Tags: timetravel

15

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Tuesday, November 12th, 2024

The meaning of “AI”

There are different kinds of buzzwords.

Some buzzwords are useful. They take a concept that would otherwise require a sentence of explanation and package it up into a single word or phrase. Back in the day, “ajax” was a pretty good buzzword.

Some buzzwords are worse than useless. This is when a word or phrase lacks definition. You could say this buzzword in a meeting with five people, and they’d all understand five different meanings. Back in the day, “web 2.0” was a classic example of a bad buzzword—for some people it meant a business model; for others it meant rounded corners and gradients.

The worst kind of buzzwords are the ones that actively set out to obfuscate any actual meaning. “The cloud” is a classic example. It sounds cooler than saying “a server in Virginia”, but it also sounds like the exact opposite of what it actually is. Great for marketing. Terrible for understanding.

“AI” is definitely not a good buzzword. But I can’t quite decide if it’s merely a bad buzzword like “web 2.0” or a truly terrible buzzword like “the cloud”.

The biggest problem with the phrase “AI” is that there’s a name collision.

For years, the term “AI” has been used in science-fiction. HAL 9000. Skynet. Examples of artificial general intelligence.

Now the term “AI” is also used to describe large language models. But there is no connection between this use of the term “AI” and the science fictional usage.

This leads to the ludicrous situation of otherwise-rational people wanted to discuss the dangers of “AI”, but instead of talking about the rampant exploitation and energy usage endemic to current large language models, they want to spend the time talking about the sci-fi scenarios of runaway “AI”.

To understand how ridiculous this is, I’d like you to imagine if we had started using a different buzzword in another setting…

Suppose that when ride-sharing companies like Uber and Lyft were starting out, they had decided to label their services as Time Travel. From a marketing point of view, it even makes sense—they get you from point A to point B lickety-split.

Now imagine if otherwise-sensible people began to sound the alarm about the potential harms of Time Travel. Given the explosive growth we’ve seen in this sector, sooner or later they’ll be able to get you to point B before you’ve even left point A. There could be terrible consequences from that—we’ve all seen the sci-fi scenarios where this happens.

Meanwhile the actual present-day harms of ride-sharing services around worker exploitation would be relegated to the sidelines. Clearly that isn’t as important as the existential threat posed by Time Travel.

It sounds ludicrous, right? It defies common sense. Just because a vehicle can get you somewhere fast today doesn’t mean it’s inevitably going to be able to break the laws of physics any day now, simply because it’s called Time Travel.

And yet that is exactly the nonsense we’re being fed about large language models. We call them “AI”, we look at how much they can do today, and we draw a straight line to what we know of “AI” in our science fiction.

This ridiculous situation could’ve been avoided if we had settled on a more accurate buzzword like “applied statistics” instead of “AI”.

It’s almost as if the labelling of the current technologies was more about marketing than accuracy.

Thursday, May 2nd, 2024

It’s OK to Say if You Went Back in Time and Killed Baby Hitler — Big Echo

Primer was a film about a start-up …and time travel. This is a short story about big tech …and time travel.

Monday, May 8th, 2023

Tragedy

There are two kinds of time-travel stories.

There are time-travel stories that explore the many-worlds hypothesis. Going back in time and making a change forks the universe. But the universe is constantly forking anyway. So effectively the time travel is a kind of universe-hopping (there’s a big crossover here with the alternative history subgenre).

The problem with multiverse stories is that there’s always a reset available. No matter how bad things get, there’s a parallel universe where everything is hunky dory.

The other kind of time travel story explores the idea of a block universe. There is one single timeline.

This is what you’ll find in Tenet, for example, or for a beautiful reduced test case, the Ted Chiang short story What’s Expected Of Us. That gets straight to the heart of the biggest implication of a block universe—the lack of free will.

There’s no changing what has happened or what will happen. In fact, the very act of trying to change the past often turns out to be the cause of what you’re trying to prevent in the present (like in Twelve Monkeys).

I’ve often referred to these single-timeline stories as being like Greek tragedies. But only recently—as I’ve been reading quite a bit of Greek mythology—have I realised that the reverse is also true:

Greek tragedies are time-travel stories.

Hear me out…

Time-travel stories aren’t actually about physically travelling in time. That’s just a convenience for the important part—information travelling in time. That’s at the heart of most time-travel stories; informaton from the future travelling back to the past.

