Friday, November 19, 2021

I am super determined to write this post

The topic:  superdeterminism as a "solution" to the quantum measurement problem.

The reason I am writing it:  possibly, because my future self is causing me to do so; but more clearly, because I see that everyone's favourite Youtube physicist Sabine Hossenfelder appears as co-author on a paper up at Arxiv with the title The Quantum Eraser Paradox

She made a recent Youtube video in which she downplayed the retro-causality interpretation of the experiment.  Let me post it:  here we go -

 

Now, she has previously come out as suggesting that superdeterminism is probably going to turn out to be the best explanation of quantum measurement issues, and she has also gone on about how free will in humans does not exist.   

In this new Arxiv paper, if I understand it correctly (and I have only had a quick read), it would seem that she and her fellow authors propose a new quantum experiment the results of which may show a difference between retrocausation as the explanation, and superdeterminism.  

Sounds like an important experiment to me!

But what does superdeterminism mean?   The Wikipedia explanation seems not very good, but this essay by Tim Anderson on Medium Superdeterminism may have solved the quantum measurement problem is a pretty good read.

Interestingly, it seems there is some potential cross over between both explanations (the future causing the past, and the now being predetermined.)   On the Wiki page, for example, it notes:

Some authors consider retrocausality in quantum mechanics to be an example of superdeterminism, whereas other authors treat the two cases as distinct. No agreed-upon definition for distinguishing them exists. 
But is that what Sabine addressing in her proposed experiment:  a way of distinguishing the two, empirically?

In Anderson's article, he writes:

Although there is no information transfer from future to past, so you can’t remember the future, there can be causal effects at the quantum level and relativity is not violated provided cause and effect are within light speed of one another. In that sense, you cannot know the future yet it can cause the present and the past. It can change reality itself, switching the electron spin orientation for example, or changing what reality was before you became aware of it.

This is why a better term for superdeterminism is “Future Input Dependency”. Thus, my actions in the future might, counter-intuitively, be determining my actions now rather than the reverse. Moreover, my future actions might even determine reality itself in the present. Thus, how I set up an experiment years in the future might determine the state of an electron emitted now.

Well, still count me as confused, then.

But, I don't know - if what I do in the future in some sense influences a decision I made in the past, is that a backdoor way to let a kind of free will in?   Because if it's myself doing the retrocausation, it has at least a whiff of free will about it.  

But how much I trust my future self to make the best retrocausative decisions?   Being good now seems a sound way to ensure your future self is not a complete jerk - hence retrocausation might fit in well with your classic way of thinking about ethics.  It's just that it's all circular (perhaps with a Mobius strip twist) instead of straight line running in one direction.

It's funny, too, isn't it, how we feel it's comforting to think our love relationships were meant to be - we give free will a hall pass to wander off when it comes to something like that, but want it back if it also means we're destined to die an early death (or end up in Hell forever.)

Anyway, I've written posts about retrocausation before on this blog.   I find it appealing, and I'm just here trying to work out why.


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