|
|
Thread Tools | Display Modes |
#171
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wednesday, September 26, 2018 at 6:52:19 AM UTC-6, Martin Brown wrote:
On 26/09/2018 12:11, Gary Harnagel wrote: On Tuesday, September 25, 2018 at 2:01:11 PM UTC-6, Paul Schlyter wrote: And how do you know that intelligent civilisation will not self-destruct within a few millennia or so? Out of MILLIONS of civilizations, all that's needed is ONE to survive. We don't know of any other ET civilisations though. As yet we haven't found life arising independently on another planet either That's because we haven't looked except in a very few places. Wanna bet on the oceans of Enceladus? although there may be hints of life having been on Mars back when it had liquid water. (it may still be there deep in underground rocks or dormant as cysts) I wouldn't consider proof of life elsewhere in the solar system as proof of interstellar life. It could have come from earth. Anyone with a grasp of probability theory and no preconceived notions would disagree with you. No, they would disagree with you. I have a grasp of probability theory and I disagree with YOU. You have a rather weak grasp of probability theory You are very funny :-)) and an even weaker grasp of the Drake equation. Planets now appear to be far more common than was once thought but a lot of them are hot Jupiters tidally locked to their parent star (a side effect of present experimental methods which are particularly good at detecting planetary transits and Doppler shifts as the hefty planet orbits its parent star close in). And you seem to be very weak on present theory that posits Jupiter having started out close to Sol. Comparatively few have been found in the Goldilocks zone (although that may be a selection effect of present observational techniques). Indeed. We should be looking at OLD G and K-type stars for old civili- zations. Tabby's Star may qualify although it's a 6-billion-year-old F-type. You do need a sufficient base of actual data to be able to say anything about the probability, otherwise you are just guessing. We have actual data on one civilization. YOU are just guessing about its longevity, but that's irrelevant because an example of one AND proof that almost every star has planets (via Kepler), it is a VERY good "guess" that life has developed elsewhere. It is certainly possible. But whether or not it is common for life to evolve beyond the single celled stage is still an open question. "Life will find a way.” -- Michael Crichton One awkward upper bound on the timescale that a technological civilisation can operate without having to develop space faring technology is the time it takes to exhaust the finite resources of their home planet. 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.. You are the one who is biased here, not me, :-)) since I have not claimed any probability figure about that. THAT is YOUR bias speaking. We just know too little to be able to do that reliably. Just the sheer numbers of planets in the universe shred that assertion. If intelligent life was really common in our galaxy then there should be some residual signals for our radio and optical astronomers to see. Not necessarily. The time that a civilization uses radio technology may be quite short. Consider our own civilization. It's mostly beamed or fiber. That or we would have seen self replicating probes by now a la Fermi paradox. Not if there is an over-arching civilization that has already been here. And why isn't theology an exact science like physics? Why aren't our most powerful computers running simulations of God? There, now you have some things to think about... I thought. You got nuttin'! We don't know enough about how life started to do believable simulations. We don't even know if it started here. The chemists and molecular biologists are slowly getting closer to finding out answers. The tricky step is more likely to be the point where single celled simple life makes the transition to complex multicellular organisms. Science is always a step by step refinement from present knowledge by way of experiments. https://www.the-scientist.com/featur...-complex-42874 What they find will be way more convincing than a "Just So" story. -- Regards, Martin Brown Indeed. But haven't complex organic molecules been found in the solar system? |
#172
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
Chris L Peterson wrote:
On Tue, 25 Sep 2018 22:16:25 +0200, Paul Schlyter wrote: Why should knowability influence opinion? I think it is likely that the true nature of reality, the underlying "why" of universal laws are unknowable. So what is your opinion about this unknownable "why"? Why are the universal laws as they are, according to your opinion? I don't think it's a meaningful question. They are what they are. The answer in that case is perfectly knowable. I can count the grains and know for certain. I would like to see you count several billion of grains of sand. It matters not that it would be tedious, or difficult, or take years. The point is that the sand is countable. Whether there are an even or odd number is knowable. I've certainly never met anybody who had no opinion on the question of gods. True, you haven't met me... I do not believe you have no opinion on the matter. You do not appear to be stupid. Indeed, you come across as rather silly pretending to have no opinion. To have no opinion about the existence of God is no stranger than to have no opinion about why the laws of nature are like they are. The laws of nature exist. They are describable. Even assuming that the question of "why" is meaningful, not being able to answer that simply reflects a lack of knowledge. We know beyond reasonable doubt that God (that is, the Abrahamic monster) doesn't exist, because it is logically incoherent and we can see how it was invented out of earlier gods. It is as silly to suggest it is real as to suggest Harry Potter is real. We can't say with certainty that no other gods exist, but we can observe that there is zero evidence for them, and that there is no question about the Universe that requires a god or is better answered by positing one. So the only intellectually honest position is to assume none, in the same way we assume that Russell's Teapot doesn't exist. Actually Elon Musk missed our here. He should have put a teapot on the Tesla he launched. |
