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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wednesday, October 3, 2018 at 7:24:01 AM UTC-6, Chris L Peterson wrote:
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. It took a long time, and it was awfully hard, to find out that Fermat's last theorem was true. The Riemann hypothesis still awaits solution. But math is endless, whereas physics presumably proceeds from a few basic facts. So, indeed, perhaps we could know all of them. But until we do, and know that we know all of them, how much complexity nature has is open to question. John Savard |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wed, 3 Oct 2018 13:42:30 -0700 (PDT), Quadibloc
wrote: On Wednesday, October 3, 2018 at 7:24:01 AM UTC-6, Chris L Peterson wrote: 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. It took a long time, and it was awfully hard, to find out that Fermat's last theorem was true. The Riemann hypothesis still awaits solution. But math is endless, whereas physics presumably proceeds from a few basic facts. So, indeed, perhaps we could know all of them. But until we do, and know that we know all of them, how much complexity nature has is open to question. Certainly. But I'd say the evidence is that our knowledge is approaching complete. That we have a finished jigsaw puzzle that's just missing a few pieces. They're some very important pieces, of course, but not ones that are going to make the whole picture look different. I note that our core theories have been stable for a very long time now. New discoveries (e.g. dark energy) result in tweaks to existing theory, not throwing out major areas of physics and replacing them with something completely different (the sort of thing that did happen 150 years ago). I take that as in indicator that our theories are converging on ground truth. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wednesday, October 3, 2018 at 4:43:36 PM UTC-6, Chris L Peterson wrote:
On Wed, 3 Oct 2018 13:42:30 -0700 (PDT), Quadibloc wrote: On Wednesday, October 3, 2018 at 7:24:01 AM UTC-6, Chris L Peterson wrote: 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. It took a long time, and it was awfully hard, to find out that Fermat's last theorem was true. The Riemann hypothesis still awaits solution. But math is endless, whereas physics presumably proceeds from a few basic facts. So, indeed, perhaps we could know all of them. But until we do, and know that we know all of them, how much complexity nature has is open to question. Certainly. But I'd say the evidence is that our knowledge is approaching complete. That we have a finished jigsaw puzzle that's just missing a few pieces. They're some very important pieces, of course, but not ones that are going to make the whole picture look different. I note that our core theories have been stable for a very long time now. New discoveries (e.g. dark energy) result in tweaks to existing theory, not throwing out major areas of physics and replacing them with something completely different (the sort of thing that did happen 150 years ago). I take that as in indicator that our theories are converging on ground truth. Yes, but that much has been true since Newton. Relativity and quantum mechanics are also "tweaks" that didn't overturn the basic physics on which most of our technology is based. To say that they overturned everything, while dark matter is a "tweak" is debatable. Although it is true that relativity and quantum mechanics did revise the very roots of physics, even if the outcome in everyday life didn't change much. But then, what about the much later discovery of quarks? John Savard |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wednesday, October 3, 2018 at 5:33:13 PM UTC-6, Quadibloc wrote:
On Wednesday, October 3, 2018 at 4:43:36 PM UTC-6, Chris L Peterson wrote: Certainly. But I'd say the evidence is that our knowledge is approaching complete. That we have a finished jigsaw puzzle that's just missing a few pieces. They're some very important pieces, of course, but not ones that are going to make the whole picture look different. I note that our core theories have been stable for a very long time now. New discoveries (e.g. dark energy) result in tweaks to existing theory, not throwing out major areas of physics and replacing them with something completely different (the sort of thing that did happen 150 years ago). I take that as in indicator that our theories are converging on ground truth. Yes, but that much has been true since Newton. Relativity and quantum mechanics are also "tweaks" that didn't overturn the basic physics on which most of our technology is based. I think QM did. Semiconductor technology depends on it. To say that they overturned everything, while dark matter is a "tweak" is debatable. Since we don't know what dark matter and energy are, we have no certainty about what understanding them is going to do. If they're anything like what I think they are, they will be much more than a tweak. I don't think their de-masking will change technology, but they will change our philosophy and understanding of the cosmos Although it is true that relativity and quantum mechanics did revise the very roots of physics, even if the outcome in everyday life didn't change much. Umm, looked at your I-phone lately? But then, what about the much later discovery of quarks? John Savard We really haven't done much with quark technology (technology is where physics impinges on our everyday life). |
#225
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wed, 3 Oct 2018 16:33:10 -0700 (PDT), Quadibloc
