6/5/2014 at 10:13:19 PM GMT |
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Thanks for the many comments on my questions!
The Butterfly Effect is somewhat important, at least to me, because it serves as another analogy of a disappointing trend or extrapolation of future physics. Namely that as we gain more knowledge then we can apply our improving mathematical models to the real world and, eventually, even if unstated explicitly, negate all superstition including God.
Is this a fair analogy or am I overplaying it? Perhaps I love butterflies so much that I just don’t want them to be used for nefarious, though subtle, purposes. :)
Victoria stated: “The fact that the earth's weather is a non-linear, driven, dissipative system would mean that such small perturbations would probably be damped out too quickly to have the effect that is ascribed to it.”
Yes, that looks like an accurate way to state what should be obvious. It is, however, not how I think it was represented by Cosmos, where a real life butterfly somewhere could be seen as causal to a storm in Maine.
I just read your more recent post (#10) and I’m curious if you think a causal view of the Butterfly Effect is something adopted, or adoptable, by the scientism world?
[The Tyson link was interesting and would be worth discussing in the forum section.]
Mervin stated: “ The chaotic systems that Dassen describes above actually do predict this even though there is obviously no way to test such a thing. You can also think of it as virtually infinite sensitivity to initial conditions. Shoot a pool ball at a scattered assortment of balls on the table that bounce around for a while and it is easy to model on a computer how an alteration of the initial cue ball vector by a millionth of a degree seems at first to make no discernible difference until a few sets of collisions in when the error amplifies and rather suddenly you have a totally different configuration unfolding.”
Right, what may be fine for mathematics, assuming that it might be, is not necessarily transferable to real-world physics. That, I think, is what the real “Butterfly Effect” should be about. I sure like your pool ball example. It looks a little like the “Domino Effect”, yet it is much more the Butterfly Effect.
Randy stated: “Victoria, thanks for putting the right perspective on the "butterfly effect." It isn't meant to be taken literally.” Perhaps I am overacting to what I saw as a causal claim of distant storm activity attributed, at least partially, to a local butterfly. Even Wiki seems to represent it this way.
Randy stated for #2: “I would say it's the compelling arguments from 97% of those working in the field vs the unsubstantiated questions from those not working in the field. Those arguments have been addressed and settled by the experts, as far as I know.”
Thanks. I wasn’t clear on just how strong the consensus is on this subject. No doubt the rate of temperature increase is debated. There is so much money and politics involved that it greatly muddies the water for folks far less involved like me.
Regarding #4: I suspect the Sun may prove to be a slightly bigger player in the variability. One hypothesis shows that weak solar activity produces a weaker magnetic field, which allows more cosmic particles (“rays” if you prefer) to slam our atmosphere causing greater cloud cover. How well this hypothesis holds will take more time, but it is an example of claims that come from the blue (literally in this case) that are interesting, at least. It will not serve as any long term negative feedback on warming, however. Even longer time (many millions of years) the prospect is only bad, really bad; it is 30% hotter than it first became a star, and its surface will be headed are way in a few billion.
#5: OK. :)
Again thanks for everyone’s comments on this important topic, which can get very deep quickly.
Last edited Thursday, June 5, 2014
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6/5/2014 at 10:27:08 PM GMT |
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Randy and George, regarding "not too hot or cold" or "just right", I think the argument is based on two main things. 1) that humans evolved and spread throughout the earth in an environment similar to what we have now (i.e. CO2 levels have never been as high as they are now); and 2) that our current civilization (global economy/politics/etc) and biosphere is based on the fairly recent climate past. Arguments based on 1) are not overly compelling in my opinion because of the adaptability of Homo sapiens. We have adapted to nearly every climate on the planet. I think that as a species we will adapt to whatever climate change happens (unless, of course, we get to a run-away, Venus-like situation). 2) is a different matter. While coastlines have changed throughout earth history, coastlines haven't been occupied by billions of people. What's wrong with just saying: "everyone, move inland." Well, there are political and economic consequences. People are affected. Our sense of justice is piqued. We're not willing to say, "let nature take it's course" (especially if we have contributed to that course). Additionally, there have been mass extinctions before. Why are we bothered by the great anthropocene mass extinction? Perhaps some of it is a "life as we know it attitude" (which in some way is another form of anthropocentrism) or a "we caused it, so we should do what we can to prevent the rhino from going extinct--they're such beautiful creatures." I'm not trying to be cavalier here, but I do wonder why we think the present global context (or at least before the rise of the industrial revolution) is the best. Frankly, I'm not sure that I can come up with any scientific argument for caring one way or the other. It becomes ethics, religion, economics, and politics.
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6/5/2014 at 10:30:29 PM GMT |
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Victoria, indeed, there are many kinds of fundamentalists. I have learned long ago to filter out the scientism from folks like Sagan, Gould, Dawkins, and now Tyson. (Of course, given their religion, I don't expect anything else.) However, read through that filter, they have become some of my favorite spokespersons for science.
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6/6/2014 at 4:29:27 AM GMT |
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Quote: Originally posted by G. Cooper: Thanks for the many comments on my questions!
The Butterfly Effect is somewhat important, at least to me, because it serves as another analogy of a disappointing trend or extrapolation of future physics. Namely that as we gain more knowledge then we can apply our improving mathematical models to the real world and, eventually, even if unstated explicitly, negate all superstition including God.