#173
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On 26/09/2018 20:07, Gary Harnagel wrote:
On Wednesday, September 26, 2018 at 6:52:19 AM UTC-6, Martin Brown wrote: On 26/09/2018 12:11, Gary Harnagel wrote: On Tuesday, September 25, 2018 at 2:01:11 PM UTC-6, Paul Schlyter wrote: And how do you know that intelligent civilisation will not self-destruct within a few millennia or so? Out of MILLIONS of civilizations, all that's needed is ONE to survive. We don't know of any other ET civilisations though. As yet we haven't found life arising independently on another planet either That's because we haven't looked except in a very few places. Wanna bet on the oceans of Enceladus? Life in the oceans perhaps, intelligent at the level of an octopus maybe but there is very little chance of them having any kind of technological civilisation in water even if they reached the hunter gatherer stage. Eventually they will get their opportunity when the sun expands and the temperature rises enough so that there is liquid water at the surface. (we will be toast by then) although there may be hints of life having been on Mars back when it had liquid water. (it may still be there deep in underground rocks or dormant as cysts) I wouldn't consider proof of life elsewhere in the solar system as proof of interstellar life. It could have come from earth. Depends whether or not it uses the same DNA code, handedness and amino acids. If it uses different choices to those on Earth then the odds are very good that it arose independently. If it uses the exactly the same compounds as on Earth then terrestrial contamination is by far the most likely reason. One reason to carefully sterilise anything sent to a pristine potentially life supporting environment on another planet. Until we have seen life arise in at least one other place then you are on a hiding to nothing guessing at the probability of life elsewhere. I am inclined to think that it will arise spontaneously where ever and when ever the conditions permit given how quickly it got going on Earth. But until we see another example it is just an educated guess. Much life may remain stuck at the photosynthetic slime stage though. Anyone with a grasp of probability theory and no preconceived notions would disagree with you. No, they would disagree with you. I have a grasp of probability theory and I disagree with YOU. You have a rather weak grasp of probability theory You are very funny :-)) and an even weaker grasp of the Drake equation. Planets now appear to be far more common than was once thought but a lot of them are hot Jupiters tidally locked to their parent star (a side effect of present experimental methods which are particularly good at detecting planetary transits and Doppler shifts as the hefty planet orbits its parent star close in). And you seem to be very weak on present theory that posits Jupiter having started out close to Sol. Comparatively few have been found in the Goldilocks zone (although that may be a selection effect of present observational techniques). Indeed. We should be looking at OLD G and K-type stars for old civili- zations. Tabby's Star may qualify although it's a 6-billion-year-old F-type. You do need a sufficient base of actual data to be able to say anything about the probability, otherwise you are just guessing. We have actual data on one civilization. YOU are just guessing about its longevity, but that's irrelevant because an example of one AND proof that almost every star has planets (via Kepler), it is a VERY good "guess" that life has developed elsewhere. It is certainly possible. But whether or not it is common for life to evolve beyond the single celled stage is still an open question. "Life will find a way.” -- Michael Crichton Just because your favourite science fiction writer said it does not make it true. One awkward upper bound on the timescale that a technological civilisation can operate without having to develop space faring technology is the time it takes to exhaust the finite resources of their home planet. 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. So why aren't they here then? You are the one who is biased here, not me, :-)) since I have not claimed any probability figure about that. THAT is YOUR bias speaking. We just know too little to be able to do that reliably. Just the sheer numbers of planets in the universe shred that assertion. If intelligent life was really common in our galaxy then there should be some residual signals for our radio and optical astronomers to see. Not necessarily. The time that a civilization uses radio technology may be quite short. Consider our own civilization. It's mostly beamed or fiber. If they were as common as you suppose there should be one inside the range of our radio telescopes by now. Technological civilisations are not going to be non-thermally radio bright for very long. That or we would have seen self replicating probes by now a la Fermi paradox. Not if there is an over-arching civilization that has already been here. And why isn't theology an exact science like physics? Why aren't our most powerful computers running simulations of God? There, now you have some things to think about... I thought. You got nuttin'! We don't know enough about how life started to do believable simulations. We don't even know if it started here. The chemists and molecular biologists are slowly getting closer to finding out answers. The tricky step is more likely to be the point where single celled simple life makes the transition to complex multicellular organisms. Science is always a step by step refinement from present knowledge by way of experiments. https://www.the-scientist.com/featur...-complex-42874 What they find will be way more convincing than a "Just So" story. Indeed. But haven't complex organic molecules been found in the solar system? Plenty. It is amazing what sort of a cocktail you can brew in a dense molecular cloud illuminated by fast burning brilliant young blue giants. -- Regards, Martin Brown |
