The Strange Horror of Quantum Eternity | Divided By Infinity

0:00 There are countless ways you could die today. A blood vessel could rupture in your brain. A distracted driver could cross the center line. Your heart could simply stop. Originating from somewhere above us, high energy particles pass through our bodies every second. And on exceedingly rare occasions, microscopic events can begin chains of consequences large enough to kill.

0:27 We tend not to think about this, because from our perspective, only one thing actually happens. You either make it home tonight or you don't. But what if that isn't true? What if every physically possible outcome actually occurs somewhere? There is a universe where the driver misses you, another where he doesn't, another where you never got into the car at all.

0:57 And if all of those realities exist, there is a disturbing question hiding inside the idea. What happens from your point of view? You can experience surviving, you can experience waking up after the accident, hearing the doctor say the treatment worked, discovering that the bullet missed, but you can never experience being dead.

1:26 That asymmetry between survival and death is what we need to focus on here. If consciousness can only ever find itself on branches where it continues, then survival is not luck, it's actually a forced migration through possibility. And the big question is, if the universe keeps filtering you into whatever reality still contains a living version of you, then how far can that reality drift from the world you started in?

1:59 I don't fear them. They might be lying. I know, although I doubt it. Surely not even the most alien creatures would travel hundreds of light years to a dead planet in search of a single exotic snack. I do fear their teeth, however, sharp as shark's teeth, even if, as they claim, their bodies secrete an anesthetic and euphorant venom.

2:28 And death? I don't fear death. I dread the absence of it. In nineteen ninety eight, science fiction writer Robert Charles Wilson took that idea and pushed it towards one of the most unsettling conclusions imaginable. His story was called Divided by Infinity. And its central premise is deceptively simple.

2:57 What if you can never experience your own death? Not because your body is indestructible, and not because scientists discovered a cure for aging, and not because some supernatural force has made you immortal, but simply because, somewhere among all the possible versions of reality, there will always be another version of you that survived.

3:23 At first, that sounds almost comforting. Death is humanity's oldest fear. People have spent thousands of years inventing religions, afterlives, resurrection myths, and technologies designed to escape it. But Wilson asks a different question. If death really became impossible from your own subjective viewpoint, how long would it take before immortality stopped feeling like a gift?

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5:14 That's Zocdoc.com slash Quinn's ideas. Robert Charles Wilson had already been publishing science fiction for years when Divided by Infinity appeared in Starlight 2, a 1998 anthology edited by Patrick Nielsen Hayden. It was an unusually stacked collection. The same anthology contained Ted Chang's Story of Your Life, the novella that would eventually become the film Arrival, directed by Denis Villeneuve.

5:42 And Wilson's story later became a finalist for the 1999 Hugo Award for Best Novelette. Wilson would go on to become much better known for his novellas like Spin, which won the Hugo Award for Best Novel in 2006. But Divided by Infinity already contains many of the things that would define his work. Enormous cosmic ideas that are being filtered through ordinary people, and scientific speculation and a fascination with what happens to human beings when the universe reveals that it is much stranger than we thought.

6:25 This story follows a man named Bill Keller, who is around 60 years old, and his wife Lorraine has recently died of pancreatic cancer. Keller is retired, childless, lonely, and increasingly detached from his own life. Without Lorraine, his world has contracted into a handful of routines. He walks around Toronto, watches television, pays bills, shops for groceries, and repeatedly wonders why he is continuing any of it.

6:57 He has considered ending his own life more than once. But there's always some small obligation that pushes the decision into tomorrow. This is important because Wilson does not begin with a man that is desperately afraid of death in this story. Keller enters into the story already essentially half in love with the idea of disappearing.

7:21 And that is what makes what happens to him later much more interesting and perhaps much more cruel. One day, Keller returns to Finder's, the used bookstore where Lorraine once worked. The store is owned by an eccentric old man named Oscar Ziegler. While looking through the shelves, Keller discovers a group of old science fiction paperbacks that should not exist.

7:46 They appear to be genuine books by famous writers from the 1940s and 50s and 60s. The paper is old, the bindings are old, the typography and the printing techniques are appropriate to the period. The prose even seems consistent with the authors whose names appear on the covers. But Keller knows science fiction well enough to recognize the problem.

8:09 These authors never wrote these books. He takes several of the books to another dealer, a specialist named Niemand, hoping someone can explain what he has found. Neimand examines them and reaches an absurd conclusion. They have to be forgeries, but they are forgeries without any imaginable purpose. Someone would have needed to locate period-appropriate paper and recreate obsolete printing and binding techniques, mimic the writing style of dead authors, and artificially age the books simply to manufacture counterfeit editions of novels that were never valuable because they never existed.