Even if complete physical determinism were true and we were able to perfectly and completely describe the system, would that "negate ... God"? I don't think so. This is the mode of thinking though that leads advocates of scientism to say that science has rendered religion meaningless. There is this belief that we don't need God if we can explain something scientifically. I heartily recommend Randy's talk at the Washington DC ASA Local Section "What Does Science Tell Us About God's Existence?" If you're in a hurry, fast forward in to about 37:00 and listen to his discussion of "univocity".
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6/6/2014 at 4:30:29 AM GMT |
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Last edited Friday, June 6, 2014
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6/6/2014 at 1:39:55 PM GMT |
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I was gratified to learn that Neil Degrasse Tyson’s argument was similar my global warming debate talk at http://www.authorstream.com/Presentation/paulhcarr-2136686-humans-influence-climate/ My PowerPoint of course does not have as much spectacular animation, but it does have the advantage of not having any advertisements, so it does not take so much time to view. I also included the influence of our exponentially increasing world population. The Cosmos TV was for a general non-science educated audience. My PowerPoint shows data from the UN IPCC reports and refereed science journals. I show data supporting the fact that the average solar irradiance since 1980 has not increased and therefore can not explain the observed average temperature increase. With regards to the Little Ice Age, the attached paper "Small influence of solar variability on climate over the past millennium" Andrew P. Schurer*, Simon F. B. Tett and Gabriele C. Hegerl published in Nature Geoscience 22 DECEMBER 2013 | DOI: 10.1038/NGEO2040 concludes: “Solar forcing probably had a minor effect on Northern Hemisphere climate over the past 1,000 years, while, volcanic eruptions and changes in greenhouse gas concentrations seem to be the most important influence over this period.” ,
Last edited Friday, June 6, 2014
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6/6/2014 at 11:39:59 PM GMT |
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Randy responded above: "You are really asking about negative feedback loops and there aren't any imminent major ones that I've heard of." Does this mean we are completely ignorant about any possible restorative mechanism since the earth has at times been too warm as well as too cold? If so, this is a serious deficiency for any model given that something must have "kicked in" and overpowered all of these positive feedback factors we know so much about.
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6/7/2014 at 5:41:59 AM GMT |
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As I understand it, some of the large scale temperature changes in earth's history are due to things such as the Milankovitch cycles which result in temperature oscillations in the 20,000-100,000 year range. See http://en.wikipedia.org/wiki/File:EPICA_temperature_plot.svg for example. A cooling due to these sort of planetary cycles would produce a negative feedback loop. Since gases are more soluble at lower temperature, the cooler oceans would then absorb more of the atmosphere's CO2 thus decreasing the CO2 concentrations in the atmosphere even more. This is just the opposite of the positive feedback loop seen during a warming period. There warming caused by the planetary cycles results in more CO2 being released from the ocean which then results in increased warming. You may have heard that there is debate over whether the temperature changes lead or lag behind the CO2 changes. It's both. What is interesting about this is that in terms of planetary cycles, we're at a peak that is clearly not due to anthropogenic factors (and we're due for a cooling, it seems). However, CO2 concentrations are ~40% higher than at any time during the EPICA temperature data that correlates with the fossil fuel burning era of human history. So an important question is whether or not the long scale natural cycles can "handle" the extra CO2 even if cooling would have been the "natural" response. It seems to me that removing CO2 from the atmosphere (after we stop adding it) via various carbon capture methodologies could initiate some negative feedback loops. What to do with the CO2 is a critical concern? Underground CO2 sequestration is being explored. Perhaps we create artificial White Cliffs of Dover. Ideally, I think, if we continue to need to use combustible fuels that we use carbon-free energy (nuclear, solar, wind, geothermal) to convert the CO2 back into fuels (or useful chemical feedstocks) and thus recycle the CO2 (that which we emit originally came from the atmosphere). This is what biofuels do and what the natural biotic carbon cycle with carbon flows between producers doing photosynthesis and consumers doing cellular respiration have done for millions of years. This is an interesting way to get a price on carbon--what would it cost to get it out of the way (safely) or to recycle it? Add this to the price of gas.
Last edited Saturday, June 7, 2014
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6/7/2014 at 11:47:03 AM GMT |
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Quote: Originally posted by M. Bitikofer: Does this mean we are completely ignorant about any possible restorative mechanism since the earth has at times been too warm as well as too cold? If so, this is a serious deficiency for any model given that something must have "kicked in" and overpowered all of these positive feedback factors we know so much about. Terry's answer is right on target. I would only underscore that the issue is timescale. We do know about restorative mechanisms but they're on a timescale far longer than the mechanisms adding CO2 and heat to the system. The current anthropogenic rise in CO2 levels is at least 3X faster than any rate of rise the paleoclimatologists have been able to detect historically. One concern, as Tyson mentioned, is that before the restorative forces kick in, we might reach a tipping point and become another Venus. A much more immediate concern is that from now on and through the coming decades, there is a rapidly increasing vulnerability of human populations to severe storms. Especially the vast number of poor people living on the coast in underdeveloped countries. Humans can adapt to an amazing degree, but at what cost before they do so and how far?
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6/7/2014 at 1:30:43 PM GMT |
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Thanks, Randy and Terry. The longer time scale on the restorative effects makes good sense. And the (both positive and negative) feedback of gas solubility in the oceans that Terry explains might add a perilous dynamic. By itself it would seem to lend an inherent instability to the situation much like a pencil balancing on its point. With or without anthropogenic perturbations the system driven primarily by the said oceanic effect would tip one way or the other. But on the kinds of time-scales that concern us within a series of human generations there must be numerous stabilizing factors that seem to dominate ... that is until we push them.
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