First loophole-free Bell test?

[stevendaryl]

And if there is another universe in which superdeterminism prevents science, then, well we don't live in it. It's a bit like the anthropic principle.

Well, if a superdeterministic theory can be usefully approximated by a non-superdeterministic theory, then we can certainly make scientific progress within that approximate theory in the usual way. The point is that if we want to go beyond that approximate theory to understand how the superdeterminism comes into play, it might require a drastically different way of doing science.

So it's not so much that superdeterminism would prevent us from doing science, but that the current way of doing science isn't likely to tell us much about superdeterministic theories.

On the other hand, superdeterminism only makes interpreting experiments more difficult, where the typical experiment involves intentional setting up certain conditions to see what the consequences are. But not all science involves that type of experiment. For example, astronomy is (almost?) exclusively passive observation. We don't get to put stars or planets into particular configurations to see how they evolve, we have to find instances where they are already in those configurations. I don't think that superdeterminism would have much change in the way such passive-observation science is done.

(My apologies if the word "passive" to describe astronomy is offensive. That wasn't my intention. I'm not sure whether there is a standard term for those sorts of fields where experiments are possible, such as physics, chemistry, biology, and the sorts of fields where experiments are not practical, such as astrophysics.)

 

[Ilja]

Yes, but is there any problem with believing in it and doing physics?

There is none, except that if superdeterminism "would be taken seriously", which was a condition I have made. Knowing human condition, and in particular the human ability to live with a lot of self-contradictions in what one believes, I would not think that there will be any problem in believing superdeterminism together with astrology, intelligent design and the catholic dogma and nonetheless doing physics.

There is, by the way, nothing wrong with this. It helps us to survive: Imagine we would follow what we believe consistently - in this case, we often would have to do quite stupid things, like, in the mentioned examples, to reject science. We usually don't do such stupid things, because the arguments for not doing such nonsense are strong and powerful enough. The result are contradictions in what we believe.

An excuse will be found, that's easy. Say, we reject Reichenbach's principle, because it would, together with the violation of Bell's inequality, require a hidden preferred frame, which is anathema. Do we, that's why, reject Reichenbach's principle consistently? This would mean, we could start to smoke without being afraid of cancer, because this is only a correlation, thus, does not require a causal, realistic explanation. This would be stupid, common sense is enough to tell us about this. So we continue to care about Reichenbach's principle in everyday life. Why don't we care in the case of the violation of Bell's inequality? That's quantum strangeness. Quote Feynman, nobody can understand this. Case closed.

 

[atyy]

There is none, except that if superdeterminism "would be taken seriously", which was a condition I have made. Knowing human condition, and in particular the human ability to live with a lot of self-contradictions in what one believes, I would not think that there will be any problem in believing superdeterminism together with astrology, intelligent design and the catholic dogma and nonetheless doing physics.

I did mean superdeterminism taken seriously. Does it lead to any actual contradiction? In other words, can you already rule out superdeterminism on experimental evidence?

 

[Ilja]

Why would superdeterminism lead to giving up science? Couldn't one be a Bohmian and a superdeterminist? The Bohmian theory would be an effective theory, and the superdeterminist theory would be the true unknowable theory.

Also, couldn't one still make operational predictions if one gives up Reichenbach's principle? In quantum mechanics, we would still be able to say that a preparation and measurement yields certain correlations. So we would still be able to say that a preparation involving smoking, and a measurement involving cancer would still give the correlations.

First, the usual studies do not use smoking as a preparation. It is purely observation of correlations between people smoking, for some periods, and lung cancer. Then, with superdeterminism a preparation would not give you anything. Because your act of preparing the experiment is superdetermined.

 

[stevendaryl]

An excuse will be found, that's easy. Say, we reject Reichenbach's principle, because it would, together with the violation of Bell's inequality, require a hidden preferred frame, which is anathema. Do we, that's why, reject Reichenbach's principle consistently? This would mean, we could start to smoke without being afraid of cancer, because this is only a correlation, thus, does not require a causal, realistic explanation.

