Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!hao!gatech!bbn!uwmcsd1!csd4.milw.wisc.edu!markh From: markh@csd4.milw.wisc.edu (Mark William Hopkins) Newsgroups: sci.misc Subject: Re: more Velikovsky Message-ID: <5265@uwmcsd1.UUCP> Date: 19 Mar 88 23:43:01 GMT References: <5236@uwmcsd1.UUCP> <1138@PT.CS.CMU.EDU> <5250@uwmcsd1.UUCP> <1167@PT.CS.CMU.EDU> Sender: daemon@uwmcsd1.UUCP Reply-To: markh@csd4.milw.wisc.edu (Mark William Hopkins) Organization: University of Wisconsin-Milwaukee Lines: 105 Summary: The big V. In article <1167@PT.CS.CMU.EDU> lindsay@K.GP.CS.CMU.EDU (Donald Lindsay) writes: >In article <5250@uwmcsd1.UUCP> markh@csd4.milw.wisc.edu (Mark William Hopkins) writes: >>>>The dinosaur-extinction hypothesis, as I understand it, is that dust >>>>raised by a large meteorite striking the earth caused climactic changes >>>>that the dinosaurs couldn't survive. >>>>Velikovsky's hypothesis was that the climatic change brought about by the >>>>near collision caused the mass extinction at the end of the Ice Age ... the >>>>very same kind of hypothesis. >>> >>>A planet floating by, and an asteroid ramming us, are not "the same kind of >>>hypothesis". >> >>In both cases we are talking about collisions or near collisions. > >No. Read carefully. A planet floating by is a near-collision. It is not a >collision. An asteroid ramming us is a collision. It is not a near- >collision. Okay. However, the difference is still superficial because in both cases we are talking about a catastrophe caused by a collision OR a near collision bringing about the extinction of species. This is what Velikovsky had hypothesized about the Ice Age extinctions *and also prior extinctions*. He had stated that the dinosaurs had probably become extinct either through a collision or the after effects of one. What these ideas were going against was the ingrained belief of that time that extinctions were brought about naturally, as per Darwin (as opposed to extinction by catastrophe.) I hope this clears things up, because we do not really disagree on matters here. > >If an asteroid missed the Earth, it would have no serious tidal effect. If >it grazed the atmosphere, it would do at most local damage. (A side note: >some mountain climbers once photographed a grazing meteor that was **going** >**up** ! ) The lack of damage follows from the fact that it retained enough >energy to escape, hence didn't leave the energy here. So, the asteroids that >do damage are the ones that collide. Large bodies will do damage regardless of whether they collide or not. If orbits intersect, near collision is more probable in any case (something to be thankful for.) The real question to focus on, as far as Velikovsky is concerned, is why the orbits of Venus and Earth (or Mars and Earth) do not STILL intersect. It has supposedly been only a few thousand years or so. >interaction would be via tidal effects. (If the atmospheres mixed, then the >planets would have to be separated by about one percent of their diameters, >and the tides would shatter every continental plate.) So. Let's look at >tidal effects. If the earth's rotation stopped and restarted (as Velikovsky >claimed) then volcanoes should have broken out simultaneously everywhere. >(Dust again.) Earthquakes everywhere should have flattened all the limestone >caverns that are in fact still there. IF they were formed PRIOR to the event. Having dating methods that are consistent with both views is crucial here. Methods that use radiation counts to date things prior to a supposed catastrophe cannot be used to disprove the catastrophe existed. Formation rates cannot be assumed to be uniform either, given the existence of a prior catastrophe. The best test I can think of would use tree ring analysis. Tree rings are perfectly reliable calendars for determining past dates and past climate accurate to the year, once one has calibrated the rings. >>This is another puzzle I pose to you, that I have already solved. Find a >>mechanism that will circularize planetary orbits in a small time span. No >>cheating, you can't use electromagnetic forces, only gravity. Further, it >>has to be consistent with today's observations. > >It also has to be consistent with the currently-best topographic map of >Venus, and its greenhouse effect, and its atmospheric composition, and its >rotation rate. Don't let me stop you trying. Venus is a strange planet no matter what how think of it. Trying what? My point is that most of the disproofs of the collision hypothesis that I have seen are not valid. This includes the one that attempts to show that no catastrophes existed in the past by extrapolating planetary orbits into the past. It's a simple fact that if an EXPULSION had taken place in the past then the perturbation analysis would not be valid beyond the time of the expulsion. This is one thing I can think of that will put a wrench into the whole process. "Imagination" is the word. > >>>There was no mass extinction at the end of the Ice Age. >>To the best of my knowledge, all the horses and camels (!) on this continent >>died out. The mammoths became extinct, the saber tooth tiger, to name a few. >>I would call this a mass extinction. In any case, this is what I am >>referring to. Particularily the mammoths in Siberia. > >A "mass extinction" is the extinction of a major fraction of all species in >the fossil record - like, 40% of them. At the end of the ice age, the >extinction was not massive at all. I have the impression that it was mostly >higher mammals, and that the extinctions were localized - American horses, >but not Asian, for example. Also, the last I heard, there was some reason to >believe that Man killed off e.g. the saber tooth tiger. Note that a near >collision with a planet should not have localized effects. Right. It should have global effects. That point is a two edged sword when we find that the effects actually were global. But listen, I'm not going to stand around playing V.'s advocate. We've gotten quite beyond the point made by the example in my posting: Velikovsky was wronged and the conditions that led to this happening have not changed all that greatly.