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Methanol is easily produced by direct distillation of wood. And that would totally work, because it tastes and produces similar (short-term) effects as ethanol. But then it kills you.

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Along similar lines, have you come across the hypothesis that different isotopes of lithium have different psychiatric properties, and the inference that this implies quantum effects are important in cognition? see e.g. https://www.kitp.ucsb.edu/sites/default/files/users/mpaf/Ettenberg%20et%20al%20Lithium%20Isotope%20v.2%20.pdf and https://www.news.ucsb.edu/2018/018840/are-we-quantum-computers. The person pushing this argument (Matthew Fisher) is as distinguished as they come, and it actually seems maybe crazy enough to be right (although I'm a physicist, not a neuroscientist or psychiatrist).

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Huh, at atomic number three the kinetic isotope effect might be more relevant (I say that as someone who isn’t a chemist, but just knows that lower atomic weight is better). In random papers I looked at for unrelated reactions, lithium isotopes led to an effect of .5-2%. Seems a bit small but maybe that’s unrelated. And other groups also found lithium isotope effects in rats, but idk.

This relating to “quantum effects in cognition” is ... really quite unlikely. Scott Aaronson has a great blog post on that sort of thing, iirc, but there’s both a number of very good reasons it shouldn’t happen and no particular suggestion it would. In particular, quantum effect != quantum computing. Gold being yellow because of quantum effects doesn’t make it factor primes, light absorption being quantum doesn’t mean paint isn’t classical

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Quantum effects in cognition would not have to imply anything about quantum computing, and I for one wasn't interpreting it that way.

I'd see it as much closer to quantum effects in smell (https://en.wikipedia.org/wiki/Vibration_theory_of_olfaction). The wiki articles seem to paint it as this all-or-nothing battle between two models, though as far as I can tell neither the vibrational or the docking theory is quite right -- but it seems very likely there is *some* quantum component of smell, which implies nervous tissue can respond to quantum effects.

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As Dan says, all chemistry is quantum in a sense, and quantum effects would play many sorts of roles in the physics/biology of neurons and brain there, but that’s somewhat vacuous. I was responding to the link - “Are We Quantum Computers?

Led by UCSB’s Matthew Fisher, an international collaboration of researchers will investigate the brain’s potential for quantum computation“

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In some sense all of chemistry is quantum, and thus everything in the world is a quantum effect. I would not be too surprised to learn that chemistry could be a bit different in some surprising way because of nuclear spins. I wouldn't be too surprised because I have no opinion on the matter because I am not a chemist.

As far as the human brain doing anything resembling quantum computation: there is just no way. I don't care how distinguished the scientist is who is researching it. Roger Penrose believes in this stuff and he's wrong. He also said some wildly wrong stuff about Gödel's Incompleteness Theorem and the human mind. If I were a perfect rationalist, I'd take this trend to mean he's probably also wrong about there being another universe after the end of eternity, but that one is cool enough that I have to believe.

bored-anon mentions skepticism from Scott Aaronson. You should listen to anything Scott Aaronson says because he's always right about everything (at least when it comes to quantum computing).

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When did I say anything about quantum computing? Your putting words in my mouth that were never there. The claim is that quantum coherence (of nuclear spins) is important to cognition, the way quantum coherence is known to be important to photosynthesis. Quantum computing doesn’t enter into it.

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Oh I see the second link has a clickbaity title. Well forget that, the point is quantum mechanics can be involved even if quantum computing is not, and I don't think Aaronson has any argument ruling out that (indeed, he cannot, because there are biological processes where quantum coherence is known to be important).

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Yes, I went to the second link to get a quick overview of what Fisher is studying. It's not just the clickbait title - Fisher seems to in fact be looking for long range quantum effects that could be doing computation. As for whether quantum coherence is affecting the chemistry... I'll leave that to the chemists to debate. You mention photosynthesis. I've also heard there's something like that going on with the magnetic compass sensors in bird brains.

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Well there is also the stupid matter of semantics where any process can be termed a `computation,' and in the modern era with all the hype around `quantum computing' people increasingly tend to rebrand perfectly ordinary quantum mechanics as `quantum computation.' See e.g. https://www.linkedin.com/pulse/quantum-computing-hype-bad-science-victor-galitski-1c/. Which is not wrong per se, but it's hype without insight. But that doesn't mean it isn't quantum mechanics.

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I just wanted to add that the penrose model is more complicated that "the brain is a quantum computer".

In particular he believe that quantum mechanics does not apply at our mass scale because gravity breaks the evolution by collapsing the wave function (which is not a bad idea, actually). What he proposes then is that in some way (?) stuctures in the brain organize to "orchestrate" a collapse of the wave function (?) This last part is probably wrong (and I am not even sure how this is supposed to help with the whole consciousness stuff), much like his use of Godel th.m.

However I wanted to stress this because i always found weird that he is put in the "quantum brain" field when his idea explicitly violates standard quantum mechanics (and thus i do not think Tengmark's decoherence of the brain counterargument is valid, as it assumes QM).

(And also because I quite like his "interpretation" of qm given that my preferred quantum gravity seems to be non unitary anyway)

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Though i can only refute you with my intuition, please bear with me for a moment? Because i’ve been very curious for a long time for some perspective on this intuition of mine. Some background:

I only took one class on quantum chemistry in undergrad, but i was struck by how many of the equations were functionally identical to the equations of “statistical mechanics” in physical chemistry, only expressed in different terms (i think it took a lot of very mathy scientists a lot of heartache to prove this). Somehow, whether we’re dealing with particles or waves, the math gets all *statically* wavey at the right scale anyway (this is a super-gisted description, but i don’t think i’m too far off at this point…).

Then, after going into psychiatry and becoming somewhat taken with the physical mysteries of EEG/MEG and brainwaves, when a couple computational theories of mind-mechanisms became much-touted in these here circles, namely Carhart-Harris/Nutt et al’s “Entropic Brain Theory” and Friston’s “Free Energy Principle” interpretation of the brain as a Bayesian inference engine (links below, though Slatestarcodex has great links too, i believe), what really struck me was that in all my constant scrambling to understand the brain during residency, my most deep-seated, idiosyncratic internal model of the human mind already lined up remarkably well with these theories, and the trick was that i was just applying the energetic principles of complex, dynamical systems that i had as holdovers from an undergrad chemistry degree.

The danger to my mind in affirming either of these two theories was that they might only seem so juicy to me because i was “looking where the light is,” so to speak, but to the extent that we might consider them viable theories…. (aaand here’s my thesis, for your evaluation):

On a computational level, if the math in either case is all just statistical collisions of weird waviness from multiple directions (basically exactly how i see any atom or molecule…), wouldn’t a “quantum brain” look exactly like a “statistical mechanics” brain?

Obviously the actual relevance to global mental calculations of molecular quantum effects is…dubious… But does it actually matter? How plausible is it that similar or identical principles apply to how the brain actually works, given the validity of the below theories, and given that we’re working with funky complex wave dynamics in the first place?

Help? Does this conceptualization do nothing to bridge the gap between disparate understandings of the mind?

https://www.wired.com/story/karl-friston-free-energy-principle-artificial-intelligence/

https://www.frontiersin.org/articles/10.3389/fnhum.2014.00020/full

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Which equations of quantum mechanics are functionally identical to those in statistical mechanics? This is an unfamiliar assertion to me, and I know both fields pretty well. Are you thinking of the typographical similarity between a Poisson bracket and a commutator? That's the only example that comes to mind, but they are only similar to look at, mathematically they mean very different things and I would have to think about it for a while (or get some argument on the point) to decide if they nevertheless have some deep conceptual similarity.

