Michael Watson 的帖子

141) 留言板 : SETI@home Science : Would the Governments of the World Try to Suppress News of a SETI Discovery? (消息 1946530) 发表于：27 Jul 2018 作者： Michael Watson Post: It is contended by some, that government security services, throughout the world, would 'black out' news of a genuine SETI discovery. The reasons given for their wanting to do this are: 1.) That such a discovery might contain information on technology that could be made into dangerous new weapons of war. The nation receiving this information could obtain a tremendous military advantage. 2.) That news of such a discovery could provoke unrest in certain portions of society, such as the conservatively religious. 3.) That humanity is, in general, ill prepared to cope with the news of such a discovery, and its implications, and would be better off not knowing of such a discovery. Further, that benevolent extraterrestrials would refrain from contacting us for the above reasons. In 1967, the world was full of the news of the discovery of the first PULSAR. There were speculations that its superbly regular pulsing could be some kind of extraterrestrial beacon. There was no apparent effort to suppress this news. If the supposed censoring were to have been applied only if the source had turned out to be intelligent, instead of natural, it would have been too late. The facts would have already been too widely known. Even if militarily exploitable technology could be derived from a SETI signal, it would require lengthy study to do this. The simple fact of the existence of such a signal, the point of origin of the message, details about the nature of the life forms sending it, and of their planet could be safely released. National security agencies would not take it upon themselves to shield certain conservative religious sects from the potentially disturbing news of intelligent life on other worlds. There has been no analogous effort to protect such groups from other scientific information, which they find upsetting, such as the gradual evolution of life over billions of years. Humanity is not well situated to know the motives, plans, reasoning, or judgements of a wholly alien species. If such extraterrestrials have acquired experience in contacting other intelligent species in space, they could be in a far better position to judge when, or if we could be productively contacted. I used the analogy of a baby about to be born, yet very unhappy at being thrust into the cold, bright, larger world. This, because it is comfortably used to its current accommodations. I submit that we could be in a similar situation, with respect to our being born, as a species, into the larger universe of intelligent life.
142) 留言板 : News : Revised scale of significance of ET detection published. (消息 1946439) 发表于：26 Jul 2018 作者： Michael Watson Post: It doesn't seem at all likely that the National Security Agency would suppress news of a SETI discovery, as you suggest, in order to favor or protect a certain kind of religious belief. It's not clear to me that any particular religious sect in the modern world has a dogma which insists that Earth is the only planet in the universe with intelligent life. I understand that certain religious groups literally believe that the world in only a few thousand years old. The governments of the world don't take it upon themselves to suppress scientific evidence to the contrary, in order to prevent 'unrest' in such groups. It doesn't seem any more likely that they would do so where a SETI discovery were concerned. I doubt that we are in any position to know the motives, judgments or conclusions of a wholly alien race of intelligent beings. If they have had experience in dealing with contact with other races in space, they will be in a far better position to decide if, and when it would be appropriate to contact a particular species of intelligent life, such as ourselves. Human attitudes toward such contact are highly variable, so can't tell us much, really. If one could ask a nine-month-old fetus if it would like to be born into the cold, bright world, it would probably resist the suggestion, being comfortably used to its current accommodations. Never-the-less, it is as appropriately prepared to be born as it possibly can be. It may be that humanity is in roughly the same circumstances, where being born into the larger universe of intelligent life is concerned.
143) 留言板 : News : Revised scale of significance of ET detection published. (消息 1946418) 发表于：26 Jul 2018 作者： Michael Watson Post: How would we know if a super-secret organization, such as the National Security Agency, has a policy of 'blacking out' news of a genuine SETI signal? They obviously don't share their plans openly. Would they have the legal authority, or even practical ability to do this? There have been a number of cases where a detected signal could, in time, have proved to be the real thing. For example, shortly after the discovery of the first PULSAR, it was seriously wondered if it could be a SETI signal. This discovery, and the possibility of it being an intelligent signal from space were widely disseminated by the news media at the time. I recall, as a youth, hearing of this over the radio. There was no apparent attempt to suppress this news. Suppose the first PULSAR had finally been determined to be an intelligent signal from space. At what point would the news have been suppressed? If this was done prior to a definite, conclusive announcement from the scientists involved, we should have seen a censoring reaction to the initial PULSAR news, even though it did not turn out to be a SETI signal. Such a reaction was not seen. If a news black-out was instituted after the announcement, it would have been too late. The essential fact would be out in the open. If the thought was to supress information that might be militarily exploitable, a question arises. Such detailed information would very probably emerge only after much study of the signals, if at all. Why would it be necessary to conceal the bare facts about the signal-- its extraterrestrial origin, the location of the senders, the sort of planet they lived on, how much power was put into the signal, etc, etc.?
