The Unexpected and the Unexplainable

(This image, which is not directly related to the post, is by Josef Spalenka at spalenkaletters.blogpost.ca)

Niels Bohr, the quantum theorist, once said “If quantum theory hasn’t shocked you, that just means you haven’t understood it yet”. People love this quote because it gets at how counterintuitive quantum mechanics can be. But it’s also discouraging, making it sound like quantum mechanics is something only a few select people will ever get. Like rocket science or brain surgery. And if there is no way you’re going to understand something, why even bother trying?

But non-specialists shouldn’t give up on quantum mechanics. The same goes for rocket science and brain surgery – just as long as we remember to be realistic about what we don’t know rather than just jumping into trepanning after looking up “the brain” on wikipedia.

Quantum reality is never far away, from laser scanners at the store, to the transistors that make your computer work, to, for some reason, this Czech real estate company. It makes sense to find out about it. And to learn enough to be surprised isn’t very hard. That’s the difference we need to be clear about: being shocked by something unexpected – which is what the Bohr quote says will happen – on one end, and being confused by something difficult on the other.

One thing that really shocked me when I was first learning about quantum mechanics is something that’s pretty well known: the Einstein-Podolsky-Rosen (EPR) paradox. It is the “spooky action at a distance” you may have heard of, in, for example, your favourite vampire movie. What the EPR  paradox says is that, according to one interpretation of quantum mechanics, measuring something in one part of the universe could have a strong effect on another part of the universe. A part of the universe that could be located light years away and should have no way to find out whether you’re doing quantum mechanics or eating a sandwich is still affected. Podolsky, Rosen and their funny-haired friend weren’t the first to claim that this is what happens, but the first to be troubled by how spooky this seems. Too spooky, they said, for it to be true. Still, as far as we can tell, that is an interpretation consistent with how the world works.

But how is it that we can tell? That always should be the first and most important question in science. If someone can’t answer that, then they aren’t talking about surprising results anymore – they are just confusing people.

In quantum mechanics, we can create a situation (called an entangled state) where two particles (say photon A and photon B) have to have opposite values in some measurable quantity (say “spin up” and “spin down”). But which particle has which value is not set unless you measure them. They both exist in a superposition of “up” and “down”. (Confused about the meaning of entanglement and superposition? Check them on wikipedia above, and also, I talk more about what each means in the Schroedinger’s Cat post). The EPR paradox says: let’s wait and not measure these two photons for a while, until they are really far away from one another. Then, when we check A and see that it’s “up”, does B become “down” only then?

Experimental physicists came up with a way to check. What they do is randomly choose what direction to measure “up” and “down” in. If they pick that direction right before measuring particle A, there is no way that information could have gotten to particle B. When they pick different measurement directions for the two particles, they find that the results for A and B are correlated in a way that only makes sense if the measurement of one had affected the other. That is spooky, sure enough, and people disagree about what it means. But even if we can’t explain why the universe works this way, we can explain why we believe that it does.

But not if we give up before we even start. Not if a specialist says, oh quantum mechanics is too hard for you, you won’t get it. Not if a non-specialist says, oh, why bother trying to understand something I’ll never understand. If we do that, we’re ceding the territory to people who don’t care if they can be understood, or if what they say is even true.

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Insomnia 6

Remember when I posted a couple of translations from Marina Tsvetaeva’s Insomnia cycle and said I also made other ones? I thought I would post another one. What better time to post it than at 4:30 AM on a Monday night?

(6)
This night I wander through the night alone
A Sister of a homeless, sleepless Order
This night in the lone capital I own
The key to every gate within its border

Insomnia has given me no rest
Oh my dim Kremlin, how you seem enchanted
This night I place a kiss upon the breast
Of this entire round and warring planet

It is not hair but fur that stands on end
A stifling wind stirs that my soul cannot resist
This night I’m moved to pity, which I send
To all the pitied and to all the kissed

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Iran Deal Post №4: Tale of the Nefarious Negotiators

You may have noticed that every opinion piece I’ve linked to on the Iran deal so far, for or against, has been by an American Jew. But, you might be surprised to learn, American Jews aren’t the only people with opinions on the matter! There are also, for example, Iranians. I was reading this report of Iranian opinion by Iranian scholar Abbas Milani and former Ambassador to Russia, Michael McFaul. What struck me is that the opposition to the deal in Iran largely mirrors the western opposition.