As far as I can tell, the only reason people want to invoke quantum mechanics for describing the brain is because they want to discover a core source for free will, since if you treat the brain entirely classically there doesn't seem to be any origin of free will other than being occasionally pseudo-random as a matter of design principle, to compensate for ignorance.

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Yeah, I saw a talk about this by Fisher when I was in grad school. It was really interesting, and he seemed appropriately uncertain about it himself. It still seems unlikely to me that this is relevant to brain function, but it is hard to rule it out entirely.

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Chemically what's going on is that deuterium substitution causes the vibrational energy states of molecules to change, because it's heavier. This messes with things like hydrogen bonding and also causes the kinetic isotope effect (reactions with deuterium happen more slowly).

I'm highly skeptical of the claims that depleting deuterium in water can cure cancer. The amount naturally present just isn't very high to start with, and I don't think it's likely to have cancer-promoting effects.

Also:

>every time he drinks water, Castro calls in a chemist to test it for any impurity first; the tests can detect any contaminant to within a trillionth of a gram.

Presumably the chemists would notice the increased density?

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Deuterated water is still water. Maybe the paranoid chemists are only checking for other elements.

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Pfft...only if they were amateurs. If they were TRUE paranoid chemists they would use a gas chromatograph-mass spectrometer and get back a bunch of peaks that made no sense because the masses would be off due to multiple deuterations. Then they would probably all get fired and/or sent to prison for failing at their jobs so miserably. They would probably live out the remainder of their life half-crazed, obsessed over the data they got back from their GC-MS that fateful day. They would analyze fragmentation patterns on scraps of paper for hours, days, years...until finally they'd figure it out on their deathbed. They'd try desperately to explain to their grieving family the dastardly American plot to kill El Commandante! They'd plead to see old colleagues and military commanders from decades ago. Alas, these would only be interpreted as the ramblings of a disgraced old scientist.

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Should've done an NMR to explain the inscrutable GC-MS results!

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Naturally, but alas it wouldn't provide any revealing evidence, as the deuterated hydrogens would be invisible.

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Yeah but the splitting patterns would all be fucked.

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Lol true. Just like the MS lmao. Funny how just looking at the density would be a tell tale indicator while all our high tech instruments would spit back painful rubbish.

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Nice

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If you have regular access to Castro's kitchen and kitchen appliances you don't need to poison him at all; just grab a knife and shank him!

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Especially easy with the time gizmo!

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At this point the time gizmo would be a requirement

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I had the same thought. Just pause time and introduce a single high dose of carbon steel between the clavicles.

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Use the time gizmo to accelerate a kitchen knife to 0.99c and it doesn't matter where in the facility you do it.

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It does matter if you want to survive. I expect 0.99c would trigger a nuclear explosion.

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If it’s too sudden, they might be too enamored by him to actually do it. A female CIA agent sent to kill him was seduced by him and couldn’t do it. https://nypost.com/2017/09/02/how-fidel-castros-sexy-mistress-almost-took-him-down/ I just learned that he was a previous gal of his, which makes that a bit less impressive than it was before, but still

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Reminded me of the "Soviets just used a pencil" thing.

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The better analogy is when the Russians used a rare radioactive isotope of polonium to poison an oligarch who got out of line. (https://en.wikipedia.org/wiki/Alexander_Litvinenko)

Plus, my understanding was that the problems with 'regular' pencils in space are made of wood (which you want to reduce in the high-oxygen environment), and that they leave trace amounts of graphite dust that can get into the electronics and mess things up (so you have to use an expensive modified wax pencil). NASA didn't develop the pressurized pen, but once an independent developer in the US spent a million dollars inventing it (and patented his invention) he sold it to both NASA and the Russians, who both saw the benefits and incorporated them into their manifests.

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Geez. The “we use cookies” disclaimer at the site selling light water displays in Hungarian in my browser. Seriously. Just this once I’m not joking

[Insert your own joke about the Scott’s high expectations of his readers here]

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“ Light water speeds up plant growth. It slows aging in rats. It decreases rats' triglycerides and bad cholesterol. It can even cure depression in rats.”

I’d only be interested if the rats pressed a lever to get more of it. [Now I am joking]

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It decreases cholesterol, blood pressure, lowers bodyfat, AND tones your belly! Scientifically demonstrated! In rats! Only ninety nine ninety nine.

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I'd be perfectly healthy - if only I were a depressed, overweight rat being given light water to drink as part of an experiment 😀

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On mine too. But I often see that in links (doesn't bother me, these things at least have a standard look). The order page is in English.

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I'm Hungarian and I'm confused. What's the issue here?

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No issue, Greg. Just a light hearted comment about the "We use cookies" blurb being in such an interesting language. One of only a handful in Europe that fall out the Indo European family. I studied linguistics in college and thought it was fun to run into Hungarian unexpectedly. Certainly no offense was meant. I'm completely down with all the Uralic languages. :)

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Google hasn't set riddles for over a decade. Now it's a standard coding interview.

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How many many man hole covers in the US?

(About 12 million. Next question.)

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Excuse me, MAN hole covers? I certainly don't want to work for a sexist, repressive, bigoted company that uses such crudely and offensively gendered terms!

https://theconversation.com/the-uproar-over-taking-man-out-of-manhole-120821

And apparently Sacramento got there before Berkeley, back in 1990:

https://www.nytimes.com/1990/06/24/us/manholes-by-another-name.html

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Did changing the name increase the number of women who wanted jobs that involved using them?

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I think we should start using these terms to replace “chastity belt”.

We can come up with a new entirely unrelated name for the portals in the street.

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Yep. Google figured out those questions don't work. Usually the interviewer knows a lot more about the question than the interviewee because they've already asked the same question dozens of times. It puts the interviewee at a huge disadvantage to no one's benefit. The question has too little relevance to the job to provide useful information.

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If the interviewee told the interviewer "this question has too little relevance to the job to provide you useful information", then that would provide useful information about their judgement.

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Ugh we did these little riddles all the time in investment banking interviews. It served entirely to make the interviewers feel smart, which is almost itself a kind of IQ test: “if you think you’re smart because you know the answer to a question that you learned from someone else, does that actually make you smarter than the person who didn’t get the tip ahead of time?”

It’s a great way to make insecure people of middling ability feel powerful, though—which, when you’re asking them to work 100 hour weeks, can be a little bit of extra emotional compensation.

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“If you were to walk up a narrow mountain path one day and the following day… What are the odds you would be able n the exact same spot at the exact same time.”

It’s a certainty. Imagine a simple temporal overlay You would have to bump into yourself at some point.

“You are the few first person to get this correct!”

Really? They teach this one to CSci undergrads now.

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I don't get it. If I walk up one day at 11am and the next day at 11:30am, and it takes 5 minutes to get through, there will be no temporal overlap.

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I would have said it's impossible, since at the least in 24 hours the Earth will have moved some 60 million km along its orbit.

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I'd be impressed by that answer if I were interviewing you.

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"I would have said it's impossible, since at the least in 24 hours the Earth will have moved some 60 million km along its orbit."

