False vacuum: the universe playing quantum suicide

Dear anthropics: PLEASE STOP HURTING MY HEAD. Thank you.

None of these assumptions make any difference to what we'd expect to see observationally:

Shouldn't I expect to live in a young universe? I would expect that scientists would soon uncover evidence that the universe is much younger than they previously believed, barely young enough so that observers such as myself had enough time to come into existence.

Let me just note that you don't need anything exotic like false vacuum for a setup like that, your garden-variety radioactive decay is no different. Your problem is equivalent to being a Schrodinger's cat.

Let's postulate an additional law of physics that says any branch of the wavefunction that tunnels into true vacuum is dropped and the rest is renormalized to measure 1. The complexity penalty of this additional law seems low enough that we'd expect to be in this kind of universe pretty quickly (if we had evidence indicating highly unstable false vacuum). This is sort of covered by #4, I guess, so I'll answer the questions given there.

This can get tricky if, for instance the vacuum collapsed more slowly that a factor of a trillion a second. Would you be in a situation where you should behave as if you believed vacuum collapse for another decade, say, and then switch to a behaviour that assumed non-collapse afterwards?

I don't see why that would happen, since the universe has already existed for billions of years. Wouldn't the transition either have happened long ago, or be so smooth that the probabilities are essentially constant within human timeframes?

Also, would you take seemingly stupid bets, like bets at a trillion trillion trillion to one that the next piece of evidence will show no collapse (if you lose, you're likely in the low measure universe anyway, so the loss is minute)?

I don't think the law of physics postulated above would provide any evidence that you can bet on.

Perhaps a little reframing is in order. Let's go with shminux's suggestion. You're locked in a room with a cake and a vial of deadly gas. The vial is quantumly unstable, and has a 1/2 measure of breaking every minute. Do you eat the cake now, or later, if you know you'd enjoy it a little more if you ate it in 10 minutes?

"Now" corresponds to not thinking you have quantum immortality
"Later" corresponds to thinking you have quantum immortality

Thee reason I think a reframing like this is better is because it doesn't by construction have a negligible probability if you choose #1 - humans are bad at hypotheticals, particularly when the hypothetical is nearly impossible.

None of these assumptions make any difference to what we'd expect to see observationally

Seems wrong. Vacuum decay would depend on the state of the observable fields, and the condition of non-decay should affect the observed probabilities (rather than observing P(A) we are observing P(A | vacuum didn't decay) ). For a very simple example, if vacuum was pretty stable but "the creation of high-energy particles" triggered the decay, then we couldn't observe that interaction which is triggering decay. Or some particles would be popping out of nowhere from the fluctuations, preventing decay.

The problem with the many worlds interpretation and in particular with the quantum suicide thought experiment is that all sorts of completely arbitrary ridiculous things can happen. There should be a me who spontaneously grows extra arms, or cat ears and a tail, or turns into a robot, or finds himself suddenly on Mars without a spacesuit, or .... and yet here I am, with nothing like that ever having happened to me. If my survival ever requires something extraordinarily unlikely to happen in order to keep me going, just like a bad bill in congress (all of them), it's inevitably going to be attached to something else which is not, shall we say, status quo preserving.

As it relates to this scenario, imagine an Earth about to be annihilated by the oncoming shockwave of the expanding bubble of vacuum decay. Whether it is destroyed a moment later or not isn't a binary decision. That shockwave is there, like it or not, and there won't be an alternate universe that splits off from one which is later destroyed, which is not later destroyed. That bubble isn't going away in any universe, it's there, and it's coming. The only way the quantum suicide thought experiment can work in the way you describe is if we always find ourselves in a universe where the bubble nucleation event never happened in the first place, whether it happened a billion light years away a billion years ago, or in an alien laboratory on alpha centauri 4.3 years ago. But if you apply this logic to ANY bad thing that happens, you can see that it clearly fails. One should expect one to always find oneself in a universe where nothing bad ever happens to oneself. I was hit by a car and got brain damage among other physical damage. No quantum kung fu thought experiment saved me from that. My identity CHANGED that moment. I have lost about 50 IQ points. When I changed, that other me died. If I were to die all the way, that would just be a change. That's all death ever is. A change. Simply a more drastic one than the usual bad things that happen to oneself. Where do you draw the line? Is something special about death, is that the threshold? This is why I say the quantum suicide thought experiment makes no sense to begin with. If that bubble of deeper vacuum is nucleated, our fate at that moment is SEALED, and no alternate universe splitting will save us. For your proposition to work, some force would have to stop bad things from ever BEGINNING to happen to us. And there is no such force at work. Believe me, I know from experience.

