Talking to the Past

Puzzling through time with Professor Davies.  Published by Viking 1995.  Cover illustration by Russell Mills.

Puzzling through time with Professor Davies. Published by Viking 1995. Cover illustration by Russell Mills.

The well-known paradoxes which would occur if time travel was ever possible suggest that it will always be a fantasy.  The supposed ability to go back in time and change one’s own past seems to be something of a deal-breaker.

Even so, the idea of taking personal advantage of a few subtle, or not-so-subtle, alterations to the past has often featured in science fiction.  On a fairly basic level, you only need think of how the unscrupulous Biff Tannen, in the 1989 film Back to the Future Part II, manages to use an almanac from the future to re-shape how things will turn out for him.

But actual time travel, if it were possible, would inevitably become widespread sooner or later.  It could never be restricted forever to just a select few individuals – everyone would be at it eventually – which has rather serious implications for its effects on society as a whole.  It’s well expressed in Synchrony, an episode of The X-Files from 1997 concerning attempts to prevent time travel ever being developed since it would cripple the future of humanity – it would create “a world without history – without hope – where anyone can know everything that will ever happen.”

So it may be a comforting thought that actual physical time travel will probably always remain impossible.  But having said that, sending messages into the past might be another matter.  In his far-reaching 1995 analysis About Time: Einstein’s Unfinished Revolution, the physicist Paul Davies explains that the existence of the currently hypothetical particles known as tachyons could enable signals to be sent into the past, even if we couldn’t travel there ourselves.  He describes how such signalling might occur, and it might not be quite so far-fetched as we suppose…or hope.

In many respects, simply telling people in the past about their future has the same implications as visiting them in person.  And those implications could be severe.  The novelist John Buchan wrote about this in his 1932 book The Gap in the Curtain.  Several people are given glimpses of future events which will have a significant impact on them personally, and their lives are changed.  You only have to imagine how you would live your life from now on if you knew, for certain, the date of your own death.  If it’s thirty years from now, you might take a somewhat relaxed, or even cavalier, view of your actions in the interim, but what if it’s sometime next year?

The science fiction author James Blish tackled this subject in his 1954 short story Beep, later developed into his 1973 novel The Quincunx of Time.  If a new form of technology permits certain knowledge of events in the future, though not necessarily all events, then the individual becomes no more than an observer of things which are already determined.  The concept of free will disappears.

And it might be necessary to ensure that events happen as described to make certain that future history turns out as it should, in which case strict precautions would be needed to ensure that the date of a person’s death is never revealed.  But equal emphasis may be required to ensure that the appropriate people are born in the first place.  The present ends up being dictated by the future.  In Isaac Asimov’s 1955 novel The End of Eternity it is expressed as “the reversal of cause and effect.  Knowing the effect, one adjusts the cause.”

It all hinges on people in the future telling people in the past what to expect.  It’s one-way traffic, but then nothing special needs to be done to send a message to people in the future – just leave it lying around and they’ll get it eventually.  But we don’t see any evidence whatsoever of communication from our descendants – unless, of course, it’s so obvious we don’t realise it’s happening all the time.

Richard Hayes, Assistant Editor (Odyssey)

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