That reminded me of this part from Lewis' "Perelandra", where Ransom meets the Eldila of Mars and Venus on Venus:

"Whenever he looked straight at them they appeared to be rushing towards him with enormous speed: whenever his eyes took in their surroundings he realised that they were stationary. This may have been due in part to the fact that their long and sparkling hair stood out straight behind them as if in a great wind. But if there were a wind it was not made of air, for no petal of the flowers was shaken. They were not standing quite vertically in relation to the floor of the valley: but to Ransom it appeared (as it had appeared to me on Earth when I saw one) that the eldils were vertical. It was the valley— it was the whole world of Perelandra— which was aslant. He remembered the words of Oyarsa long ago in Mars, “I am not here in the same way that you are here.” It was borne in upon him that the creatures were really moving, though not moving in relation to him. This planet which inevitably seemed to him while he was in it an unmoving world— the world, in fact— was to them a thing moving through the heavens. In relation to their own celestial frame of reference they were rushing forward to keep abreast of the mountain valley. Had they stood still, they would have flashed past him too quickly for him to see, doubly dropped behind by the planet’s spin on its own axis and by its onward march around the Sun."

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The riddle has the details about starting at the same time, the trip taking hours and blah blah where I put the ellipses. Sorry I confused in my attempt not to bore.

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I am but a simple and poor peasant, and it was my lowly understanding that two objects cannot occupy the same space at the same time, so the answer should either be "never" or "*boom* oooh, that's going to be messy to clear up".

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I am always in the same space and time as myself.

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The missile knows where it is at all times. It knows this because it knows where it isn't. By subtracting where it is from where it isn't, or where it isn't from where it is (whichever is greater), it obtains a difference, or deviation. The guidance subsystem uses deviations to generate corrective commands to drive the missile from a position where it is to a position where it isn't, and arriving at a position where it wasn't, it now is. Consequently, the position where it is, is now the position that it wasn't, and it follows that the position that it was, is now the position that it isn't.

In the event that the position that it is in is not the position that it wasn't, the system has acquired a variation, the variation being the difference between where the missile is, and where it wasn't. If variation is considered to be a significant factor, it too may be corrected by the GEA. However, the missile must also know where it was.

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Yes, riddles were gone before I interviewed in 2010. But I'm skeptical of the story that the riddles didn't work.

It seems more likely that they wanted to make the test as similar as possible to the job to avoid disparate impact lawsuits resulting from inevitable group differences in performance.

I worked at a startup after that which did standard coding questions plus some riddles and I think we got a higher quality set of engineers (but a less diverse one, because I suspect the riddles are more g-loaded than the coding questions).

If IQ test like questions didn't predict performance, maybe they sucked at measuring performance.

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I think it's more a matter that riddles don't give you a useful signal after you've already applied the filters Google does to its candidate pool prior to interviews. Google gets an absurdly high number of resumes (something like 4000 applicants per hire when I was there around 2010) and filters out the overwhelming majority before they get a callback from the recruiter.

For a long time, although I hear they've retreated from this in recent years, Google had a strong preference for advanced degrees and for degrees from top universities. And they'd ask for college GPAs at the recruiter screening stage even for industry hires with several years of experience. If you've already filtered your candidate pool heavily on higher education like that, that's got a pretty aggressive intelligence filter baked in since 1) selective universities filter their applicants on highly g-loaded standardized test scores, and 2) high GPAs in STEM degree programs also seems like a pretty strong filter for high intelligence.

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Sounds like the modern version of the Victorian gentleman banker sharing a chuckle over a mutually recognized quote from Cicero. 'Ha! I see we went to the same schools my jolly fellow -- you'll fit right in.'

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Why would you expect random trivia questions to provide a better signal than something that's at least tangentially related to the job?

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It's not trivia -- It's creative problem solving. If the interviewee has ever heard the question or answer before that would invalidate it. Sites like glassdoor enable sharing of interview questions and answers, so I guess that disadvantages recycled questions whose answers are compact enough to memorize. But when you are just hiring a dozen engineers for a startup, you don't have to recycle questions, and there is no cheat sheet on glassdoor.

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"The Hunza people of Pakistan drink mostly glacial meltwater. Because its freezing-and-melting cycle replicated Castro's freezer in reverse, their water is naturally lighter than usual."

Wait, I'm confused how these processes are opposites, as I'm reading this they seem like the same process? What am I missing?

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In each step of Castro's freezer, you discard the half of the water that hasn't frozen. The frozen chunk has more than half the heavy water molecules, so the water you discard must have less than half of the heavy water molecules. The Hunza are basically drinking discard water.

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Yeah, sure, but Scott says it "replicated this same *cycle* in reverse" (emphasis, of course, mine).

No numbers are given, but the freezing-and-discarding process apparently takes many, many repetitions to have a noticeable effect — as you'd expect, given what must be very, very minor variations in freezing point (or buoyancy-at-temp, or whatever the mechanism is).

So if it's just a case of "this water froze once and now they're drinking the melted portion", we wouldn't expect to see any real difference in the heaviness of their water consumption.

Is this because the Hunza argument is not actually very good, or is there actually something cyclic going on that would mean their water is lighter than the meltwater in the bottom of my fountain Coke?

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Not really. The Hunza water is lighter for the same reason that any glacial or even mountain stream meltwater is lighter. When water flows over ice, there is significant exchange of water molecules between the water and the ice at the interface. If you mix ice and water for a long time, you will deplete the water fraction of some of the heavy water. If you kept your water at exactly 0C, this process would probably reach an equilibrium when the surface of the ice was deuterated to the point that the rate of deuterated ice melting matched the rate of deuterated ice freezing. However, with glacial ice, the path is always changing, the water encountering new ice, refreezing, melting and refreezing daily over the course of years as it melts off the glacier...so maybe that explains it? Honestly, I read a couple papers on this and I'm still not sure if I'm satisfied myself.

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There's also some stuff about climactic changes causing H1/H2 ratios from different time periods to be frozen in time in glaciers. This is something measurable experimentally by taking core samples, but I'm not too clear about how these changes work to understand how that relates to the Hunza's glacier in particular.

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Thank you for the explanations, I also did not get why they were opposite processes, now it is very clear.

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Scott basically says later that the Hunza argument is not actually very good.

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Oops. I just saw that the original commenter was asking "how are these not the same process", which you've adequately explained.

(I just read up to "Wait, this part confused me", really, and then assumed s/he was confused by the same part I was... )

Okay,I guess read my other comment as essentially an entirely separate thread, asking:

"Wait, what part of the process of forming Himalayan glaciers meant that the meltwater got repeatedly selected?"

(..."rather than being essentially indiscriminate in selection between melted-fraction and frozen-fraction — or even selecting for the *more* readily-frozen bits, as the more liquid stuff would, one might think, escape the glacial system first — with at most _one_ instance of the process occurring for the water the Hunza drink?")

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I'm surprised you didn't explore the implications of this on climate change. For a second I thought you were heading that direction.

