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New evidence shows water separates into two different liquids at low temperature
- exmadscientist 4y agoEvidence? > computer simulations > model > model > computational work > computational evidence > colloidal model I'm sorry, theory's great and all, but I'm not interested. Call me when you see this in water not dreamed up in silico, okay? Yeah, I know, supercritical is hard, but... that's kind of the point, yeah? Why trust your model if we know this stuff is hard? Why care if it can never be realized? (Okay, you got me, I'm a constructivist too.) (Must every press release by a British university be trash?)
- indymike 4y ago> Call me when you see this in water not dreamed up in silico, okay? The article, surprisingly was pretty clear about this. The headline? Pretty sensationalist. > (Must every press release by a British university be trash?) This has been the bane of science for as long as science has been around: How do you take something that isn't particularly interesting to laypersons and help them understand how important this little micro-bit of progress might be... on not be... It's hard.
- jaywalk 4y agoThis little micro-bit of progress simply is not important to laypersons. I'm sure it's interesting to people in the field, but otherwise it's nothing.
- indymike 4y ago> This little micro-bit of progress simply is not important to laypersons Yes. Unfortunately, a little press goes a long way in getting funded, so we'll all be reading these over-hyped science press releases for a long time.
- exmadscientist 4y ago> This has been the bane of science for as long as science has been around: How do you take something that isn't particularly interesting to laypersons and help them understand how important this little micro-bit of progress might be... on not be... It's hard. I mean, I've seen my own work go through the Science News Cycle ( https://phdcomics.com/comics/archive.php?comicid=1174 https://phdcomics.com/comics/archive.php?comicid=1174 ). I know what it's like. I'm just pointing out that British universities have a reputation for being absolutely terrible about this, to the degree that there's no point trusting a single thing their PR departments say anymore.
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- arrrg 4y agoIt seems the article extremely clearly communicates (as your plentiful quotes aptly demonstrate) that the evidence in question is a computational model. I do not get your point about this being bad science communication at all. Your own quotes demonstrate that the press release is crystal clear about the type of evidence. Your beef is with the science, not the communication. And you shouldn’t mix those two up.
- exmadscientist 4y ago> Your beef is with the science, not the communication. And you shouldn’t mix those two up. No, my beef is that communicating this was irresponsible because it does not represent meaningful progress in an accurate understanding of the physics of water, and thus no impression should be given that it does. Science grows through communication. The two are not separable.
- throwawaymaths 4y agoI am someone that regularly rails against in silico work, but come on. Treat this as a sanity check to start understanding 1. if the colloidal thought model explains unexplained observables 2. If the colloidal model makes predictions not observed yet. It might be too harsh to say this is not a meaningful advance. The system may be too difficult to make predictions without a computer, so having a thought model is useless. Now that we have a computer model, we can start doing experimental work that we wouldn't have chosen to do otherwise.
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- verisimi 4y agoI couldn't agree more. There is no evidence here. There is a model of water that apparently does something. Like FIFA22 (the game) is a model of the football (soccer) teams. But the model doesn't mean this can be translated to reality. And at least with FIFA22 you can check against reality for accuracy!
- Koshkin 4y ago> Evidence >> computer simulations But we live inside a computer, didn’t you know that? That the Universe itself is one big computer (and physics is computation)? A 42-bit one, unlike your fancy laptops…
- seba_dos1 4y ago> Call me when you see this in water not dreamed up in silico, okay? But it's you who's calling.
- mdaniel 4y ago> New evidence > ... > The team has used computer simulations to help explain what features distinguish the two liquids at the microscopic level I regrettably(?) don't have the physics background to interpret the actual paper (linked in the sibling comment), but saying "computer simulations" are "evidence" seems suspect to me
- galaxyLogic 4y agoEvidence is not proof, it is evidence. It is still valuable because it can guide the way to experiments that give us empirical proof, or refutation of the conjecture.
- hackernewds 4y agoIt behooves the authors to present the limitations of the study. Lay people, unfortunately the majority, will interpret this to be definitive.
- thfuran 4y ago>Lay people, unfortunately the majority, will interpret this to be definitive. They're not the target audience of scientific papers.
- feet 4y agoOn top of that, the linked article is simply a press release and not the research paper itself. Papers usually list limitations and such, that's very normal
- salahaldden422 4y ago
- gregoryl 4y agoThis leads me to a different path. Some (most?) papers require an almost absurd amount of context; in the extremes, single digit audiences with the knowledge to understand. Perhaps putting that context into publications would be more effective?
- sidlls 4y agoNature article link: https://www.nature.com/articles/s41567-022-01698-6 https://www.nature.com/articles/s41567-022-01698-6
- colinsane 4y ago> The researchers used a colloidal model of water in their simulation, and then two widely used molecular models of water. Colloids are particles that can be a thousand times larger than a single water molecule. By virtue of their relatively bigger size, and hence slower movements, colloids are used to observe and understand physical phenomena that also occur at the much smaller atomic and molecular length scales. > Dr Chakrabarti, a co-author, says: “This colloidal model of water provides a magnifying glass into molecular water, and enables us to unravel the secrets of water concerning the tale of two liquids.” this seems backward to me? the colloidal model sounds like a higher level model of molecular water: the opposite of a magnifying glass. or is it that they model several molecules within the context of a single colloid, and by modeling only one colloid instead of a larger volume it becomes computationally feasible to use a more detailed model of the molecular behavior within that small space?