William Gibson’s The Peripheral—very much a many-worlds story with its alternate universe “stubs”—takes this to its extreme. Nothing phyiscal ever travels in time. But in an age of telecommuting, nothing has to. Our time travellers are remote workers.

That book also highlights the power dynamics inherent in information wealth. Knowledge of the future gives you an advantage that you can exploit in the past. This is what Mark Twain’s Connecticut yankee does in King Arthur’s court.

This power dynamic is brilliantly inverted in Octavia Butler’s brilliant Kindred. No amount of information can help you if your place in society is determined by the colour of your skin.

Anyway, the point is that information flow is what matters in time-travel stories. Therefore any story where information travels backwards in time is a time-travel story.

That includes any story with a prophecy. A prophecy is information about the future, like:

Oedipus will kill his father and marry his mother.

You can try to change your fate, but you’ll just end up triggering it instead.

Greek tragedies are time-travel stories.

Tuesday, September 8th, 2020

T E N Ǝ T

Jessica and I went to cinema yesterday.

Normally this wouldn’t be a big deal, but in our current circumstances, it was something of a momentous decision that involved a lot of risk assessment and weighing of the odds. We’ve been out and about a few times, but always to outdoor locations: the beach, a park, or a pub’s beer garden. For the first time, we were evaluating whether or not to enter an indoor environment, which given what we now know about the transmission of COVID-19, is certainly riskier than being outdoors.

But this was a cinema, so in theory, nobody should be talking (or singing or shouting), and everyone would be wearing masks and keeping their distance. Time was also on our side. We were considering a Monday afternoon showing—definitely not primetime. Looking at the website for the (wonderful) Duke of York’s cinema, we could see which seats were already taken. Less than an hour before the start time for the film, there were just a handful of seats occupied. A cinema that can seat a triple-digit number of people was going to be seating a single digit number of viewers.

We got tickets for the front row. Personally, I love sitting in the front row, especially in the Duke of York’s where there’s still plenty of room between the front row and the screen. But I know that it’s generally considered an undesirable spot by most people. Sure enough, the closest people to us were many rows back. Everyone was wearing masks and we kept them on for the duration of the film.

The film was Tenet). We weren’t about to enter an enclosed space for just any ol’ film. It would have to be pretty special—a new Star Wars film, or Denis Villeneuve’s Dune …or a new Christopher Nolan film. We knew it would look good on the big screen. We also knew it was likely to be spoiled for us if we didn’t see it soon enough.

At this point I am sounding the spoiler horn. If you have not seen Tenet yet, abandon ship at this point.

I really enjoyed this film. I understand the criticism that has been levelled at it—too cold, too clinical, too confusing—but I still enjoyed it immensely. I do think you need to be able to enjoy feeling confused if this is going to be a pleasurable experience. The payoff is that there’s an equally enjoyable feeling when things start slotting into place.

The closest film in Christopher Nolan’s back catalogue to Tenet is Inception in terms of twistiness and what it asks of the audience. But in some ways, Tenet is like an inverted version of Inception. In Inception, the ideas and the plot are genuinely complex, but Nolan does a great job in making them understandable—quite a feat! In Tenet, the central conceit and even the overall plot is, in hindsight, relatively straightforward. But Nolan has made it seem more twisty and convuluted than it really is. The ten minute battle at the end, for example, is filled with hard-to-follow twists and turns, but in actuality, it literally doesn’t matter.

The pitch for the mood of this film is that it’s in the spy genre, in the same way that Inception is in the heist genre. Though there’s an argument to be made that Tenet is more of a heist movie than Inception. But in terms of tone, yeah, it’s going for James Bond.

Even at the very end of the credits, when the title of the film rolled into view, it reminded me of the Bond films that would tease “The end of (this film). But James Bond will return in (next film).” Wouldn’t it have been wonderful if the very end of Tenet’s credits finished with “The end of Tenet. But the protagonist will return in …Tenet.”

The pleasure I got from Tenet was not the same kind of pleasure I get from watching a Bond film, which is a simpler, more basic kind of enjoyment. The pleasure I got from Tenet was more like the kind of enjoyment I get from reading smart sci-fi, the kind that posits a “what if?” scenario and isn’t afraid to push your mind in all kinds of uncomfortable directions to contemplate the ramifications.