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Greg Cochran had a similar idea in 2015: "So, you can poison someone with heavy water – but although the authorities probably wouldn’t detect it, it takes a lot, and it’s expensive. Stick to thallium. However, just because small amounts of of deuterium are nonlethal, doesn’t mean that they’re harmless. They might be: or they might not. Nobody knows, because nobody has ever looked. You could think of deuterium as a source of noise in biological systems – and maybe those systems would work better without that noise." https://westhunt.wordpress.com/2015/02/05/dont-drink-the-water/

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_Kampen om tungtvannet_ (The Heavy Water War) is a very good six-part historical drama about Norsk Hydro's heavy water plant at Rjukan, a key strategic asset during WWII because of heavy water's importance to Nazi atomic weapons research, and the Allies' attempts to sabotage the factory. The Germans intended to use the deuterium-rich water as the main neutron absorbing agent. Thankfully this turned out to be the wrong choice. Anna Friel and Christoph Bach, who plays Heisenberg, gave especially good performances.

https://en.wikipedia.org/wiki/The_Heavy_Water_War

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"Anna Friel and Christoph Bach, who plays Heisenberg ..."

Until you look, you don't know who is playing Heisenberg in any given scene ...

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That happens with Schrödinger. With Heisenberg, it's impossible to accurately know both the actor playing the role & how good his performance is, and, simultaneously, what his role in the story is.

It's the famous diegetic uncertainty principle.

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Isn't the effect of removing a very tiny fraction of Deuterium going to basically be nothing? Like if water is normally 1/3200 deuterium, even removing 100% of the deuterium is a very small absolute increase. Whereas heavy water is 3200 times different. Further, we already know based on the heavy water stuff that swapping to regular hydrogen for deuterium is not that impactful except at incredibly high amounts, so one would not expect there to be any noticeable or meaningful change from light water.

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I would have thought the same, but if a 5x increase in concentration can indeed kill shrimp, then it doesn't seem inconceivable that eliminating it would have some non-zero effect.

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Look at the figure in the paper. The difference is like between 6 vs 7 shrimp. And their sample size is 50 shrimp (across all the jars).

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If it depends linearly on it, probably. But (probably not) maybe one reaction out of a hundred thousand in your body depends in particular on a deuterated reactant

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You could apply the same argument for 1:3200 solution of cyanide - after all, it's almost pure water, so even removing 100% of the cyanide is a very small absolute change.

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Well, no. HCN and H2O obviously have different chemical reactivities. You could make the same argument for a 1:3200 solution of HC15N and HC14N, in which case, yeah, taking out all the HC15N would reasonable be expected to not change the effect of drinking the stuff by a hair.

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But heavy water is a normal thing cells always had to tolerate; cyanide isn't. This heavy water claim is more like the claim that "slightly raising CO2 levels lowers cognitive levels", which is implausible for similar reasons (but not easy to rule out completely).

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> Isn't the effect of removing a very tiny fraction of Deuterium going to basically be nothing?

What's basically nothing multiplied by the number of DNA duplications your cells undergo in your lifetime? Does it add up to a reasonable chance of a cancerous coding error? And when you have one cancerous cell...

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Someone should do a long term evolution experiment in D2O. (E. coli grow at reduced rates in D2O, but are otherwise fine). Ideally you could do this in some kind of minimal media and have all hydrogen sources be deuterium (though maybe that would cost too much to be worthwhile).

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Counterargument: Searching Amazon for "deuterium depleted water" turned up "Liquid Death Mountain Water" (https://amzn.to/3jUJSQv).

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And it’s from “Whole Foods” so it’s gotta be good for you.

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The story of Liquid Death (the company/brand) is fascinating. A guy that was on the periphery of the punk/metal scene noticed that band members were chugging Monster energy drinks on stage, asked, and found out that when Monster sponsors a concert/band/venue, they provide cans of water that look like energy drinks so the bands can be good brand ambassadors without going into cardiac arrest from caffeine overdoses. So this guy hypothesizes that if rock stars want water that doesn't make them look like hippies, probably lots of other people want that, too. So he starts a company that makes just water, in cans, and calls it Liquid Death, and it's a huge success. As of last year, they'd raised something like $11M and were valued at $45M.

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Great story!

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> seems to kill shrimp

N = 50.

Also, using NASA BYOES kits made of "plastic" (batch controlled? probably not) and which included "normal water" and "marine salts" is ... uncontrolled, and the "office desk" environment and shuffling method are not described. Nor is the lighting controlled in the methodology.

There might be something worth investigating, is the best that can be said.

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Also from personal experience shrimp are pretty easy to kill. Especially if you have metals contaminants (copper being the most common problem for the average person).

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Weird “Lattice of Coincidence” moment just now. I had turned the page of a book to a chapter heading “The Unbearably Heaviness of Remembering” when I check my email and saw the ACX update.

The Lattice of Coincidence moment in “Repo Man”

https://m.youtube.com/watch?v=4ToUAkEF_d4

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Shrimp!

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If light water is a lot better, I think it might taste better. I wonder how it tastes.

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Would Castro taste it and ask for better tasting water?

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I assume most of the taste of water is due to the impurities, salts and such that are dissolved in it.

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> And there's the oncological argument (that's the St. Anselm thing, right?)

I see what you did there...

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Minor pedantic point: you wouldn't be making "semiheavy water" specifically; you're just increasing the fraction of deuterium in the water generally, since the water molecules (in a liquid) are constantly exchanging hydrogen ions. If you keep the deuterium enrichment process going long enough, you'll end up with mostly D2O.

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> It's just that your body is 70% water

I think that the exact proportion of water that a human body is made of is somewhat controversial: some quick searches turned up many different figures between 47% and 80%. IIRC there once was someone who searched up the phrase "Your body is X% water" for every value of X, but I can't seem to find records about that now.

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Seems like the sort of thing that’s entirely doable to measure

1979 > The percentage of water in fat-free wet weight for most mature animals is estimated at 73.2%, although the mean values in the literature range from 63% for the beagle to 80% for the mouse, with the mean for the majority of species between 70 and 76%.

Can’t find any studies on this after 2000 for some reason.

I imagine it’s also varying with hydration

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Well, I guess we just need to stick a few recent corpses in dehydrators and measure weight loss.

Science!

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It varies from person to person (mostly, it decrease with age, from ~75% in infants to ~50% in elders, but it also depends on sex, muscle mass, and body fat)

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Along those lines - this is pretty convincing.

https://slimemoldtimemold.com/2021/07/07/a-chemical-hunger-part-i-mysteries/

Basically a preponderance of the evidence points to some food additive that entered the food supply in the mid 70s triggered the obesity epidemic.

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I found that entirely unconvincing - everything is correlated with everything else, and each individual detail can be explained by many other things. The watershed thing is kinda off because lots more stuff are correlated with watersheds (cities? farming?) and even without that it’s super easy to map match. And each individual contaminant would probably be noticeable if it was a primary cause. Also, island nations that have imported food still get fat, refuting watershed theory. And in general it seems like lots of inferences are made from small and unreliable studies, even though it’s noted they’re unreliable. The CICO and lipostat things are also eh. A 20% difference in calories, which he called negligible, really isn’t, and even then the lipostat thing (which I don’t think is quite right) would work through its effect on CICO, and calorie moderation would still work.

However, obesity and many of those “contaminants” are still bad. And should both be addressed! And I appreciate people putting effort into this sort of thing, even if this one was misguided IMO, and still learned many new things.

Despite that, Dominic Cummings, a politically relevant person in the UM, liked it enough to ask several people in UK government to review it, lol

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What is your theory for why the lab animals have gotten fat along with their handlers despite no change in diet?

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1700s and 1900s and 2000s wheat are very different varieties, and grown in very different soils. Different fertilizer and growing practices as well. It’s also possible that 1900s rats are different from 2000s rats, or that their food is differently composed somehow. Could also be pesticides! Or maybe that study is just wrong somehow, that study seems like a hard one to do. That’s one of the more interesting and potentially correct parts of that blog anyway.