8:57 But there is no obvious financial motive, and no joke sophisticated enough to justify the effort. The books almost seem like objects, artifacts that have somehow arrived from another version of history. When Keller confronts Ziegler, Ziegler gives him an explanation that is far more disturbing than a foragery could ever be.

9:25 He tells Keller that he is immortal. More importantly, he tells Keller that Keller is immortal too. To explain himself, Ziegler gives him another strange book called You Will Never Die, written by an obscure figure named Carl Sozier. Sozier's argument does not describe immortality in the usual sense.

9:50 It essentially describes an infinite multiplication of the self. You should not imagine yourself as one person traveling along one timeline. You should imagine an enormous collection of possible versions of yourself spreading across countless histories. In one, you survive an accident. In another, you die.

10:14 In one, the cancer responds to treatment. In another, it does not. The versions that die stop experiencing anything. The versions that survive continue. So from the inside, Sozier argues, consciousness can only ever find itself among the survivors. Keller eventually reduces the whole nightmare into one sentence.

10:40 He does not die. He simply becomes more and more less probable. Consider, suppose, tomorrow afternoon, you walk in front of a speeding 18-wheeler. The grill work snaps your neck, and what remains of you is sausaged under the chassis. Do you die? Well, yes, an infinity of you does die. But infinity is divisible by itself.

11:12 Another infinity of you steps out of the path of the truck, or didn't leave the house that day, or recovers in the hospital. The you-ness of you doesn't die. It simply continues to reside in those remnant selves. An infinite set has been subtracted from infinity, but what remains remains infinite. The subjective experience is that the accident simply doesn't happen.

11:43 Consider that bottle of glothnipem I keep beside the bed. Six times I reached for it, meaning to kill myself. Six times I stopped myself. In the great wilderness of worlds, I must have succeeded more often than I failed. My cold and vomit-stained corpse was carted off to whatever grave or urn awaits it, and a few acquaintances briefly mourned.

12:10 But that's not me. By definition, you can't experience your own death. Death is the end of consciousness, and consciousness persists. In the language of physics, consciousness is conserved. I am the one who wakes up in the morning. Always. Every morning. I don't die. I just become increasingly unlikely.

12:40 That is the point where divided by infinity more or less comes head-to-head with a real-world interpretation of quantum mechanics. In 1957, physicist Hugh Everett proposed what he called relative state formulation of quantum mechanics, an attempt to solve one of the strangest problems in the theory. Quantum systems can be described as combinations of multiple possible outcomes, yet, when we perform a measurement, we only seem to observe one.

13:08 Traditional interpretations introduced the idea of wave function collapse, some process by which one possibility becomes real while the others disappear. Everett asked, what would happen if collapse simply never occurred at all? Under what later became popularly known as the Mini Worlds interpretation, all of the possible outcomes remain a part of the evolving quantum state.

13:37 The observer is not standing outside the system, the observer becomes entangled with it. There is a version of the observer correlated with one result and another version correlated with another. Popular explanations often turn this into the idea that a new universe appears every time someone makes a choice, but that's not really how the physics works.

14:00 Many worlds is about quantum states, entanglement and decoherence, not a cosmic machine that's producing a new timeline because you decided to order chicken instead of fish. Still, the philosophical consequence is enormous. If the interpretation is correct, then reality may contain branches corresponding to outcomes that we ordinarily think of as mutually exclusive.

14:27 I also think the timing of Wilson's story is particularly interesting because almost exactly when Divided by Infinity was published, physicist Max Tegmark was discussing a thought experiment now widely known as quantum suicide. Now, imagine a device that measures a quantum event and then either leaves the experimenter alive or kills them depending on the result.

14:52 Under ordinary probability calculation, repeated trials quickly become almost certainly fatal. Under many worlds, however, there would still be branches in which the experimenter survives. After one trial, there is a surviving version. After another, a smaller set of surviving versions remains, repeated again and again, and the overwhelming majority of branches contain a dead experimenter.

15:20 But somewhere there continues to be a conscious person staring at the machine, wondering how they survived again. But one big area where Wilson takes more steps beyond the real world physics and more into fiction is many worlds does not say that consciousness is somehow transferred into whichever version of you survives.

15:43 There is no known law of conservation of consciousness. Physics gives us conservation laws for quantities like energy, momentum, and electric charge, but there is no established quantity corresponding to some indivisible essence of you that must always continue somewhere. If two future versions of you exist, many worlds does not require one to become the real continuation of your consciousness while the other is discarded.

16:11 Both exist. The claim that you should therefore expect to experience only the branch in which you survive is controversial at best, and many physicists and philosophers reject quantum immortality entirely. But that's not really the point. Wilson is not trying to prove the idea. He is using the concept to tell a very interesting story.