I guess I should say something though - there actually IS a tiny, tiny possibility for a massive nucleated bubble of deeper vacuum to just rearrange its energy distribution and just all go away, since anything which can happen in the forward direction can be undone, with an extraordinary amount of luck. So if you're a many-worlds purist, I guess I haven't really disproved it. But again, I would still expect to live on a much stranger world than the one that's here if I always lived on one of the universe branches that contrived itself to survive somehow. Just like, if you were to find ice spontaneously form in a pot of boiling water, it would more likely than not, not be an ice CUBE. And just like, if this were a poincare recurrence universe, there should be things observable in the universe which are not consistent with a universe that directly developed from a big bang, there should be weird things out of place.

Are you sure that this hypothesis makes no observable predictions?

For one of many possible predictions, I ask whether the tunneling is truly independent of the arrangement of matter and energy in the area. If there is some arrangement that makes it more possible, we should see effects from it. Exotic matter physics experiments seem like a good candidate to create such. Perhaps high energy particle collisions, or Bose-Einstein condensates, or negative temperature quantum gases, Ccassimir effect setups, or something else.

If those experiments, when successful, decrease the measure of their resultant universe, we should expect to see them fail more often than normal.

So, a proposed test: set up an experimental apparatus that flips a quantum coin, and then either performs or doesn't perform the experiment in question. You expect to see the "not performed" result with p > 0.5 in your recorded data.

Of course, the effect may be very weak at that scale, if it "only" reduces the measure of the universe by a factor of 10^12 per second across the entire universe. You might have trouble getting enough of the measure from your experiment to detect something.

(Also, a minor nitpick: the per-microsecond discount rate should be about 0.0028%, as 1.000028^(1E6) ~= 1E12.)

A similar problem can be created with other scenarios. For instance, suppose you are planning on spending all day doing some unpleasant activity that will greatly benefit you in the future. Omega tells you that some mad scientist plans on making a very large amount of independent lockstep-identical brain* emulators of you that will have the exact same experiences you will be having today, and then be painlessly stopped and deleted after the day is up (assume the unpleasant activity is solitary in order to avoid complications about him having to simulate other people too for the copies to have truly identical experiences).

Should you do the unpleasant activity, or should you sacrifice your future to try to make your many-copied day a good one?

I'm honestly unsure about this and it's making me a little sick. I don't want to have to live a crappy life because of weird anthropic scenarios. I have really complicated, but hopefully not inconsistent, moral values about copies of me, especially lockstep-identical ones, but I'm not sure how to apply them here. Generally I think that lockstep-identical copies whose lifetime utility is positive don't add any value (I wouldn't pay to create them), but it seems wrong to apply this lockstep-identical copies with negative lifetime utility (I might pay to avoid creating them). It seems obviously worse to create a hundred tortured lockstep copies than to create ten.

One fix that would allow me to act normally would be to add a stipulation to my values that in these kind of weird anthropic scenarios where most of my lockstep copies will die soon (and this is beyond my control), I get utility from taking actions that allow the whichever copies to survive to live good lives. If I decide to undergo the unpleasant experience for my future benefit, even if I have no idea if I'm going to be a surviving copy or not (but am reasonably certain there will be at least some surviving copies), I get utility that counterbalances the unpleasantness.

Obviously such a value would have to be tightly calibrated to avoid generating as crazy behavior as the problem I devised it to solve. It would have to only apply in weird lockstep anthropic scenarios and not inform the rest of my behavior at all. The utility would have to be high enough to counterbalance any dis-utility all of the mes would suffer, but low enough to avoid creating an incentive to create suffering-soon-to-die-lockstep-identical copies. It would also have to avoid creating an incentive for quantum suicide. I think it is possible to fit all these stipulations.

In fact, I'm not sure it's really a severe modification of my values at all. The idea of doomed mes valiantly struggling to make sure that at least some of them will have decent lives in the future has a certain grandeur to it, like I'm defying fate. It seems like there are far less noble ways to die.

