5 ms·

Here's what worries me about this type of extrapolation: "The researchers also compared salt samples from other halite deposits of different ages — including t

Here's what worries me about this type of extrapolation: "The researchers also compared salt samples from other halite deposits of different ages — including the modern day — when oxygen concentrations were known and found their results matched up with known concentrations. That gave them confidence in their result, they said." OK, so you take a recent sample and it matches up. Great. But this seems to assume there is some sort of barrier at the atomic level that "traps" the atmosphere at the time the salt crystals were formed and that time and pressure will never have an impact on what components of the atmosphere remain in the salt crystal.

phaemon 10y ago
I suppose that's the kind of question Prof Blamey might have considered when he was a first year student back around 1975. He probably knows what he's doing by now though.
- IanDrake 10y ago
  Well if he knows what he's doing, who am I to question any unexplained assumptions made in the article.
  - lorenzhs 10y ago
    In "Random Guy from the Internet -vs- Professor on the Subject", you can't really blame anyone for giving the scientists the benefit of the doubt. The paper is open access, btw, maybe they addressed your question or provided a citation? You can read it at http://geology.gsapubs.org/content/early/2016/07/08/G37937.1.full.pdf http://geology.gsapubs.org/content/early/2016/07/08/G37937.1...
    - IanDrake 10y ago
      I'm surprised (but not really) at the amount of resistance to to questioning these results, when at the very least you have to agree with the following: This method AND the prior method can't BOTH be right. That means at least one of them is WRONG. Had I questioned the prior method's claims and techniques yesterday I would have had the same response from the same people. Science (to some) is still about questioning everything. It scares me how many people on HN have lost sight of that.
      - reitanqild 10y ago
        Smile and upvote from me on this.
      - mikeash 10y ago
        Being right for the wrong reasons doesn't win you any points. If you had questioned the prior method's claims and techniques yesterday based on this same sort of "what about this obvious problem?" then you would have had the same response and deservedly so. If I declare that the Earth is round because I drew a circle on a piece of paper, I can't wave away criticism of my method just because the result is correct.
        IanDrake 10y ago
        No, I'm right for the right reason. All extrapolations of this type are difficult to prove out. They are based on a lot of assumptions. Those assumptions may not all be right and some critical components might be missing. The model being used to compute slippage over time might be overfit to the parameters. If I declared the world to be flat then proved it by going to a truly flat field to provide parameters to a mathematical model that showed I was correct, it wouldn't make me correct no matter how convincing my credentials or my paper.
        mikeash 10y ago
        You have no idea if you're right or if this conclusion is actually correct. If the conclusion is wrong, you have no idea if it's wrong because of the problem you posted, or if it's wrong because of something completely different. Virtually all science is wrong in some respect. You can get a great batting average by just saying "no, wrong" to everything you see. That doesn't make it useful, nor does it make your reasons for saying "wrong" correct.
      - lorenzhs 10y ago
        Your comment didn't read like an ode on the scientific method to me. Instead, I saw a cheap dismissal of the research in it. And the article even addresses your concerns: > "They're using an indirect method," he said. "We're using a direct measurement and we're measuring from a mineral that has actually trapped atmosphere. It's a huge step forward, really." The previous number was an estimate derived from other, indirect findings. In other words, "given what we know, 2.x% O₂ seems most likely and plausible" versus "we dug up some salt with air from the time trapped in it, and measured 10.9% O₂". So they did exactly what you're referring to: questioning previous results and giving evidence to support their claims. And yet you question their results without providing any evidence. Your criticism boils down to "well this isn't what we used to believe". How else could science progress if not by surpassing what was previously known or accepted as the best answer to date? Science is about questioning stuff, coming up with new ideas and backing them up with evidence, not about making dismissive comments on the internet.