wrote: Certainly. But I'd say the evidence is that our knowledge is approaching complete. That we have a finished jigsaw puzzle that's just missing a few pieces. They're some very important pieces, of course, but not ones that are going to make the whole picture look different. I note that our core theories have been stable for a very long time now. New discoveries (e.g. dark energy) result in tweaks to existing theory, not throwing out major areas of physics and replacing them with something completely different (the sort of thing that did happen 150 years ago). I take that as in indicator that our theories are converging on ground truth. Yes, but that much has been true since Newton. Relativity and quantum mechanics are also "tweaks" that didn't overturn the basic physics on which most of our technology is based. To say that they overturned everything, while dark matter is a "tweak" is debatable. I disagree. Both relativity and quantum mechanics were radically new physics that completely changed our understanding of the Universe. Dark energy (and even less, dark matter) are nothing at all like that. Although it is true that relativity and quantum mechanics did revise the very roots of physics, even if the outcome in everyday life didn't change much. But then, what about the much later discovery of quarks? Quarks were proposed on purely theoretical grounds as the Standard Model was approaching its current (and presumably nearly final) form. Again, jigsaw pieces within a picture that could be broadly seen, not an entirely new picture at all. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Tue, 2 Oct 2018 14:09:34 -0700 (PDT), Gary Harnagel
wrote: 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. Neither do you have any idea about it. So you have no basis whatsoever to claim it is "almost certain" such civilization will form and succeed in interstellar travel. It is just fantasies and wishful thinking from you. The "law of big numbers" doesn't help you here since there are too many unknown and possibly extremely small numbers involved. 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? These are by now quite old ideas. Yes, SF ages too as time passes. However, wild hypotheses are definitely "almost certain" to be true. Dream on, and get back if and when solid evidence for the existence of these phenomena appears. And note that science fiction is not science fact. 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. Having vision is easy, you just fantasize. Making it actually happen is much much harder. 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! I know, that's why you also are religious. 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. And in what way could VISION alone give us knowledge? 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. Without any solid base, you are. It is easy to get caught up in wishful thinking. But even a visionary must distinguish what we know from what we merely believe, or else his visions will at some stage fall flat to the ground. 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. Nope. Realists are those who make reality happen. Dreamers just dream, and when one dream fails they switch to another dream. To make things happen you must be careful about distinguish speculation from knowledge. But regarding extraterrestrial civilizations we humans cannot make that happen. It either has happened or has not happened and we cannot do anything about that. Your dreams can never create extraterrestrial civilizations billions of years into the past. 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. The reality **is** 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 :-)) Calling yourself a visionary is clarifying, since it says you are talking about your visions, not about reality. And, no, your visions will never be able to create extraterrestrial civilizations billions of years into the past. 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. That's fine, however you should admit that it's just a vision. Reality itself can be very different. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wed, 3 Oct 2018 18:55:39 -0700 (PDT), Gary Harnagel
wrote: Although it is true that relativity and quantum mechanics did revise the very roots of physics, even if the outcome in everyday life didn't change much. Umm, looked at your I-phone lately? Far from everyone has I-phones. As a matter of facts, some 90% of all smartphones are not I-phones. |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Tue, 02 Oct 2018 07:01:20 -0600, Chris L Peterson
wrote: 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. If you would live for another 100-200 years I think you'd become quite surprised about the development in physics more than once. The current situation is really the same as the situation 150 years ago: now, as well as back then, we don't clearly see the holes in our knowledge. In the future, we'll be able to see it more clearly - but of course it is always easier to be wiser after the fact... |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On 03/10/2018 14:23, Chris L Peterson wrote:
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. In practice there are potentially whole regions of physics at ultra high energies and very short length scales where we can never know what really happens since it is not possible to probe them experimentally. (and never will be) We can make conjectures about the underlying structure but never test them in any meaningful way so it will be impossible to choose between any competing physical theories that make the same predictions for all of the things that we can actually measure. The Godel incompleteness theorem probably also applies to the real world every bit as much as it does to mathematics. There are always some true things that can't be expressed in any formal grammar or world model. Succinct explanation of the incompleteness theorem for others: https://blog.plover.com/math/Gdl-Smullyan.html You should also recall that every time some eminent physics has stood up at a major event and said "physics will be solved in the next twenty years" some new observation has completely up turned the apple cart. Last time was when radioactivity and relativity were discovered. Science is always an approximation to reality that is as good as our mathematical models will permit but since physics rests on mathematics and we know mathematics can't describe everything you are always in a position where there could be true statements about the universe that we cannot know and will remain forever inaccessible. -- Regards, Martin Brown |
