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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Mon, 01 Oct 2018 07:44:29 -0600, Chris L Peterson
wrote: On Mon, 01 Oct 2018 07:53:36 +0200, Paul Schlyter wrote: The existence of radio communication is definitely knowable. A few centuries ago, it would have been considered supernatural to be able to send messages apparently instantly (and definitely much faster than with a courier riding a fast horse) over long distances, even when direct visual contact was not possible. Sure. But it's difficult to imagine what we might find supernatural today. Today we understand most of nature. I doubt Clarke's Law applies anymore. I don't imagine we could encounter any technology advanced enough to appear as magic. We now have enough knowledge to recognize the likely natural law underlying anything we encounter, You sound like a physicist from the late 1800's. Back then, physics was believed to be understood almost completely. Only a few minor details needed to be clarified. However, those "minor details" soon expanded into relativity and QM, making physics quite different compared to earlier... even if we lack perfect understanding. Btw I encountered some new worlds the other day: Nontheism - vaguely similar to atheism but still different. There are nontheistic religions for instance, like some varieties of Buddhism. In actual usage, nontheism and atheism are synonyms. Apatheism - having no interest in the question about the eventual existence of deities. An apatheist is therefore neither a theist nor an atheist. You say apatheists do not exist, but if so, why invent a word for a non-existing property? "Apatheism" is a portmanteau of "apathetic" and "atheism". A recent word which refers to unreflective atheism. An apatheist is an atheist who doesn't give the matter any thought and isn't interested in any underlying philosophical questions about the matter. All apatheists are atheists, but not all atheists are apatheists. Why couldn't an apatheist just as well be a theist? He mcould believe there might be deities but he doesn't care about them. Og course an apatheist is nonreflective. But being nonreflective is getting fashionable these days. Consider the increasing number of people believing in a flat Earth. Or the election of Donald Trump as the US president. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Mon, 1 Oct 2018 18:41:05 -0700 (PDT), Gary Harnagel
wrote: On Saturday, September 29, 2018 at 3:55:55 AM UTC-6, Paul Schlyter wrote: On Fri, 28 Sep 2018 05:49:40 -0700 (PDT), Gary Harnagel wrote: On Friday, September 28, 2018 at 3:47:01 AM UTC-6, Paul Schlyter wrote: You are hopelessly overoptimistic. The typical distance between galaxies is millions of light years or more. That's true ... TODAY. What about 9 billion years ago? Back then the galaxies were some 3 times closer to one another than today, so the typical intergalactic distance were perhaps about a million instead of millions of light years. But, more importantly, back then there were few if any population I stars in existence. All stars back then were population II stars, which have very little, if any, elements heavier than H and He. Those heavier elements are required to form life. So back then there was no life in the universe, that we can say with great certainty. Back then, our Sun and our Earth did not even exist. Life, of all kinds, formed later. 9 billion years ago there certainly WERE stars with heavy elements: http://www.astronomy.com/news/2016/0...rly-galaxies-c hallenges-star-forming-theory Although their metallicity was only 20% of stars near us, that's pretty good for 11 billion years ago, wouldn't you say? Lower metallicity means less material from which life can form. Therefore you are saying that any civilisation would with great probability learn interstellar travel at or near light speed. I believe there are other alternatives. Such as wormholes? Or did you have something else in your mind? Wormholes, Alcubierre=type drives, transit to other branes, and ways not even a glimmer in the eyes of theoretical physicists. Now you've entered the realm of science fiction... Are you even aware of the difficulties involved? For instance, colliding with a grain of sand near light speed would mean the end of your expedition. Indeed, I am quite aware of the difficulties. That's why I think there are alternatives. WHICH alternatives? How can you travel millions of light years in just millions of years without traveling at near light speed? Answered above. So that one survivor can spread its DNA over the whole galaxy in a few million years. Now you are getting more modest, which is good. Earlier you claimed that this one survivor could spread its DNA to **other** galaxies within the same time span of a few million years. That would require travel near light speed. Not necessarily. If this civilization developed, say, 5 billion years after the big bang, the galaxies would have been closer together. Not by much. Since the big bang happened 13.5 billion years ago, 5 billion years ago the intergalactic distances already had about 60% of their current value. And maybe