tag:blogger.com,1999:blog-7721098568390636553.post1149453307736116812..comments2023-06-06T07:02:56.002-07:00Comments on The Spark of Reason: When Listening to Scientists, Be Sure to Check Their ShoesDavehttp://www.blogger.com/profile/18290594860469294453noreply@blogger.comBlogger23125tag:blogger.com,1999:blog-7721098568390636553.post-89597449587409451312011-06-22T20:24:28.467-07:002011-06-22T20:24:28.467-07:00@Ms X, Okay, Biology IS my strong suit (as opposed...@Ms X, Okay, Biology IS my strong suit (as opposed to physics), so I'm going to jump in on this. First of all, one does not need to agree on a mechanism to accept evolution as a fact. Innumerable fossils show it happened in the past and we can observe it occurring constantly in the present, so we can, indeed, accept evolution as a fact as much as we can accept that the sun is the center of our solar system. Secondly,natural selection is by no means "merely one suggested (and increasingly dismissed) causal mechanism", as you say, except perhaps by creationists and others of their ilk. Scientists may tweak it, as they tend to tweak all theories (and natural selection is a theory, not an hypothesis)as new evidence rolls in, but the basic concept--as outlined by Darwin and further refined by many in the 150+ years since, continues to provide the most plausible mechanism and, as far as I know, no one has yet come up with one that explains the evidence better. Natural Selection is and will continue to be the (one) theory that scientists who work in the field accept as the most likely mechanism--unless and until someone uses it to make a prediction that turns out to be false, and that hasn't happened yet. Richard Dawkins'book, "The Greatest Show on Earth", is a terrific explanation of all the avenues of evidence for evolution and Natural Selection.Margaretrchttps://www.blogger.com/profile/17160051189722454020noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-18243787756532724282011-06-22T19:16:40.811-07:002011-06-22T19:16:40.811-07:00Thanks, Dave! You definitely are a Spark of Reason...Thanks, Dave! You definitely are a Spark of Reason. I am working my way through the article you linked (that's actually what I was thinking of when I mentioned "an earlier post"!)and it is very informative. I am not a physicist--my strong suit is more chemistry, particularly as it relates to biological systems, so it is going to take me a while to get through it. But I will persist. And I'll keep checking back here.Margaretrchttps://www.blogger.com/profile/17160051189722454020noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-74951116869340313412011-06-21T17:19:05.538-07:002011-06-21T17:19:05.538-07:00@Margaretrc
I think it's a reasonable hypothe...@Margaretrc<br /><br />I think it's a reasonable hypothesis that human activity *might* be having a significant effect on global climate. But there's an awful lot of "know what we don't know" in there, particularly considering that the Earth's climate has been all over the place in the past. I expect if we were to rigorously compare different hypotheses, we would not find one to be heavily favored.<br /><br />And comparing hypotheses as to the cause of climate change is somewhat academic. It does somewhat inform the hypothesis that humans might be able to effect a reversal, or at least slowing. But what we really need to do is make decisions on where to put resources. Do we continue on the current path and hope for the best? Do we put massive resources into trying to change the direction of climate change? Or do we make hedge our bets, and put some resources into getting ready in case the climate changes significantly regardless of anything people do? The bickering over whether or not "global warming" is anthropogenic or not misses the big picture on both sides.<br /><br />The Rocket Scientist's Journal I linked earlier in the comments is a great place to start. If nothing else, it shows just how complicated climate is, and how little we really know about it.Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-33698566876489283932011-06-21T11:26:27.733-07:002011-06-21T11:26:27.733-07:00I don't know if this comment thread is still o...I don't know if this comment thread is still open, but I'm going to try. Please help me understand your position on AGW. Are you skeptical that we humans have had anything to do with the current warming trend--that it is nothing more than a warming trend that is part of a natural process? Are you saying there is no point in trying to reverse our contribution--however small or big--to the greenhouse gases in the atmosphere? I am not looking to get into a debate here--I am keeping an open mind and I do trust not only your credentials, but your motives. I just want to learn. I did see an earlier post on sunspots (I think--it was late at night/early in the morning and my brain may have been a bit fuzzy)and Climate change and it certainly makes sense. My husband has pointed out something similar. Can you point me to some unbiased, reliable sources on this topic? We will be going on a "Global Warming" cruise to Alaska with the Skeptic Society in August and I do want to be "checking their shoes" so to speak. Despite their name, they don't seem to have a lot of skepticism re AGW--at least I haven't seen any. Likewise mainstream nutrition info., BTW, which is why I'm prepared to keep an open mind and will"check their shoes". Thanks, and I do enjoy your blog. Keep that information coming! PeggyMargaretrchttps://www.blogger.com/profile/17160051189722454020noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-57673260457324567522010-09-27T09:02:44.246-07:002010-09-27T09:02:44.246-07:00"I doubt that the people making key decisions...