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Specifically, from the article: > New measurements of that weak background glow show that the unseen galaxies are less plentiful than some theoretical studies

Specifically, from the article: > New measurements of that weak background glow show that the unseen galaxies are less plentiful than some theoretical studies suggested, numbering only in the hundreds of billions rather than the previously reported two trillion galaxies. We used to think that we couldn't see 90% of the galaxies/stars, this study proposes that we can't say about ½ of the galaxies/stars.

dclowd9901 6y ago
One of my favorite statistics is the "we don't even know what we don't know" statistic. Every time, it's a session of imagination trying to figure out how they figured that out.
- iso1631 6y ago
  Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tends to be the difficult ones That statement was ridiculed at the time, and not by people pointing out the unknown knowns https://en.wikipedia.org/wiki/There_are_known_knowns https://en.wikipedia.org/wiki/There_are_known_knowns
  - detritus 6y ago
    I never unserstood that ridicule - I always thought it was an apt-description of the levels of ignorance we can honestly presume for ourselves. Refreshingly honest of Rumsfeld, if anything.
    - mncharity 6y ago
      > I never unserstood that ridicule Perhaps try the response with a different issue and respondent swapped in? Q: There are reports there is no evidence of a direct link between [...] Vaccination-autism policy advocate: Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; [...] But there are also unknown unknowns—the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tends to be the difficult ones. Q: The real situation is worse than the facts show? (later NATO press event) UFO-abduction policy advocate: The message is that there are no "knowns." [...] Absence of evidence is not evidence of absence.[1] [1] https://www.nato.int/docu/speech/2002/s020606g.htm https://www.nato.int/docu/speech/2002/s020606g.htm
      - TeMPOraL 6y ago
        The ridicule such as in the examples reveals epistemic immaturity. The {known, unknown} X {knowns, unknowns} classification is a statement of existence. Just because any of the four combinations here exist, doesn't mean they're equally likely. The error in reasoning such vaccination-autism policy advocate makes is: they correctly observe the possibility of unknown unknowns in vaccination, but then they incorrectly assume that a) they're likely, significant and impactful, and b) they have to do with body's reaction to the vaccine. (Hell, arguably the primary unknown unknown in vaccination was the degree to which anti-vaccination memes will spread and prevent populations from being effectively protected.) Additionally, the focus on this is itself a sign of immaturity. The adult answer here to note that various kinds of knowns/unknowns exist, and then talk about how we can make turn unknowns into knowns, how to estimate the importance and impact of the unknowns, and how to deal with them if they happen. > UFO-abduction policy advocate: (...)Absence of evidence is not evidence of absence. Actually, absence of evidence is evidence of absence. If your hypothesis predicts something should happen, and it does not happen, it does count as evidence against your hypothesis.
        mncharity 6y ago
        I agree with most of that. But those questionable replies? They're Rumsfeld's. > Actually, absence of evidence is evidence of absence. Agreed. And yet Rumsfeld says, in the linked press event transcript, > Now what is the message there? The message is that there are no "knowns." There are thing we know that we know. There are known unknowns. That is to say there are things that we now know we don't know. But there are also unknown unknowns. There are things we don't know we don't know. So when we do the best we can and we pull all this information together, and we then say well that's basically what we see as the situation, that is really only the known knowns and the known unknowns. And each year, we discover a few more of those unknown unknowns. > It sounds like a riddle. It isn't a riddle. It is a very serious, important matter. > There's another way to phrase that and that is that the absence of evidence is not evidence of absence. It is basically saying the same thing in a different way. Simply because you do not have evidence that something exists does not mean that you have evidence that it doesn't exist. And yet almost always, when we make our threat assessments, when we look at the world, we end up basing it on the first two pieces of that puzzle, rather than all three. [emphasis mine] > The ridicule such as in the examples reveals epistemic immaturity. Almost. The example replies, were Rumsfeld's, at the two events. Extracts, but I suggest fair ones. The example questions were paraphrased. Then I prefaced the alternate contexts, hoping to better illuminate the flaws in the replies. The epistemic immaturity you observe, is a property of Rumsfeld's replies, and what I sought to illustrate, in support of GGP seeking to understand the historical ridicule. I'm sorry that ended up less than clear.

