[meteorite-list] Cyclic mass extinction?
From: TMS/TNS/HRC <musnat_at_meteoritecentral.com>
Date: Thu Apr 22 10:00:10 2004 Message-ID: <007f01c233af$707367e0$378d70d1_at_museumst> This is a multi-part message in MIME format. ------=_NextPart_000_007C_01C2336C.609BC120 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I must be more organized than I thought! Found the book smushed between = a biography of Alexander the Great and "How to Clean Just About = Anything". OK, maybe I'm not that organized....but I did find it! : ) NEMESIS The Death-Star and Other Theories of Mass Extinction by Donald = Goldsmith, copyright 1985 (I've dated myself!!!) and published by = Berkley Books, NY. A blurb: "(The Nemesis theory) relies on an entirely unknown object to cause the = (cometary) perturbations. Hence, the theory can assign the Nemesis star = the most effective orbit to produce the observed results, which the = Nemesis theorists insist is a period close to 26 million years in the = extinction rate, and close to 28.4 million years in the impact crater = record.... Skeptics say the Nemesis Theory requires that the sun be a = member of an unusual star system, a double-star system in which a low = mass companion moves in an extremely large orbit around the system's = center of mass, which would be close to the much more massive star in = the system, our sun. Such a double star system would be unlike almost = all the stars and star systems we observe around us. (snip) Nemesis would have to move in a highly, but not tremendously elongated = orbit, one in which its distance from the sun falls to a minimum of = 26,000 A.U. and increases to a maximum of 150,000 A.U....Since the force = of gravity increases in proportion to one over the square of the = distance between two objects, Nemesis at its close approaches to the sun = would have a far stronger effect on comets in the Oort cloud, most of = which are from 10,000 to 40,000 A.U. from the sun, than it would at its = average distance (88,000 A.U.) let alone at its maximum distances from = the sun." It goes on to talk more about the theorists, and the theoretical orbit, = mass and luminosity of Nemesis. If anyone would like more information = on anything regarding this, let me know and I'll look it up. Off to bed, Jeannie ----- Original Message -----=20 From: Edward R. Hodges=20 To: meteorite-list_at_meteoritecentral.com=20 Sent: Wednesday, July 24, 2002 10:58 PM Subject: [meteorite-list] Cyclic mass extinction? I happened to catch the last few minutes of a show on PBS about = extinction. One of the scientist had compiled data on thousands of = extinct species and graphed the times of their extinction. In the = timeline he created there seemed to be above normal rates of mass = extinction every 26 million years. Another scientist is working on a = theory that the sun has a companion star, "Nemesis" that perturbs the = orbit of comets in the Oort cloud which impact the Earth roughly every = 26 million years.=20 Who can shed some light on this topic? Wouldn't there be clear = evidence of meteoritic dust fallout in clay deposits in strata spanning = every 26my?=20 Interesting, very interesting. Didn't catch the name of the show, or = the names of the scientists.- Edward Edward R. Hodges www.meteoriteonline.com IMCA#4173 ------=_NextPart_000_007C_01C2336C.609BC120 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=3DContent-Type content=3D"text/html; = charset=3Diso-8859-1"> <META content=3D"MSHTML 5.50.4134.600" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV><FONT size=3D4>I must be more organized than I thought! Found = the book=20 smushed between a biography of Alexander the Great and "How to = Clean Just=20 About Anything". OK, maybe I'm not that organized....but I did = find=20 it! : )</FONT></DIV> <DIV><FONT size=3D4></FONT> </DIV> <DIV><FONT size=3D4>NEMESIS The Death-Star and Other Theories of Mass = Extinction=20 by Donald Goldsmith, copyright 1985 (I've dated myself!!!) and published = by=20 Berkley Books, NY.