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.
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
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.
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“
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).
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.
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).
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.
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.
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)
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?
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.
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.
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?
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.
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.
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
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.
“ 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]
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. :)
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!
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.
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.
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.
“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.
"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."
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.
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".
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.
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.
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.
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.'
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.
"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?
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.
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?
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.
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.
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?")
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/
_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.
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.
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.
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.
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
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.
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.
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).
> 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...
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).
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.
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.
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).
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.
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.
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.
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.
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)
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
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.
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
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.
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?
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.
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.
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.)
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.)
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?
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.
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.
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.)
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...
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.
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.
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.
Funny enough, heavy water actually tastes better. It has a "subtle sweetness". https://blog.pnas.org/2021/04/heavy-water-tastes-sweeter/#:~:text=Now%2C%20an%20international%20team%20of,like%20Sweet%27n%20Low.%E2%80%9D
I assume most of the taste of water is due to the impurities, salts and such that are dissolved in it.
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).
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
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.
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“
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).
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.
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).
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.
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.
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)
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
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.
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.
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?
Deuterated water is still water. Maybe the paranoid chemists are only checking for other elements.
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.
Should've done an NMR to explain the inscrutable GC-MS results!
Naturally, but alas it wouldn't provide any revealing evidence, as the deuterated hydrogens would be invisible.
Yeah but the splitting patterns would all be fucked.
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.
Nice
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!
Especially easy with the time gizmo!
At this point the time gizmo would be a requirement
I had the same thought. Just pause time and introduce a single high dose of carbon steel between the clavicles.
Use the time gizmo to accelerate a kitchen knife to 0.99c and it doesn't matter where in the facility you do it.
It does matter if you want to survive. I expect 0.99c would trigger a nuclear explosion.
Obligatory: https://what-if.xkcd.com/1/
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
Reminded me of the "Soviets just used a pencil" thing.
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.
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]
“ 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]
It decreases cholesterol, blood pressure, lowers bodyfat, AND tones your belly! Scientifically demonstrated! In rats! Only ninety nine ninety nine.
I'd be perfectly healthy - if only I were a depressed, overweight rat being given light water to drink as part of an experiment 😀
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.
I'm Hungarian and I'm confused. What's the issue here?
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. :)
Google hasn't set riddles for over a decade. Now it's a standard coding interview.
How many many man hole covers in the US?
(About 12 million. Next question.)
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
Did changing the name increase the number of women who wanted jobs that involved using them?
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.
I suggest: https://en.wikipedia.org/wiki/Wookey_Hole
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.
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.
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.
“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.
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.
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.
I'd be impressed by that answer if I were interviewing you.
"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."
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.
https://condor.depaul.edu/dallbrit/extra/360/420_22MONK.HTM
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".
I am always in the same space and time as myself.
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.
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.
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.
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.'
Why would you expect random trivia questions to provide a better signal than something that's at least tangentially related to the job?
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.
"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?
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.
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?
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.
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.
Thank you for the explanations, I also did not get why they were opposite processes, now it is very clear.
Scott basically says later that the Hunza argument is not actually very good.
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?")
I'm surprised you didn't explore the implications of this on climate change. For a second I thought you were heading that direction.
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/
_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
"Anna Friel and Christoph Bach, who plays Heisenberg ..."
Until you look, you don't know who is playing Heisenberg in any given scene ...
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.
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.
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.
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).
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
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.
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.
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).
> 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...
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).
Counterargument: Searching Amazon for "deuterium depleted water" turned up "Liquid Death Mountain Water" (https://amzn.to/3jUJSQv).
And it’s from “Whole Foods” so it’s gotta be good for you.
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.
Great story!
> 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.
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).
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
Shrimp!
> And there's the oncological argument (that's the St. Anselm thing, right?)
I see what you did there...
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.
> 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.
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
Well, I guess we just need to stick a few recent corpses in dehydrators and measure weight loss.
Science!
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)
See https://en.wikipedia.org/wiki/Body_water
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.
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
What is your theory for why the lab animals have gotten fat along with their handlers despite no change in diet?
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.
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
“ Could also be pesticides! ”
That’s his claim! Some new chemical in the food chain.
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.
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?
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.
Oooooh, okay. That makes sense, thanks.
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.
I think we've found the answer.
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.)
Rationally, without an actual time limit here there's minimal reason not to kill Castro here as well surely?
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.)
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?
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.
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.
Probably just crack open a window, if you’re already in space. Or get a pet rock made from old watch coatings!
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.)
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...
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.
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.