  - bsder 10y ago
    First, you need to go read the actual paper, rather than some journalistic paraphrase, and them come back. After that, you can ask a specific question about what was done and what was not done. Generally with an eye toward a useful mechanism that might explain things. Then, you need to come up with a prediction based upon that question that can be tested. At that point, you are contributing to the discussion. "Could invisible sky fairies could have contaminated the results?" is not a useful question. "Is it possible that nuclear decay could have transmuted something into oxygen trapped in NaCl? (answer, no, for various reasons)" is at least in the vein of a useful question.
- pbhjpbhj 10y ago
  Oh great an appeal to authority that'll set it right. /s If what you say is correct then there's most likely a paper that's been widely cited and remains unfalsified that shows there aren't any changes in the ratios of gases in these crystal interstices (or the changes are well known and quantifiable). Such a citation would be a suitable rebuff.
  - mikeash 10y ago
    IMO an appeal to authority is a perfectly reasonable response to an assumption of incompetence. It's tiresome to always see comments assuming that such-and-such science is flawed because a mainstream news article doesn't spell out every single detail. If it were phrased more neutrally, like "I'm amazed that this stuff can be contained without any contamination for hundreds of millions of years, how do they know that it works that way?" I wouldn't have a problem with it. Start assuming that you've missed something, not the scientist who does this for a living. Maybe the scientist has missed something, they're certainly not perfect, but to me it's ridiculous and counterproductive to be "worried" about the results of years of professional work based on one popular article and five minutes of thought (if that).
    - jdmichal 10y ago
      If your complaint is not the message, but rather the phrasing, then I'd say that you're not being very charitable.
      - mikeash 10y ago
        It's both. The phrasing contains a message of "these scientists didn't consider this obvious problem."
        jdmichal 10y ago
        That's fair. To the point, this person [0] doesn't seem to be having any issues with downvotes, even though the comment raises the same basic issue -- the reliability of the crystalline entrapment. [0] https://news.ycombinator.com/item?id=12186872 https://news.ycombinator.com/item?id=12186872
zdkl 10y ago
I don't know who downvotes this because parent does have a point: there are extensive chemical transfers involved in the creation of minerals and crystals, it's not obvious at all that the atmospheric bubbles where chemically isolated from the encasing crystal afaict
- akamaka 10y ago
  I don't even need to read the article or paper to see that the commenter didn't think through what he was saying. He specifically uses a quote that says "different ages - including the modern day" were used, but then suggests that the researches only used one "recent" sample.
- maxerickson 10y ago
  I didn't down vote the above comment, but when the paper is available, complaints should usually be about something specific in the paper, not hand wavy concerns about methodology. http://geology.gsapubs.org/content/early/2016/07/08/G37937.1.full.pdf http://geology.gsapubs.org/content/early/2016/07/08/G37937.1... The paper discusses the type of crystal they studied and how they formed (and cites further work on those topics).
chris_va 10y ago
Not a bad question, and they attempt to address it in the paper with their multi-sample calibration: It is highly unlikely that oxygen could have been injected into halite inclusions without evidence of morphochemical disruption, and we must conclude that Cretaceous atmospheric oxygen was most likely higher than present-day levels. The tests performed on the modern, Messinian, and Cretaceous halites support halite’s robustness as an atmospheric oxygen archive.