#174
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Thursday, September 27, 2018 at 4:42:54 AM UTC-6, Martin Brown wrote:
On 26/09/2018 20:07, Gary Harnagel wrote: On Wednesday, September 26, 2018 at 6:52:19 AM UTC-6, Martin Brown wrote: On 26/09/2018 12:11, Gary Harnagel wrote: We don't know of any other ET civilisations though. As yet we haven't found life arising independently on another planet either That's because we haven't looked except in a very few places. Wanna bet on the oceans of Enceladus? Life in the oceans perhaps, intelligent at the level of an octopus maybe but there is very little chance of them having any kind of technological civilisation in water even if they reached the hunter gatherer stage. Eventually they will get their opportunity when the sun expands and the temperature rises enough so that there is liquid water at the surface. (we will be toast by then) although there may be hints of life having been on Mars back when it had liquid water. (it may still be there deep in underground rocks or dormant as cysts) I wouldn't consider proof of life elsewhere in the solar system as proof of interstellar life. It could have come from earth. Depends whether or not it uses the same DNA code, handedness and amino acids. If it uses different choices to those on Earth then the odds are very good that it arose independently. If it uses the exactly the same compounds as on Earth then terrestrial contamination is by far the most likely reason. One reason to carefully sterilise anything sent to a pristine potentially life supporting environment on another planet. I suspect that ALL life will have the same DNA. Until we have seen life arise in at least one other place then you are on a hiding to nothing guessing at the probability of life elsewhere. Some guesses are better than others. I think it's very arrogant to believe that nobody's out there, and it's even more arrogant to believe they haven't been around longer than we have. I am inclined to think that it will arise spontaneously where ever and when ever the conditions permit given how quickly it got going on Earth. But until we see another example it is just an educated guess. Educated versus arrogant. Much life may remain stuck at the photosynthetic slime stage though. I sometimes entertain panspermia thoughts. You have a rather weak grasp of probability theory You are very funny :-)) and an even weaker grasp of the Drake equation. Planets now appear to be far more common than was once thought but a lot of them are hot Jupiters tidally locked to their parent star (a side effect of present experimental methods which are particularly good at detecting planetary transits and Doppler shifts as the hefty planet orbits its parent star close in). And you seem to be very weak on present theory that posits Jupiter having started out close to Sol. Comparatively few have been found in the Goldilocks zone (although that may be a selection effect of present observational techniques). Indeed. We should be looking at OLD G and K-type stars for old civili- zations. Tabby's Star may qualify although it's a 6-billion-year-old F-type. It is certainly possible. But whether or not it is common for life to evolve beyond the single celled stage is still an open question. "Life will find a way.” -- Michael Crichton Just because your favourite science fiction writer said it does not make it true. He's not my favorite, but just because a SF writer said it doesn't make it false. One awkward upper bound on the timescale that a technological civilisation can operate without having to develop space faring technology is the time it takes to exhaust the finite resources of their home planet. 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. So why aren't they here then? How do you know they aren't? Surely a billion-year-old civilization has capabilities to completely hide themselves from us. OTOH, I sometimes wonder about UFOs .... I read Ruppelts "The Report on UFOs" back in the 50's, then a couple of years ago I read his 1960 updated version where he said that no credible sightings occurred with radar confirmation, so I switched back to thinking they were natural phenomena. And then this happened: https://video.search.yahoo.com/searc...b&action=click If intelligent life was really common in our galaxy then there should be some residual signals for our radio and optical astronomers to see. Not necessarily. The time that a civilization uses radio technology may be quite short. Consider our own civilization. It's mostly beamed or fiber. If they were as common as you suppose there should be one inside the range of our radio telescopes by now. As you said, probability is a guess. What I said was that all that is needed is ONE civilization. One civilization early in the galaxy's life (say, 4 billion years ago in our 9-billion-year-old galaxy) can spread a mere 100 thousand lightyears in a few million years. Technological civilisations are not going to be non-thermally radio bright for very long. I'm having trouble with your triple negative :-| I think you're saying that such civilizations will become radio bright in a non-thermal manner in a short time? I say that radio-brightness is a phase that civilizations go through in a fairly short time. They may develop means for communication and energy distribution that we can't detect at our present level of technology. IR brightness, OTOH, is more difficult to control due to energy dissipation. That or we would have seen self replicating probes by now a la Fermi paradox. Not if there is an over-arching civilization that has already been here.. The chemists and molecular biologists are slowly getting closer to finding out answers. The tricky step is more likely to be the point where single celled simple life makes the transition to complex multicellular organisms. Science is always a step by step refinement from present knowledge by way of experiments. https://www.the-scientist.com/featur...-complex-42874 What they find will be way more convincing than a "Just So" story. Indeed. But haven't complex organic molecules been found in the solar system? Plenty. It is amazing what sort of a cocktail you can brew in a dense molecular cloud illuminated by fast burning brilliant young blue giants. -- Regards, Martin Brown Yeah, and in the nursery where our sun was born, we may have been quite close to one or two of those. Our DNA may be shared with a whole swarm of stars spread all over the galaxy. Or maybe the biblical account is not so far off: that old, old civilization may have planted us :-) |