Well, such philosophical principles (including Occam's razor and Popper's falsifiability) can be understood as "more of a guideline than a rule". Given two theories, you prefer the one that satisfies some cherished principle, unless it contradicts some other cherished principle. "Cigarettes are harmless" isn't considered, by people other than tobacco executives, to be a cherished scientific principle.

 

[stevendaryl]

First, the usual studies do not use smoking as a preparation. It is purely observation of correlations between people smoking, for some periods, and lung cancer. Then, with superdeterminism a preparation would not give you anything. Because your act of preparing the experiment is superdetermined.

As I said in another post, superdeterminism might call into question the notion of a "controlled experiment", but certain kinds of science can be done in spite of the lack of controlled experiments. We can figure out the evolution of stars, for example, even though we don't have any way of preparing a star with a particular mass and angular momentum.

 

[stevendaryl]

I did mean superdeterminism taken seriously. Does it lead to any actual contradiction? In other words, can you already rule out superdeterminism on experimental evidence?

I don't think that there is any way to rule out superdeterminism on the basis of experimental evidence. To rule out superdeterminism, you would need to show that things could have happened differently than they actually happened. But since we only get one "run" of the universe, I don't see how you could possibly show that.

 

[Ilja]

I did mean superdeterminism taken seriously. Does it lead to any actual contradiction? In other words, can you already rule out superdeterminism on experimental evidence?

No, superdeterminism simply does not allow to make any reasonable predictions, thus, is unfalsifiable.

My point was that this, taken alone, is not yet sufficient to reject a metaphysical principle. Because this is a quite typical situation for principles. For example, if one takes into account the possibility of yet undetected forms of energy, energy conservation would be empty too, as well as its rejection. So, I propose to reject superdeterminism not because it is unfalsifiable (even if it is) but because, if taken seriously, it would make experimental science a meaningless exercise.

 

[atyy]

First, the usual studies do not use smoking as a preparation. It is purely observation of correlations between people smoking, for some periods, and lung cancer. Then, with superdeterminism a preparation would not give you anything. Because your act of preparing the experiment is superdetermined.

I didn't mean to believe in superdeterminism and give up Reichenbach's principle together. Let's just give up Reichenbach's principle, and accept quantum mechanics and be agnostic about hidden variables. Then let's consider smoking to be the preparation - in the usual studies, this would be a mixed state of the different smokers with their different life histories and smoking habits. Then we could compare this with another preparation of non-smokers - that would be a different mixed state. So comparing the two mixed states, we would be able to show that cancer was more common in one preparation than another.

 

[atyy]

No, superdeterminism simply does not allow to make any reasonable predictions, thus, is unfalsifiable.

My point was that this, taken alone, is not yet sufficient to reject a metaphysical principle. Because this is a quite typical situation for principles. For example, if one takes into account the possibility of yet undetected forms of energy, energy conservation would be empty too, as well as its rejection. So, I propose to reject superdeterminism not because it is unfalsifiable (even if it is) but because, if taken seriously, it would make experimental science a meaningless exercise.

But if superdeterminism cannot be ruled out, then it is consistent with all available data.

Also, available data shows that science is possible.

So by logic, superdeterminism is consistent with the possibility of science.

 

[Heinera]

Another point is what would be the consequence of rejection: It could be that, once it is rejected, one would have to give up doing science, because, if the rejection would be taken seriously, no experiment could tell us anything nontrivial. Superdeterminism would be of this type.

With superdeterminism, would you actually have the luxury of choosing to give up doing science?

 

[Dale]

Closed pending moderation

Edit: the thread will remain closed. Everyone has had a chance to pontificate on their pet philosophy of the day.

 

[ZapperZ]

The Hansen et al. paper has now been published in Nature in this week's (Oct. 21, 2015) issue. As a reminder, the preprint can still be found on ArXiv, with the link listed in the first post of this thread.

Zz.