tag:blogger.com,1999:blog-8587336.post600707680573547589..comments2024-03-28T10:56:52.861-07:00Comments on CONTRARY BRIN: The Deadly Thing at 2.4 Kiloparsecs: Are we sharing the galaxy with something large, dangerous and periodic?David Brinhttp://www.blogger.com/profile/14465315130418506525noreply@blogger.comBlogger46125tag:blogger.com,1999:blog-8587336.post-21152744271368994272020-12-16T15:48:26.248-08:002020-12-16T15:48:26.248-08:00What about the 26 my cycle?
Assume a body orbiti...What about the 26 my cycle? <br /><br />Assume a body orbiting closer to us. That requires less "power" to cause results on the Earth. The difference degree of catastrophe is possibly accounted for by alignment. When the Earth is above the galactic plane but the, uh hem, nemesis is below the impact is obviously less than when both are on the plane. <br /><br />I'd suggest that the big failing is assuming there is only one nemesis. Nothing is unique in the galaxy so there should be many all having impacts at intermittent times. Rud Merriamnoreply@blogger.comtag:blogger.com,1999:blog-8587336.post-7391450615625190662018-10-30T02:13:18.154-07:002018-10-30T02:13:18.154-07:00This comment has been removed by a blog administrator.siskahttps://www.blogger.com/profile/07076079736141144027noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-40553846180726298462017-12-02T07:22:39.655-08:002017-12-02T07:22:39.655-08:00Dark Matter and the Dinosaurs is about this same i...Dark Matter and the Dinosaurs is about this same idea. I enjoyed it, I don't know if it stands to recent developments and discoveries or not. The author is a particle physicist, who not a crank, so it's not a waste of time.<br /><br /><br />In this brilliant exploration of our cosmic environment, the renowned particle physicist and New York Times bestselling author of Warped Passages and Knocking on Heaven’s Door uses her research into dark matter to illuminate the startling connections between the furthest reaches of space and life here on Earth.<br /><br />https://www.amazon.com/Dark-Matter-Dinosaurs-Astounding-Interconnectedness/dp/0062328476Donhttps://www.blogger.com/profile/14457773946084846715noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-15347785147821421992015-07-07T15:40:35.592-07:002015-07-07T15:40:35.592-07:00DM we should have been spending on hardening EMP r...DM we should have been spending on hardening EMP resistance for 50 years...David Brinhttps://www.blogger.com/profile/14465315130418506525noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-35489091193550860152015-07-07T13:41:10.095-07:002015-07-07T13:41:10.095-07:00Agreed that chicken-littling over asteroids is mor...Agreed that chicken-littling over asteroids is more sensible than over The Beast. Even smarter, I submit, is to worry about Carrington events. We provably haven't had a civilization-destroying asteroid in at least thousands of years, but we had a Carrington event that would now lay us very low, only a few decades before it would have been relevant. Hardening our power grid wouldn't even be that expensive compared to asteroid survivability.Doctor Mistnoreply@blogger.comtag:blogger.com,1999:blog-8587336.post-3988329054137696552015-07-07T07:43:36.270-07:002015-07-07T07:43:36.270-07:00Add the end of the Eocene as yet another minor ext...Add the end of the Eocene as yet another minor extinction event some 34 MY ago. Global climate changed to colder and stayed that way ever since. Caldera outbreak going on in Colorado. Several large impacts - Chesapeake Bay and Popogai being the largest - clustered around that time. <br /><br />If you want to have some real fun, start looking into the YD / Taurus Complex some 11k years ago. Cheers -agimarchttps://www.blogger.com/profile/09631716689015396192noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-45679420107179206082015-07-06T17:33:46.906-07:002015-07-06T17:33:46.906-07:00Link to Muller talk at SETI: Discovery of Strong ...Link to Muller talk at SETI: <a href="http://www.seti.org/seti-institute/weeky-lecture/discovery-strong-cycles-fossil-diversity" rel="nofollow">Discovery of Strong Cycles in Fossil Diversity</a>. I'm afraid I was one of the questioners at the end (thank God I cannot be identified).Alex Tolleyhttps://www.blogger.com/profile/01556422553154817988noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-26509979790774158852015-07-06T16:26:18.136-07:002015-07-06T16:26:18.136-07:00Glad to see that you've brought this one back ...Glad to see that you've brought this one back up. I read the original articles about the periodicity of mass extinctions back in the 1980s. Most of the stuff I read then speculated on a brown dwarf or similar that was in a very long period orbit around our sun getting closer and disrupting the Oort Cloud which would dump stuff on us. <br /><br />Nice to see you're thinking about this again, David.