If anyone has a less crazy method of avoiding these dilemma's though, please, please, please let me know. I like Wei Dai's idea, but am not sure I understand MWI enough to fully get it. Also, I don't know if it would apply to the artificially-created copy scenario in addition to the false vacuum one..

*By "lockstep" I mean that the copy will not just start out identical to me. It will have identical experiences to me for the duration of its lifetime. It may have a shorter lifespan than me, but for its duration the experiences will be the same (for instance, a copy of 18 year old me may be created and be deleted after a few days, but until it is deleted it will have the same experiences as 18 year old me did).

So ... how do you tell if this is actually true or not? Without that, it's entirely unclear to me what difference this can make to your knowledge.

I'll pick door #2, I think...

For instance, would they be in favour of programming an AI's friendliness using random quantum bits, if it could be reassured that if friendliness fails, the AI would kill everyone immediately?

If you already have an is_friendly() predicate that will kill everyone if the AI isn't friendly, why not make it just shut down the AI and try again? (If you don't have such a predicate, I don't know how you can guarantee the behavior of a random non-friendly AI)

Whatever weird physics arguments you make, it all adds up to reality. So I would look through the self-consistent theories and choose the one that didn't make me make decisions I disapprove of all the time.

So now assume that the false vacuum we're in is highly unstable - the measure of the branch in which our universe survives goes down by a factor of a trillion every second.

Or a factor of two every 25 milliseconds.

I quite like option 1. I've always been intuitively uncomfortable with the notion that I should e.g. save money and then use it altruistically just before I die rather than using money altruistically now.

I think Option 2 comes closest, even if you throw anthropics and many-worlds completely out the window (so let's just hypothesize that there is a 99% probability that all life will die during any given second)

Once you are dead, you will cease to care about your utility function. It won't matter how much fun you had in the moments before you died, nor will it matter what happens after, since everything that matters is gone. Your last words to your loved ones will not matter either, because they will be gone too. There will be nothing.

On the off chance that all life does not end, however, the future continues to matter. You'll care what happens to you in the future, or, if dead, you'll still care about what happens to the people who come after you.

By this logic, you also have to take the "stupid" low collapse bets (if you lose, it's all ending soon so who cares?)

Practically speaking, if you embody this logic, you will not emphasize short term pleasures in the moments before you die. (Stuff like the "last meal" on death row, looking at the sky one last time, drugs, etc). You will only care about long term stuff, like what happens to your loved ones after you die and what message you leave them with.

Actually, I think that's a pretty accurate description of the stuff I imagine myself caring about pre-death. I don't feel that the part of my utility function which only cares about the present moment suddenly gets more weight prior to impending death. So yeah, I'll definitely be doing a modified version of option 2, in which you carry on as normal.

If I know with 100% chance of all life will die, however...well, them I'm actually stumped on how I'm supposed to maximize utility. U = a.short term utility + b.long term utility = a.short term utility + b.null, unable to complete operation... but this is not as pathological as you might imagine, since one never reaches 100% certainty.

How could humanity have evolved a morality that cares about this?

It is just a kind of objective collapse theory. Especially if vacuum decay is gravitational in nature (i.e. is triggered by massive objects). I've been thinking about on and off that since 2005 if not earlier - the many worlds look like the kind of stuff that could be utilized to make a theory smaller by permitting unstable solutions.

edit: to clarify: the decay would result in survivor bias, which would change the observed statistics. If a particle popping up out of nowhere prevents decay in that region, you'll see that particle popping up. Given that any valid theory with decay has to match the observations, it means that the survivor bias will now have to add up to what's empirically known. You can't just have this kind of vacuum decay on top of the laws of physics as we know them. You'd need different laws of physics which work together with the survivor bias to produce what we observe.

Let's upgrade this into something terrifying: Life may exist in a state of quantum suicide.

Suppose there exists some phenomenon which instantly ends life, and has a relative frequency of happening to a given sector of the universe of 1/100 in any given month. Suppose moreover that there's some means of detecting such an event with 100% accuracy two months in advance of it occurring.

The Anthropic Principle combined with MWI means such a phenomenon could very well exist, and the only reason we're still around to consider it is we haven't yet built a detector for that event.

ETA: Actually, it's entirely possible some people did, and it's simply that nobody else knew about it. AP and MWI can turn knowledge into an existential risk. The universe could be full of basilisks.