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I.e. if some change in the food is causing the obesity, maybe that food change just got propagated to the rats while still being labeled as the same thing

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“ Could also be pesticides! ”

That’s his claim! Some new chemical in the food chain.

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I had much the same feeling, in particular re the calories: a 400-calorie increase per day is just enormous--the equivalent of gaining a pound a week of fat.

And your description of how he handled all the correlations is spot-on.

I thought the description of the problems with our understanding of obesity today was better than his speculations for culprits.

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I realize just am nitpicking a single detail, but...

"because heat preferentially increases the evaporation of heavier water" Don't you mean preferentially increases evaporation of _lighter_ water?" that is, lighter water evaporates more, and what heavy water does evaporate will be quicker to precipitate?

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That threw me as well when I first read it because it's very oddly phrased. At any temperature, H2O will evaporate more quickly than DHO because it's lighter. But the key thing is how much more quickly. As temperature increases, the evaporation rate of both molecules increases, but the ratio is less skewed in favour of H2O than it is at low temperatures. In other words, the fact that one of the molecules is heavier matters less to evaporation rate at higher temperatures.

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Oooooh, okay. That makes sense, thanks.

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The Hungarians are working for [HYD LLC](https://www.researchgate.net/institution/HYD-LLC-for-Cancer-Research-and-Drug-Development), a company [selling depleted water](https://multi-vitamin.hu/markak-szerint/hyd-rakkutato-es-gyogyszerfejleszto-kft-preventa-csokkentett-deuterium-c103447) (for $5/l or so; the Amazon reseller must be making a hefty profit). The lead scientist, Gábor Somlyai, is the founder of HYD LLC. The company has been fined by the Hungarian Competition Authority a couple times for advertising medical benefits without going through any medicine approval process ([article in Hungarian](https://index.hu/tudomany/egeszseg/2014/01/24/1400_forint_a_csodaszer_literje)) and making a rather nice profit.

Somlyai is also [principal scientist](https://www.ddcenters.com/dr-somlyai/) at the Center for Deuterium Depletion, which is selling deuterium testing kits and "Metabolic Wellness" courses; and he is running an [annual conference on deuterium depletion](https://deuteriumdepletion.com/). So yeah, it does seem a bit sketchy - the people behind this line of research seem much more interested in commercial activities than in producing solid proof.

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I think we've found the answer.

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My first thought was "If I had a time gizmo giving me a thousand years to dink around, I suspect I could find something more valuable to do with it than killing Castro."

I actually figured there was maybe a ~20% chance that this was exactly the point you were planning to make. "Noticing when the resources you have been offered permit a greater accomplishment than the one you were originally aiming for" seems like the sort of rationalist skill that you might write a blog post to promote. (Even if it tends to annoy the authors of lateral-thinking puzzles.)

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Rationally, without an actual time limit here there's minimal reason not to kill Castro here as well surely?

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If I have literally unlimited time (rather than merely "preposterously large amounts of time"), then I suppose opportunity costs denominated in time would no longer count as a reason to not do something. But after I have mastered every human skill, read the entire Internet, cracked every open problem in mathematics, plumbed the secrets of the universe, and generally ascended to godhood, I suspect I might come up with some plan for Castro that my handlers would like even better than killing him. (And also that no one will care very much anymore, because I'll be conquering the world with superintelligence or nanotech or something.)

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What happens if you run this process in reverse and drink nothing but heavy water? In the tabletop game High Frontier, the Heavy Water Survivalists are a bunch of "Libertarians, doomsayers, gun-nuts, and others" who "are convinced that the Earth is kaput.". Since they're fleeing to space, "Survivalists drink only Heavy Water (D2O) to improve their resistance to radiation." - but (a) would this actually work, and (b) would it negatively affect their health, given the effects of heavy water discussed here?

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Yeah, once you reach 50%ish heavy water mitosis stops working and (probably that is why) you die. I’m not a physicist so I’m probably wrong (seriously, probably this is wrong!) but it doesn’t look like deuterium is any better at absorbing any sorts of radiation than water, and is used in nuclear reactors sometimes for the specific purpose of absorbing neutrons less than water while still slowing.

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That makes sense. What about if you still *did* want to increase your radiation resistance though? Would it be worth doing something like only eating C-14 foods (foods which use more of the slightly radioactive Carbon-14 in place of the regular Carbon-12) to constantly expose yourself to low doses of radiation in order to build up a tolerance? That probably wouldn't help with acute radiation poisoning (example a nuclear bomb going off near you), but it might help with the high doses of background radiation you'd get in space.

Of course on the ground if you want to do this you could just live in a high-altitude place that already gets more background radiation, like Denver, Colorado... but if you're already in space, and training up for a future mission, then eating C-14 foods might be a reasonably effective way to 'train up' your body as well.

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Probably just crack open a window, if you’re already in space. Or get a pet rock made from old watch coatings!

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I'm not sure you can build up a tolerance to radiation. There are things that cannot be tolerated (like nitrogen narcosis).

(At least, not on the individual scale. On the scale of evolution, you most definitely can.)

Biologically-based foods that are 100% 14C seem possible, but only barely - you're talking about something like 1 gray per second for living tissue with total isotope replacement, so it'd have to be made out of super-rad-hardened microorganisms. (I use the term "food" loosely, here, as eating that in any kind of quantity would obviously give you fatal radiation poisoning.)

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Hmm, damn. Thanks though. At least it sounds like C-14 foods would be good for a murder mystery. Not quite as good as heavy water of course, since the beta particles would show up on Geiger counters in a way that heavy water doesn't, but poisoning someone with a 100% C-14 meal seems like such an unorthodox way to do things that the average reader will still be surprised.

Though now that I think about it, if you wanted to poison someone like that you would just give them some Polonium in their tea or something... that's more available (at least in terms of the doses required to kill someone) and near-invisible to Geiger counters. Perhaps C-14 is instead used to administer a more gradual kill? Feed someone a few dozen 10% C-14 meals over the course of a week so it seems like they fell ill and died on their own - that might carve out a niche for C-14 over Polonium, administering smaller doses of radiation. Though I have no idea how you'd produce all the necessary C-14 foods, or even just the C-14 itself...

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I think the average reader would be surprised because they never hear about anyone using methods like this in real life because it would be massively expensive and inefficient. Making a meal where all the carbon was carbon 14 would require infrastructure-level investment to actually pull off. That in itself would be hard to hide, putting aside the cost.

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That's true. There is one benefit though to going with a Carbon-14 plot: it's more original than reusing the Polonium poisoning plot like plenty of novels and TV shows have already done.

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If something can't be tolerated individually how would it actually be tolerated on an evolutionary scale? Some individual has to develop tolerance to pass it on surely?

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Tardigrades somehow did it. They look cuddly, too.

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If there are individual variations in how well organisms can handle radiation, then natural selection can improve the species over time, regardless of whether each individual's tolerance can change.

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Not if the range of variations is not great enough for any individual organism to survive. If exposure to something is fatal in all cases, then it seems unlikely immunity will develop, unless I'm missing something here.

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Same way you get a 7 foot NBA star from two parents, both of whom are under 5 feet 6. Mutations, random gene re-arrangements, all the usual grist for the natural selection mill.