<br /><br />Forrest Higgshttps://www.blogger.com/profile/17208965471464716174noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-89121680326674273292015-07-06T15:25:10.949-07:002015-07-06T15:25:10.949-07:00onwardonwardDavid Brinhttps://www.blogger.com/profile/14465315130418506525noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-35778112063190089352015-07-06T15:12:15.295-07:002015-07-06T15:12:15.295-07:00Alex, Rampino's new theory... that we pass thr...Alex, Rampino's new theory... that we pass through a dense plane of dark matter every 26 My or so, the pancake of the galactic plane, has a quirk. It suggests that BOTH comet falls and volcanic activity might be set off that way.David Brinhttps://www.blogger.com/profile/14465315130418506525noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-68239582526237384382015-07-06T13:54:34.491-07:002015-07-06T13:54:34.491-07:00The talk that Richard Muller gave at SETI in 2009....The talk that Richard Muller gave at SETI in 2009. You can see how he analyzed the data to get his 62my cycles and judge whether this is even correct. Without listening again, IIRC, his team needed to adjust the dating of some fossils to get the cycles, which were exposed with Fourier analysis and also wavelets. <br /><br />What bothers me is that we know, or think we know, the events and possible causes of some of these extinction events, suggesting we don't need some distant phenomenon to explain it, although if the cycles are correct, the extinctions cannot be random as Raup has suggested in the past. Recent work has suggested that impacts can also cause massive volcanic activity, and with a possible identification of an impact site, might explain the onset of the Permian extinction. <br /><br />Also recall that Muller also once supported the Nemesis hypothesis - a star bound to our solar system, and causing extinctions every 26my. Why the data could support a 26my and a 62my extinction cycle is rather strange, and suggests that this may be more in the eye of the beholder than real. In any case, Nemesis has been almost completely ruled out by the WISE mission.<br /><br />This paper <a href="http://www.mpg.de/4372308/nemsis_myth?filter_order=L&page=1" rel="nofollow">Nemesis is a Myth</a> rules out cycles of period increases in impacts as a statistical artifact. This article in MIT Technology review conforms the 27my extinction cycle over 500my, but rules out the Nemesis explanation.<br /><br />So where does that leave us? It seems that the older 26/27my extinction rate is apparently stronger than Muller's 62my cycle. If true, the lack of impact cycles suggests that the impact + vulcanism hypothesis is just coincidental. If the cause is something in the galaxy co-orbiting with the Sun, it must be very close to the galactic center. Perhaps it is a very intense beam of high energy electromagnetic radiation (UV/x-ray/gamma ray) that could penetrate the Earth's atmosphere. Alex Tolleyhttps://www.blogger.com/profile/01556422553154817988noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-63060150534425009252015-07-06T13:16:25.586-07:002015-07-06T13:16:25.586-07:00Chandra Wickramasinghe is a remnant colleague of F...Chandra Wickramasinghe is a remnant colleague of Fred Hoyle who does solid science... but is also the focus figure of a borderline Cult of Panspermia that earns the epithet via havens of tendentious "science" such as the so-called Journal of Cosmology. <br /><br />Having said that, let me add that I have no problem at all with positing the possibility that comets may have been the reactor vessels that cooked up the original primordial life-stuff. There was a period in the early solar system when decaying aluminum 26 from a recent supernova might have heated a trillion comets enough to give them liquid interiors protected by ice-cold shells. A hell of a bunch of test tubes. Indeed, might this account for the "sink-holes" that the Rosetta Probe seems to have found, at comet 67/P?