</FONT></DIV> <DIV><FONT size=3D4></FONT> </DIV> <DIV><FONT size=3D4>A blurb:</FONT></DIV> <DIV><FONT size=3D4>"(The Nemesis theory) relies on an entirely = unknown=20 object to cause the (cometary) perturbations. Hence, the theory can = assign=20 the Nemesis star the most effective orbit to produce the observed = results, which=20 the Nemesis theorists insist is a period close to 26 million years in = the=20 extinction rate, and close to 28.4 million years in the impact crater = record....=20 Skeptics say the Nemesis Theory requires that the sun be a member of an = unusual=20 star system, a double-star system in which a low mass companion moves in = an=20 extremely large orbit around the system's center of mass, which would be = close=20 to the much more massive star in the system, our sun. Such a = double star=20 system would be unlike almost all the stars and star systems we observe = around=20 us. (snip)</FONT></DIV> <DIV><FONT size=3D4></FONT> </DIV> <DIV><FONT size=3D4>Nemesis would have to move in a highly, but not = tremendously=20 elongated orbit, one in which its distance from the sun falls to a = minimum of=20 26,000 A.U. and increases to a maximum of 150,000 A.U....Since the force = of=20 gravity increases in proportion to one over the <EM>square</EM> of the = distance=20 between two objects, Nemesis at its close approaches to the sun would = have a far=20 stronger effect on comets in the Oort cloud, most of which are from = 10,000 to=20 40,000 A.U. from the sun, than it would at its average distance (88,000 = A.U.)=20 let alone at its maximum distances from the sun."</FONT></DIV> <DIV><FONT size=3D4></FONT> </DIV> <DIV><FONT size=3D4>It goes on to talk more about the theorists, and the = theoretical orbit, mass and luminosity of Nemesis. If anyone would = like=20 more information on anything regarding this, let me know and I'll look = it=20 up.</FONT></DIV> <DIV><FONT size=3D4></FONT> </DIV> <DIV><FONT size=3D4>Off to bed,</FONT></DIV> <DIV><FONT size=3D4>Jeannie</FONT></DIV> <DIV><FONT size=3D4></FONT> </DIV> <DIV><FONT size=3D4></FONT> </DIV> <DIV>----- Original Message ----- </DIV> <BLOCKQUOTE dir=3Dltr=20 style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV=20 style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B>=20 <A title=3Dedwardrhodges1_at_san.rr.com=20 href=3D"mailto:edwardrhodges1_at_san.rr.com">Edward R. Hodges</A> </DIV> <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A=20 title=3Dmeteorite-list_at_meteoritecentral.com=20 = href=3D"mailto:meteorite-list_at_meteoritecentral.com">meteorite-list@meteor= itecentral.com</A>=20 </DIV> <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Wednesday, July 24, 2002 = 10:58=20 PM</DIV> <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [meteorite-list] = Cyclic mass=20 extinction?</DIV> <DIV><BR></DIV> <DIV><FONT face=3D"Arial Black"> I happened to catch = the last=20 few minutes of a show on PBS about extinction. One of the scientist = had=20 compiled data on thousands of extinct species and graphed the times of = their=20 extinction. In the timeline he created there seemed to be above normal = rates=20 of mass extinction every 26 million years. Another scientist is = working on a=20 theory that the sun has a companion star, "Nemesis" that perturbs the = orbit of=20 comets in the Oort cloud which impact the Earth roughly every 26 = million=20 years. </FONT></DIV> <DIV><FONT face=3D"Arial Black">Who can shed some light on this topic? = Wouldn't=20 there be clear evidence of meteoritic dust fallout in clay deposits in = strata=20 spanning every 26my? </FONT></DIV> <DIV><FONT face=3D"Arial Black">Interesting, very interesting. Didn't = catch the=20 name of the show, or the names of the scientists.- Edward</FONT></DIV> <DIV><FONT face=3D"Arial Black"></FONT> </DIV> <DIV><FONT face=3D"Arial Black">Edward R. Hodges</FONT></DIV> <DIV><FONT face=3D"Arial Black"><A=20 = href=3D"http://www.meteoriteonline.com">www.meteoriteonline.com</A></FONT= ></DIV> <DIV><FONT face=3D"Arial Black">IMCA#4173</FONT></DIV> <DIV><FONT face=3D"Arial = Black"></FONT> </DIV></BLOCKQUOTE></BODY></HTML> ------=_NextPart_000_007C_01C2336C.609BC120-- Received on Thu 25 Jul 2002 03:46:48 AM PDT |
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