there's a way to "wink out" there and "wink in" here vitually instantaneously. We haven't had millions of years of scientific development yet. More sci-fi... And as we seem to agree, travel near light speed has certain high-probability risks. I think there are alternative ways to get from one place to another. You are very quiet about these alternative ways... why? "Wink out", "wink in" :-) Your grasp of probability theory must be very weak, or else you would not make such claims. I have to laugh at your assertion again :-)) Are you familiar with the Law of Large Numbers? Do you consider one to be a large number? One is the number of planets known to have life... The law of large numbers say that if you repeat an experiment a large number of times, the outcome will be very close to the expected value. But, in the case of life in the universe, we have no idea what the expected value is. So the law of large numbers does not help us here. Sure it does. We don't have to know the expectation value. We KNOW it happened ONCE. Given ENOUGH chances, it will happen again. Sure, but have there been ENOUGH chances? We don't know, we can only guess or believe. Given what we know about planetary systems today, about the number of stars in our galaxy, about the number of galaxies in just the VISIBLE universe and the tininess of the visible universe, you don't believe it hasn't happened MANY times? If so, you are an amazing pessimist! You see? All we can do is believe, we don't know. We are getting to know the first few factors of the Drake equation, but several factors remain unknown to us. And these unknown factors are the hardest to get to know. For instance, what is the typical lifetime of a technologically advanced civilization? Apart from beliefs and guesswork, hov can we actually get to KNOW that value? And how can we be certain that this lone surviving intelligent ? civilization would devote itself to space travel over intergalactic distances? Or develop some alternative means where distance isn't important? If "a" civilization didn't, another one would. That's your guess, and it is a far cry from "absolutely certain" that it actually is so. YOU are the only one talking about "absolute certainty." I'm talking about probabilities. Even if you call it "very high probability' it's really the same thing. One thing about extraterrestrial life is that ve cannot be "almost certain" about anything. You and I are working from different assumptions. Are you familiar with Paul Steinhardt's Ekpyrotic theory? https://arxiv.org/abs/hep-th/0103239 https://en.wikipedia.org/wiki/Ekpyrotic_universe It posits a cyclic universe. If it has any credence it means that past universes existed. If intelligent life is as rare as some here believe, it becomes a virtual certainty that it developed in a previous genesis, maybe millions of times. If some couldn't find a way to transport itself from one genesis to the next, one would have. Imagine, a civilization billions of years old appearing on the scene 13 billion years ago! But what if it doesn't have any credence? We don't know if it has, so we can only guess. And you must do much better than guesswork to be able to reliably claim that something is "almost certain". Don't be such a pessimist! It's bordering on a mania :-) Don't be such a dreamer... When you talk about extraterrestrial life, don't you mean real life in the real universe and not just your fantasies and wishes? That might make a great SF story to outdo even Olaf Stapledon. But I don't think it's SF. Anyway, now you see why no argument about probability has any affect on me whatsoever. So, want to discuss the probability of Steinhardt et al. being right? :-) You can fantasize as much as you want, but please stop trying to misuse probability to claim something is "almost certain" when it actually just is a guess of yours. Pessimist! No, I'm a realist. Nope! Something supernatural is something which contradicts physics. https://www.merriam-webster.com/dictionary/supernatural "departing from what is usual or normal especially so as to appear to transcend the laws of nature" With that definition, radio communication would have been "supernatural" a few centuries ago. Exactly! Now you're getting it :-) The scientific method requires that a phenomenon be repeatable by any competent researcher. It also requires the ability to change the inputs. No it doesn't. Astronomers cannot experiment with the universe by changing the input, but despite that astronomy is regarded as a science. Astronomical science requires that experiments performed here on earth be valid elsewhere in the solar system, galaxy, universe. Now that we have sent missions throughout the solar system, that part is no longer assumption, and we have no choice but to assume it's true throughout the universe. It SEEMS to be, anyway, but it IS a weakness that certain scientific disciplines have. Cosmology is a case in point. We have the Big Bang model, but there are alternatives ... There are no alternatives today that match empirical data so well. Irrelevant since we're talking about billion-year-old civilizations. You are then talking about something neither you nor anyone else on Earth know anything about. The discovery of the cosmic background radiation made the "big bang" win over the "steady state" cosmology. But note that this is not final. If and when a cosmology appears that matches empirical data even better, then it will replace the "big bang" as the standard cosmological model. The standard model assumes inflation. There are scientists that dispute that. https://www.wired.com/2008/02/physic...ng-wasnt-the-b eginning/ There are always people questioning, that's a natural part of the scientific process. Time will tell who is right. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Tuesday, October 2, 2018 at 8:37:08 AM UTC+1, Paul Schlyter wrote:
Og course an apatheist is nonreflective. But being nonreflective is getting fashionable these days. Consider the increasing number of people believing in a flat Earth. ....or people unable to express the fact of a round and rotating Earth where the maximum Equatorial speed is 1037.5 miles/ 1669.8 km per hour - https://books.google.ie/books?id=PE9...g e&q&f=false Who is worse ? - people who mock others because they can with a flat-Earth notion or people who are dead serious that the Equatorial rotational velocity is 1674.4 km per hour thereby generating a nonsensical distance corresponding to a 40,185.6 km circumference. This is what theorists get when they link the Earth's rotation directly to stellar circumpolar motion via the 24 hour and calendar system. It is not that people here should be ashamed of themselves, it is that those who can acutely feel the inability to affirm the correct rotational velocity at the Equator as 1669.8 km per hour and the 40,075 km circumference are saying and doing nothing. I really wished you believed in a flat Earth because making a mess of things via timekeeping is far worse. |
#214
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On 28/09/2018 10:46, Paul Schlyter wrote:
On Wed, 26 Sep 2018 12:07:27 -0700 (PDT), Gary Harnagel wrote: As I said, it only takes ONE civilization to make it.* It can then spread to other galaxies in a few million years, a very short time in the universe= Only in fantasy science fiction like Star Trek is this possible. You are hopelessly overoptimistic. The typical distance between galaxies is millions of light years or more. Therefore you are saying that any civilisation would with great probability learn interstellar travel at or near light speed. Are you even aware of the difficulties involved? It may well be the case that the distances between stars are so vast that no civilisation can realistically travel between them unless they happen to be in a privileged place with a very high density of nearby stars. Robotic Fermi probes ought to be possible - they don't need to sustain life and can wake up only when in proximity to a star. It is an interesting question of how small a probe we could make with existing technology to get to Proxima Centuri and send information back. Milner and Hawking proposed one way to get there in about 20 years if you accept the assumptions behind their methodology. https://www.smithsonianmag.com/smart...tem-180958745/ For instance, colliding with a grain of sand near light speed would mean the end of your expedition. And you will get cooked by the blue shifted cosmic background radiation as well. The faster you travel the better your heat shield has to be. -- Regards, Martin Brown |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On 30/09/2018 17:50, Chris L Peterson wrote:
On Sun, 30 Sep 2018 18:32:16 +0200, Paul Schlyter wrote: So deities which lack this power to hide, their existence is knowable? It seems likely. I've seen nothing to suggest that anything in nature is unknowable, so I'd only reserve certainty of unknowability for the supernatural. Conjugate variables in Heisenberg's uncertainty principle is the most obvious counter example. You cannot simultaneously know the momentum and position of a particle in phase space to arbitrary precision. -- Regards, Martin Brown |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Tue, 02 Oct 2018 09:37:04 +0200, Paul Schlyter
wrote: Sure. But it's difficult to imagine what we might find supernatural today. Today we understand most of nature. I doubt Clarke's Law applies anymore. I don't imagine we could encounter any technology advanced enough to appear as magic. We now have enough knowledge to recognize the likely natural law underlying anything we encounter, You sound like a physicist from the late 1800's. Back then, physics was believed to be understood almost completely. Only a few minor details needed to be clarified. However, those "minor details" soon expanded into relativity and QM, making physics quite different compared to earlier... Back then we lacked the knowledge to know what knowledge we lacked. That doesn't appear to be the case anymore. We have a good understanding of where the holes in our knowledge are, and we have good ideas about the sort of things that are likely to fill them. And we have a much better understanding of the nature of nature, meaning that I doubt there's anything we could observe that