<br /><br />OTOH the dark, quasi-organic dust Philae and Rosetta see are far simpler to explain -- and WERE explained in my doctoral thesis -- as simply the same stuff as we already see in carbonaceous chondrites. David Brinhttps://www.blogger.com/profile/14465315130418506525noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-10009894668846437092015-07-06T12:43:08.029-07:002015-07-06T12:43:08.029-07:00The fun thing studying geology during the mid-'...The fun thing studying geology during the mid-'80s was that the field was still sorting itself after the work done on plate tectonics had established crustal plate movement. With the Alvarez's paper came a major challenge set to the field, as what they claimed could easily be demonstrated by just going to K-T boundary layers and taking a sample of that layer...or for some departments just pulling out their drill cores. If plate tectonics shifted our understanding of how planetary changes happened due to such movement, then the K-T theory expanded the reach of things that could change terrestrial environment into space.<br /><br />What both plate tectonics and the K-T boundary theory did was also give a number of other items that could be checked to prove or disprove the theory. The only 'land bridge' that could be easily demonstrated were those due to simple shifts in water level due to glaciation, and that didn't explain the geographic distribution of species while tectonics did so. Likewise 3-axis shocked quartz and soot appearing with the boundary layer, and the hard cut-offs for survival mass, along with sole-survivor radiation of forams were outcomes that other theories did not have as features but an impact event did.<br /><br />A theory must not only explain all of the past framework, and lay down a new one to supercede and also encapsulate the past known work, but must also generate up events or other phenomena which can be predicted and measured (like the bending of a light passing close to a star or frame dragging for Mercury's orbit for Einstein's work) that prior theories cannot predict as those are not things that they cover. Any hypothesis that can do all of that and then lay the groundwork for new work has a higher likelihood of having merit to it. If there is some astronomical object speeding along just slightly faster than our sun around the galaxy, then what else does it do? One would imagine that such a fingerprint of a thing like that would also disturb other parts of the observable galaxy in some way or be currently interacting with some other objects in a way not predicted by the current understanding of relative galactic motion.<br /><br />One can have a right idea, like Weggener did for movement of continents, but be completely wrong on the mechanism, which was the case with him. The idea can be seen as having some relative merit, but by not being rigorous in mechanism it fell into disfavor. Identify the mechanism, link it to events and then give a novel proposal that can then be examined for other effects and you have something there that can suffer under scrutiny and examination. When the Alvarez's put out their concept of how the K-T extinction worked, they rang the dinnerbell and anyone able to simply disprove the hypothesis would have taken down one of the old guard of physics. He knew that science was a full contact sport, and his team played it that way. That was a good time to be learning geology.A Jacksonianhttps://www.blogger.com/profile/07607888697879327120noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-43554304898093376542015-07-06T11:57:13.461-07:002015-07-06T11:57:13.461-07:00This isn't bogus pattern recognition. It's...This isn't bogus pattern recognition. It's just hypothesis generation. It's what we scientists are supposed to do so our peers and students have something to shoot at with future experiments. For example, I think it is more likely there are long cycles regarding fluid flows within the Earth. I look at the pancake volcanoes on Venus and think it might be the place to learn about these long cycles because it doesn't have plates moving around destroying the evidence. How old is the oldest piece of oceanic crust at the bottom of the Pacific after all? We know hotspots matter, but do we really know the currents deep in the mantle and deeper still in the core?