<i>"I doubt that the people making key decisions, like grounding airplanes, have anywhere near the mental analytic capabilities of a chess grandmaster. So they play CYA, and hide behind the word "might" without actually ever digging in to the details. For them, all "mights" are created equal, which leads to complete stupidity."</i><br /><br />I'm not sure the grounding was an example of CYA so much as an “OMG we never got around to calculating what level of volcanic (invisible) ash will damage planes to the extent of crashing them and killing lots of the public” -- who will raise bloody murder if such engine damage occurs again. (Stampeding the sheep, anyone?)<br /><br />They did, in fact, DO the calculations AFTER grounding (almost) all of Europe, and determined a level of risk and 'reward' that would allow (some) flights in many circumstances, not in others. (And if Katla blows, it's probably all over for a year of air travel in Europe! But at least that's (probably) provably not anthropogenic!)Elenornoreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-85624354191638051692010-08-21T06:18:04.515-07:002010-08-21T06:18:04.515-07:00Hi Dave,
I definitely agree that fitting the data...Hi Dave,<br /><br />I definitely agree that fitting the data is insufficient in and of itself for a theory, and that all observations must be taken into account. This sounds like it will be a useful read.<br /><br />Thanks!<br />ChrisChris Masterjohnhttps://www.blogger.com/profile/09922003080748568167noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-35387470677784482392010-08-08T10:49:25.318-07:002010-08-08T10:49:25.318-07:00Hi Chris.
You know, I dislike the term "stat...Hi Chris.<br /><br />You know, I dislike the term "statistical analysis". It sounds picky, I know, but a "statistic" is really just a number derived from data. There's nothing wrong with statistics per se, they just are what they are, and I think it's important to distinguish between analyses that are data-centric vs. model-centric. Frankly, I think an awful lot of confusion in nutrition and health has its roots here.<br /><br />Anyway, what we want to do is to quantitatively and transparently assess the plausibility of propositions based on information, e.g. "How much do I believe that saturated fat causes heart disease?" Part of this is obviously related to data, but the meat of the thing is really the model under test. In building models of the real world, we make choices about what include/exclude, postulate cause-effect relationships, etc. Ultimately we need to test the plausibility of this model, and want to update that plausibility as we gather new information.<br /><br />For instance, I can always come up with a model that fits the data perfectly ("pixies did it"). You can't reject this simply through the likelihood of the null hypothesis, since I can basically make that as small as I like by invoking pixie magic. Other judgments come into play, and these are necessarily subjective (unless you have some data that indicates pixies don't exist). The key is to make this subjectivity transparent and quantifiable, to the greatest extent possible. The recent dust-up with T. Colin Campbell is a nice illustration of the problems that arise when this sort of subjective judgment is locked up in someone's brain, rather than being performed in a manner which is consistent, repeatable, and transparent.<br /><br />Jaynes' "desiderata" would seem to outline the principles we desire:<br /><br />1) If a conclusion can be reasoned out in more than one way, then every possible way must lead to the same result.<br /><br />2) We always take into account all of the evidence relevant to a question. We do not arbitrarily ignore some of the information, basing our conclusions only on what remains. In other words, we must be completely non-ideological.<br /><br />3) Equivalent states of knowledge are represented by equivalent plausibility assignments. That is, if in two problems our state of knowledge is the same (except perhaps for the labeling of the propositions), then we must assign the same plausibilities in both.<br /><br />I've numbered these slightly differently than in Jaynes' book. We also want the framework to reflect "common sense", e.g. if the truth of A depends on the truth of B, and we find new information that makes B more plausible, then A should also be more plausible (and "not A" less plausible). Add to this the requirement that we quantify "plausibility" as a real number between 0 and 1, and you have the basis for Probability Theory. The rest of it is just math starting from these basic statements.Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-19263191733593146112010-08-08T10:03:24.817-07:002010-08-08T10:03:24.817-07:00Hi Dave,
Oh I definitely agree that scientists qu...Hi Dave,<br /><br />Oh I definitely agree that scientists quite frequently do not confine their interpretations to the limitations of their analysis (or to their study design).<br /><br />What type of statistical analysis is, in your view, required for scientific inference?<br /><br />ChrisChris Masterjohnhttps://www.blogger.com/profile/09922003080748568167noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-647614682476802962010-08-08T06:59:52.108-07:002010-08-08T06:59:52.108-07:00@Chris,
