Are the implications of MWI really this horrifying?

[hungrybear]

TL;DR Summary

The implications of MWI theory seem to me to be horrifying for each us individually. Am I getting something wrong?

Please excuse my massive ignorance but I find this really troubling and I would hugely appreciate some input from people who know more than me.

The implications of the many-worlds interpretation of quantum mechanics seem to be awful for individuals. Am I getting something wrong?

As I understand it, many worlds means that for us, the observer, we split into multiple copies which experience every possible outcome of quantum measurement. A number of physicists have stated MWI means all physically possible realities exist.

The implications of this seem really disturbing to me. It means that with 100% certainty each of us sitting here reading this forum will experience the most distressing and painful possible outcomes. Yes it will be split parts of us but it seems we must think of these split selves as us or the alternative is that we cease to exist and new copies of us are created, which also isn't great.

If each possible human movement causes a new world to split off, then it seems like there are some really bizarre consequences. Is that right? Or are human beings on a macro scale not able to cause quantum splits?

If I make a decision to get on a plane, does it mean there is 100% certainty that I will experience the terror of a plane crash through human error. Yes millions of copies of me won't crash, but from the viewpoint of me right now making the decision to fly, the future self that crashes is also me.

In at least some worlds incredible technologies would be possible just from random movements humans make. This sounds insane but it seems like it follows there must be worlds where we are kept alive by technology and tortured, if all possible human actions occur in all possible orders.

People often talk about many-worlds in the sense of "oooh cool, in another world you're the lead singer in a band!" but it doesn't seem like the disturbing philosophical implications have been explored enough.

As I understand it, some physicists claim the world doesn't actually split, but all possible worlds exist along side each other at all times, and they become 'discreet', unreachable from each other, when quantum states split. So it's not that we literally split, but that multiple copies of us exist all along and the timeline of their experiences splits. This seems more bearable to us individually, as we're unlikely to be on the timeline with the worst possible outcomes.

I really genuinely appreciate any help with understanding this as it scares the hell out of me to be honest.

 

[A. Neumaier]

MWI has no observable consequences beyond the standard consequences of quantum mechanics. Hence there is nothing horrifying to worry about.

 

[PeroK]

Summary:: The implications of MWI theory seem to me to be horrifying for each us individually. Am I getting something wrong?

If MWI is correct, then the consequences are already happening. Whatever horrors you might fear are already with us.

 

[CoolMint]

There's only one you. The other you's aren't you any more than Joe Biden is you. Horrors do happen for whatever reason to each and all of us all the time but this is on an individual basis.

 

[DaveE]

As I understand MWI there is absolutely no ability to communicate or know about any of the worlds except the version you inhabit. Those worlds only exist as a theoretical construct. My view is that they simply can't be real in any current world context. Perhaps there are many worlds, but you can only ever be in one. Your existence is what you experience, also what you think, both of which are only in your present world.

Also, yes, you might die tomorrow (hit by a meteorite, massive undiagnosed aneurysm, quickly, slowly, whatever), even in your present world; for real. If that doesn't terrify you, I can't imagine why dying in a world you'll never know about would.

 

[Keith_McClary]

Also, yes, you might die tomorrow (hit by a meteorite, massive undiagnosed aneurysm, quickly, slowly, whatever)

There was a sci-fi short story where the main character experienced the branches where he didn't die, for increasingly unlikely reasons (one involving aliens).

 

[PeterDonis]

As I understand it, many worlds means that for us, the observer, we split into multiple copies which experience every possible outcome of quantum measurement.

This is the basic idea, yes. (Note, however, that if you actually try to match this up with what the math of QM says, there are plenty of issues lurking: for example, there is no "split into multiple copies" in the math--the time evolution is unitary, and unitary evolution can't create or destroy anything.)

it will be split parts of us but it seems we must think of these split selves as us

That's a question of philosophy, not physics: what you think counts as "you". On at least one obvious viewpoint, that "you" are defined by the exact sequence of experiences you have had, then the other "selves" in the MWI are not "you", because they have experienced different results of measurements.

If I make a decision to get on a plane, does it mean there is 100% certainty that I will experience the terror of a plane crash through human error.