American opponents complain that Iran was “let off the hook” for past offenses. Iranian opponents:

Abbasi ripped into every facet of the talks, saying that the negotiators, “especially Mr. Rouhani … have accepted the premise that [Iran] is guilty.” Several conservative clerics and IRGC commanders have expressed similar sentiments.

American opponents claim the U.S. gave up on its red lines and asked nothing in return. Iranian opponents:

One prominent critic of the deal claimed that of the 19 redlines stipulated by the supreme leader, 18 and a half had been compromised in the current agreement.

American opponents worry that the inspections are insufficiently intrusive and will allow Iran to keep a clandestine program. Iranian opponents:

Conservative opponents of the deal tend to emphasize its near-term negative security consequences. […] They have denounced the system for inspecting Iranian nuclear facilities as an intelligence bonanza for the CIA.

American opponents say Kerry and company were hoodwinked by Iranian negotiators. Iranian opponents:

[Conservative Iranian commentators] have issued blistering attacks on the incompetence of Iran’s negotiating team, claiming that negotiators caved on many key issues and were outmaneuvered by more clever and sinister American diplomats.

This says nothing, of course, about whether the deal is a good idea. But to me it suggests that opposition to the deal is in many cases motivated by the suspicion that negotiating at all is already losing. That having a clear enemy is more important than having a deal.

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My 10 favourite Brazilian music albums

When people ask me what music I like, I used to say “uh, I dunno?” and then I used to say “everything”. But while both of those are true, they’re not very illuminating nor fodder for further conversation. So now about half the time I say “Brazilian music”. What kind of Brazilian music? Mostly the 60’s and 70’s mpb-samba-bossa nova-tropicalia kind of music. Keeping in mind that I don’t understand music at all, and without any consideration for what I think is actually best by some sort of general metric, here are ten of my favourite albums of Brazilian music.

Caetano Veloso – Transa Defiant and angry and sad and sarcastic and jubilant and always changing. Wonderfully dipping into quotes of the best Brazilian music of the era, and freely mixing English and Portuguese. You Don’t Know Me Nine Out of Ten It’s a Long Way

Gal Costa – Legal Another of the best from that maximally eclectic start-of-tropicalia aesthetic. Always lovely as it switches between quiet, sweet lullabies and freewheeling electric guitar yells. Deixa Sangrar The Archaic Lonely Star Blues London, London

Jorge Ben – 10 anos depois Jorge Ben has an unmatchable ability to make everything unbelievably catchy. Potpourris of several songs at once let him do this to maximal effect. You’ll be singing some phrase from this record, guaranteed, whether you know what it means or not. A Minha Menina País Tropical Vendedor de Bananas

Tom Zé – Estudando a samba Combines the requisite catchiness and songcraft with a bizarre sensibility. At times melancholy, at times just crazy, but always somehow a little off, in a wonderful way. Vai

Astrud Gilberto – The Astrud Gilberto Album I actually haven’t heard this album as an album all the way through, but Astrud Gilberto being probably every North American’s first Brazilian music love, she was also mine. Once I Loved Água de Beber Só tinha de ser com você

Baden Powell – Os Afro-sambas Amazing guitar skills, creepy songs about marrying your love at the bottom of the sea in homage to an afro-brazilian goddess, you know, that kind of thing. Canto de Ossanha Tristeza e Solidão Canto de Iemanjá

Zélia Barbosa – Sertão e Favelas Simply arranged, percussion-heavy, powerful “songs of protest” (that’s what the American re-release is called) – but sometimes of resigned poverty. Funeral do Lavrador Opinião Canção da Terra

