[Jizzle]

It's the most obvious counter-interpretation. I think it's become remarkably successful, but also suffers in its embrace of causality. While the Copenhagen interpretation can skirt the issue completely, Bohm's must wrangle with the implications of both relativity and non-locality and no one has been completely successful as such. Also, if it were the leading view, I don't think discussions of a simulated universe would be as popular.

[naasking]

> While the Copenhagen interpretation can skirt the issue completely, Bohm's must wrangle with the implications of both relativity and non-locality and no one has been completely successful as such.

Some might consider that a feature. John Bell of Bell's theorem thought QM's non-locality was the most important unresolved issue, so placing it front and center where it couldn't be ignored was a great idea. Interpretations like Copenhagen simply let you paper over the problems which will inevitably just arise elsewhere.

Finally, I think there's been some promising work in deriving covariant Bohmian mechanics. For instance, a preferred foliation of spacetime can be derived from the wave function itself [1], which means a preferred reference frame is actually a part of every interpretation of QM. This is the kind of result that probably would have never been found without research into Bohmian mechanics.

> Also, if it were the leading view, I don't think discussions of a simulated universe would be as popular.

I don't see why. Simulated reality is a purely logical argument [2].

[1] https://arxiv.org/abs/1307.1714

[2] http://www.simulation-argument.com/

[Jizzle]

You're right that simulation arguments generally don't rely on QM interpretations. I mention it as potentially detracting from simulation because a common argument includes the need for computational shortcuts. QM as it is popularized now simply fits the shortcut narrative better than it would under the Bohmian approach.

[dghf]

> It's the most obvious counter-interpretation.

More obvious than many worlds?

[gpsx]

Yes. Many worlds is the single obvious solution. It seems some people don't understand many worlds though. Or maybe there is some other definition I am not aware. I want to describe my understanding here for people's benefit.

The idea is that when you make an observation nothing special happens at all. For one, there is no wave function collapse. This is more an idea about how the observer experiences making a measurement. The salient feature is that the observer is not external to the system. He is a part of the system. His belief that the result was heads or tails is coincident in the wave function with the coin being heads or tails. In other words, the user becomes entangled with the system.

A toy wave function would look like this (I am leaving off normalization since I can't write a square root of 2):

Coin flip result, no observer: |heads> + |tails>

Coin flip with observer, "Tom": |heads>|Tom: it was heads> + |tails>|Tom: it was tails>

There is no collapse here. However, to Tom it appears as if the world did collapse. For the "version" of him that thinks the coin flip came up heads, his entire world is consistent with the measurement coming up heads.

I assumed most people who really understand quantum mechanics believe this (but I may be wrong). And that among them, there is no effort to say "There is no collapse" because indeed the effective result of the measurement is a collapse. I also use the language "wave function collapse" to describe what happens. This not because it is an objective reality of the universe but because it is the way we observe the universe.

[dghf]

That was my understanding too. It's disappointing that it keeps getting explained along the lines of "every time there's a decision point at the quantum level, the universe splits in two", when it doesn't say anything of the sort (at least, not if I've understood it correctly).