#175
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Thu, 27 Sep 2018 05:27:17 -0700 (PDT), Gary Harnagel
wrote: I suspect that ALL life will have the same DNA. That seems unlikely. We have created alternate forms of DNA in the lab, using different bases than A, G, T, C, and U. And which code differently. I can believe we might see similar genetic chemistry, but many different bases and coding. Some guesses are better than others. I think it's very arrogant to believe that nobody's out there, and it's even more arrogant to believe they haven't been around longer than we have. Life, yes. Technological life, maybe no. We appear on the verge of destroying ourselves, and that may be the norm for technological species. They may not get much older than us. |
#176
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Thursday, September 27, 2018 at 6:27:20 AM UTC-6, Gary Harnagel wrote:
I suspect that ALL life will have the same DNA. Why? Some forms of life on Earth actually code for proteins slightly differently from most, and so even if DNA were the only way to store genetic information, the genetic code would be completely different in life that had developed independently. John Savard |
#177
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Thursday, September 27, 2018 at 6:27:20 AM UTC-6, Gary Harnagel wrote:
Yeah, and in the nursery where our sun was born, we may have been quite close to one or two of those. Our DNA may be shared with a whole swarm of stars spread all over the galaxy. Or maybe the biblical account is not so far off: that old, old civilization may have planted us :-) The notion of life being seeded on Earth by an alien civilization is something used in a lot of science-fiction stories, and, for that matter, in some of the flying-saucer literature. There are basically two forms this notion could take. One is that aliens put *man* on an already-living planet. Now that we know how similar humans are to chimpanzees genetically, the idea that we have alien DNA is hard to take seriously. Plus, of course, there are fossils of H. erectus and of various forms of Australopithecus. Australopithecus skeletons strongly resemble those of chimpanzees, but with adaptations to walking upright, and larger brains. The other is that life is what the Earth was seeded with. If so, except for ensuring the Earth had life on it, the aliens would not have had much influence on what type of life it had. The development of life from its earliest forms took place on Earth - slowly, over billions of years. This is recorded by fossils in the ground. John Savard |
#178
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Wednesday, September 26, 2018 at 5:11:40 AM UTC-6, Gary Harnagel wrote:
Out of MILLIONS of civilizations, all that's needed is ONE to survive. I have no quarrel with the statement that it is possible, and it even seems likely, that there should be aliens far more advanced than humans out there. Now, of course, somebody has to be first, and the fact that aliens don't seem to have made themselves obvious in the Universe could be taken as evidence that they don't exist. But that is projecting our own behavior on them. Yes, it's a universal characteristic of life to expand as far as its environment will allow. And, at the moment, humans don't really show that much sign of behaving differently than aphids or yeast in this matter. That we could grow up, and limit our reproduction for the sake of responsible stewardship of our world, however, is not something I would characterize as impossible; indeed, it would be a necessary condition for long-term survival. No, my quarrel is far more simple. Those you speak of are in the category "elder brother", not "father"; we should heed their greater wisdom, but not worship them in the place of God. John Savard |
#179
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Thursday, September 27, 2018 at 8:04:27 AM UTC-6, Chris L Peterson wrote:
On Thu, 27 Sep 2018 05:27:17 -0700 (PDT), Gary Harnagel wrote: I suspect that ALL life will have the same DNA. That seems unlikely. We have created alternate forms of DNA in the lab, using different bases than A, G, T, C, and U. And which code differently. I can believe we might see similar genetic chemistry, but many different bases and coding. That depends on what one's assumptions are. Some guesses are better than others. I think it's very arrogant to believe that nobody's out there, and it's even more arrogant to believe they haven't been around longer than we have. Life, yes. Technological life, maybe no. We appear on the verge of destroying ourselves, and that may be the norm for technological species. They may not get much older than us. There's always a distribution when you have a "norm" and all that's necessary is a survivor out in the sunny side of the bell curve. Given the age of our galaxy at nine billion years (and it has incorporated stars far older than that - there is a red dwarf only 150 LY away that is estimated to be 14 billion years old). So that one survivor can spread its DNA over the whole galaxy in a few million years. |
#180
|
|||
|
|||
Neil DeGrasse Tyson headed down same loony road as Carl Sagan?
