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A Transistor Made of Wood

Scientists from Linköping University and the KTH in Sweden have created the world's first wooden transistor. They used balsa wood and removed its lignin, a substance that makes wood hard and rigid. Then, they filled the wood with a conductive polymer called PEDOT:PSS that is semiconducting. The wood acts as a housing for the polymer, which can switch on and off by applying a voltage. The wooden transistor is slow and bulky compared to conventional transistors, but the researchers say it might have potential for future applications in biodegradable electronics. Press release here. Paper here.

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Cat Memes are Good for you, Science Says

I’ve long suspected that the reason people like consuming news on Twitter is because it’s easier to cope with the status of the world with jokes and asides sliced in between. A study by researchers at the University of Essex has now put this to the test. Study participants saw real reports and footage from major disasters and crime stories, as well as stories of kind acts and funny items. The researchers found that those who saw balanced bulletins had better moods, societal beliefs, and willingness to act for the benefit of society. They argue that balanced reporting can help people maintain a core belief that the world and the people in it are fundamentally good. So don’t hold back on the cat memes. Press release here. Paper here.

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Yet Another Bell-Type Test, yet Another Round of Terrible Headlines

A group of researchers at ETH Zurich has done an entanglement measurement that demonstrates a violation of Bell inequalities. These tests have been done since the 1970s and it’s what the 2022 Nobel Prize in physics was awarded for. There isn’t really anything new about their experiment, except that they used superconducting qubits that were more than 30 metres apart, and that they used 1.3 tonnes of copper and 14,000 screws for what is otherwise an undergrad experiment. Paper here

The press release proclaims that this “disproves the concept of ‘local causality’ formulated by Albert Einstein in response to quantum mechanics.” Alas, local causality wasn’t formulated by Albert Einstein but by John Bell, and it can’t be disproved by Bell-type tests. To make matters worse, the popular science press then conflated local causality with entanglement, which is something else entirely and promptly proclaimed that Einstein was wrong. To top things off, an article that tried to set things right made it even worse by conflating local causality with Einstein’s relativity.

Here’s the correct version. A violation of Bell type tests shows that either the laws of nature are not locally causal, or they violate a condition known as statistical independence. Since Einstein’s relativity is locally causal, the reasonable conclusion to draw is that nature violates statistical independence. The latter has also been referred to as “superdeterminism,” though I find the word extremely misleading. 

Yes, I know that most physicists would tell you otherwise. But give it a decade or so and they’ll understand what I say. You heard it here first…

Comments

Anonymous

As far as the Bell stuff, Sabine (and anyone else), what do you think about this: https://www.youtube.com/watch?v=rk8PF7gcevQ? The guy suggests that the Bell correlations already happen with classical E&M. I am skeptical, though it was already known to Oppenheimer that the Maxwell Equations can be recast to look like a Schrodinger equation for a photon wave function that is the positive frequency decomposition of E+iB (the h cancels out in the equation unless you measure energy or momentum), or alternatively as a 6 component vector of 3 Es and 3 Bs (I can provide peer reviewed papers if requested). My guess is that this works for independent photons, but not entangled pairs (or n-tuples where n>1). Second, the wooden transistor looks cool, not just for biodegradable electronics, but for enabling more local, small scale production! I wonder if the polymer can be made from recycled plastic, maybe 3D printed?

Anonymous

Perhaps what Ghenadie is saying in that video (and he has a paper in a seemingly sometime preadory journal, Entropy) is that measurement of two non-commuting observables is not statistically independent, regardless of how far they are, so the distance in the Aspect type experiments is a red herring.

Anonymous

Hi Sabine, these topics are quite interesting, should find the way to your science news. The research of Buchanan reads like a life-guide for the depressed ones among us. Nice and predictable.

Anonymous

Hi luval, thanks. Have to look on this in the evening again, I'm sceptical too, though my knowledge about QM is quite 'intuitive'. Sabine said earlier, that superdeterminism is not correlated with a 'backwards in time' - retrocausality. Hope she finds time, to have a look and gives an insight.

Sabine

You get correlations with classical EM but they don't violate Bell inequalities. I'm not sure why we even need to discuss this, if someone thinks that's the case they could just do a measurement and demonstrate it. Haven't heard of anyone doing that tho...

Sabine

It's always hard to decide what goes in the video and what doesn't. It's partly just a question of what day of the week a news item appears, so it's a bit random admittedly. In any case, I'm working on a video about just what we mean by "non-locality" in quantum mechanics.

Anonymous

He claims that you DO get correlations that violate the Bell inequalities (actually the CSHS inequality) with classical EM waves, that these measurements are routinely done all the time with polarizers that obey the classical Malus' law. Just watch the video, or read the paper Sabine! I know you are busy, but I would be eternally grateful if you could either debunk this or tell us that it's correct.