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Radiation tolerance? Like a tan? There are energetic effects to which one might get a little bit accustomed to but the stochastic cancer induction is a different issue. Like a smoking training for cigarette tolerance. Good luck with that.

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That's kind of backwards. The gamma and X-ray absorption don't seem to be especially different (although the gamma spectra are different of course), and as for absorbing neutrons, normal *light* water is significantly better at this than D2O.

In fact, that's *why* D2O was considered a good moderator candidate for nuclear reactors, because the absorption cross section of D for thermal neutrons is much lower than that of H, so it didn't eat up your valuable thermal neutrons while still slowing down your fast neutrons.

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what about the C and N and O isotopes? Those probably have less effect, due to the difference in atomic weight being much less as a percentage, but maybe some. Many of these isotopes are also naturally fractionated, “ Some plants,

such as rice and wheat, are depleted in C-13, and you can enrich water in D2O by running it through barley mash” Rarer (sometimes radioactive, or in the case of measuring water turnover deuterium) isotopes of common elements are extremely useful for measuring the movement of chemicals or the movement of those elements through reactions with chemicals in biology. https://en.m.wikipedia.org/wiki/Isotope_analysis (Also goes into a lot of natural isotope fractionation).

Nature casual article about testing heavy water in animals and humans - https://sci-hub.se/downloads/2019-03-22/76/10.1038@s41557-019-0242-9.pdf also mentions that “some have suggested” heavy water might extend lifespan, and slow metabolism

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Wait a minute, wouldn't this make the perfect murder mystery-thriller novel combo? An untraceable poison, so expensive that it must have taken a conspiracy of the most wealthy and powerful people in the world, and so technical that the average reader wouldn't be able to see the twists and turns coming... with a bit of work, I think this could be a Hollywood worthy script.

You could probably only sell it to the sort of people who make movies like '2012' or 'The Core', who are looking for the thinnest veneer of 'Science!' to justify regular old movie plotlines, though... if you want to have more negotiating power to insist on a more braintwisting movie though, one that focuses on the murder mystery as much as the thriller, you'd most likely have to publish the idea as a novel first and hope it takes off. Then if it does, hope Hollywood approaches you asking for a movie adaptation. If all goes well, you might have another 'The Andromeda Strain'-level techno-thriller on your hands.

(Though if it doesn't, you'll be nothing but just another failed genre writer... then again, if you don't invest too much into this, that won't be such a bad fate.)

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Reminds me of the political thriller The Zero Game where the secret conspiracy's plot involves building a neutrino observatory in order to conduct alchemy because reasons. It was actually kind of amazing how not a single step in their plan made any sense. Apparently the author was inspired by reading a news story about a real life neutrino observatory.

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I'm not a doctor or even a scientist, but I was diagnosed with metastatic prostate cancer last year and have read a lot of papers on the subject since then. Most studies that actual current treatments are based aren't all that great in my opinion, but the "Deuterium Depletion May Delay the Progression of Prostate Cancer" paper is *much* worse than that. For the prospective part: N=44, P~=0.05 and a relatively big difference in initial PSA (406.4 vs 521) between the treatment and control groups. Retrospective studies are always dubious and this one is also very small.

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I, personally, would not want to kill Castro, as he brought many social advancements to Cuba and assassinations are historically a terrible way of changing a country for the better. Now if the riddle was about assassinating someone i didn't like, i would painstakingly freeze and refreeze that water.

Or just just use a double mechanism serving teapot with only one chamber full of poison. https://www.youtube.com/watch?v=kkrgUT70Mbo

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I was thinking I'd poison Castro by using electrolysis to separate hydrogen from oxygen, then ignite the water in his presence. He just has to die, right?

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It wouldn't still be water at that point, or look like water.

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Technically it would become water as it killed him.

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smalid

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"And every time he drinks water, Castro calls in a chemist to test it for any impurity first; the tests can detect any contaminant to within a trillionth of a gram. "

According to homeopathy such dilution is still orders of magnitude greater than what's required to poison him!

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My impression is that you need at least 20% D2O for promptly noticeable effects in mammals, and IIRC lower beasts like protzoans and such can adapt to survive just fine at 100%. So I'm pretty comfortable with the prior that reducing the amount of HDO and D2O in normal water from 1 part in 3000 or 6000, respectively, to 1 part in a million or so will do absolute bupkis.

Or more precisely, whatever effect it *might* have will be utterly drowned out by whether your neighbor is smoking again with his living room window open, or you sat behind a diesel truck at a stoplight this morning, or happened to be standing below a cosmic ray shower in your backyard this afternoon, or you caught an extra whiff of radon when you walked by a fresh posthole on your way to get an ice cream, or there were a few thousand Aspergillus flavus on the peants you had with your martini.

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I happen to have thought about this in the past, but mostly for plants. My background is experimental physics, and I was working at a neutron scattering facility, where we used neutrons diffraction to measure the crystal structure of things. I'd heard claims about bananas frozen at liquid nitrogen temperatures having a different crystal structure to bananas frozen at standard freezer temperatures. So naturally, I wanted to test it, using neutron diffraction.

The thing is, it's a lot harder to use neutron scattering to measure the crystal structure of normal ice than it is with heavy ice. So we wanted to deuterate a banana. But I wasn't sure how to do that. I figured a banana tree would probably die if I tried to grow it using heavy water. But then someone suggested that we just give it heavy water while it's growing bananas. I still think this would be likely to kill it?

Unfortunately, I moved on before we ever tried the experiment. I'd still like to know how to deuterate a banana, though.

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Could you just surround sufficiently small pieces with heavy water and wait a while? Water can just leave (dehydration), so it could just exchange instead.

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Presumably it’s good enough if the water and not the other molecules are deuterated to see the structure?

https://moscow.sci-hub.se/160/8d924c9942bffdf2b0609554fececa3e/blake1964.pdf This guy tested peppermint plants with d2o, and they grew (if slower) at up to even 50% deuterium. Although the surprisingly linear effect between 0% and 70% is odd (and suggests 10-20% d2o might still be bad for humans), it should work. You’d probably need an impractical amount of heavy water for a tree though.

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Yeah, honestly I'm not sure how much more you learn from a deuterated banana than you would from, say, a partially hollowed-out banana filled with heavy water.

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Seems like a using a piledriver to hammer in a nail. What's wrong with X-ray diffraction??

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X-ray diffraction is for cowards.

Also, x-ray diffraction has a very low penetration depth. Neutrons scatter through the bulk.

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Well yeah. Hence the several feet of concrete behind which one hides while the experiment runs. Brr. I don't like neutrons. Nasty sneaky little bastards, kind of the viruses of the nuclear world, sneak up on you and before you know it you're spitting out positrons, changing hue and sex and drinking herbal tea instead of coffee.

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There's a small flaw in the insidious poisoning plan: it turns out that heavy water tastes different, namely, noticeably sweet, which would probably raise some suspicion somewhere along the way. The chemist/ skeptic Phil Mason (known on Youtube as Thunderf00t) got a fascinating video ("Why does Heavy Water taste sweet?") on that discovery (that he was involved in).

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The "a review paper here" link (oncological argument) took me to a page that downloaded a paper entitled "How E-Business Platform Channels Influence Chinese

Auto-parts Wholesale Market?"