Like I said, the central conceit—objects or people travelling backwards through time (from our perspective)—isn’t actually all that complex, but the fun comes from all the compounding knock-on effects that build on that one premise.

In the film, and in interviews about the film, everyone is at pains to point out that this isn’t time travel. But that’s not true. In fact, I would argue that Tenet is one of the few examples of genuine time travel. What I mean is that most so-called time-travel stories are actually more like time teleportation. People jump from one place in time to another instaneously. There are only a few examples I can think of where people genuinely travel.

The grandaddy of all time travel stories, The Time Machine by H.G. Wells, is one example. There are vivid descriptions of the world outside the machine playing out in fast-forward. But even here, there’s an implication that from outside the machine, the world cannot perceive the time machine (which would, from that perspective, look slowed down to the point of seeming completely still).

The most internally-consistent time-travel story is Primer. I suspect that the Venn diagram of people who didn’t like Tenet and people who wouldn’t like Primer is a circle. Again, it’s a film where the enjoyment comes from feeling confused, but where your attention will be rewarded and your intelligence won’t be insulted.

In Primer, the protagonists literally travel in time. If you want to go five hours into the past, you have to spend five hours in the box (the time machine).

In Tenet, the time machine is a turnstile. If you want to travel five hours into the past, you need only enter the turnstile for a moment, but then you have to spend the next five hours travelling backwards (which, from your perspective, looks like being in a world where cause and effect are reversed). After five hours, you go in and out of a turnstile again, and voila!—you’ve time travelled five hours into the past.

Crucially, if you decide to travel five hours into the past, then you have always done so. And in the five hours prior to your decision, a version of you (apparently moving backwards) would be visible to the world. There is never a version of events where you aren’t travelling backwards in time. There is no “first loop”.

That brings us to the fundamental split in categories of time travel (or time jump) stories: many worlds vs. single timeline.

In a many-worlds story, the past can be changed. Well, technically, you spawn a different universe in which events unfold differently, but from your perspective, the effect would be as though you had altered the past.

The best example of the many-worlds category in recent years is William Gibson’s The Peripheral. It genuinely reinvents the genre of time travel. First of all, no thing travels through time. In The Peripheral only information can time travel. But given telepresence technology, that’s enough. The Peripheral is time travel for the remote worker (once again, William Gibson proves to be eerily prescient). But the moment that any information travels backwards in time, the timeline splits into a new “stub”. So the many-worlds nature of its reality is front and centre. But that doesn’t stop the characters engaging in classic time travel behaviour—using knowledge of the future to exert control over the past.

Time travel stories are always played with a stacked deck of information. The future has power over the past because of the asymmetric nature of information distribution—there’s more information in the future than in the past. Whether it’s through sports results, the stock market or technological expertise, the future can exploit the past.

Information is at the heart of the power games in Tenet too, but there’s a twist. The repeated mantra here is “ignorance is ammunition.” That flies in the face of most time travel stories where knowledge—information from the future—is vital to winning the game.

It turns out that information from the future is vital to winning the game in Tenet too, but the reason why ignorance is ammunition comes down to the fact that Tenet is not a many-worlds story. It is very much a single timeline.

Having a single timeline makes for time travel stories that are like Greek tragedies. You can try travelling into the past to change the present but in doing so you will instead cause the very thing you set out to prevent.

The meat’n’bones of a single timeline time travel story—and this is at the heart of Tenet—is the question of free will.

The most succint (and disturbing) single-timeline time-travel story that I’ve read is by Ted Chiang in his recent book Exhalation. It’s called What’s Expected Of Us. It was originally published as a single page in Nature magazine. In that single page is a distillation of the metaphysical crisis that even a limited amount of time travel would unleash in a single-timeline world…

There’s a box, the Predictor. It’s very basic, like Claude Shannon’s Ultimate Machine. It has a button and a light. The button activates the light. But this machine, like an inverted object in Tenet, is moving through time differently to us. In this case, it’s very specific and localised. The machine is just a few seconds in the future relative to us. Cause and effect seem to be reversed. With a normal machine, you press the button and then the light flashes. But with the predictor, the light flashes and then you press the button. You can try to fool it but you won’t succeed. If the light flashes, you will press the button no matter how much you tell yourself that you won’t (likewise if you try to press the button before the light flashes, you won’t succeed). That’s it. In one succinct experiment with time, it is demonstrated that free will doesn’t exist.