Anonymous

It would be nice to include in that video an experiment that can be done by undergraduates (and better if we can do it at home).

Anonymous

Just tried to understand that video, not sure, if I 'm too stupid, or this is such a pseudoscientific stuff, that it's too stupid to be understandable. "Colors are hidden variables" "what we see is not real, what we imagine is real" I bet on the second possibility.

Anonymous

Proud of your attention Sabine, and not megalomaniac enough, to discuss QM with you. I trust you and I'm with you. Hope, you didn't misunderstand. In your book, you consciously don't mention superdeterminism, so I think, it's a hot iron. Followed your dispute with that philosopher (is he?) Bernardo Kastrup recently, so I know, you make suggestions for experiments since about ten years (?) now, but nothing happened. Is it too difficult, expensive, or scientific inquisition? Looking forward your report about non-locality.

Anonymous

Hi Thomas, so Ghenadie is offering an alternative to superdeterminism. But is he, really? He claims that Alice's choice of how to polarize (measure) the beam influences what happens at Bob's detector (since her two choices/"transformations" lead to two different statistics/lotteries at Bob's end), and I think this happens not just for a beam, but for entangled pairs of individual photons. Sounds like spooky action at a distance to me. This is not my area of expertise either, which is why I was hoping for Sabine's debunking powers (or else confirmation that he's right). But for that she will need to do, in the modern equivalent of Galileo's "looking through the telescope", is watch the video and/or read the paper.

Anonymous

Spooky, yes, it would mean, that the detectors were entangled before? But how? Heavy stuff. Had difficulties to understand him, english isn't my first tongue and there was no translation tool. Let's hope, but I 'm afraid Sabine won't find time to make it clear. I find superdeterminism superinteresting, and I know, that she worked on concepts to measure it. Well, she just promised to make a video about non -locality in the text below. Thanks Iuval, and have a nice day.

Sabine

Iuval, I don't have to watch the video to tell you it's wrong. If he thinks you can violate Bell inequalities classically, he either computed or measured the wrong observable. I can't think of a reason why it would be worth my time checking his calculation.

Sabine

David, I'm a theorist. I have zero experimental equipment and can't do any demonstrations in my video. If your students have access to an optical lab they should be able to do almost all of the basic quantum experiments themselves.

Anonymous

Hi Sabine, thank you very much for your amazing scientific bulletin. I love your way of telling scientific news. You are really the top of the scientific divulgation. I read this interview https://www.quantamagazine.org/renate-loll-blends-universes-to-unlock-quantum-gravity-20230525 and I was astonished. I do not understand where are the evidences and the probes of what Prof. Loll claims. Please could you help me to understand? Thank you very much and congratulations!!!

Anonymous

Sabine, I checked his calculations and they are correct (I guess I have more time than you)! So the problem is more subtle, perhaps the fact that polarizers that give Malus' law are fundamentally measuring a quantum mechanical phenomenon. Still if we are going to be humble scientists instead of conceited priests (hence my Galileo "just look through the telescope" comment), we might be able to learn something. At no point in his gedanken experiment (which could very well be a real experiment that has been done many times already) is there a counting of individual photons by two observers at a spacelike separation. So "contexuality" makes sense philosophically, but not when Alice's contextual transformation of photons has an effect (even if only a statistical effect) on Bob's contextual transformation of his photons.

Anonymous

https://youtu.be/kJmBmopxc1k Hi Iuval, come back to this again, because, well, I think Ghenadie isn't Galileo, so you were a bit too hard on Sabine perhaps. The link above might show, why she is a bit annoyed about that. Perhaps you know it...

Anonymous

Dear Thomas, can you give me a synopsis of that long video before I decide whether I want to watch it (about 2x longer than Ghandie's)? Does it address Ghanadie's points in it? He may not be Galileo, but the catholic priests probably said something similar (like "Galileo is not Ptolemy") while refusing to look at new data. I am not being hard on our host, the decision to look at something new is something we each need to make based on our own personal criteria. I think Ghenadie is worth it and there is something to be learned about how unentangled photons already can violate Bell's inequality, or maybe the experiment he proposes has entangled photons? She is more of an expert than I am, so maybe she knows something more that makes her decide it's a waste of time.

Anonymous

Hi Iuval, well, yes, you don't have to look it really, I did it last year, cause I didn't know much about the topic that time. The video is about the criticism of Bernardo Kastrup, on superdeterminism. What I wanted to point out, was, that she has to defend that since about ten years now, she worked out the math, suggested experiments and so. But still there are coming up guys like Kastrup (don't know his qualification, but he gave a lame number in this video), who are far away from her knowledge, to discuss it. After so many years it might be normal, to deny wasting time useless, if you're sure, to know the facts. See you