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My favourite thing about this freezing discrepancy is how it comes about - I learned it mid-undergrad, and while I've forgotten some of the exact workings, still find it absolutely delightful:

The vibrational states that a molecule like water can attain are determined by the symmetries of the molecule - we spent a lot of time on some pseudo-group theory until we could work out from the shape of a (small) molecule which vibrational states it can attain. Here's where I can no longer do the precise working, but the symmetries of H20 and D20 are such that they each access a subset of the same set of energy levels, one of them can only access even-numbered levels, and the other one only odd-numbered levels!

Where does that get us different freezing temperatures? Well the gaps between energy levels diminish as you go up - so the gap from level 0 to 1 is larger than from 1 to 2 is larger than from 2 to 3 etc... That means the gap from 0 to 2 is just enough larger than the gap from 1 to 3 that it affects how much energy it takes to freeze the different molecules!! So really you'd be aiming to kill Castro with group theory.

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Are you sure you're not mixing up the vibrational spectra of H2O/H2O with the rotational spectra of ortho- and para-water (or maybe ortho- and para-H2 which have a much more famous and noticeable effect on the heat capacity of hydrogen)? I don't see why the nuclear spin wavefunction should be coupled to the *vibrational* wavefunction, since the nuclei don't switch places, the way they do in rotation.

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ohhhhhhhhhhhhhhh you're entirely correct and I stand rather embarrassed.

I'd been trying to work out all yesterday how a neutron could affect the spin, and I had myself convinced I was just missing a detail in remembrance - which in fairness I was.... Thanks and sorry!

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>Heavy or semiheavy water is pretty toxic.

When something's less toxic than table salt, I feel "pretty toxic" is an overstatement.

>The basis of cellular energy generation is the proton pump in the mitochondria, which moves hydrogen nuclei around to create a charge gradient. If the hydrogen nuclei have unexpected neutrons, that could jam the pump or change how the gradient works. I'm not entirely able to follow this, but maybe then there is some kind of cellular signaling cascade?

The basic problem with deuterating organisms is that the kinetics of acid-base reactions are significantly different with deuterium (and the thermodynamics are somewhat different - pH of neutral heavy water is 7.44 instead of 7.0 i.e. only 36% as much is dissociated) and screwing up the relative kinetics of things disrupts the functioning of highly-tuned systems like multicellular eukaryotes. Less complex organisms tend to have wider tolerances on these things (partially due to less things to go wrong, partially because the environment of single cells in a multicellular organism is subject to homeostasis and as such adaptability on the cell level isn't normally required), hence why you can grow 100%-deuterated bacteria.

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If it came to my attention that Google was genuinely and openly asking about killing Castro in employee interviews, or about doing any other illegal American security state stuff, I'd grow highly concerned and endeavor to stop using Google products as much as a I can (well, in addition to my efforts to already do so, of course).

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Why would you not resign from your job at the CIA? Why would you wish to kill Castro? Only an American would not ask these questions.

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Also, he's dead already, so there needs to be a different target.

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My mind skids off to alternate humans with nine lives like cats, so you can't just kill most people the first time.

Conclusion: Rasputin was a cat.

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I'm not American and I didn't ask those questions. But I don't think the CIA uses employees to (hypothetically) murder people: if they did this much better to use deniable assets who for whatever reason can't resign.

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Now that I think about it, the puzzle would have been the same with an imaginary dictator, and would be less distracting.

I think you're overestimating how mentally active all non-Americans are, and also ignoring that not all of them are fond of Castro.

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Presumably the reason he chose Castro is because of the wacky real life CIA assassination attempts against him.

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Because from a certain point of view for a certain period Castro and Communism were considered evil and dangerous. It would have been an honor for someone who believed these things to kill Castro.

Personally I was always glad when the attempts failed. I would have been considered to be a terrible US citizen for feeling this way by those straight thinking patriots.

The United States really, really didn't like Castro. There were numerous attempts to assassinate him.

https://en.wikipedia.org/wiki/Assassination_attempts_on_Fidel_Castro

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There are tons of biochemicals besides deuterium where deviating above or below the normal homeostatic levels can kill cells. So when high-D and depleted water both kill cancer cells, not too surprising and I wouldn't count one claim as evidence against the other.

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Scott, the link of the supposed cancer review paper link [0] redirects me to [1]: "How E-Business Platform Channels Influence Chinese Auto-parts Wholesale Market?" A curious topic for a pharmaceutical journal, but who am I to judge?

Still, I find the claim of a 50% growth rate reduction in deuterium free water (as opposed to our normal almost deuterium free water) extraordinary. Not quite superluminous neutrino level extraordinary, but still surprising enough that one should get the late James Randi [2] involved or something.

I am not a physician, but from my understanding, cancer cells are not undead Chaos cells thriving on poisons, but basically normal human cells with an unfortunate mutation, running in a nonstandard mode. Generally, I would assume that the environmental requirements for cancer growth are a smallish subset of the environmental requirements of a healthy human. There are certainly things which harm cancer cells disproportionally (e.g. chemo therapy, radiation), but these things also tend to harm healthy tissue to a lesser degree?

[0] https://www.sysrevpharm.org/fulltext/196-1568985381.pdf

[1] https://www.sysrevpharm.org/articles/role-of-ebusiness-in-the-wholesale-market-of-china.pdf

[2] As in the 'memory of water' debacle (https://doi.org/10.1038/333816a0)

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Cancer cells aren't individually undead Chaos cells thriving on poison, but chemo has an evolutionary effect on cancers, so there's a risk of selecting for cancer cells which are immune to that particular chemo.

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This was pretty much exactly the plot of the final episode of the UK series Eleventh Hour starring Patrick Stewart, where scientists were testing water from a spring to see if they could find any contaminants that would explain why local people were being sickened, but all their tests came back negative till he thought to check the density of the water and found it was a secret government heavy water source. https://en.wikipedia.org/wiki/Eleventh_Hour_(British_TV_series)

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Has anybody read The Unbearable Lightness of Being? It's pretty good. It's sort of a test kitchen for how different people can answer the questions of existentialism in different ways, and how it feels to live in each different answer. I should reread it sometime.

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I have! And also a long time ago and should reread it. I remember the style as a fascinating mix between the author telling a story and ‘addressing’ you as a reader.

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Sure, although not in decades. I quite enjoyed the American movie, too, although I'm told Kundera was deeply disappointed -- not broody enough maybe. Anyway, Daniel Day-Lewis in his prime and a gorgeous young Lena Olin, a treat.

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If you (or the CIA) have a fancy time gizmo, why bother with mundane poisoning? Just use it to accelerate his aging until he dies of natural old age.

Though this is really fascinating, and I've learned a lot more about heavy water than I previously knew!

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Anyone here read Medical Nihilism by Jacob Stegenga? I'd be curious to hear Scott's take on it.

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Sounds good. I sent the free sample to my iphone. I require myself to finish the sample before buying, so I won't impulse purchase books I won't read.

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Forget Deuterium, it is simpler to remove the salts and ions from the water. I think distilled and/ or deionized water will kill you.

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How would it kill people?

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I think it's osmotic pressure. Water with no salt rushes into your cells and causes them to burst. I guess this is for deionized water. https://www.thoughtco.com/distilled-versus-deionized-water-609435

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But you'd probably get enough electrolytes from food that drinking deionized water with it wouldn't kill you. My grandpa drank distilled water for years.

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I heard “distilled water will kill you” many times and never quite believed it because of exactly that, and even outside that people drink rainwater

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I'd heard that distilled water leaches minerals out of your bones, but when I checked, there didn't seem to be any evidence for it.