144) 留言板 : SETI@home Science : Liquid Water Beneath Mars' South Pole (消息 1946399) 发表于：26 Jul 2018 作者： Michael Watson Post: Here is a link to a CBC video, which includes an image of the subsurface radar returns that indicate water. The idea of 'basal melting' beneath Mars' South polar cap is discussed. Pressure from the ice would decrease the freezing temperature of water, and so keep t in a liquid state. Other sources question whether a depth of only ~1.5 kilometers would be enough, on low-gravity Mars, to create sufficient pressure for this. The solution of various minerals in the water may act as 'anti-freeze', which can also lower its freezing point. This high concentration of sodium-based minerals could present a problem for any life forms that might exist in the water. But given the almost fantastic ability of life to adapt to extreme conditions, already observed on Earth, it seems possible that life on Mars could exist in such underground lakes. https://www.youtube.com/watch?v=d6hBHuKRw_c
145) 留言板 : SETI@home Science : Liquid Water Beneath Mars' South Pole (消息 1946219) 发表于：25 Jul 2018 作者： Michael Watson Post: Strong evidence of liquid water below the surface of Mars has been announced. Radar studies of the subsurface have produced returns very like those from underground lakes in Antarctica. A separate project's radar was unable to find the same evidence, so the matter is unsettled, and in need of further confirmation. A lake, some 20 kilometers in extent, though perhaps only a meter deep, situated about 2 kilometers beneath Mars' South polar region was indicated. This water would presumably be filled with minerals that lower its freezing point to below that of this strata of Mars. There were reported to be signs that there could be multiple lakes. The presence of persistent lakes of liquid water would improve the chances for life on the Red Planet considerably. At this depth, it would be shielded from temperature extremes and radiation from space, which, due to Mars' very thin atmosphere, would be very serious problems for life at the surface. Please find a link, below, to an article with further details: https://www.cnn.com/2018/07/25/world/mars-subsurface-water-lake-evidence/index.html
146) 留言板 : Science (non-SETI) : Confused about signals. (消息 1945961) 发表于：23 Jul 2018 作者： Michael Watson Post: Welcome to the forum, MjMdM; Despite what some people seem to believe, these are still very early days in SETI. If we were to find a signal from intelligent life on another world, it would mean that such life is very likely to be very common in the galaxy. This discovery would amount to the most important and interesting discovery in the history of science! Even if 'back and forth' conversation proved impractical, this would not alter the basic importance of the discovery. There is no telling what sort of valuable information we might extract from the signals, in time. At the very least, we would have learned that it is possible for a civilization to reach, and surpass our level of technical development and continue to flourish. A very valuable lesson for us.
147) 留言板 : SETI@home Science : Oumuamua (消息 1944072) 发表于：13 Jul 2018 作者： Michael Watson Post: We'd probably give them severe indigestion, if not food poisoning! The biochemistry of life evolving independently on another world would very probably be so different, that it would be incompatible with our own. Then, too, one suspects that beings able to master the problem of interstellar spaceflight could very likely synthesize whatever food they needed, seemingly a much simpler task.
148) 留言板 : Science (non-SETI) : 3D Movie of Asteroid Ryugu (消息 1943989) 发表于：13 Jul 2018 作者： Michael Watson Post: For those without access to 3D colored glasses, A conventional 'movie' of the asteroid rotating is available at the link, below. The most interesting feature on Ryugu is the light-colored object near the top of the image. One is reminded of the especially bright spot on the asteroid Ceres, in the Occator crater. This isn't a flattish spot, though, but more like a boulder. Ryugu seems too small to have geological layering, like salt deposits that can be driven to the surface by impacts, which is probably what happened at Ceres. This light-colored object is notable for having at least two quite flat, vertical surfaces, almost as if rough surfaces had been sheared off. These surfaces are quite efficient at catching and reflecting sunlight. http://www.unmannedspaceflight.com/index.php?act=attach&type=post&id=43177
149) 留言板 : SETI@home Science : Detecting Life on Other Worlds by Seasonal Variations in their Atmospheres (消息 1943984) 发表于：13 Jul 2018 作者： Michael Watson Post: It's been proposed in a new paper that it may be possible to detect life on exoplanets by examining the way their atmospheres vary slightly in composition. Gases like oxygen, carbon dioxide, and methane are expected to vary in their abundances in time with the seasons, as life's metabolism responds to varying temperatures, light levels, and moisture. Spectroscopic measurements, taken over extended periods of time may be able to tease out these differences. Please find a link, below, with further information: https://www.skyandtelescope.com/astronomy-news/astrobiology/identifying-life-from-varying-atmospheres/
150) 留言板 : SETI@home Science : Oumuamua (消息 1943861) 发表于：12 Jul 2018 作者： Michael Watson Post: If we assume, for the sake of discussion, that Oumuamua is a space vehicle, it could have been a 'dry run' to see how we'd react. Since there was interest, and even the realization that it could be a spacecraft, yet no panic, we could be in for a more conspicuously artificial object, the next time. For all we know such a thing could be on its way to us right now, just waiting for us to discover it. If this were to occur, it would probably turn up in an astronomical survey. This is the main reason I keep track of the latest news about near- Earth, and other unusual asteroids and comets. Such a space vehicle could be interpreted as a comet or asteroid, at first, just as Oumuamua was.