16:32 And he's doing something very interesting. He grants himself one impossible assumption and then follows it as far as he can. Suppose the character Sozier is right. Suppose subjective consciousness is somehow guaranteed to continue in any branch where continued experience remains possible. What happens next?

16:57 Initially Keller finds the idea strangely comforting, because if all possibilities exist, then somewhere Lorraine might be still alive. There must be histories in which her cancer was discovered earlier, histories in which the treatment worked, histories in which some medical breakthrough saved her. Keller begins wondering whether he might somehow drift into one of those realities.

17:28 But Deodre, the woman now working at Ziegler's bookstore, immediately recognizes the opposite possibility. Immortality doesn't mean that Keller gets to choose the pleasant branches. It only means that somewhere there must continue to be a Keller capable of having another experience. Imagine Keller reaching 90, that's ordinary enough, then 100.

17:55 Perhaps medication advances faster than expected. At 120, maybe organ replacement and genetic therapies have become routine in this society. At 150, perhaps the explanation becomes stranger. The pool of realities in which Keller is still alive keeps shrinking. Eventually, ordinary human biology might no longer be enough to explain him.

18:25 Perhaps he becomes dependent on machines. Perhaps his brain is preserved. Perhaps he is copied into some future computer system. Perhaps civilization itself changes beyond recognition. Every time Keller reaches another situation that should kill him, the versions that die disappear from his subjective experience, and the surviving versions become more improbable.

18:54 From Keller's own perspective, however, nothing supernatural has occurred. He simply woke up again. That is the horror at the center of this particular story. Keller doesn't necessarily become strange, reality does. His continued existence becomes this kind of filter that keeps selecting increasingly unlikely universes simply because those are the only universes containing someone capable of wondering why he's still alive.

19:29 And this idea, in some ways, kind of resembles a grotesquely exaggerated form of anthropic reasoning. At its simplest, anthropic reasoning says that any universe we observe must be compatible with the existence of observers like us. We should not be surprised to find ourselves in a region of reality where life is possible, because regions where observers cannot exist contain nobody capable of being surprised.

20:02 So, simply, Bill Keller requires a universe compatible with Bill Keller's existence. But another interesting idea presented in this story is that reality kind of begins to show scars. The impossible books are the first sign. Zegler believes that objects can somehow leak between histories as the probability of Keller's continued existence becomes increasingly strange.

20:27 Books are particularly interesting because they are information in a physical form. Kind of like entire alternate worlds compressed into ink and paper. There's also a point in the story where Keller goes looking for Neiman again, the dealer who examined the impossible books and he discovers that Neiman is gone.

20:46 The shop is gone entirely. And then neighboring businesses don't remember him. There is no listing. There is no evidence that the man ever existed. Keller still remembers speaking to him, but his current reality no longer contains anyone who can confirm the memory. And then as time goes on and Keller is slowly shifted into stranger realities, the background becomes increasingly disturbing.

21:12 At some point, scientists detect an extraterrestrial signal. Humanity initially treats it as the discovery that people have dreamed about for generations, proof that we are not alone in the universe. But the message is not a greeting, it's a warning. The aliens are directing our attention towards a pair of neutron stars that are going to collide.

21:36 And the resulting gamma ray burst may be capable of devastating Earth. Realistically, a nearby gamma ray burst could really be catastrophic. Gamma rays are among the highest energy forms of electromagnetic radiation, and sufficiently powerful burst aimed towards Earth could radically alter the chemistry of the upper atmosphere.

22:00 One major danger would be the destruction of the ozone layer, allowing much more ultraviolet radiation from the sun to reach the surface. Depending on the distance and strength of the burst, biological consequences could be enormous. In the story, total sterilization of the planet will be the outcome.

22:20 But for Keller, the approaching extinction event presents a pretty interesting philosophical problem. Quantum immortality has always depended on there being some surviving version of Keller somewhere, but what happens if the entire planet dies? The gamma ray burst does eventually come and the catastrophe is global.

22:41 Human civilization dies all around him. If the entire biosphere is destroyed, there should be simply nowhere left for Keller's consciousness to go. The burst arrives, the earth dies, and yet Keller wakes up again. And this time 10,000 years have passed. Humanity is extinct. The surface of the earth has become a dead world, and standing over Keller are enormous alien creatures, beings from the civilization that had sent humanity the original warning.

23:17 Thousands of years after the disaster, they developed the ability to travel between the stars and eventually reached Earth. They found what remained of Keller, and through technology he cannot begin to understand, reconstructed him. Not merely his DNA, not merely something that looks like his body. They somehow recreated his memories, his personality, and the mental pattern that believes itself to be Bill Keller.