"I have never read a standard statis...@Chris,<br /><br />"I have never read a standard statistics text that advocates testing the research hypothesis directly or advocates using the rejection of the null hypothesis as proof or definitive confirmation of the research hypothesis."<br /><br />Agreed. But as with much of standard statistics, scientists are rather poor at confining their conclusions to the limitations of the analysis, probably in no small part because standard statistics doesn't provide the framework for the sort of inferential reasoning you want to do in science.Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-25421178424495814722010-08-07T20:32:30.707-07:002010-08-07T20:32:30.707-07:00In the statistics texts that I've read, it is ...In the statistics texts that I've read, it is the null hypothesis that is assumed "given" for the statistical test, not the research hypothesis. So if you hypothesize that the mean of A is different than the mean of B, your statistical test would be the null hypothesis that there is no difference between A and B. You then ask the question, if the null hypothesis is true, what is the likelihood of obtaining the observed difference in the means of A and B? If the likelihood is more than the proposed level of significance, often 95%, then you fail to reject the null hypothesis and conclude there is no evidence for your research hypothesis. However, if the likelihood is less than 95%, then you reject the null hypothesis, and you consider this support for the tenability of your research hypothesis.<br /><br />I have never read a standard statistics text that advocates testing the research hypothesis directly or advocates using the rejection of the null hypothesis as proof or definitive confirmation of the research hypothesis.<br /><br />ChrisChris Masterjohnhttps://www.blogger.com/profile/09922003080748568167noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-20240831502929702162010-06-11T05:44:48.549-07:002010-06-11T05:44:48.549-07:00@Mike,
Thank you for your comment. It serves as a...@Mike,<br /><br />Thank you for your comment. It serves as an excellent example of the level of rational discourse employed by supporters of anthropogenic global warming.Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-79304814200597228242010-06-10T18:21:13.393-07:002010-06-10T18:21:13.393-07:00Check your shoes too- It is the acceleration of cl...Check your shoes too- It is the acceleration of climate change that is the issue= always was. The damage from oil exploration and the faith of the Gulf after BP lack of concern for safety regulations is Climate Change Accelerated. But nothing said will change your mind. Freedom has a darkside- dumbass bloggers for one.Unknownhttps://www.blogger.com/profile/13159792349613255438noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-17371269910302394692010-05-13T06:28:27.719-07:002010-05-13T06:28:27.719-07:00@Ms. X
Please elaborate. Thanks.@Ms. X<br /><br />Please elaborate. Thanks.Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-41044089746949425862010-05-12T13:00:44.727-07:002010-05-12T13:00:44.727-07:00Natural selection is not evolution. It is merely ...Natural selection is not evolution. It is merely one suggested (and increasingly dismissed) causal mechanism. Problem is, without solid mechanism it is difficult (or should be) to say a theoretical process like evolution is anything like a fact.Ms. Xhttps://www.blogger.com/profile/00841651748765791866noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-25234333013242416102010-05-11T14:13:10.802-07:002010-05-11T14:13:10.802-07:00Take a look at this paper by Jeff Glassman, and co...Take a look at this paper by Jeff Glassman, and compare to the Science letter by Gleick et al:<br /><br /><a href="http://www.rocketscientistsjournal.com/2010/03/sgw.html" rel="nofollow">http://www.rocketscientistsjournal.com/2010/03/sgw.html</a><br /><br />I contacted Dr. Gleick and invited him to respond to my criticisms here. I hope he takes me up on my invitation, and can point us to some evidence of quality similar to Glassman's. To be fair, Dr. Gleick did point out that a short letter to Science cannot possibly cover the complexities of climate science. But that's my complaint: if you can't add information to the discussion, then why are you bothering? And how can one possibly assess the "facts" cited there if no supporting evidence is given, or at least referenced?Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-16575120535608809942010-05-11T10:05:16.229-07:002010-05-11T10:05:16.229-07:00@LeonRover,
Yeah, I see what you're getting a...@LeonRover,<br /><br />Yeah, I see what you're getting at. Your volcanic ash example shows the limitations of language. "Might" includes the entire range of possibilities between 0% and 100%, but says nothing about the degree. In the case of grounding the planes, grounding to "err on the side of caution" may or may not have been the right decision.<br /><br />The thing that is annoying (but not very surprising) is that the mathematical tools exist to change a vague "might" into a number, and further quantify the values of choices given the available information. A decision with any degree of complexity (more than a couple of variables) is well beyond the capability of humans to mentally assess even as a good approximation.<br /><br />I like to use computer chess as an example (all the better since there's no uncertainty in chess). The chess software on my laptop will defeat the top players in the world something like 4 out of 5 times. The computer is relentlessly rational - it always makes the "right" move (at least within the limits of the chess knowledge given to the software). A top grandmaster makes a suboptimal move about 10% of the time.<br /><br />I doubt that the people making key decisions, like grounding airplanes, have anywhere near the mental analytic capabilities of a chess grandmaster. So they play CYA, and hide behind the word "might" without actually ever digging in to the details. For them, all "mights" are created equal, which leads to complete stupidity.Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-15519408875676815532010-05-11T03:15:29.155-07:002010-05-11T03:15:29.155-07:00Hello Dave
