The fate of the Earth?
in [Physics]
|
Prev: Partially crystalline materials
Next: Speciation Process: Excrement Color Skin Proven Harmful (Poverty, Crime and Disease)
From: dow on 13 Sep 2009 14:52 On Sep 12, 9:47 pm, "Peter Webb" <webbfam...(a)DIESPAMDIEoptusnet.com.au> wrote: > ___________________________ > I know you are wrong. If the Sun suddenly lost 90% of it mass, then the > Earth would move into a highly elliptical or hyperbolic orbit, with its > minimum distance from the Sun 1 AU and a velocity at that distance the same > as it is now. This is conservation of kinetic energy plus angular momentum. > > Therefore the ellipticity of an orbit is not preserved if the body being > orbitted loses mass. > > If nobody pointed out this simple thought experiment proves your simulations > are incorrect, its probably because nobody read your article. Just to remind you, here's a paragraph from a posting I made here on September 11: > Back in 2003, I ran some simulations of what would happen if a planet > were in an elliptical orbit around a star that is slowly (compared > with the orbital period) losing mass. The result was that the > eccentricity of the orbit would not change, but its dimensions would > be inversely proportional to the mass of the star. This was true no > matter whether the loss of mass was at a constant rate or a non- > constant one, provided that the rate did not have a periodic component > that was synchronized with the motion of the planet. If there is such > a periodic component, the eccentricity of the orbit changes. Please read it this time. dow
From: oriel36 on 13 Sep 2009 16:23 On Sep 13, 7:45 pm, Sam Wormley <sworml...(a)mchsi.com> wrote: > oriel36 wrote: > > > Tell me how long it takes the Earth to turn once and remind me just > > how desperate the situation is. > > The earth rotates exactly 360° in 86,164.09+ seconds. It's a direct > observation anybody can make and is referred to a sidereal day. > Your open response, that will exist without objection, is the sound of Western civiliisation rotting itself from within for even though all planetary facts such as dimensions and rotational characteristics are organised around rotation through 15 degrees every hour and once in 24 hours,the empiricists have organised around the 23 hours 56 minute 04 second value.I know of no nightmare worse than this one,not so much the reasoning which goes into the 'sidereal time' value but the absolute absence of any authority to deal with this urgent matter effectively even with the enormous sprawling history of clocks and longitudes,the equable day/calendar system and all the history that supports the 24 hour value. The 'predictive' nature of Ra/Dec observing which determines astronomical events like an eclipse within the equable 365/366 day calendar system cannot be used in tandem with the Earth's planetary dynamics for it loses all references to daily and orbital characteristics for all types of geological,climatological and many other purposes but that is not the worst part,it is the wanton glee of continuing with something which is intellectually perverse and amounts to pure treason against Western achievements and traditions. I personally do not know how any of you live with yourselves for even though I consider the darkness period of Western involvement in celestial/terrestrial phenomena is now over,at least the mantra spout 'scientific method' cult,there has to be an authority to pick up the pieces and halt the ridiculous spread of this new social tyranny which uses climate to introduce stealth taxes under the guise of scientific inquiry. I watch as you draw your 'sidereal time' conclusion without the slightest sense of what is lost or excluded and know all too well the same cult outlook has now descended on the climate conclusion ,not so much the conclusion itself but the liberties which it allows the opportunistic to thrive.Again,the ideology which cannot affirm the most basic of all planetary facts such as daily rotation in 24 hours conceals something which conceals a type of treason that reduces Western achievements to dust and erode its goodness and the ability to be genuinely productive.