23:45 And this is why I really like this story. This is yet another really interesting, very philosophical conundrum. What exactly has to survive for you to survive? Imagine creating a perfect copy of your brain. Every single neuron is reproduced, every synaptic connection is duplicated, every single memory is preserved.

24:07 The copy wakes up convinced that it is you because from its perspective, it remembers your entire life. But does that mean your consciousness moved into the copy? Probably not, right? If the original were still standing beside it, we would simply say we have two people who remember the same past. Destroying the original before activating the copy does not create any known mechanism by which consciousness is transferred.

24:38 This is the same reason science fiction teleportation is often much darker than it appears. If a machine scans you, destroys your body, and then perfectly reconstructs you, do you really travel, or did you just die while someone with your memories appeared at the destination? This is the famous question that people bring up when Star Trek is concerned, but Star Trek actually rarely worries about this idea because the transporter is treat it like ordinary technology in Star Trek.

25:07 But divide it by infinity kind of makes this concept unavoidable. Keller's original brain has been gone for 10,000 years. Whatever biological continuity existed between the man who watched Earth die and the creature now standing among the aliens has been completely severed. And yet, from Keller's subjective viewpoint, there was no 10,000-year wait.

25:31 There simply could not have been, because you cannot experience non-existence. One moment ends and another moment begins. The interval can be as long as you want, but subjectively the gap contains the same amount of experience, which is zero. If Sozier's law is that consciousness must always find a way to continue, then the universe no longer needs to preserve Keller's original body.

25:59 It only actually needs to produce another structure capable of being Keller, which is an interesting idea because the range of possible survival mechanisms suddenly becomes almost unlimited. Keller can be shot, he could be burned, he could be irradiated and buried and reduced to microscopic remains or lost for countless years.

26:26 And somewhere, there may still be a sequence of events that eventually reconstructs the informational pattern that calls itself Bill Keller. And the thing is, if that recreation experiences itself as continuous with Keller, how could Keller ever know the difference? So in the story, the aliens preserve him partly because he is now the last surviving source of information about humanity, and he begins writing down everything he remembers, you know, people, places, culture, history.

27:02 Eventually he realizes the absurdity of the project because there are no humans left to read any of it. The civilization that produced his language is gone. At the end of the story, the aliens reveal another technology. They have some way to transmit information backward through time. Not bodies or machines, just fragments of thoughts, ideas, dreams, and pieces of memory.

27:30 So Keller's memories can be sent backward into human history. Pieces of his experience could appear in people's dreams and stories and poems. Perhaps they reach science fiction writers. Perhaps they reach Ziegler. Perhaps they reach Lorraine. It's possible that the impossible books Keller found at the beginning of the story were never physical artifacts crossing between universes at all.

27:57 Now, yes, this is a story about quantum mechanics, but really divided by infinity is ultimately a story about grief and loss. Keller wants his wife back. There is no meaning in his life without her. He thinks if every possibility exists, surely there must be some world where her cancer was cured. There must be some version of reality where she lived.

28:20 But ultimately, infinity could not return the person that he lost to him. Eventually, the aliens offer Keller one final possibility. They possessed a vast information network capable of preserving minds, and they believe they can place Keller inside of it. The process is grotesque. One of the enormous creatures must physically consume him, somehow extracting or encoding the informational structure that constitutes his consciousness.

28:50 By this point, Keller has spent the entire story searching for an ending. At the beginning, he contemplated death because grief made his life feel empty. Then he discovered that death might be impossible. Now, after watching humanity disappear and then waking 10,000 years later as the last human being on a dead Earth, he no longer fears death at all.

29:12 The scariest possible thing to him is that death may never come. Human beings imagine immortality on human timescales. We imagine another hundred years, maybe another thousand. We imagine seeing the future, watching technology advance and traveling to other planets. But infinity is not simply a very long time.

29:37 A million years is nothing compared with infinity. A trillion years is nothing compared with infinity. Even the lifespan of stars is temporary. Given enough time, star formation slows, galaxies change, stellar remnants dominate the universe. We instinctively treat survival as the favorable outcome. Alive is good, dead is bad, and therefore more life is better.

30:05 But infinity destroys that intuition. Eventually you'd look around into the universe you had survived, and realize that something had gone terribly wrong. Everyone else is gone. History no longer fits your memories. Objects exist that should never have existed. Entire people seem to have vanished from the past.

30:27 Humanity has been extinct for 10,000 years. Somehow the universe keeps inventing new explanations for why you are still here. And somewhere inside that impossible reality, you open your eyes again. Thank you guys so much for watching. Make sure you like and subscribe for more science fiction literature videos.