science wouldn't quickly provide plausible hypotheses for, without anybody feeling the need to draw on magic or the supernatural. We have a different worldview today regarding natural law. Why couldn't an apatheist just as well be a theist? He mcould believe there might be deities but he doesn't care about them. Because the word itself refers to atheists. Og course an apatheist is nonreflective. But being nonreflective is getting fashionable these days. Consider the increasing number of people believing in a flat Earth. Or the election of Donald Trump as the US president. Yes, lack of reflection is a problem. All rational people are atheists, because critical thinking always leads to atheism. But not all atheists are rational, because there are atheists who are such simply because they were never brainwashed as children. Those atheists, like lots of other people, may lack critical thinking skills and therefore easily adopt the same sort of silly ideas that any irrational people can fall for. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Tue, 2 Oct 2018 09:34:30 +0100, Martin Brown
wrote: On 30/09/2018 17:50, Chris L Peterson wrote: On Sun, 30 Sep 2018 18:32:16 +0200, Paul Schlyter wrote: So deities which lack this power to hide, their existence is knowable? It seems likely. I've seen nothing to suggest that anything in nature is unknowable, so I'd only reserve certainty of unknowability for the supernatural. Conjugate variables in Heisenberg's uncertainty principle is the most obvious counter example. You cannot simultaneously know the momentum and position of a particle in phase space to arbitrary precision. Yes, but that's a triviality. Like saying you can't know what's on the side of sphere that you can't observe. We're really talking about the knowability of natural law and structure, not "things". It is Heisenberg's uncertainty principle that informs us. That allows us to know. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Tuesday, October 2, 2018 at 2:02:36 AM UTC-6, Paul Schlyter wrote:
On Mon, 1 Oct 2018 18:41:05 -0700 (PDT), Gary Harnagel wrote: On Saturday, September 29, 2018 at 3:55:55 AM UTC-6, Paul Schlyter wrote: Back then the galaxies were some 3 times closer to one another than today, so the typical intergalactic distance were perhaps about a million instead of millions of light years. But, more importantly, back then there were few if any population I stars in existence. All stars back then were population II stars, which have very little, if any, elements heavier than H and He. Those heavier elements are required to form life. So back then there was no life in the universe, that we can say with great certainty. Back then, our Sun and our Earth did not even exist. Life, of all kinds, formed later. 9 billion years ago there certainly WERE stars with heavy elements: http://www.astronomy.com/news/2016/0...rly-galaxies-c hallenges-star-forming-theory Although their metallicity was only 20% of stars near us, that's pretty good for 11 billion years ago, wouldn't you say? Lower metallicity means less material from which life can form. Less, but not zero. You have NO idea how much less prevents life and neither do I, so this is just yammering. Such as wormholes? Or did you have something else in your mind? Wormholes, Alcubierre=type drives, transit to other branes, and ways not even a glimmer in the eyes of theoretical physicists. Now you've entered the realm of science fiction... So you believe only scientists can have new ideas? You DO realize that some SF authors ARE scientists, don't you? Not by much. Since the big bang happened 13.5 billion years ago, 5 billion years ago the intergalactic distances already had about 60% of their current value. And maybe there's a way to "wink out" there and "wink in" here vitually instantaneously. We haven't had millions of years of scientific development yet. More sci-fi... More lack of vision. Do you consider one to be a large number? One is the number of planets known to have life... The law of large numbers say that if you repeat an experiment a large number of times, the outcome will be very close to the expected value. But, in the case of life in the universe, we have no idea what the expected value is. So the law of large numbers does not help us here. Sure it does. We don't have to know the expectation value. We KNOW it happened ONCE. Given ENOUGH chances, it will happen again. Sure, but have there been ENOUGH chances? We don't know, we can only guess or believe. I BELIEEEVE! Given what we know about planetary systems today, about the number of stars in our galaxy, about the number of galaxies in just the VISIBLE universe and the tininess of the visible universe, you don't believe it hasn't happened MANY times? If so, you are an amazing pessimist! You see? All we can do is believe, we don't know. We are getting to know the first few factors of the Drake equation, but several factors remain unknown to us. And these unknown factors are the hardest to get to know. For instance, what is the typical lifetime of a technologically advanced civilization? Apart from beliefs and guesswork, hov can we actually get to KNOW that