The fate of the Earth?
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From: Sam Wormley on 15 Sep 2009 18:03 oriel36 wrote: > On Sep 15, 2:04 pm, Sam Wormley <sworml...(a)mchsi.com> wrote: >> oriel36 wrote: >> >>> The Earth , as a sphere, will rotate at different speeds from a >>> maximum speed at the Equator down to zero at the geographical >>> poles. >> Actually, that's not quite right, Gerald. the rotation rate of >> the earth (all parts) is exactly exactly 360° in 86,164.09+ seconds. > > I told you before,it is not a matter of right and wrong but whether > that 'sidereal time' value and those who subscribe to the reasoning > behind it deserve a fool's pardon or treason insofar as Western > society has traits which rise above cultural or social differences or > individual countries and the loss of information contained in the 24 > hour value is so severe that it is far more a crisis than many would > dare to believe. The universe works fine without your complaints, Gerald. Furthermore, Kepler's, Newton's and Einstein's laws, theories and models work remarkably well. It appears that you alone, think that there was a collapse of Western scientific traditions, whereas the history of science shows otherwise. The only catastrophe is your own. You obsess to the point of mental illness. And you argue without an adequate understanding of Copernicus, Kepler and Newton's work. You can even understand the mathematics of any of those gentlemen. It is a real shame you are so poorly educated, Gerald.
From: Sam Wormley on 15 Sep 2009 22:41 oriel36 wrote: > Equatorial Earth rotates through 1669.8 km every 15 degrees and > its entire 40,075 km circumference in 24 hours so conjure up 'solar > day'/sidereal day' if you wish,the only interest people should have is > the average 24 hour cycle as opposed to the variations in the natural > noon cycle.If you have difficulties adjusting to the fact that the > average 24 hour day serves to keep daily rotation as a constant > through the now dormant Equation of Time correction,not as an > observation but as a convenience,you might even see the recent genius > behind the system as a new facet added to the original creation of the > equable day/calendar system in antiquity. > Actually, that's not quite right, Gerald. The rotation rate of the earth (all parts) is exactly exactly 360° in 86,164.09+ seconds.
From: dow on 15 Sep 2009 22:55 > > Put two objects in space, far from any others, so that the distance > > between them is initially constant. Let them go and watch what > > happens. If they move directly toward each other, attracted by their > > gravity, and eventually collide exactly centrally, then they were > > initially not revolving around each other. They were rotationally > > stationary in an absolute sense. But if they go into orbit around > > their common centre of gravity, they were initially revolving in an > > absolute sense. It has nothing to do with fixed stars - maybe. > > The second case is simply physically impossible. It requires one or > both objects be given a lateral component of motion at release. The lateral component need not exist if the frame of reference is rotating in an absolute sense. If the frame is rotating, both objects can initially be stationary in it, but will still end up in orbit after release. > > Now, one for you. Cause the objects to rotate around their own > centers before release, on axes perpendicular to a line drawn between > their centers. What happens? Are hou getting around to frame dragging? > > > Have you heard of Mach's Principle? > > Yes. It's completely irrelevant. No it isn't. It's an observed fact that a frame of reference in which distant galaxies are not revolving is, at least very nearly, the same as the frame that is absolutely rotationally stationary. Mach proposed that somehow distant galaxies define the absolutely stationary frame, but the mechanism by which they might do so is still highly conjectural. dow
From: Androcles on 16 Sep 2009 00:14 "dow" <williamsdavid65(a)gmail.com> wrote in message news:67356fce-a6e0-49af-bfe3-497a82e5e52b(a)l35g2000vba.googlegroups.com... > > Put two objects in space, far from any others, so that the distance > > between them is initially constant. Let them go and watch what > > happens. If they move directly toward each other, attracted by their > > gravity, and eventually collide exactly centrally, then they were > > initially not revolving around each other. They were rotationally > > stationary in an absolute sense. But if they go into orbit around > > their common centre of gravity, they were initially revolving in an > > absolute sense. It has nothing to do with fixed stars - maybe. > > The second case is simply physically impossible. It requires one or > both objects be given a lateral component of motion at release. The lateral component need not exist if the frame of reference is rotating in an absolute sense. If the frame is rotating, both objects can initially be stationary in it, but will still end up in orbit after release. ============================================ No they won't, they'll approach as recede from each other. The Earth approaches and recedes from the Sun, the Moon approaches and recedes from the Earth. The frame is rotating by your rules and you don't get to frame jump. > > Now, one for you. Cause the objects to rotate around their own > centers before release, on axes perpendicular to a line drawn between > their centers. What happens? Are hou getting around to frame dragging? > > > Have you heard of Mach's Principle? > > Yes. It's completely irrelevant. No it isn't. It's an observed fact that a frame of reference in which distant galaxies are not revolving is, at least very nearly, the same as the frame that is absolutely rotationally stationary. Mach proposed that somehow distant galaxies define the absolutely stationary frame, but the mechanism by which they might do so is still highly conjectural. dow =========================================== Newton stated that the absolutely stationary frame is the one in which the sum of the momenta of all the objects within it is zero. One can arbitrarily assign a velocity to the entire universe if it were not for the fact that there is nothing against which that velocity can be measured.
From: Odysseus on 16 Sep 2009 00:28
In article <286949db-1d41-4a2d-aee5-817f0b38e13d(a)e4g2000prn.googlegroups.com>, alien8er <alien8752(a)gmail.com> wrote: > On Sep 13, 4:53�am, oriel36 <kelleher.ger...(a)gmail.com> wrote: > > > Tell me how long it takes the Earth to turn once > <snip> > > (3) The stars aren't really fixed either; that idea assumes there's > something out there that they're attached to (the "crystal spheres"). > > The bottom line is that there's no fixed reference anywhere against > which to measure the Earth's rotation period; it isn't even measurable > against itself, though its absolute rotation _rate_ is measurable. True in principle, but reference systems like the FK3-4-5 series, and their successor the ICRF, do seem to be 'fixed' enough for most practical purposes. -- Odysseus |