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Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On 04/10/2018 07:24, Paul Schlyter wrote:
On Tue, 2 Oct 2018 14:09:34 -0700 (PDT), Gary Harnagel wrote: On Tuesday, October 2, 2018 at 2:02:36 AM UTC-6, Paul Schlyter wrote: 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. Neither do you have any idea about it. So you have no basis whatsoever to claim it is "almost certain" such civilization will form and succeed in interstellar travel. It is just fantasies and wishful thinking from you. The "law of big numbers" doesn't help you here since there are too many unknown and possibly extremely small numbers involved. Since the biggest stars burn out the fastest I think that locally a few places may have been favoured with high metallicity very early on and you only need enough to make a few planets here and there to get going. But the early universe was a much more violent place than today and things closer together so any developing life would be more likely to get zapped and reset by a close supernova or merging black hole pair. 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? These are by now quite old ideas. Yes, SF ages too as time passes. Some of it ages quite well. When Kubrick flat imaging tablet devices for watching TV in 2001 the idea was ridiculous but today they are everywhere likewise for "communicators" in Star Trek. Partly I think because the engineers and scientists who grew up watching these programs thought they were cool ideas and tried to make them in reality. However, wild hypotheses are definitely "almost certain" to be true. Dream on, and get back if and when solid evidence for the existence of these phenomena appears. And note that science fiction is not science fact. However much you wish to make a wormhole it isn't going to happen without a heck of a lot of energy and some very exotic matter. And even if you could make one its stability and unwelcome tendency to spagettify things near it is an open question. 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. Having vision is easy, you just fantasize. Making it actually happen is much much harder. Chances are that any civilisation that has been around for so long will be unrecognisable to us - we could even be living inside one of their computer simulations of universes. 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! I know, that's why you also are religious. Believing doesn't make it true. It just means that believers will stick to what they think they know in the face of all evidence to the contrary (even to the extent of being burnt at the stake as a heretic - popular with the two most prominent brands of Christianity in the middle ages). 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. And in what way could VISION alone give us knowledge? Show me a hyper advanced space faring civilisation or a signal from one and I will be the first to agree that they exist. Until that time they are at best a figment of your imagination. I am inclined to think that the energetics and timescales for interstellar travel are so great that very few if any civilisations ever expand beyond the confines of their own solar system. Space is big - really really big. HHGG http://www.quotationspage.com/quote/33085.html 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. Without any solid base, you are. It is easy to get caught up in wishful thinking. But even a visionary must distinguish what we know from what we merely believe, or else his visions will at some stage fall flat to the ground. No they can persist in the face of all the evidence to the contrary. 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. Nope. Realists are those who make reality happen. Dreamers just dream, and when one dream fails they switch to another dream. To make things happen you must be careful about distinguish speculation from knowledge. Dreamers and creative people can think of things but it takes engineers and scientists to make something that will actually work. But regarding extraterrestrial civilizations we humans cannot make that happen. It either has happened or has not happened and we cannot do anything about that. Your dreams can never create extraterrestrial civilizations billions of years into the past. If there was one they would probably be so abstract by now that we wouldn't recognise them anyway. They would almost certainly have made the transition to being a self improving AI singularity. 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? I consider it possible that they exist. But I'm not expecting to see LGMs shopping in Tesco's any time soon. 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. The reality **is** that we don't know... I think the evidence is tilting towards the idea that simple life might be more common than we thought but unless and until we find an independent occurrence on Mars, Enceledus or Europa there is no evidence one way or the other. It is all about belief in the absence of evidence. 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 :-)) Calling yourself a visionary is clarifying, since it says you are talking about your visions, not about reality. And, no, your visions will never be able to create extraterrestrial civilizations billions of years into the past. Chances are they died with their star anyway. Interstellar travel for life forms is in the seriously too difficult category. Interplanetary travel for humans is still very very tough with only the moon having ever been visited (and that was done 50 years ago). 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. That's fine, however you should admit that it's just a vision. Reality itself can be very different. I don't think you can alter the world view of a true believer they have proved willing to be burnt at the stake for their beliefs in the past. (often by a rival group of believers in the same "One True God") Now Mr Galileo do you believe that the Sun goes around the Earth or would you like more house arrest and a molten lead ear wash? -- Regards, Martin Brown |
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