value? It comes down to how much vision you have vs. how big a pessimist you are. That's your guess, and it is a far cry from "absolutely certain" that it actually is so. YOU are the only one talking about "absolute certainty." I'm talking about probabilities. Even if you call it "very high probability' it's really the same thing. One thing about extraterrestrial life is that ve cannot be "almost certain" about anything. I am. You and I are working from different assumptions. Are you familiar with Paul Steinhardt's Ekpyrotic theory? https://arxiv.org/abs/hep-th/0103239 https://en.wikipedia.org/wiki/Ekpyrotic_universe It posits a cyclic universe. If it has any credence it means that past universes existed. If intelligent life is as rare as some here believe, it becomes a virtual certainty that it developed in a previous genesis, maybe millions of times. If some couldn't find a way to transport itself from one genesis to the next, one would have. Imagine, a civilization billions of years old appearing on the scene 13 billion years ago! But what if it doesn't have any credence? We don't know if it has, so we can only guess. And you must do much better than guesswork to be able to reliably claim that something is "almost certain". Don't be such a pessimist! It's bordering on a mania :-) Don't be such a dreamer... Why not? Dreamers make reality happen. Pessimists just sit around moping. When you talk about extraterrestrial life, don't you mean real life in the real universe and not just your fantasies and wishes? I believe in ET. Why wouldn't you? You can fantasize as much as you want, but please stop trying to misuse probability to claim something is "almost certain" when it actually just is a guess of yours. Pessimist! No, I'm a realist. No, you're a mope-around. And you cannot possibly be a "realist" since you admit that we don't know. There are no alternatives today that match empirical data so well. Irrelevant since we're talking about billion-year-old civilizations. You are then talking about something neither you nor anyone else on Earth know anything about. So you admit that calling yourself a realist is just as nonsensical as my calling myself a visionary :-)) The discovery of the cosmic background radiation made the "big bang" win over the "steady state" cosmology. But note that this is not final. If and when a cosmology appears that matches empirical data even better, then it will replace the "big bang" as the standard cosmological model. The standard model assumes inflation. There are scientists that dispute that. https://www.wired.com/2008/02/physic...ng-wasnt-the-b eginning/ There are always people questioning, that's a natural part of the scientific process. Time will tell who is right. Indeed. As a human being, however, I want to have a "world view." It's important to me. I have developed mine over many years and I'll hold it until and if the evidence refutes it. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On 02/10/2018 14:03, Chris L Peterson wrote:
On Tue, 2 Oct 2018 09:34:30 +0100, Martin Brown wrote: On 30/09/2018 17:50, Chris L Peterson wrote: On Sun, 30 Sep 2018 18:32:16 +0200, Paul Schlyter wrote: So deities which lack this power to hide, their existence is knowable? It seems likely. I've seen nothing to suggest that anything in nature is unknowable, so I'd only reserve certainty of unknowability for the supernatural. Conjugate variables in Heisenberg's uncertainty principle is the most obvious counter example. You cannot simultaneously know the momentum and position of a particle in phase space to arbitrary precision. Yes, but that's a triviality. No. It isn't. It is a fundamental part of how our universe operates. Quantum mechanics would be entirely different if you could know both conjugate variables precisely and at the same time. Like saying you can't know what's on the side of sphere that you can't observe. We're really talking about the knowability of natural law and structure, not "things". It is Heisenberg's uncertainty principle that informs us. That allows us to know. It also allows us to know what we do not know. That Rumsfeld speech about known knowns, known unknowns and unknown unknowns that got him ridiculed in the press was actually right on the mark: "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." It is a 2x2 contingency table so he missed out unknown knowns. Facts we don't yet know (one of which was that Iraq did not have any WMD). -- Regards, Martin Brown |
#220
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wed, 3 Oct 2018 10:23:50 +0100, Martin Brown
wrote: Conjugate variables in Heisenberg's uncertainty principle is the most obvious counter example. You cannot simultaneously know the momentum and position of a particle in phase space to arbitrary precision. Yes, but that's a triviality. No. It isn't. It is because it isn't what I'm talking about as "knowability". There are certainly "things" we can't know. That's not important. The question is are there rules of nature we can't know? I don't see evidence of that. I think our understanding of nature can be complete. |
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