No. One "branch" of the wave function will only include the plane crashing if some event with quantum uncertainty has a nonzero probability of making the plane crash. MWI proponents often wave their hands and assume that every event you can possibly imagine has some nonzero probability, but that is not at all obvious when you actually look at the math.

if all possible human actions occur in all possible orders.

The MWI does not necessarily imply that. More precisely, "all human actions that somebody can imagine" is not the same as "all human actions that have nonzero probability given the initial wave function". The latter is the only thing the MWI says anything about.

they become 'discreet', unreachable from each other

That is correct. In more technical language, the different "branches" of the wave function in which different outcomes occur are decohered, so they cannot interact with or communicate with each other. So from the standpoint of anyone single "branch", the other branches might as well not exist.

 

[valenumr]

My personal opinion is that MWI is sensationalist. It's an entirely philosophical view point I suppose. But I think QM interpretations fit into the "other" category for discussion.

 

[DaveE]

But I think QM interpretations fit into the "other" category for discussion.

So one vote for "shut up and calculate" then?

 

[valenumr]

My personal opinion is that MWI is sensationalist. It's an entirely philosophical view point I suppose. But I think QM interpretations fit into the "other" category for discussion.

So one vote for "shut up and calculate" then?

I wouldn't put it that way. It is very much a scientific question how perceived reality arises from quantum principles. But to date, all we can do is conjecture from a philosophical point of view. No opinion is even wrong.

 

[Demystifier]

MWI has no observable consequences beyond the standard consequences of quantum mechanics. Hence there is nothing horrifying to worry about.

It is legitimate to be horrified by non observable consequences. For example, the idea that billions of people suffer in an unobservable parallel universe can be quite horrifying.

A religion analogy: Someone who believes in paradise and hell in afterlife can be horrified by all those souls that will suffer in hell, even if he believes that his own soul will end up in paradise and hence never observe the hell.

 

[Drakkith]

I really genuinely appreciate any help with understanding this as it scares the hell out of me to be honest.

Right now in our world there are people being worked to death as slaves, drowning, dying in fires, being murdered, or experiencing one of a million other terrible things. I find them to be far more worrisome than some parallel universe. That is, I think it's tragic but it doesn't bother me nearly as much as it should.

There's no reason to be more horrified about MWI's implications than about some kid being worked to death in a mine somewhere in the world today. I at least have the potential to change one of these.

 

[A. Neumaier]

It is legitimate to be horrified by non observable consequences. For example, the idea that billions of people suffer in an unobservable parallel universe can be quite horrifying.

It is legitimate to be horrified about anything, even about the death of simulated people in a computer game. But for those who don't want to be horrified, the cure is to constrain their fantasies.

A religion analogy: Someone who believes in paradise and hell in afterlife can be horrified by all those souls that will suffer in hell, even if he believes that his own soul will end up in paradise and hence never observe the hell.

Paradise and hell are quite different from parallel universes. In the former.
Each observer on Earth is supposed to end up in either heaven or hell. Hence heaven and hell are part of the present universe in the sense of MWI, rather than being parallel universes.

 

[Demystifier]

But for those who don't want to be horrified, the cure is to constrain their fantasies.

The issue here is whether the parallel worlds are a fantasy or real. If they are real, then being horrified is justified. The religion analogy is useful because there one can also ask whether heaven and/or hell is a fantasy or real.

 

[valenumr]

The issue here is whether the parallel worlds are a fantasy or real. If they are real, then being horrified is justified.

But, as a realist, the only objectively real world is the one experienced. Why should any alternative reality concern me based on my concrete experience?

 

[Demystifier]

But, as a realist, the only objectively real world is the one experienced. Why should any alternative reality concern me based on my concrete experience?

There are 7+ billion people in the world. Most of them I will never see or experience in any way. Should I worry about them?

 

[valenumr]

There are 7+ billion people in the world. Most of them I will never see or experience in any way. Should I worry about them?

Well, solipsism is one line of thought...

 

[akvadrako]

As I understand it, some physicists claim the world doesn't actually split, but all possible worlds exist along side each other at all times, and they become 'discreet', unreachable from each other, when quantum states split. So it's not that we literally split, but that multiple copies of us exist all along and the timeline of their experiences splits. This seems more bearable to us individually, as we're unlikely to be on the timeline with the worst possible outcomes.