<br /><br />The Three Body Problem is different again. That one is inherently unsolvable except in special cases. Knowing the rules of a physical model does not always lead to predictions that can be generated from pretty and ordered equations. Not all Diff Eq's have to have closed solutions. Sometimes you just have to do the integrations by brute force. So much numerical joy to be found proving yet again how silly it is to believe in a deterministic universe. 8)Alfred Differhttps://www.blogger.com/profile/01170159981105973192noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-88845147974721847942015-07-05T17:31:37.520-07:002015-07-05T17:31:37.520-07:00Philae comet could be home to alien life, say top ...<a href="http://www.theguardian.com/science/2015/jul/06/philae-comet-could-be-home-to-alien-life-say-top-scientists" rel="nofollow">Philae comet could be home to alien life, say top scientists</a>.<br /><br />Great headline, and very "Heart of the Comet". Unfortunately the scientists include Chandra Wickramasinghe who sees life as an explanation for phenomena everywhere he looks. Chances of this being true, close to zero IMO.Alex Tolleyhttps://www.blogger.com/profile/01556422553154817988noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-54769639673492801332015-07-05T13:46:55.113-07:002015-07-05T13:46:55.113-07:00Alex & Jumper... that has been used as a devic...Alex & Jumper... that has been used as a device in countless sf'nals. In fact, I'm pretty sure I have.David Brinhttps://www.blogger.com/profile/14465315130418506525noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-38036453161101525742015-07-05T12:17:59.966-07:002015-07-05T12:17:59.966-07:00I'd say someone who hallucinates all the time ...<i>I'd say someone who hallucinates all the time with no hallucinogenic drugs might have some medical problems.</i><br /><br />Like people who claim to see and feel the invisible sky fairy's son? :) Alex Tolleyhttps://www.blogger.com/profile/01556422553154817988noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-80211943227203120502015-07-05T11:57:59.457-07:002015-07-05T11:57:59.457-07:00Of course, I've had those too. I'd say som...Of course, I've had those too. I'd say someone who hallucinates all the time with no hallucinogenic drugs might have some medical problems.Jumperhttps://www.blogger.com/profile/11794110173836133321noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-2684898214976253102015-07-05T11:48:24.041-07:002015-07-05T11:48:24.041-07:00hallucination is a classic symptom of insanity.
L...<i>hallucination is a classic symptom of insanity.</i><br /><br />Let's clarify that. Believing your hallucinations are real is a sign of insanity.<br /><br />I've had hallucinations when deprived of sleep. But I recognize them as unreal. However, suppose you were permanently kept sleep deprived, would those hallucinations start to seem real? We don't question the reality of our dreams when we are in them, so it doesn't seem impossible to believe hallucinations when you are ostensibly awake.Alex Tolleyhttps://www.blogger.com/profile/01556422553154817988noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-26552663577171526672015-07-05T10:36:45.694-07:002015-07-05T10:36:45.694-07:00Perhaps sterilizing the slaves was seen as merely ...Perhaps sterilizing the slaves was seen as merely a "good neighbor" policy much as we neuter our dogs not so much for our own benefit as for the benefit of the neighbors and the community in general.<br />https://books.google.com/books?id=f7yNAgAAQBAJ&pg=PA17&lpg=PA17&dq=richard+burton+on+eunuchs&source=bl&ots=8d7HyCw0ax&sig=bwo0TXgp-_J33dPI-rYgelvrCUc&hl=en&sa=X&ei=dUWZVZavGIW4-QHJpIjADw&ved=0CDsQ6AEwBQ#v=onepage&q=richard%20burton%20on%20eunuchs&f=false<br /> I have no more to say. (I am <i>so</i> glad to change the subject... however this is good fuel for further thought on many topics, from structural feudalism to current thoughts on transgender issues.)<br /><br />On pattern recognition, which likely many of us have seen recently:<br />http://googleresearch.blogspot.com/2015/06/inceptionism-going-deeper-into-neural.html<br />In any case, the resemblance of excessive pattern recognition to blatant hallucination is also instructive, as hallucination is a classic symptom of insanity. It also happens to be an excellent theory of what is happening in the brain affected by hallucinogenic drugs.Jumperhttps://www.blogger.com/profile/11794110173836133321noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-7348721231846145852015-07-05T09:42:21.197-07:002015-07-05T09:42:21.197-07:00And yet matrilineal descent is a tiny minority in ...And yet matrilineal descent is a tiny minority in state-level societies. You see it most commonly in tribe-level societies, primarily where fully-grown males tend to be gone for long periods of time, either on long-distance raiding expeditions or long-distance trading expeditions (caravan trade). Tibet is an interesting exception. Paul SBnoreply@blogger.comtag:blogger.com,1999:blog-8587336.post-77178638202338679322015-07-05T09:01:29.194-07:002015-07-05T09:01:29.194-07:00* "The history of monarchies is rife with suc...