Tenet has a similarly simple object to explain inversion. It’s a bullet. In an exposition scene we’re shown how it travels backwards in time. The protagonist holds his hand above the bullet, expecting it to jump into his hand as has just been demonstrated to him. He is told “you have to drop it.” He makes the decision to “drop” the bullet …and the bullet flies up into his hand.

This is a brilliant bit of sleight of hand (if you’ll excuse the choice of words) on Nolan’s part. It seems to imply that free will really matters. Only by deciding to “drop” the bullet does the bullet then fly upward. But here’s the thing: the protagonist had no choice but to decide to drop the bullet. We know that he had no choice because the bullet flew up into his hand. The bullet was always going to fly up into his hand. There is no timeline where the bullet doesn’t fly up into his hand, which means there is no timeline where the protagonist doesn’t decide to “drop” the bullet. The decision is real, but it is inevitable.

The lesson in this scene is the exact opposite of what it appears. It appears to show that agency and decision-making matter. The opposite is true. Free will cannot, in any meaningful sense, exist in this world.

This means that there was never really any threat. People from the future cannot change the past (or wipe it out) because it would’ve happened already. At one point, the protagonist voices this conjecture. “Doesn’t the fact that we’re here now mean that they don’t succeed?” Neil deflects the question, not because of uncertainty (we realise later) but because of certainty. It’s absolutely true that the people in the future can’t succeed because they haven’t succeeded. But the protagonist—at this point in the story—isn’t ready to truly internalise this. He needs to still believe that he is acting with free will. As that Ted Chiang story puts it:

It’s essential that you behave as if your decisions matter, even though you know that they don’t.

That’s true for the audience watching the film. If we were to understand too early that everything will work out fine, then there would be no tension in the film.

As ever with Nolan’s films, they are themselves metaphors for films. The first time you watch Tenet, ignorance is your ammuntion. You believe there is a threat. By the end of the film you have more information. Now if you re-watch the film, you will experience it differently, armed with your prior knowledge. But the film itself hasn’t changed. It’s the same linear flow of sequential scenes being projected. Everything plays out exactly the same. It’s you who have been changed. The first time you watch the film, you are like the protagonist at the start of the movie. The second time you watch it, you are like the protagonist at the end of the movie. You see the bigger picture. You understand the inevitability.

The character of Neil has had more time to come to terms with a universe without free will. What the protagonist begins to understand at the end of the film is what Neil has known for a while. He has seen this film. He knows how it ends. It ends with his death. He knows that it must end that way. At the end of the film we see him go to meet his death. Does he make the decision to do this? Yes …but he was always going to make the decision to do this. Just as the protagonist was always going to decide to “drop” the bullet, Neil was always going to decide to go to his death. It looks like a choice. But Neil understands at this point that the choice is pre-ordained. He will go to his death because he has gone to his death.

At the end, the protagonist—and the audience—understands. Everything played out exactly as it had to. The people in the future were hoping that reality allowed for many worlds, where the past could be changed. Luckily for us, reality turns out to be a single timeline. But the price we pay is that we come to understand, truly understand, that we have no free will. This is the kind of knowledge we wish we didn’t have. Ignorance was our ammunition and by the end of the film, it is spent.

Nolan has one other piece of misdirection up his sleeve. He implies that the central question at the heart of this time-travel story is the grandfather paradox. Our descendents in the future are literally trying to kill their grandparents (us). But if they succeed, then they can never come into existence.

But that’s not the paradox that plays out in Tenet. The central paradox is the bootstrap paradox, named for the Heinlein short story, By His Bootstraps. Information in this film is transmitted forwards and backwards through time, without ever being created. Take the phrase “Tenet”. In subjective time, the protagonist first hears of this phrase—and this organisation—when he is at the start of his journey. But the people who tell him this received the information via a subjectively older version of the protagonist who has travelled to the past. The protagonist starts the Tenet organistion (and phrase) in the future because the organisation (and phrase) existed in the past. So where did the phrase come from?

This paradox—the bootstrap paradox—remains after the grandfather paradox has been dealt with. The grandfather paradox was a distraction. The bootstrap paradox can’t be resolved, no matter how many times you watch the same film.

So Tenet has three instances of misdirection in its narrative:

  • Inversion isn’t time travel (it absolutely is).
  • Decisions matter (they don’t; there is no free will).
  • The grandfather paradox is the central question (it’s not; the bootstrap paradox is the central question).