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Yeah and if not it would be a slow death. Still there's something I like about super pure water being bad for you. (It looks like deionized water is more toxic than distilled.)

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I think deionized and distilled water would be similarly bad for you, because they both have zero sodium and I think the mechanism of death would be sodium deficiency. This has happened to people who drink too much regular tap water while running marathons. The amount of sodium you get from regular tap water is negligible, so it hardly makes any difference which kind of water you are drinking. If you drink a lot of water without eating, you run low on sodium and die. But food can have enough electrolytes in it to compensate for the tiny differences between different types of water.

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Lots of ways:

(1) You could be immersed in it over your head, and not be allowed to come up to breathe.

(2) You could fall onto it from a great height, say 300 feet or more.

(3) A strong current of the stuff could sweep you over a tall waterfall onto sharp rocks below.

(4) A pirate ship could come sailing across a wide body of it nearby, take you prisoner, and after the ransom is not paid the pirates could make you walk the plank (see [1] above).

(5) A large chunk of the frozen variety could fall on your head as you were carefully ice-axing up a Swiss glacier.

(6) There could be none of it handy nearby when you are choking on a chicken bone, to wash the wretched bone down or out.

(7) You could accidentally walk through a plume of the superheated gaseous variety emitted by a power plant turbine and get scalded to death.

(8) You could be walking along a cliff when a surge of the current at the base critically weakens the cliff, leading to a landslide.

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No matter how pure it is in the bottle, it won't be pure by the time it hits your stomach.

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"And there's the oncological argument (that's the St. Anselm thing, right?)"

The heaviest possible water would certainly be made heavier by existing...

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I'm a lazy spy: tell the CIA to make me the chemist instead

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For whatever it says about me, my answer was to contaminate his water with small amounts of my poop. I don't have cholera or anything, but that has to be at least a little deleterious to health, right? Poop water? ...Google would not hire me with this answer, I think.

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Overcharging car batteries would be an easier source than fractional freezing.

https://www.youtube.com/watch?v=bCXB6BdMh9Y

Anyway, why stop at two? Make a nice glass of tritium oxide.

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Props for the Milan Kundera-esque title

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Scott, in your psychiatric practice have you encountered the use of Austedo (deutetetrabenazine)? A deuterated form of tetrabenazine, it is approved since 2017 for use in tardive dyskinesia and Huntington's disease.

https://www.austedo.com/

There are also deuterated forms of paroxetine, venlafaxine, dextromethorphan, vitamin A, and other drugs, that have been of interest. The latter two are in phase 3.

The advantage of deuterated drugs is an alteration of pharmacokinetics, causing either prolonged or shortened duration of action or reduction of toxic metabolites. These effects are in some cases related to deuterium changing the interaction of the compounds with the active sites of various cytochrome subtypes, especially 2D6 and 3A4.

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That sounds like a modestly interesting avenue of research, since (1) you can alter the acid-base chemistry a smidge, plus the H-bonding forces in the active site, and (2) in many cases it might be a relatively cheap thing to do, just work up your final reaction(s) in D2O. One might speculate that your chances of improving specificity aren't great, however.

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Well, if light water really is better for us, then we should invest heavily in fusion reactors and use up all of that heavy water!

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I'm surprised nobody's raised this nitpick yet, but -- surely you need to start with an amount of water that's much larger than "several thousand times Castro's daily consumption"? (Unless your values of "several" are extremely large, of course.) It seems like you need to end up with at least 100x Castro's daily consumption, and you're halving your amount of water at every freeze/melt iteration.

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Depends how you do your enrichment. If you're in possession of a magical filter that only passes D2O, then to raise the concentration by a factor of 3000 (from 1 part in 6000 to 1 part in 2) you need 3000x in feedstock what you want in adulterated product. But if you do it by actually extant methods, which only achieve a slight enrichment at each step, you might indeed need to have your feedstock delivered by tanker truck each morning...to the vast complex you surreptitiously erect in the palace gardens...

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"We are just refilling the swimming pool for Comrade President, hence the bulk tankers! And this large building is to make sure the water is properly treated before it is pumped in!" 😁

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You could store the D2O in the pool. I'll bet it would be a treat to swim in it, super bouyant.

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Would it be absorbed in through the skin that way, when/if Castro went for a swim? You would have achieved your aim then, without suspicion about poisoned food or drink!

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I would guess not. Skin is on purpose fairly watertight, so I doubt enough diffuses across. But the pleasures of swimming in D2O might be enough to sell El Presidente on funding the project himself, and I'll bet you could get a Congressional commendation if you pull off an expensive assassinatiion paid for by the victim himself. That's pretty moby.

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CIA handler arrives for secret briefing on progress of "Project Poison El Presidente", finds me lounging on lilo in middle of vast swimming pool, sunglasses on, sipping from a cocktail.

Handler: "What the heck is this?"

Me: "This is the poisoned water! Isn't it a great disguise?"

Handler: "So why are you in the pool?"

Me: "Well, I have to test that it works, don't I? I think I might be feeling a slight tingling in my fingertips, I need to spend a few more hours here to test it out"

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IIRC the reason ²H is toxic is because proton pumps are evolved to pump ¹H. ²H has twice the mass, so by F = ma you need twice the force. But obviously proton pumps aren't evolved to push with twice the force.

Also, a fun bit of trivia is that D₂O is slightly sweet.

>You would never think to check whether attempts to mine the Martian icecaps for drinkable water will result in dangerous water that could sicken the unfortunate astronauts who drink it (answer: it might! Martian water has five times more deuterium than Earthly water and seems to kill shrimp)

And if there's anything I learned from Doctor Who, it's that drinking Martian water is a baaaaaad idea.

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Well....two issues here:

1. At the atomic scale, dynamics is viscous, not inertial, or more colorfully Aristotelian rather than Galilean (or more precisely it's at low instead of high Reynolds number). From the point of view of a molecule, water is kind of a thick glop, molasses-like, sort of how to a water strider the surface of a stream is a springy semi-solid. So the energy cost of acceleration is not an important part of the energy cost of motion, the energy cost of overcoming viscous drag is much more important -- and this depends almost entirely on the shape and size of molecules (or atoms), not on their mass.

2. Protons pumps don't actually move protons. The H+ are attached to various big molecules, e.g. Coenzyme Q10 (mass ~ 800 g/mol), and these are what actually move around. Changing an H for a D in a molecule the size of Co-Q10 changes the mass that's being moved by 1 part in 1000 or so (and the mass doesn't matter much anyway, cf. 1).

The main reason changing H for D might change the efficiency of a proton pump is probably more in the change in the rate of acid/base reactions that attach or detach the H+/D+ to the various carrier molecules, and this happens because the change in mass changes the vibrational frequency of the O-H/O-D or N-H/N-D bonds that have to break or form during these reactions. That, in turn, changes the amount of energy that needs to be supplied to make or break the bond. There are almost certainly additional subtle chemical dynamic effects -- it's a complicated quantum problem, on which you could spend tons of money and research time.

I'm also a priori doubtful that it's known that the primary effect of D/H substitution is on proton pumps. Since acid/base reactions are ubiqituous in biochemistry, and each of these involves the making or breaking of an O-H/O-D or N-H/N-D bond, there are zillions of other places that could easily be more important.

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Thanks for the correction.

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