phaemon 10y ago

I suppose that's the kind of question Prof Blamey might have considered when he was a first year student back around 1975. He probably knows what he's doing by now though.

IanDrake 10y ago
Well if he knows what he's doing, who am I to question any unexplained assumptions made in the article.
- lorenzhs 10y ago
  In "Random Guy from the Internet -vs- Professor on the Subject", you can't really blame anyone for giving the scientists the benefit of the doubt. The paper is open access, btw, maybe they addressed your question or provided a citation? You can read it at http://geology.gsapubs.org/content/early/2016/07/08/G37937.1.full.pdf http://geology.gsapubs.org/content/early/2016/07/08/G37937.1...
  - IanDrake 10y ago
    I'm surprised (but not really) at the amount of resistance to to questioning these results, when at the very least you have to agree with the following: This method AND the prior method can't BOTH be right. That means at least one of them is WRONG. Had I questioned the prior method's claims and techniques yesterday I would have had the same response from the same people. Science (to some) is still about questioning everything. It scares me how many people on HN have lost sight of that.
    - reitanqild 10y ago
      Smile and upvote from me on this.
    - mikeash 10y ago
      Being right for the wrong reasons doesn't win you any points. If you had questioned the prior method's claims and techniques yesterday based on this same sort of "what about this obvious problem?" then you would have had the same response and deservedly so. If I declare that the Earth is round because I drew a circle on a piece of paper, I can't wave away criticism of my method just because the result is correct.
      - IanDrake 10y ago
        No, I'm right for the right reason. All extrapolations of this type are difficult to prove out. They are based on a lot of assumptions. Those assumptions may not all be right and some critical components might be missing. The model being used to compute slippage over time might be overfit to the parameters. If I declared the world to be flat then proved it by going to a truly flat field to provide parameters to a mathematical model that showed I was correct, it wouldn't make me correct no matter how convincing my credentials or my paper.
        mikeash 10y ago
        You have no idea if you're right or if this conclusion is actually correct. If the conclusion is wrong, you have no idea if it's wrong because of the problem you posted, or if it's wrong because of something completely different. Virtually all science is wrong in some respect. You can get a great batting average by just saying "no, wrong" to everything you see. That doesn't make it useful, nor does it make your reasons for saying "wrong" correct.
    - lorenzhs 10y ago
      Your comment didn't read like an ode on the scientific method to me. Instead, I saw a cheap dismissal of the research in it. And the article even addresses your concerns: > "They're using an indirect method," he said. "We're using a direct measurement and we're measuring from a mineral that has actually trapped atmosphere. It's a huge step forward, really." The previous number was an estimate derived from other, indirect findings. In other words, "given what we know, 2.x% O₂ seems most likely and plausible" versus "we dug up some salt with air from the time trapped in it, and measured 10.9% O₂". So they did exactly what you're referring to: questioning previous results and giving evidence to support their claims. And yet you question their results without providing any evidence. Your criticism boils down to "well this isn't what we used to believe". How else could science progress if not by surpassing what was previously known or accepted as the best answer to date? Science is about questioning stuff, coming up with new ideas and backing them up with evidence, not about making dismissive comments on the internet.
- bsder 10y ago
  First, you need to go read the actual paper, rather than some journalistic paraphrase, and them come back. After that, you can ask a specific question about what was done and what was not done. Generally with an eye toward a useful mechanism that might explain things. Then, you need to come up with a prediction based upon that question that can be tested. At that point, you are contributing to the discussion. "Could invisible sky fairies could have contaminated the results?" is not a useful question. "Is it possible that nuclear decay could have transmuted something into oxygen trapped in NaCl? (answer, no, for various reasons)" is at least in the vein of a useful question.
pbhjpbhj 10y ago
Oh great an appeal to authority that'll set it right. /s If what you say is correct then there's most likely a paper that's been widely cited and remains unfalsified that shows there aren't any changes in the ratios of gases in these crystal interstices (or the changes are well known and quantifiable). Such a citation would be a suitable rebuff.
- mikeash 10y ago
  IMO an appeal to authority is a perfectly reasonable response to an assumption of incompetence. It's tiresome to always see comments assuming that such-and-such science is flawed because a mainstream news article doesn't spell out every single detail. If it were phrased more neutrally, like "I'm amazed that this stuff can be contained without any contamination for hundreds of millions of years, how do they know that it works that way?" I wouldn't have a problem with it. Start assuming that you've missed something, not the scientist who does this for a living. Maybe the scientist has missed something, they're certainly not perfect, but to me it's ridiculous and counterproductive to be "worried" about the results of years of professional work based on one popular article and five minutes of thought (if that).
  - jdmichal 10y ago
    If your complaint is not the message, but rather the phrasing, then I'd say that you're not being very charitable.
    - mikeash 10y ago
      It's both. The phrasing contains a message of "these scientists didn't consider this obvious problem."
      - jdmichal 10y ago
        That's fair. To the point, this person [0] doesn't seem to be having any issues with downvotes, even though the comment raises the same basic issue -- the reliability of the crystalline entrapment. [0] https://news.ycombinator.com/item?id=12186872 https://news.ycombinator.com/item?id=12186872

zdkl 10y ago

I don't know who downvotes this because parent does have a point: there are extensive chemical transfers involved in the creation of minerals and crystals, it's not obvious at all that the atmospheric bubbles where chemically isolated from the encasing crystal afaict

akamaka 10y ago
I don't even need to read the article or paper to see that the commenter didn't think through what he was saying. He specifically uses a quote that says "different ages - including the modern day" were used, but then suggests that the researches only used one "recent" sample.
maxerickson 10y ago
I didn't down vote the above comment, but when the paper is available, complaints should usually be about something specific in the paper, not hand wavy concerns about methodology. http://geology.gsapubs.org/content/early/2016/07/08/G37937.1.full.pdf http://geology.gsapubs.org/content/early/2016/07/08/G37937.1... The paper discusses the type of crystal they studied and how they formed (and cites further work on those topics).

chris_va 10y ago

Not a bad question, and they attempt to address it in the paper with their multi-sample calibration: It is highly unlikely that oxygen could have been injected into halite inclusions without evidence of morphochemical disruption, and we must conclude that Cretaceous atmospheric oxygen was most likely higher than present-day levels. The tests performed on the modern, Messinian, and Cretaceous halites support halite’s robustness as an atmospheric oxygen archive.