<b>*</b> "<i>The history of monarchies is rife with succession crises anyway, but without such taboos it would have been much worse, making feudalism even less stable</i>"<br /><br />which ignores the elephant in the room: that the most stable pre-DNA-sequencing form of succession is the matrilineal one.<br /><br />***<br /><br /><b>*</b> "<i>If you mean the property-owning man had been cuckolded, wouldn't the "son" have already been raised within the family? How would a son of the wife (but not the husband) be out there ready to pounce on a claim after the husband's death?</i>"<br /><br />Bloodline fetichization. For its adherents, the fact that the kid you raised regards you as his father is much less important than the fact that his cells don't contain half your chromosomes.Laurent Weppenoreply@blogger.comtag:blogger.com,1999:blog-8587336.post-54095823569192897602015-07-05T08:43:45.707-07:002015-07-05T08:43:45.707-07:00Larry, you're right here. I think I should wai...Larry, you're right here. I think I should wait until I have been adequately caffeinated before coming here. I can do that during the summer, but not during the school year. It would be the illegitimate offspring of different women by the deceased that seems to cause most of the problems, although one could always challenge the legitimacy of a purportedly legitimate inheritor (an episode of the original Black Adder is swirling around in my neural pathways). <br /><br />On overactive pattern recognition, it's just so much fun to mess with - drives grad students crazy!<br /><br />Eric, I think many of us would love to hear about your plant breeding experiments. What kinds of characteristics would you breed for to survive a crust-busting meteoric catastrophe? High tolerance to both sulfuric and carbonic acid, I would guess. But if we are looking at a scale of millions of years, we couldn't be sure that any selected genes would not be removed from the pool by mutation and replacement, unless you have come up with much more effective repair enzymes. Am I in the ballpark? Paul SBnoreply@blogger.comtag:blogger.com,1999:blog-8587336.post-41041525450528114242015-07-05T08:22:49.242-07:002015-07-05T08:22:49.242-07:00IRONIC that David's cosmic discussion on mass ...IRONIC that David's cosmic discussion on mass extinctions devolved to this.<br />My only concern was wheather we are about to meet the deadly thing soon (within the next million years or so) or if we have another 100+ million years. I am sure whatever it is does correspond to the earth taking some hits while catacylsmic volcanic activity is triggered. <br /> The timing of the next encounter might change my approach to my plant breeding and introductions. <br />ETAAnonymoushttps://www.blogger.com/profile/04275082890812525658noreply@blogger.comtag:blogger.com,1999:blog-8587336.post-63370817843299450962015-07-05T07:33:56.757-07:002015-07-05T07:33:56.757-07:00Paul SB:
Before the discovery of mini satellite D...Paul SB:<br /><i><br />Before the discovery of mini satellite DNA which led to DNA fingerprinting, the maternity of a child has always been easy to determine but paternity was shrouded in mystery. This means that after a property-owning father dies, men could show up to claim the right to inherit who might not actually be offspring of the deceased though they were offspring of the deceased's wife.<br /></i><br /><br />I feel I must be missing something obvious.<br /><br />I understand the concept of a stranger showing up claiming to be the man's illegitimate son, whether true or not. But how does "offspring of the deceased's wife" affect the claim one way or another? If you mean the property-owning man had been cuckolded, wouldn't the "son" have already been raised within the family? How would a son of the wife (but not the husband) be out there ready to pounce on a claim after the husband's death?<br /><br /><br />LarryHartnoreply@blogger.com