I’m looking forward to seeing Tenet again. Though it can never be the same as that first time. Ignorance can never again be my ammunition.

I’m very glad that Jessica and I decided to go to the cinema to see Tenet. But who am I kidding? Did we ever really have a choice?

Wednesday, April 6th, 2016

Monday, August 10th, 2015

dConstruct 2015 podcast: Ingrid Burrington

The dConstruct podcast episodes are coming thick and fast. Hot on the heels of the inaugural episode with Matt Novak and the sophomore episode with Josh Clark comes the third in the series: the one with Ingrid Burrington.

This was a fun meeting of minds. We geeked out about the physical infrastructure of the internet and time-travel narratives, from The Terminator to The Peripheral. During the episode, I sounded the spoiler warning in case you haven’t read that book, but we didn’t actually end up giving anything away.

I really enjoyed this chat with Ingrid. I hope you’ll enjoy listening to it.

Oh, and now you can subscribe to the dConstruct 2015 podcast directly from iTunes.

And remember, as a podcast listener, you get 10% off the ticket price for dConstruct using the discount code “ansible.”

Friday, March 27th, 2015

100 words 005

I enjoy a good time travel yarn. Two of the most enjoyable temporal tales of recent years have been Rian Johnson’s film Looper and William Gibson’s book The Peripheral.

Mind you, the internal time travel rules of Looper are all over the place, whereas The Peripheral is wonderfully consistent.

Both share an interesting commonality in their settings. They are set in the future and …the future: two different time periods but neither of them are the present. Both works also share the premise that the more technologically advanced future would inevitably exploit the time period further down the light cone.

Tweets out of Context

Primer, but Twitter.

Friday, January 18th, 2013

Interview with Lauren Beukes about Shining Girls

Lauren talks about The Shining Girls and the tools she uses to write with.

The paradoxes of time travel by David Lewis

A well-written white paper on time travel. Alas, it relies a bit too much on semantic nitpickery to offer any real insight.

Thursday, January 17th, 2013

A question of time

Some of the guys at work occasionally provide answers to .net magazine’s “big question” feature. When they told me about the latest question that landed in their inboxes, I felt I just had to stick my oar in and provide my answer.

I’m publishing my response here, so that if they decide not to publish it in the magazine or on the website (or if they edit it down), I’ve got a public record of my stance on this very important topic.

The question is:

If you could send a message back to younger designer or developer self, what would it say? What professional advice would you give a younger you?

This is my answer:

Rather than send a message back to my younger self, I would destroy the message-sending technology immediately. The potential for universe-ending paradoxes is too great.

I know that it would be tempting to give some sort of knowledge of the future to my younger self, but it would be the equivalent of attempting to kill Hitler—that never ends well.

Any knowledge I supplied to my past self would cause my past self to behave differently, thereby either:

  1. destroying the timeline that my present self inhabits (assuming a branching many-worlds multiverse) or
  2. altering my present self, possibly to the extent that the message-sending technology never gets invented. Instant paradox.

But to answer your question, if I could send a message back to a younger designer or developer self, the professional advice I would give would be:

Jeremy,

When, at some point in the future, you come across the technology capable of sending a message like this back to your past self, destroy it immediately!

But I know that you will not heed this advice. If you did, you wouldn’t be reading this.

On the other hand, I have no memory of ever receiving this message, so perhaps you did the right thing after all.

Jeremy

Monday, September 6th, 2010

Abyss & Apex : Fourth Quarter 2007: Wikihistory

An oldie but goldie: time travel in the age of the internet.

Thursday, May 21st, 2009

Rules for Time Travelers | Cosmic Variance | Discover Magazine

How to ensure consistency in time travel narratives.

Tuesday, April 1st, 2008

Gmail: Google's approach to email

New from GMail: send email back in time. "Gmail utilizes an e-flux capacitor to resolve issues of causality." In all seriousness though, remember when GMail launched on April 1st, 2004 and everyone that it was a joke?

Sunday, August 27th, 2006

dog or higher: phone sex with mars - or why latency matters as well as bandwidth

Brian Suda has a theoretical solution to real-time interplanetary communication: "I get on my tachyon voip phone and make a call from mars to earth at 9:00am it takes 10 minutes to travel there, but the tachyons travel backwards (so i think) that would be