Invoking The Voyagers Against Id |
Invoking The Voyagers Against Id |
Oct 24 2005, 03:04 PM
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
Cornell President Rawlings Condemns Intelligent Design
Drawing from sources ranging from Cornell's founders to Voyager space missions, Interim President Hunter R. Rawlings III condemned the push to teach intelligent design in public schools Friday. The attack came during the president's State of... http://www.cornellsun.com/vnews/display.v/...4/435c7762cf891 "The desire to understand the world and the desire to reform it are the two great engines of progress." - Bertrand Russell -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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Guest_Richard Trigaux_* |
Nov 20 2005, 08:53 AM
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Guests |
Thank you all for this nice conversation. Just are missing some more ingredients for the "hell breaking lose":
-if the neutron star is submitted to a quickly changing gravitationnal field, it will have waves on its surface. And these waves will in turn produce gravitational waves which effect will not be negligible... -The same wih the the black hole, which can oscillate in a wave-like pattern. -Add to this the Lens-Thiring effect of both bodies (NS will have some too) (for non-specialist readers, this effect is the equivalent of the magnetic field into the gravitation domain: when electric charges rotate, they produce a magnetic field, which can in turn make rotate other electric charges, like in a transformer. In the same way a rotating black hole will induce rotation of all the surrounding bodies). -And also magnetic fields, which can be very strong in neutron stars. It is currently believed (but, as far as I know, not really proven) that it is the magnetic field which produces jets in quasars, accreting stars, etc... We can expect that the result of swallowing a magnetar (neutron star with very strong magnetic field) will be more complex than with a weak field neutron star. So to know what happens will require a complex simulation accounting with all the parametres: magnetic field, states of matter, gravitationnal waves... some simulations of this kind were done with coalescence of black holes, and they are already very complicated (for instance we can know if a point is within the horizon event only after many steps of simulation). However I think that such kind of coalescence, in more of being relatively common, may be the most powerful source of gravitationnal waves (a perfectly symmetrical supernova should produce none, in fact, but recent works showed that supernovas are turbulent and thus not symmetrical). So that simulations of coalescence of neutron stars/black holes are an important domain. A simple simulation would however, I think, be possible to set the lower limit of mass for a neutron star (the lowest stable mass for a lump of broken neutron star, not the minimum mass at formation, which is known to be 1.3 solar mass). For this some parametres are needed: -the density of neutronic matter -the mimimum pressure to maintain it in this state. Things are complicated by the fact there would be a white-dwarf-like layer of matter around it, more a layer of ordinary gas with variable density. |
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