THE ULTIMATE TEMPORAL PARADOX

Philip Brian Hall

You probably remember the business earthquake that overtook the financial markets, the betting industry and everything else based on speculative uncertainty when Froelich patented his time travel system. When he set up the first commercial service, he proved only forward time travel was feasible. You could go into the future but not into the past; you couldn’t travel back from the future any further than your present departure date.

Back then I’d just got my master’s and I was working on a doctorate in temporal engineering. I needed money; what student doesn’t? So I was more than a little upset to see the end of the amusement that generations of science fiction fans had derived from imagining temporal paradoxes. I’d been hoping I might supplement my meager income by writing stories for one or two of the speculative magazines that had just been put out of business.

Well, there I was one day, sitting in a coffee bar in mid-town, staring at the dregs of my espresso, when the idea came to me. It was one of those sultry, humid days in August when the cooling shade of the big umbrella over your table just about makes it tolerable to sit out on the baking sidewalk and smell the traffic fumes. That is, until the continual honking of car horns drives you back into the excessively refrigerated interior. Anyway, on this occasion I was less concerned about the temperature than the temporal, specifically temporal crime.

It seemed to me it had to be possible to go into the future and commit a robbery, then return to the present with the loot. How could I be arrested in the present for a crime that had not yet taken place? And by the time it did take place it would be impossible for the cops to travel back to the present and arrest me, because for them that would mean traveling into the past. Also, since my future self would know exactly the time for which I needed an alibi, I could arrange to be very publicly elsewhere just when I pulled the job. It seemed like the perfect crime!

Well, I was on the point of getting up from the table and going over to the Greyhound Time Travel Station when this guy came over and sat down across from me without asking. He was an ordinary sort of Joe; you know, not someone who’d stand out in a crowd unless the crowd did not consist of ordinary Joes. Whoever bought his clothes must have spent a lot of time scouring charity shops for out of fashion fashions. He gave me a nod and a crooked sort of smile.

“Mr Smith,” he said, “I’m Agent Marcus, FBI.” He flashed a smart looking badge. “You’re under arrest for stealing a million in diamonds from the mid-town branch of Big Rocks Jewels. We don’t want any trouble, now do we? If you confess, it’ll be better for you.”

When he’d finished reading me my rights and I’d picked my jaw off the table, I asked the obvious question.

“What are you talking about? I haven’t stolen anything from anybody.”

“That’s what they all say,” he drawled in a matter of fact way. He drew out a flimsy from an inside pocket and took a squint at it. “It says on the warrant you committed the robbery on 23rd January 2075.”

“Ridiculous!” I protested. “That’s fifty years from now. You can’t arrest me for something that hasn’t happened yet!”

“They all say that too,” he said, smirking like one of those insufferably smug know-it-alls who go on TV quiz shows. “Fact is, when I sat down you were just about to go over to Greyhound and book yourself a round trip to 2075.”

I wasn’t sure which was more astonishing, the fact that Marcus knew about my idea when I hadn’t told anyone, or that he specified a date which I hadn’t even got round to working out myself.

“Only you didn’t do your research properly first,” Marcus continued. “If you had done, you’d have discovered that by 2065 temporal crime like yours will have become so popular that these United States will pass a law to apply all criminal statutes retrospectively; that means you, Mr Smith.”

Now as it happened I had been doing research on the late 2060’s only the previous month and I was pretty certain that in the time-line I knew there was no such law. Had the future somehow changed? Deciding to play for time, I demanded another sight of his credentials. It appeared that Marcus had joined the FBI in 2070.

“You can’t arrest me;” I said, “you’re almost half a century out of your jurisdiction!”

“But he isn’t,” said Marcus, pointing in an amused fashion to a uniformed cop strolling by. “If you want to make a fuss we’ll all go down the precinct house and straighten everything out.”

By this time I had worked out a much better line of defense. “You’ve jumped the gun, Agent Marcus. If I’d committed this robbery and returned to the present, then I’d remember having committed it, but I don’t remember it because I haven’t done it. So, even if I would have taken a trip to 2075 and robbed a jeweler, you can now be quite sure I won’t. You can’t send me down for something I’m thinking, even if I admit to thinking it, which I don’t, see?”

“That’s what you said you’d say, when I interrogated you,” Agent Marcus was more than amused now; his face was screwed up like an over-ripe plum about to burst and spray juice everywhere. “Or, perhaps more accurately, that’s what you would have said in an hour’s time, when I would have arrested you for the first time. That’s the first time in my time line, you understand, but the second time in yours.”

“That’s easy for you to say.”