Chico Buarque – Construção Chico Buarque is the only person that I can think of that has written a song I like and a novel I like. This record has some of my favourites, songswise. Cordão Cotidiano Samba de Orly

Cartola – 1976 My favourite choro album. Do you seriously doubt the greatness of this record after seeing the cover (Cartola is the guy on the left)? Sala de Recepção Preciso Me Encontrar Aconteceu

Adoniran Barbosa – 1974 Jokes, self-sabotaging songs, all in the real dialect of São Paulo. Adoniran Barbosa is your cool grandpa, if he was the coolest grandpa ever. Abrigo de Vagabundo Saudosa Maloca Trem das Onze

 

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Who is Schroedinger’s Cat?

The light was ebbing, and the observer could not distinguish the cat’s state…

Knorozov’s Cat

Schroedinger’s cat occupies a weird space in popular knowledge of science. It is familiar to many people, partly because the name has an aura of mystery, and partly because the internet is a machine for spreading cat-related things. Schroedinger’s Cat-themed webcomics, for example, are a popular and fertile field. And most people have probably heard of the thought experiment, and have an idea that it involves a cat in a black box that is both dead and alive until you check. But it’s not always clear to me that people get the significance. Because Schroedinger’s Cat is a startling thought experiment, and something you don’t know about until you check isn’t necessarily all that startling. After all, people have no difficulty accepting a coin in flight. That coin could land either heads or tails with equal probability, and you don’t know until it lands. There is nothing strange about that. Or how about a black box that contains either a cabbage or a set of car keys? Depending on how you feel about cats, cabbages and cars, that may have a similar emotional effect to the Schroedinger’s Cat experiment. Yet there’s nothing strange about the cabbage-car box at all.

Lenin’s Cat

Schroedinger’s Cat experiment as conceived by Schroedinger has a radioactive isotope and a hammer and a vial of poison, but let’s make it even simpler, if less realistic. There is a quantum particle, say an electron, with a spin that can be either negative or positive. The cat is deathly allergic to isolated positive spin particles, so if the spin is positive, the cat dies. Otherwise, the cat lives.  So in what way does this situation differ from the cabbage-car box? If we want to get at the quantum mechanical explanation, we have to talk about two quantum mechanical concepts: superposition, and the difference between a pure state and an ensemble state.

First, superposition. Quantum superposition is just the statement that a quantum particle can be in a combination of states. Imagine a guitar string that’s just been plucked. Is it vibrating at the fundamental frequency, or at an overtone? The answer, of course, is that it’s doing both. Because quantum particles have wave-like properties, it’s not a stretch to imagine that the same logic can apply to two different quantum states of the same system. Mathematically, it’s the statement that if you have two solutions to an equation, a linear combination of the solutions is also a solution. Thus the spin of our electron in the cat’s box can be a superposition of negative and positive.

Harper’s Cat

Now let’s talk about pure and ensemble states. I like to think of it like this: imagine that we have two coins. We will take one of these coins, flip it, and see whether it comes up heads. We would get a 50% chance of getting heads if we have two fair coins (pure state), or one coin that has both sides heads, and another that has both sides tails (ensemble state). Let’s go through what happens in both of these situations. In both cases, we pick one coin, but we don’t look at it before flipping it. If we had to guess our probability of getting heads at this point, we would guess 50%. In the case of two fair coins, that’s actually true. With maximally unfair coins, though, it’s that in 50% of the cases our chance for heads is in reality 0%, and in the other 50% of cases, it’s 100%. Another way to say it is that if after a flip where we got heads, we went back in time and performed that flip again, we would get heads 100% of the time in the unfair (ensemble) case, but only 50% of the time in the fair (pure) case.

The cabbage-car box behaves like a box picked out of an ensemble state. If you took the box, got a cabbage, went back in time and opened the same box again, it would always contain a cabbage. The Schroedinger’s Cat box is a pure state. If you got a dead cat, went back in time to right before you opened the box, and tried again, you might get a live cat. OK, you may say, that’s not so strange – it’s like a coin that hasn’t been flipped yet. Except it’s not: this is where superposition becomes important again. The experiment with the cat and the electron – the analogue of flipping the coin – is already performed inside the box. Only both results exist in superposition. So it’s a coin that’s already been flipped, but is both heads and tails – until you look at it. This is shocking: we are used to things in the future being indeterminate, but things in the past and present either are or aren’t – even if we don’t know which it is.