151) 留言板 : SETI@home Science : Oumuamua (消息 1943709) 发表于：11 Jul 2018 作者： Michael Watson Post: Reviewing the articles from a few months ago about Oumuamua, one is struck with how firm was the asteroidal interpretation. Now that we have seen enough acceleration to put it 100,000 kilometers farther out in space than expected, there is this effort to fit it into the comet mold, even if it doesn't fit very well. Alternately, some have suggested that it is an asteroid, but is being affected by the Yarkovsky Effect. This seems far too negligible to have moved an asteroid to anywhere near this extent, in a matter of months. I understand that it is typically measured in distances of one or a few kilometers per year. One also wonders if it had a magnetic field which interacted with the solar magnetic field to produce some unexpected forces. The discussed letter to the journal Nature mentions that magnetic interaction of Oumuamua with the Sun was considered, but was found inadequate to explain the acceleration of the object. For details on this, please consult the letter, which I linked, a few posts back.
152) 留言板 : Science (non-SETI) : 3D Movie of Asteroid Ryugu (消息 1943695) 发表于：10 Jul 2018 作者： Michael Watson Post: The asteroid Ryugu is being approached by the Japanese space probe Hayabusa2. The craft will eventually land on the asteroid, collect mineral samples, and return them to Earth. For now, we have the animation sequence, linked below. It is made of images of the asteroid as it rotates. These are processed with red and cyan filters to produce three dimensional images. To view this movie, one needs to watch through similarly colored 3D glasses; red for the left eye, cyan for the right. These glasses are widely available. The rotation of the asteroid is represented in two sequences, in the upper one, the rotation is very rapid, to give a good impression of smooth motion, In the lower, the rotation proceeds much more slowly, step by step. This enables closer study of details of the asteroid's terrain. http://www.hayabusa2.jaxa.jp/topics/20180710je/index.html
153) 留言板 : SETI@home Science : Oumuamua (消息 1943640) 发表于：10 Jul 2018 作者： Michael Watson Post: 100,000 kilometers, cosmically speaking, is not too much to be off. I haven't read the research myself, but as I understand it, they're still pouring over the data as best they can, and will probably be arguing and disagreeing over assertions for quite some time. Possibly forever. However, scientifically speaking, it is better to suggest a natural conclusion (asteroid, comet) than to suggest an unnatural one without stronger evidence. Merely having an odd orbit and traveling faster than expected are not enough to claim it was an alien spacecraft. Extraordinary claims require extraordinary evidence. Besides the decidedly hyperbolic orbit of Oumuamua, and its poorly-explained acceleration, we have the extreme oddity that it may be as much as 10 times as long as it is wide. I'm not claiming that it is settled that Oumuamua is an interstellar space vehicle, of course, but these do seem an extraordinary set of facts about this object. This fascinating possibility was entertained by both the SETI Institute and the Breakthrough Listen project , as evidenced by their repeated radio monitoring of Oumuamua, for any intelligent signals it might be emitting.
154) 留言板 : SETI@home Science : Oumuamua (消息 1943506) 发表于：9 Jul 2018 作者： Michael Watson Post: You can read the paper , which I linked a few post back. It doesn't appear that any errors of the sort mentioned were likely, given the degree of care taken. If you find any fault in their methodology, I'd like to learn of it. The 'Flyby Effect', which affected several of our space probes rounding the Sun, was somewhere suggested as a possible source of the extra speed. I looked into this, but found that, it would be unlikely to account for more than a few hundred kilometers, in the length of time concerned.