On Thursday, September 27, 2018 at 9:42:06 AM UTC-6, Quadibloc wrote:
On Thursday, September 27, 2018 at 6:27:20 AM UTC-6, Gary Harnagel wrote: Yeah, and in the nursery where our sun was born, we may have been quite close to one or two of those. Our DNA may be shared with a whole swarm of stars spread all over the galaxy. Or maybe the biblical account is not so far off: that old, old civilization may have planted us :-) The notion of life being seeded on Earth by an alien civilization is something used in a lot of science-fiction stories, and, for that matter, in some of the flying-saucer literature. There are basically two forms this notion could take. One is that aliens put *man* on an already-living planet. Now that we know how similar humans are to chimpanzees genetically, the idea that we have alien DNA is hard to take seriously. Plus, of course, there are fossils of H. erectus and of various forms of Australopithecus. Australopithecus skeletons strongly resemble those of chimpanzees, but with adaptations to walking upright, and larger brains. Yeah, I don't think that one will fly. The other is that life is what the Earth was seeded with. If so, except for ensuring the Earth had life on it, the aliens would not have had much influence on what type of life it had. The development of life from its earliest forms took place on Earth - slowly, over billions of years. This is recorded by fossils in the ground. John Savard The aliens took their time, kind of like the pan-dimensional beings in Hitchhiker's guide :-) I suspect that ALL life will have the same DNA. Why? See the argument I gave Chris P. Some forms of life on Earth actually code for proteins slightly differently from most, and so even if DNA were the only way to store genetic information, the genetic code would be completely different in life that had developed independently. Yes, IF it developed independently. Out of MILLIONS of civilizations, all that's needed is ONE to survive. I have no quarrel with the statement that it is possible, and it even seems likely, that there should be aliens far more advanced than humans out there. Now, of course, somebody has to be first, and the fact that aliens don't seem to have made themselves obvious in the Universe could be taken as evidence that they don't exist. But that is projecting our own behavior on them. Indeed. We are children in an adult universe. Yes, it's a universal characteristic of life to expand as far as its environment will allow. And, at the moment, humans don't really show that much sign of behaving differently than aphids or yeast in this matter. Aphids don't build spaceships. That we could grow up, and limit our reproduction for the sake of responsible stewardship of our world, however, is not something I would characterize as impossible; indeed, it would be a necessary condition for long-term survival. If there are limits. Certainly, there are limits to growth even in the solar system, but that's way beyond where we are now. Could some of these maverick planetary systems with weird worlds be terraformed? Maybe "terraformed" isn't the right word since we may not be as we now appear. No, my quarrel is far more simple. Those you speak of are in the category "elder brother", not "father"; we should heed their greater wisdom, but not worship them in the place of God. John Savard Some call Jesus Christ "Elder Brother" and they worship Him :-) |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Denial of Neil deGrasse Tyson's Science | Pentcho Valev | Astronomy Misc | 3 | April 24th 17 06:58 PM |
NEIL DEGRASSE TYSON DISHONEST OR JUST SILLY? | Pentcho Valev | Astronomy Misc | 3 | August 6th 15 12:14 PM |
Neil (EGO) Degrasse Tyson STEALS directly from Sagan | RichA[_6_] | Amateur Astronomy | 4 | April 17th 15 09:38 AM |
NEIL DEGRASSE TYSON : CONSPIRACY OF THE HIGHEST ORDER | Pentcho Valev | Astronomy Misc | 2 | July 14th 14 04:32 PM |
'My Favorite Universe' (Neil deGrasse Tyson) | M Dombek | UK Astronomy | 1 | December 29th 05 12:01 AM |