dclowd9901 6y ago

One of my favorite statistics is the "we don't even know what we don't know" statistic. Every time, it's a session of imagination trying to figure out how they figured that out.

iso1631 6y ago
Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns—the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tends to be the difficult ones That statement was ridiculed at the time, and not by people pointing out the unknown knowns https://en.wikipedia.org/wiki/There_are_known_knowns https://en.wikipedia.org/wiki/There_are_known_knowns
- detritus 6y ago
  I never unserstood that ridicule - I always thought it was an apt-description of the levels of ignorance we can honestly presume for ourselves. Refreshingly honest of Rumsfeld, if anything.
  - mncharity 6y ago
    > I never unserstood that ridicule Perhaps try the response with a different issue and respondent swapped in? Q: There are reports there is no evidence of a direct link between [...] Vaccination-autism policy advocate: Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; [...] But there are also unknown unknowns—the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tends to be the difficult ones. Q: The real situation is worse than the facts show? (later NATO press event) UFO-abduction policy advocate: The message is that there are no "knowns." [...] Absence of evidence is not evidence of absence.[1] [1] https://www.nato.int/docu/speech/2002/s020606g.htm https://www.nato.int/docu/speech/2002/s020606g.htm
    - TeMPOraL 6y ago
      The ridicule such as in the examples reveals epistemic immaturity. The {known, unknown} X {knowns, unknowns} classification is a statement of existence. Just because any of the four combinations here exist, doesn't mean they're equally likely. The error in reasoning such vaccination-autism policy advocate makes is: they correctly observe the possibility of unknown unknowns in vaccination, but then they incorrectly assume that a) they're likely, significant and impactful, and b) they have to do with body's reaction to the vaccine. (Hell, arguably the primary unknown unknown in vaccination was the degree to which anti-vaccination memes will spread and prevent populations from being effectively protected.) Additionally, the focus on this is itself a sign of immaturity. The adult answer here to note that various kinds of knowns/unknowns exist, and then talk about how we can make turn unknowns into knowns, how to estimate the importance and impact of the unknowns, and how to deal with them if they happen. > UFO-abduction policy advocate: (...)Absence of evidence is not evidence of absence. Actually, absence of evidence is evidence of absence. If your hypothesis predicts something should happen, and it does not happen, it does count as evidence against your hypothesis.
      - mncharity 6y ago
        I agree with most of that. But those questionable replies? They're Rumsfeld's. > Actually, absence of evidence is evidence of absence. Agreed. And yet Rumsfeld says, in the linked press event transcript, > Now what is the message there? The message is that there are no "knowns." There are thing we know that we know. There are known unknowns. That is to say there are things that we now know we don't know. But there are also unknown unknowns. There are things we don't know we don't know. So when we do the best we can and we pull all this information together, and we then say well that's basically what we see as the situation, that is really only the known knowns and the known unknowns. And each year, we discover a few more of those unknown unknowns. > It sounds like a riddle. It isn't a riddle. It is a very serious, important matter. > There's another way to phrase that and that is that the absence of evidence is not evidence of absence. It is basically saying the same thing in a different way. Simply because you do not have evidence that something exists does not mean that you have evidence that it doesn't exist. And yet almost always, when we make our threat assessments, when we look at the world, we end up basing it on the first two pieces of that puzzle, rather than all three. [emphasis mine] > The ridicule such as in the examples reveals epistemic immaturity. Almost. The example replies, were Rumsfeld's, at the two events. Extracts, but I suggest fair ones. The example questions were paraphrased. Then I prefaced the alternate contexts, hoping to better illuminate the flaws in the replies. The epistemic immaturity you observe, is a property of Rumsfeld's replies, and what I sought to illustrate, in support of GGP seeking to understand the historical ridicule. I'm sorry that ended up less than clear.