I use weasel to describe a word which ...Hello Dave<br /><br />I use weasel to describe a word which describes a possible causation without also saying that it is speculative and there is a lot of investigation needed to produce a mechanism of explanation. <br /><br />Might and may are thus weasel words for me. <br /><br />Sorry about garbage in edits!<br /><br />The "precautionary principle" when coupled with "might" grounded airline travel in Europe recently because non-zero levels of volcanic ash "might" damage jet engines.<br /><br />Thank you for blog.LeonRoverhttps://www.blogger.com/profile/07219165631035107225noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-15048995209118078792010-05-11T01:17:05.872-07:002010-05-11T01:17:05.872-07:00If I understand what Gary Taubes has said about sc...If I understand what Gary Taubes has said about science the presence of weasel words is a good thing - defining the limits and conditions under which something is true for instance.Walterhttps://www.blogger.com/profile/16167398425720472638noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-81741002261994417532010-05-10T16:45:37.919-07:002010-05-10T16:45:37.919-07:00@Tony,
Thanks.
@LeonRover,
Why is "might&q...@Tony,<br /><br />Thanks.<br /><br />@LeonRover,<br /><br />Why is "might" a weasel word? And who decides that "experts" are indeed expert? Usually, it's other "experts", i.e. birds of a feather flocking together.<br /><br />Not sure what you were getting at in the last paragraph, looks like it got garbled.Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-49872987012080830822010-05-10T15:28:59.349-07:002010-05-10T15:28:59.349-07:00For my money the equivalent of "checking the ...For my money the equivalent of "checking the shoes" is the presence of the weasel word "might".<br /><br />In my mental universe "might" ALWAYS includes OR "might not" by implication. Whatever view one is being asked to endorse, it is on the basis of a judgment or opinion provided by an expert.<br /><br />For example, in an entirely different field, that of a murder trial in England of a mother for the deaths of her three children from SIDS, the expert paediatric witness Sir Roy Meadows was severely criticized.<br />http://www.guardian.co.uk/news/2005/jun/20/childprotection.<br /><br />My other "bete noir" is the "precautionary principle", by which we must act, because the outcome might be as the proposers theory suggests.ineakingLeonRoverhttps://www.blogger.com/profile/07219165631035107225noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-90512272199428299402010-05-10T15:22:02.257-07:002010-05-10T15:22:02.257-07:00I love this part.
"The only real conclusion ...I love this part.<br /><br />"The only real conclusion is the relative belief in one hypothesis over competing hypotheses, as opposed to a specific identification of "truth". But standard statistics is completely backwards on this point, instead testing if observed data are likely given that a hypothesis is true. It's not the likelihood of the hypothesis being tested, but that of the data. The truth of the hypothesis is assumed in this analysis."<br /><br />That is a really cool way of thinking about it. Thanks.<br /><br />Tonye4ehttp://www.emotionsforengineers.comnoreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-91078172525911499972010-05-10T13:50:16.507-07:002010-05-10T13:50:16.507-07:00@Pal,
Thank you. The writing seems to come in bur...@Pal,<br /><br />Thank you. The writing seems to come in bursts like this, not sure why.<br /><br />Anything that people hold as absolute "truth" is going to cause the sort of phenomenon you describe. If it's a broadly held "truth", then being on the wrong side of it is a good way to get lynched, burned at the stake, denied research funding, etc. It's really the norm, and I think once people realize that, they will truly understand the need to think for themselves, and stop blindly following experts/priests/etc.Davehttps://www.blogger.com/profile/18290594860469294453noreply@blogger.comtag:blogger.com,1999:blog-7721098568390636553.post-12875201436522718722010-05-10T13:02:30.775-07:002010-05-10T13:02:30.775-07:00Great to see you back in the blogosphere Dave, and...Great to see you back in the blogosphere Dave, and a great post. Your writing about evolution made me think about how religion historically speaking has had a free card for criticism. Speaking out about religion has always been risky business. Now it seems much the same is happening with climate change. Being skeptical and speaking out about the human contribution to the current climate change can get you lynched just as much as accepting evolution could some years ago.Pål Jåbekkhttps://www.blogger.com/profile/14533960726900698251noreply@blogger.com