Indeed, that is another way of looking at it, called the diverging worlds view. If you want to read more on that a good starting point is Branching and Uncertainty by David Wallace. Both branching and diverging views are compatible with the math of MWI, so either could be true.

Or perhaps neither really gives a good sense of what it would be like to live in such a reality, because it's trying to describe a quantum system in classical terms which is essentially impossible. If we could describe it better in everyday language maybe you wouldn't find it so horrifying.

 

[valenumr]

Indeed, that is another way of looking at it, called the diverging worlds view. If you want to read more on that a good starting point is Branching and Uncertainty by David Wallace. Both branching and diverging views are compatible with the math of MWI, so either could be true.

Or perhaps neither really gives a good sense of what it would be like to live in such a reality, because it's trying to describe a quantum system in classical terms which is essentially impossible. If we could describe it better in everyday language maybe you wouldn't find it so horrifying.

I keep myself sane by thinking of it as, well basically the law of large numbers. On a macro scale, if we take a huge number of more or less normal random samples with a tiny standard deviations, we shouldn't notice anything other than the mean. When we craft intricate experiments to observe such behavior on very microscopic scales with low sampling rates we can see it.

 

[PeroK]

There are 7+ billion people in the world. Most of them I will never see or experience in any way. Should I worry about them?

No man is an island entire of itself; every man
is a piece of the continent, a part of the main;
...
any man's death diminishes me,
because I am involved in mankind.
And therefore never send to know for whom
the bell tolls; it tolls for thee.

 

[PeroK]

PS having quoted John Donne, I admit that I don't necessarily agree with him!

 

[Demystifier]

any man's death diminishes me

So does the death of my copy in the quantum Russian roulette suicide diminish me?

 

[valenumr]

So does the death of my copy in the quantum Russian roulette suicide diminish me?

Well, the quantum suicide argument may be intersecting, but I'm not going to test it.

 

[valenumr]

Well, the quantum suicide argument may be intersecting, but I'm not going to test it.

Interesting...

 

[PeroK]

So does the death of my copy in the quantum Russian roulette suicide diminish me?

I suspect John Donne was not familiar with the MWI interpretation of QM.

 

[Demystifier]

Interesting...

Are you discussing with your copy?

 

[martinbn]

So does the death of my copy in the quantum Russian roulette suicide diminish me?

I have a copy in one of the universes that worries about these things so that I don't have to.

 

[atyy]

A religion analogy: Someone who believes in paradise and hell in afterlife can be horrified by all those souls that will suffer in hell, even if he believes that his own soul will end up in paradise and hence never observe the hell.

That is not correct. Hell can be observed from paradise. OK, I guess you can say it's Abraham's bosom, so strictly speaking it's not clear if that's equivalent to paradise or not.
https://en.wikipedia.org/wiki/Rich_man_and_Lazarus

 

[PeroK]

That is not correct. Hell can be observed from paradise. OK, I guess you can say it's Abraham's bosom, so strictly speaking it's not clear if that's equivalent to paradise or not.
https://en.wikipedia.org/wiki/Rich_man_and_Lazarus

So, part of the reward of being in Heaven is to get to watch those in Hell be eternally tormented?

Come to think of it, just knowing that your parents or children, say, hadn't made it to Heaven would take the shine off your own eternal paradise, I would have imagined.

 

[martinbn]

I think what believers in MWI should worry about is that there is a chance they happened to be in an universe in which the MWI is wrong.

 

[MathematicalPhysicist]

You shouldn't be terrified as a new theory is around the corner to replace Quantum Physics...

Just need to wait for it until 2100...

 

[Drakkith]

I choose not to worry about most things which I find silly. And I find MWI silly.

 

[StevieTNZ]

Sounds more like a psychiatric/psychological issue than a quantum mechanical issue.

 

[phinds]

I choose not to worry about most things which I find silly. And I find MWI silly.

 

[CoolMint]

How can just one universe be real in the MWI? It makes no sense. It's more appropriate to call it OWI(one world interpretation).