- throwawaymaths 4y agoThe key preposition being "into". It gives us the ability to peer into molecular water [from our macroscopic perspective]
- quickthrower2 4y agoI wonder if this has anything at all to do with a pool of cold water at the bottom being 4 degrees C. (because at that temperature you have maximum density)
- FpUser 4y agoInteresting. Some enterprising souls will read it as well. Next thing I'll be receiving spam mail offering me to buy some "entangled water" to treat all my ills.
- handojin 4y ago(Cough) homeopathy (cough) Give 'em five hot minutes...
- salahaldden422 4y ago
- armchairhacker 4y agoSee also: heavy water (https://en.wikipedia.org/wiki/Heavy_water https://en.wikipedia.org/wiki/Heavy_water). Not so novel but still interesting
- slyrus 4y agoSo you're saying there's a chance for ice-nine?
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- kallistisoft 4y agoIce IX already exists :) https://en.wikipedia.org/wiki/Ice_IX https://en.wikipedia.org/wiki/Ice_IX
- kazinator 4y agoA new phase of article has been found at Birmingham in which, at a pressure of 800 words, key interstitial details disappear from the lexical lattice. In one example, the summary of a topic about two different forms of liquid water was found to allude to evidence of their existence coming from a computer simulation, yet without giving away the slightest hint at the expected temperature and pressure ranges at which these forms are expected to actually occur.
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- blix 4y ago> yet without giving away the slightest hint at the expected temperature and pressure ranges at which these forms are expected to actually occur. If it makes you feel better, this information isn't even clearly presented in the paper :) For computational studies like this, one should generally assume that any explicit 'Temperature' or 'Pressure' is a fiction. The important things are the shape of the trends in behavior with T and P. But as this behavior is dependent on a number of other semi-arbitrary parameters, the actual values of T and P themselves with the simulation probably do not map particuarly well to real life. Also, physicists like to use reduced unitless parameters (e.g. this paper uses T* = kT/e_BB, where e_BB is an energy parameter used in the colloidal model). This is convenient for math, and also keeps pesky reality separate from elegant models.
- askvictor 4y agoI'm curious about all the hate for computational science in this topic; of all the places on the internet. By all means critique the model and the simulation, but the idea of simulation itself as a scientific process?
- thatguy0900 4y agoThere a lot of hate because the people here know how easily biased and misleading these models are. Simulation is fine, simulation with no ability to do it in real life or prove it and then claiming it as evidence for anything is probably very silly.
- fsckboy 4y ago> There a lot of hate because the people here know how easily biased and misleading these models are...simulation with no ability to do it in real life or prove it and then claiming it as evidence for anything is probably very silly... ... unless it's climate science, then you gotta believe it.
- vgatherps 4y ago> There a lot of hate because the people here know how easily biased and misleading these models are If only they had thought to ask HN whether it was useful. People doing this are EXCEPTIONALLY aware of the drawbacks and limitations of what they're doing. Nobody in the scientific world is under the impression that a simulation on a large approximation of molecules could be used to say "hey so water actually does behave exactly this way". If you go read the actually paper and not the press release the abstract pretty much says "This phase transition is observed in a few distinct models of water, so it's probably useful to try and understand this further" The self aggrandising press release and statements from the scientists are pretty silly, sure, but the actual publication is not making claims about demonstrating that water does anything. And if you look at statements quoted in the press release, most statements are talking about how the work might provide direction on where to look later: It's just like the string theory or dark energy threads where all the software engineers who've read a pop science book pontificate about how all the physicists are just so obviously wrong and you need to do it in so-and-so way, bonus points if you get some sort of "maybe lambda calculus is the true representation of the universe"
- phendrenad2 4y agoSo they tested a liquid made from very large molecules, and are guessing that if the large molecules do X, then water molecules will also do X. So interesting results, and there's more research to be done.
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- mikewarot 4y agoEvidence comes from experiments, not simulations. You don't get to overload the word "evidence" in this way, not on my watch. A model can't produce evidence, it can only predict its possibility, and give hints to the experimenter on where to find it.
- okamiueru 4y agoRight on. "Facts or observations presented in support of an assertion". Maybe it changes once we have a complete and exact model of the physical reality. Until then...
- longcommonname 4y agoModels based on our understanding of the world provide a level of certainty lower than experimentation but still scientifically valid. Discoveries are often statistical in their nature about how uncertain the are.
- efitz 4y agoI hope they don’t accidentally invent ice-9.
- cosmophany 4y agoIn response to those commentators puzzling over the evidential status of computer simulations, you should know that this is currently an open question being debated in the field of Epistemology of Measurement, which aims to give a rigorous account of what it means to `measure' something. It is not at all obvious that simulations should be excluded from the category of `evidence', especially when the simulation depends heavily on the input of observational data. Consider, for instance, using a simulation to interpolate the temperature in some location based on the actually observed temperatures in surrounding regions. Let's also not forget that modern precision measurement is highly dependent on making detailed computer models to predict how the measuring instruments function, blurring the line somewhat between simulation and measurement. Some references: [1] Nature: "Virtually a measurement", by Wendy Parker. https://www.nature.com/articles/s41567-020-01138-3 https://www.nature.com/articles/s41567-020-01138-3 [2] Stanford Encyclopedia of Philosophy entry on "Measurement in Science": https://plato.stanford.edu/entries/measurement-science/#EpiMea https://plato.stanford.edu/entries/measurement-science/#EpiM... [3] "The problem of observational grounding: how does measuring generate evidence?" by Eran Tal. Video: https://vimeo.com/184697369 https://vimeo.com/184697369 Article (open access): https://iopscience.iop.org/article/10.1088/1742-6596/772/1/012001/meta https://iopscience.iop.org/article/10.1088/1742-6596/772/1/0...