155) 留言板 : SETI@home Science : Oumuamua (消息 1943383) 发表于：8 Jul 2018 作者： Michael Watson Post: Reviewing the articles from a few months ago about Oumuamua, one is struck with how firm was the asteroidal interpretation. Now that we have seen enough acceleration to put it 100,000 kilometers farther out in space than expected, there is this effort to fit it into the comet mold, even if it doesn't fit very well. Alternately, some have suggested that it is an asteroid, but is being affected by the Yarkovsky Effect. This seems far too negligible to have moved an asteroid to anywhere near this extent, in a matter of months. I understand that it is typically measured in distances of one or a few kilometers per year.
156) 留言板 : SETI@home Science : Oumuamua (消息 1943091) 发表于：7 Jul 2018 作者： Michael Watson Post: The researchers who think that Oumuamua is a comet, and that this explains its otherwise-mysterious acceleration wrote a letter to the science journal Nature. In this letter, they admit that a number of assumptions are necessary, for this idea to work. They strike a much more tentative tone than most of the ordinary news articles, which trumpet the comet explanation as 'case closed'. The astronomers say that several different substances, unusual in comets, would need to be present on Oumumamua, in order for outgassing to provide the observed acceleration. I don't find this tentative chain of assumptions particularly convincing. An interstellar spacecraft would be a much more scientifically interesting possibility. Please find a link, below, to the referenced letter to Nature: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1813/heic1813a.pdf
157) 留言板 : Science (non-SETI) : Asteroids & Comets (消息 1938182) 发表于：3 Jun 2018 作者： Michael Watson Post: The asteroid probe of the Japanese Aerospace Exploration Agency (JAXA), known as Hayabusa 2, is nearing its objective, the asteroid Ryugu. On Tuesday, June 5th, it will begin the official approach phase of its mission. At that time Hayabusa 2 will be only 2500 kilometers from the asteroid. Its ion engines will then cut off, and it will coast the rest of the way. A new, though still rather low resolution, image of the asteroid is expected at that time. Ryugu is a small asteroid, about 900 meters in diameter. Its light curve suggests that it rotates in about 6.7 hours. The light curve was found to be almost steady, indicating a nearly spherical object. That's interesting, because Ryugu is too small an object for its gravity to pull it into a neat, spherical shape. Please find a link, below, to an article with further information: http://www.planetary.org/blogs/emily-lakdawalla/2018/0525-keep-up-with-hayabusa2.html
158) 留言板 : Science (non-SETI) : Asteroids & Comets (消息 1936689) 发表于：22 May 2018 作者： Michael Watson Post: Some scientific skepticism has been expressed about the interstellar origins of asteroid 2015 BZ 509. It seems that there are at least 95 other small bodies in our solar system with retrograde orbits. These, as well as 'Bee-Zed', could have had their orbits reversed by gravitational interactions with other solar system bodies. No mathematical model has been produced to show just how 2015 BZ 509 could have been captured into a co-orbit with Jupiter, supposing it actually came in from interstellar space. Please find an article, linked below, with further information: https://news.nationalgeographic.com/2018/05/interstellar-asteroid-jupiter-bz509-astronomy-space-science
159) 留言板 : Science (non-SETI) : Asteroids & Comets (消息 1936035) 发表于：17 May 2018 作者： Michael Watson Post: During its close pass, asteroid 2010 WC9 was observed to vary in brightness repeatedly, over a period of less than 20 minutes. This is presumably due to its rotation at that same rate. An asteroid rotating this rapidly is likely to be one stony mass, rather than a loosely held collection of rubble, as some asteroids are. The variations in brightness amounted to one magnitude. This suggests that the asteroid is substantially elongated, on the order of 2 & 1/2 times longer than it is wide.
160) 留言板 : SETI@home Science : U.S. House of Representatives Proposes $10 million be spent on SETI (消息 1935217) 发表于：11 May 2018 作者： Michael Watson Post: The United States House of Representatives is proposing that 10 million dollars a year be spent, so that NASA can seriously pursue the goal of searching for radio signals from extraterrestrial civilizations. This is a sharp contrast to 1993, when U.S. government funding for SETI was cut to nothing, only a year after such a program had begun. This proposal still has to make it's way through the House, and then the Senate, and funding must then actually be allocated to support the proposal. More information in the article. linked below: https://www.theatlantic.com/science/archive/2018/05/seti-technosignatures-nasa-jill-tarter/558512/

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