Monroe’s Cat

One way to react to this result is to say that cats can’t exist in superposition. It’s very easy to imagine a string that’s vibrating both at a fundamental and an overtone. You can maybe accept that an electron can behave similarly and have both positive and negative spin simultaneously. We know that electrons behave like waves (you can perform the double slit experiment with them for instance). But it’s impossible to imagine a cat that’s both dead and alive, because that can’t happen in reality. So what the experiment shows is that there is some threshold after which thinking about superpositions doesn’t make sense. But then you have another mystery: where along the line between an electron and a cat is that threshold – and what’s so special about that point?

And in any case it doesn’t get rid of a fundamental problem. Suppose you built a tiny cat that can exist in a superposition of states. You then opened the box, and you saw the cat was alive. And then you decided to measure the spin of the electron. You would for sure measure that it was negative – because if it was positive, the cat would have been dead. This is what is called entanglement – the spin of the electron is entangled with the state of the cat, so that if we measure one, we also have information about the other. If you are discussing the quantum states of the box, then, there are two possible ones: negative spin electron with living cat, and positive spin electron with dead cat. So by looking at the cat and determining that it is alive, we have also “collapsed” the superposition of spins into one definite value – negative. But what’s so special about measuring? How is it that we are fixing the spin of an electron by looking at a cat?

The cat that walked by himself

The most straightforward answer possible – but not the most popular one – is that there is in fact nothing special about looking at stuff. Instead, what has happened is that we’ve become entangled with the cat and the electron. So there is still a superposition of two states: negative spin, living cat, person who thinks cat is alive is one state, and positive spin, dead cat, person who thinks cat is dead is the other. There hasn’t been any collapse – this is just what it feels like to be in one state of a superposition. This is a simple and elegant answer, except that it leads us to the conclusion that we are living in one branch of very very many universes which all exist at the same time. This is called the Everett Many World interpretation of quantum mechanics. The other possibility – that there is only one universe and when we see the cat is alive it’s not dead somewhere else – means that there is in fact something specific about measurement that causes collapse. This leads to what are termed collapse theories, of which the most famous and popular is the Copenhagen interpretation. There is a third possibility – that what we assumed about superpositions was incorrect. This mostly leads to hidden variable theories. Very quickly then, we have gotten ourselves mixed up in the interpretation of quantum mechanics. And that’s why the Schrodinger’s Cat thought experiment is so ubiquitous – it’s a fast way to get to some very fundamental questions about how reality works.

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GMOs and the Precautionary Principle

When I read Will Saletan’s big story about anti-GMO movement, I became convinced that the anti-GMO case is pretty unscientific. So it was a surprise for me to see N.N. Taleb, the “Black Swan” and “Anti-Fragile” author, assert in his Taleb-ian way that quite the opposite was true, and everyone who was not against GMOs was either a dupe or a shill. I became curious to see what his case against GMOs was. And so I came to a paper on the precautionary principle that Taleb and co-workers have put up on the ArXiv. Stylistically, the paper is vintage Taleb: frequently coining catchy terms (albeit sometimes for already described phenomena), the talent for saying something that somehow is both obvious and counter-intuitive, blunt disparagement of people who disagree, эпатаж and безапеляционность (since these Russian words are clearly borrowings, it might be that there are analogues for them in English, but I don’t know them). Apparently the paper is being prepared for publication. When it gets published, I’d like to know where, because the journal that publishes this genre of paper probably publishes a lot of interesting stuff that is accessible for a lay reader like me.

