She argues that quantum theory and experiment show that a particle's past history is determined by the measurements that an experimenter chooses to do in the future.
But it means that the particle’s path depends on what measurement will take place. Because the particles must have known already when they got on the way whether to pick one of the two slits, or go through both. This is just what observations tell us.This requires her to reject free will. Either the future determines the past, or the past history of the particle determines the choice that the experimenter makes. Either way, we cannot learn the particle's history by choosing to make a measurement.
And that’s what superdeterminism is. It takes our observations seriously. What the quantum particle does depends on what measurement will take place.
She quotes others as saying this destroys the scientific method, but this is okay because most philosophers reject free will.
I believe that free will is one of the most obvious and self-evident aspects of life, and it can only be doubted if you suffer from a severe mental disorder like schizophrenia.
Most of those philosophers subscribe to something called free will compatibilism, where we have an illusion of free will. I agree with her quote from physicist Nicolas Gisin:
“This hypothesis of superdeterminism hardly deserves mention and appears here only to illustrate the extent to which many physicists, even among specialists in quantum physics, are driven almost to despair by the true randomness and nonlocality of quantum physics. But for me, the situation is very clear: not only does free will exist, but it is a prerequisite for science, philosophy, and our very ability to think rationally in a meaningful way. Without free will, there could be no rational thought. As a consequence, it is quite simply impossible for science and philosophy to deny free will.”Well, I actually agree with it except for the clause "the true randomness and nonlocality of quantum physics". There is no nonlocality in quantum mechanics.
Free will may be the closest thing to true randomness that we have. Free will allows us to take actions that cannot be predicted by others, and that is what randomness means.
Quantum mechanics does not correlations that some physicists have tried to explain with nonlocal hidden variables, but those explanations have never worked and they certainly are not part of quantum mechanics.
You could also say that the collapse is nonlocal, as Sabine explains:
The collapse of the wave-function doesn’t make sense as a physical process because it happens instantaneously, and that violates the speed of light limit. Somehow the part of the wave-function at the one slit needs to know that a measurement happened at the other slit. That’s Einstein’s “spooky action at a distance.”Quantum mechanics is a positivist theory that only predicts observables. The wave function is not observable, and has no direct physical meaning.
Physicists commonly deal with this spooky action by denying that wave-function collapse is a physical process. Instead, they argue it’s just an update of information. But information about… what? In quantum mechanics there isn’t any further information beyond the wave-function. Interpreting the collapse as an information update really only makes sense in a hidden variables theory. In that case, a measurement tells you more about the possible values of the hidden variables.
The flaw in her argument is to say that information about the particle must be information about values of hidden variables. Quantum mechanics most emphatically says no such thing. The wave function allows predictions about the particle, so yes, it has info about the particle, but there are no hidden variables in the theory.
After citing Gisin, John Bell, Anton Zeilinger, Shimony, Horne, Clauser, and Tim Maudlin, she says:
As you can see, we have no shortage of men who have strong opinions about things they know very little about, but not like this is news. ...I have my own disagreements with those men, but they are all extremely knowledgeable and have well thought-out opinions.
Call me crazy if you want but to me it’s obvious that superdeterminism is the correct explanation for our observations. I just hope I’ll live long enough to see that all those men who said otherwise will be really embarrassed.
Her main technical argument is the double-slit experiment.
Once you understand what’s going on with the double slit, all the other quantum effects that are allegedly mysterious or strange also make sense.R.P. Feynman once said something similar. But the double-slit is not strange at all, once you once you accept that particles have wave properties. The diffraction pattern is just what we expect from a wave. You could probably make it from water waves. It is bizarre to show an example of waves causing an interference pattern, and deduce that there is no free will and all choices have been determined since the first minute of the Big Bang.
Here’s the weird bit. If you measure which slit the particles go through, the interference pattern vanishes. Why? Well, remember that the wave-function – even that of a single particle – describes probabilities for measurement outcomes. In this case the wave-function would first tell you the particle goes through the left and right slit with 50% probability each. But once you measure the particle you know 100% where it is.
So when you measure at which slit the particle is you have to “update” the wave-function. And after that, there is nothing coming from the other slit to interfere with. You’ve destroyed the interference pattern by finding out what the wave did.
You update the wave function because you have more info, but that is not what destroys the interference pattern. The measurement destroys the pattern because it breaks the coherence between the waves going thru the slits.
I am not saying anything novel here. I am just reciting textbook quantum mechanics, as it has been understood for 90 years.
Update: Anti-free-will atheist-evolutionist Jerry Coyne comments on the video.
As far as I knew, “Bell’s theorem” and subsequent tests of it completely rejected any determinism of quantum mechanics and verified it as inherently indeterministic. But, as Hossenfelder argues in this video, this is not so. She argues that a sort of “superdeterminism” holds in quantum mechanics, so that, in the end, everything in the universe is deterministic according to the known laws of physics.More precisely, Bell's Theorem rejects a determinism of local hidden variables. Unless there is a superdeterminism that prevents experimenters from choosing what to measure.
But the part that especially interested me beyond superdeterminism is that many physicists rejected such deterministic interpretations of QM simply from their own emotional commitment to dualistic free will.More generally, philosophers for millennia have rejected determinism out of the obvious truth of free will.
What I find fascinating is that physicists were conditioning their ideas and research directions on a philosophical belief that humans must have libertarian free will. Perhaps that impeded the ideas of “superdeterminism”.No, I don't think physicists conditioned their research on free will. What impedes superdeterminism is that it makes it impossible to do an objective experiment on the natural world, and thereby rejects the scientific method.
If a medical study said that those getting a vaccine were healthier than those getting the placebo, the superdeterminists would say that an invisible hand rigged the randomization of the controls so that the experiment would come out that, and the experiment tells us nothing about the vaccine. We could never make any scientific progress on anything.
And if “superdeterminism” of QM is now widely accepted, let me know.No, it is a fringe view that is only held by a handful of people.
Update: One comment says it is a "gods-of-the-gaps argument of a perceived loophole in Bell tests", and another says:
I thought of a good analogy for superdeterminism (though posting it now is likely too late for anyone to read it!).No, of course it is not convincing. But you could say the same of simulation hypothesis, many-worlds, nonlocality, multiverse, and a lot of ideas presented by modern physics popularizers. They are all gods-of-the-gaps arguments. They appeal to spooky arguments that do not really explain anything.
Suppose we lived in a universe where, when we throw a dice, it always gives either 1, 3 or 5, and never 2, 4 or 6. And suppose that everything we knew about dice and physics and how the world works suggests that all 6 numbers should be equally likely. So the lack of 2, 4 and 6 would then be a big puzzle.
The superdeterminist would then say: easy, it’s simply that the universe is absolutely deterministic, and it just happens to be the case that the initial conditions of the Big Bang were such that, as the determined outcome plays out, 2, 4 and 6 never occur. Essentially, all the starting points that would have led to 2, 4 and 6 simply didn’t exist, only those leading to 1, 3 and 5 exist.
Would anyone find this convincing?
The term "god of the gaps" is borrowed from evolution-creationism debates. The evolutionist will point to a chain of natural development of life on Earth. The creationist will point to some gaps, and say God is responsible. I once heard of an example where an evolutionist found a fossil missing link squarely in the middle of a gap, and the creationist said that there were now two gaps!