“Look, to cut a long story short, in an hour’s time you would have committed the crime and returned to the present. Then I would have arrested you and interrogated you, and you’d have ended up offering me a plea bargain; after all a million isn’t really a lot of money in 2075; it wouldn’t even buy a new aerocar.”

I have to admit I was shocked at first when I heard this, but after a few moments the seeds of a couple more great ideas came to me. I was having a good brain day; maybe the coffee was stronger than usual. I decided to take first things first.

“And the bargain I offered you,” I suggested, “was to plead guilty to the misdemeanor of wasting police time if you would go further back and arrest me an hour earlier, that’s now, so there wouldn’t actually have been a robbery, so no one really suffered and you could let me off with a caution?”

“That’s right!” grinned Agent Marcus. “I said to myself the first time –he’s a bright one, he is. It was your idea before and now here you are coming up with it again, or in your case for the first time, if you see what I mean.”

“I see,” I answered. “But there’s still one thing I don’t understand. Time travel into the past isn’t possible; all scientific thought accepts that. I’m pretty sure all scientific thought will still accept that in an hour’s time. How come you seem to have been able to travel back fifty years to one hour in my future and then another hour back to now, which is the immediate past of my near future?”

“I’ve already tried explaining that to your future self,” he groaned. “I don’t want to have to go through it all again. To tell you the truth I’m not sure I understand the mechanics of inverting the dimensional parabola all that well myself. I don’t build time machines, I just drive ‘em. Trust me; by 2095 we’ve cracked the problem of traveling backwards through time. Just sign the confession statement and let’s get it over with.”

“2095?” I asked, pricking up my ears even more. He had come back nearly seventy years, not fifty? It had taken twenty years after this mid-town gems robbery for science to come up with a method of catching little old me?

“I can’t see why I’m worth all your time and trouble, ”I said. “If a million isn’t a lot of money in 2075, I guess it wouldn’t even buy a Greyhound ticket in 2095, assuming there still will be a Greyhound Company?”

“Oh, there still will be a Greyhound Company,” Agent Marcus sighed. “They’ll be making huge profits now they can do guided tours of the past. All right, I wasn’t going to tell you this, but since you’re a special case, I’ll make an exception. It’s true temporal crime will become very common by 2065, but FBI intelligence will work out that although your crime was last it was actually first.”

“Run that by me one more time?”

“Because you think of it before anybody else; you just go further into the future to do it. The others will all be copycats who hear about you during a future-tour of their own, since you’re rich and famous, but they will strike earlier than you so as to avoid being caught by people like me. That’s why I needed to stop you,” Marcus smiled.

Oh my, did this man need to read up on his temporal paradox theory! The seed of the other idea Marcus had helped my future self put into my present head now burst into flower.

“Congratulations, Agent Marcus,” I said. “You have stopped me, but actually I haven’t wasted police time.”

“How’s that?”

“Well you’re right, since I’ve not traveled into the future and robbed the jeweler I did not give other crooks the idea. But, without the crime wave that I didn’t inspire there was no incentive to develop backward time travel to come after me, so you, Agent Marcus, are not here!”

As I said this, the man vanished. Do you know back then I was the only person who understood how temporal paradoxes like that could happen? I’m sure since then we’ve all seen people vanish many a time, haven’t we?

Anyway. That was it.

I smiled. I didn’t need to commit a robbery now. I needed to get back to the laboratory and work out a safe way to invert the dimensional parabola so as to permit time travel into the past. Oh boy, was Greyhound going to pay me a bundle for my new invention!

Food for Thought

One of the most famous thought experiments in Ancient Greek philosophy is ascribed to Epimenides of Crete (c.600 BC), who controversially suggested that all Cretans are liars. He may not actually have intended to set off his listeners on an infinite series of syllogisms alternately proving and disproving the proposition that Epimenides was himself a liar. Nevertheless the logical paradox has delighted or infuriated philosophers ever since.

The imagined worlds of modern science fiction offer ideal opportunities to investigate such problems free from the inevitable partiality afflicting real world settings. In particular the idea of time travel into the past sets up logical difficulties that some consider insoluble obstacles to scientific problems.

About the Author

Born in Yorkshire, Oxford graduate Philip Brian Hall is a former diplomat, teacher, examiner and web designer. He has also stood for parliament, sung solos in amateur operettas, rowed at Henley and ridden in over one hundred steeplechases.

Writing mainly in speculative genres, Philip has had short stories published by AE The Canadian Science Fiction Review, T Gene Davis’s Speculative Blog, The Sockdolager, Flame Tree Publishing and Third Flatiron Publishing. His novel, ‘The Prophets of Baal’ is available as an e-book and in paperback.

He lives on a very small farm in Scotland with his wife, a dog, a cat and some horses.