The gist of the precautionary principle is this: cost-benefit calculations aren’t a good way to assess risk if one of the potential effects is total ruin. Or rather, total ruin is an absorbing barrier – that is, you can’t recover from it, it’s forever – and thus the “cost” is effectively infinite. Thus we should not do things that have total ruin as a potential effect, even in cases where most of the time the action is clearly beneficial. A crucial point is that uncertainty about outcome only strengthens this intuition. Imagine a graph of distributed outcomes that is your best guess for what might happen, with ruin off to one side somewhere. Uncertainty about outcome just spreads that guess function, and thus makes ruin more likely by your estimation. This applies, for example, if we think a certain amount of global temperature rise would cause total ruin, but are not very confident in current predictive climate modelling. People who are less certain about their predictions should be doing more to avoid ruin, rather than being more in favour of doing nothing.

But all of that’s the easy part – the hard part is figuring out what has total ruin as a potential effect, given that predictions (especially about the future) are famously hard. The answer of course, is many things do, but for most things, it’s vanishingly unlikely. What separates ruin that we should care about from ruin that we should ignore? Taleb et al. point out that global ruin has to do with the risk of spreading, and the risk of spreading hinges on the independence of events. Thus (to use the Taleb et al. example), a bunch of nuclear power plants that could melt down and destroy the environment in their vicinity do not lead to risk of total ruin, because the meltdowns would be independent events, and having them all happen at once is exceedingly unlikely. However, a nuclear war could have total ruin as an effect, because in this case the nuclear bombs are not independent of one another – the first bomb makes the second bomb much more likely, etc. The central limit theorem protects us from ruinous effects of many independent events that could all go wrong, but not from dependent ones. Taleb’s big contribution to the popular discussion as I understand it is to notice that financial transactions are not independent, but people treat them like they are – and that is why they are poorly prepared when market crashes, etc. occur.

But all of that is the easy part of the hard part – the hard part of the hard part is figuring out whether the risk of spreading is high for phenomena where a mechanism of ruin is not well established, such as GMOs. Taleb et al. point out a distinction between thin-tailed distributions (which mean that the underlying phenomenon doesn’t have a high risk of spread) and fat-tailed distributions (which mean it does). While this seems correct, it doesn’t really answer the question – because what are these distributions distributions of? Unless you actually have some idea for what the risk is, graphing a distribution of outcomes is not a trivial step. Another distinction they make is between changes that occur “bottom up” (which do not have high risk of spreading) and changes that occur “top down” (which do). The distinction in this context confuses me somewhat, because it’s clearly not meant to be literal (otherwise, all government actions lead to ruin and should not be made). They do place GMOs in the “top down” camp and artificial selection in the “bottom up” camp, but this seems more naturalistic fallacy than anything that’s well substantiated. Certainly we know that catastrophic risk of spread can exist in organisms derived from artificial selection (Panama disease) or even in the absence of any change in organism geno- or phenotype (pine beetle infestation, Dutch Elm disease).

GMOs can lead to monoculture, and in a monoculture, the risk of spread of any negative outcome is very high. However, monocultures present a risk to a given species. To what extent they present a risk to the biome as a whole has to do with the extent a given species is connected with others, thus the extent to which the destruction of different species is actually dependent rather than independent. This is a subject that requires further study, and I join with the authors of Taleb et al. in saying that I think this is urgent. Furthermore, that the most important studies for GMO safety are not toxicological or molecular genetic but actually ecological – is I think a somewhat surprising and important conclusion. However, because I strongly suspect the interdependence between at least some species to be quite weak, I am not convinced that GMOs present risk of ruin.

Thinking about (and trying to prevent) potentially civilization-ending catastrophes is incredibly important and also very interesting. Taleb et al.‘s precautionary principle paper gives a way to focus this thinking. But to me, they are not sufficiently convincing to turn me against GMOs.

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Великий и могучий

I made a post that I regret making. A man was interviewed about prison conditions in DNR controlled Eastern Ukraine, and rather than talk about what he said, I decided to talk about which swear words he used. That was shitty of me. It’s below the fold if you want to read the post for yourself, but please don’t.

Continue reading

Posted in language, translation | 2 Comments