers a convenient mechanism for the protagonist to see what that future might
be like (and that can be very interesting in itself), but gives no scope for
doing anything unusual with Time, and critically, has no possibility for
paradox. Embarrassingly, my stipulation that a Time Travel story requires
travel into the past, disqualifies the seminal and probably most famous
so-called "Time Travel" story of all.
In H.G. Wells' The Time Machine, the
Traveller does eventually go back in time when he returns to the present, but
this is a postscript to the main story, which involves Wells' ideas on the
evolution of humanity and human society.
If you go along with this,
(and here comes controversial statement number 2)
Time Travel stories, probably more than those of any other subgenre, are
all about plot. Characterization, literary merit,
and extrapolation of technology or society, are
all secondary to the 4-dimensional twists of the plot.
Maybe this explains why
many of the best Time Travel stories are short stories.
Anyway, I hope the plot-driven nature of these stores
will encourage you all later to retell some of the cool
time travel stories you have come across.
Before that, I have an admission to make.
The title of my talk is a lie.
I can't tell you how to build a time machine - sad to tell.
The Regulations for the Control of Time Travel make that plain.
But what I can tell you is how to write a Time Travel story, and hopefully
inspire you to read some good books along the way.
You need a mechanism to travel back in time
In principle this is your biggest problem, but do not despair.
Although most physicists will tell you that Time Travel is impossible,
physics gives plenty of loopholes and buzzwords to choose from.
Here are a few.
- All you need to do is travel faster than the speed of light.
Then you arrange for your superluminal device to transport you
between a rapidly-moving spaceships, and
bob's your uncle, you'll return from your jaunt before you set out.
Tachyon is a good buzzword to use at this point
(all it means is a superluminal particle).
- If you think your reader too smart for that one, you can always
arrange to fall into a black hole. Since no one really knows what happens
then, particularly if there's a singularity involved, you can have the laws of
physics break down in any way you like. The problem, of course, is that you'd
probably be converted to neutronium by the tidal forces on your way in, unless
you found a really big black hole to play with.
I'm sure I left one around here somewhere.
- This is all ignoring the gravitational physicists who keep coming out
with papers suggesting ways you really could travel round a closed causal
spacetime path (that's General Relativity-speak for returning to where
and when you started).
Sadly, the engineering requirements
are a little extreme such as structures weighing more than the rest of the
Universe. Still, if you like technobabble, there are plenty of buzzwords
to play with: as well as that closed causal spacetime path, there's also
negative energy, and
violation of time-reversal invariance.
I slipped that last one in because it is a real effect
that I am researching into - via related effect of CP violation.
Although it sounds good, it
unfortunately doesn't help in building a time machine.
You don't have to tell your readers that, though.
- You could of course cheat in the same way I did writing this talk.
Your hero may not have to understand it to make a copy of your time machine
and send it back to when she found it. This technique is used to good
effect in John Varley's latest novel Mammoth - at least I think
that's what'll happen because I haven't quite reached the dénouement.
Actually, I think his purpose in writing the book was so he could have mammoths rampaging
through downtown Los Angeles.
- If all else fails, you can always use the mad scientist or magician
dabbling in forces that no mere mortal (protagonist included) can understand.
The Anubis Gates by Tim Powers is a good example of this.
This is an excellent fantasy novel, that mixes in elements of horror,
mystery, historical romance, as well as time-travel paradox. In a wonderfully
convoluted plot, our hero meets Old Kingdom Egyptian sorcerers, Victorian romantic
poets, a werewolf, age-old secret societies, grotesques inhabiting the London
sewers,... and of course himself.
You need a theory of time
Unless you are going to be very circumspect, you need to decide how to deal with paradox.
What happens if you go back in time and try to kill your mother as a child (the more
traditional grandfather isn't such a problem given the difficulty proving
paternity)? Herein lies much of the fun.
Whatever your theory of time, the important thing is to
be consistent. There's nothing more annoying to
a reader than a gaping inconsistency, where the thrill of
dicing with paradox is much of the fun that a time travel story affords.
- Just can't be done.
You seek out your mother, but she's in hiding. You murder the little girl,
and as you mount the gallows you see her identical twin watching you.
Just as you cock the pistol, a meteorite strikes you down.
Whatever you do, History (with a capital H) conspires against you.
- A variation on this theme is The end of the Universe.
A paradox would cause the universe to be destroyed.
This thesis is carefully and thoughtfully examined
in the Back to the Future films.
- Fixed past. Perhaps one can travel backwards in time,
but can't change anything at all. One is entirely an observer,
unable to move a blade of grass (eg. An Age by OUSFG's founder, Brian Aldiss).
- Alternate Worlds.
When you kill your mother, a parallel world where you never lived
is created (or revealed).
This possibility can be convincingly justified with the Many Worlds interpretation
of Quantum Mechanics.
For more details, I'll refer you to Colin, who is the real expert -
he wrote the book.
- The Time Police prevent you.
- Although not much use for Time Travel stories,
Larry Niven has made an interesting argument.
Suppose that Time Travel were possible, with a single, malleable, timeline.
This is an inherently unstable situation. As long as people go back in time
and change the past, they will inevitably affect themselves, even if only
slightly. These small changes are cumulative - eventually a timeline will
come about where that person never invented the time machine, or didn't use it,
or was never even born.
This is the only stable state: where no one ever used a time machine.
Since systems tend to evolve towards a stable state, this has probably
already happened. Ie. Time Travel is possible, but never practiced.
At this point, let me recommend two Heinlein shorts,
"All You Zombies..." (in The Unpleasant Profession Of Jonathan Hoag) and
By His Bootstraps (in The Menace From Earth), which are classic
tales of paradox.
If your hero manages to avoid a paradox, then there's all the fun
of twisting fate. What would happen if you inoculated the Central
Americans against European diseases before Columbus's arrival?
Orson Scott Card's Pastwatch -
The Redemption of Christopher Columbus has a future
society altering history in an attempt
to bring about an enlightened present.
Could one fix up all one's past misfortunes and lead the perfect life?
Oddly, this always seems to lead to one being the instrument of one's own
How would you recognise other Time Travellers without
alerting everyone else? The Anubis Gates
has time travellers whistling Beatles tunes in Victorian London.
In Ken Grimwood's entertaining fantasy, Replay, our heros place newspaper
adverts referring to future events:
the word al-Qaeda before 1988, or
Google before 1998, would stand out, but be unrecognisable to most locals
(actually the book uses different examples).
In other ways, Replay is rather similar to
last year's OUSFG Award shortlisted
novel, The Time Traveller's Wife.
I'll gladly tell you more about any of the stories I've mentioned
(and could bore you with many more), but it's your turn now.
modified 10th October 2006 by Tim Adye, <T.J.Adye@rl.ac.uk>