From: N:dlzc D:aol T:com (dlzc) on 13 Sep 2009 16:26 Dear dow: "dow" <williamsdavid65(a)gmail.com> wrote in message news:0e633f6f-580f-4e66-a9a7-6bb4cf005b37(a)g1g2000vbr.googlegroups.com... .... > I said (but you decided to ignore) that the planet > will spiral outwad, keeping the eccentricity of its > orbit constant, *if the loss of mass from the star > is very slow compared with the orbital period of > the planet*, so only a tiny fraction of the mass > of the star is lost during each revolution of the > planet around it. Obviously, a sudden loss of 90% > of he star's mass does not satisfy this condition. .... > This was in my Orrery articles, which were very > thoroughly read and critiqued by many people. > The editor of the magazine, Greg Neill, went so > far as to re-do the entire calculation, using a > completely different method from mine. I did an > iterative simulation of the planet's path as the > star's mass changes. Greg did an iterative > numerical integration of a function that would > show any changes in eccentricity. (I don't > believe there is any general analytical method to solve the problem. Numerical iteration is always > required.) As it is in most modern *anything*. Fluid mechanics too. > In the end, Greg's conclusion was the same as > mine. *Under the conditions I specified above*, > the eccentricity of the orbit (measured at the > perihelion of each revolution) remains constant. Frankly I suspect the physics behind said analysis. Unless you assume significant tidal bulging on both the Earth and the Sun, such "circularizing" will occur exceedingly slowly (more slowly than mass loss), and will not save Earth from being roasted. > Like several readers who wrote in to say so, I > was surprised by this conclusion. Initially, I had > expected the eccentricity to change, using vague > reasoning such as yours. .... instead of vague assertions to authority, and "well I am not going to provide a reference here to published works..." > But, in science, hunches often turn out to be wrong. And just as often they turn out to be right. http://arxiv.org/abs/0909.0770 .... "significant periodic eccentricities" > Load up some programming language and tackle > the problem yourself. I don't find any comfort in keeping the Earth outside the surface of the swollen Sun after millions of years of circularizing, when the Earth will still experience a sky that is "half-filled" with a 3000 K heat sink, vaporizing the oceans and ending all life. David A. Smith
From: Sam Wormley on 13 Sep 2009 16:53 oriel36 wrote: > On Sep 13, 7:45 pm, Sam Wormley <sworml...(a)mchsi.com> wrote: >> oriel36 wrote: >> >>> Tell me how long it takes the Earth to turn once and remind me just >>> how desperate the situation is. >> The earth rotates exactly 360° in 86,164.09+ seconds. It's a direct >> observation anybody can make and is referred to a sidereal day. >> > > Your open response, that will exist without objection, is the sound of > Western civiliisation rotting itself from within for even though all > planetary facts such as dimensions and rotational characteristics are > organised around rotation through 15 degrees every hour and once in > 24 hours,the empiricists have organised around the 23 hours 56 minute > 04 second value.I know of no nightmare worse than this one,not so much > the reasoning which goes into the 'sidereal time' value but the > absolute absence of any authority to deal with this urgent matter > effectively even with the enormous sprawling history of clocks and > longitudes,the equable day/calendar system and all the history that > supports the 24 hour value. > > The 'predictive' nature of Ra/Dec observing which determines > astronomical events like an eclipse within the equable 365/366 day > calendar system cannot be used in tandem with the Earth's planetary > dynamics for it loses all references to daily and orbital > characteristics for all types of geological,climatological and many > other purposes but that is not the worst part,it is the wanton glee of > continuing with something which is intellectually perverse and amounts > to pure treason against Western achievements and traditions. > > I personally do not know how any of you live with yourselves for even > though I consider the darkness period of Western involvement in > celestial/terrestrial phenomena is now over,at least the mantra spout > 'scientific method' cult,there has to be an authority to pick up the > pieces and halt the ridiculous spread of this new social tyranny > which uses climate to introduce stealth taxes under the guise of > scientific inquiry. > > I watch as you draw your 'sidereal time' conclusion without the > slightest sense of what is lost or excluded and know all too well the > same cult outlook has now descended on the climate conclusion ,not so > much the conclusion itself but the liberties which it allows the > opportunistic to thrive.Again,the ideology which cannot affirm the > most basic of all planetary facts such as daily rotation in 24 hours > conceals something which conceals a type of treason that reduces > Western achievements to dust and erode its goodness and the ability to > be genuinely productive. Nevertheless, the earth rotates exactly 360° in 86,164.09+ seconds. It's a direct observation anybody can make and is referred to a sidereal day. For a solar day (86,400 seconds) the earth rotates about 361° and everybody knows this from the ancients to the present. You, Gerald are "out of sync" with the rest of the world.
From: BradGuth on 13 Sep 2009 17:20
On Sep 12, 2:47 pm, dow <williamsdavi...(a)gmail.com> wrote: > On Sep 12, 5:08 pm, oriel36 <kelleher.ger...(a)gmail.com> wrote: > > > > > Repeat this as many times as you like,what looks good at close > > range,and in Kepler's era,things only went as far as Saturn,but his > > correlation between orbital periods and orbital radii does not work. > > Give me one example in which this equation does not work: > >  T^2 = (2Ï)^2 a^3 / (G M) > > where G is the gravitational constant, T is the orbital period, a is > the semi-major axis of an elliptical orbit (which equals the radius if > the orbit is circular), and M is the mass of the primary, i.e. the > star or whatever that the object is going around. > > It works for all the planets, asteroids, etc., in our solar system, > using the mass of the sun for M, for all the satellites of Jupiter, > using Jupiter's mass for M, ditto for the satellites of the other > planets, and, yes, for Formalhaut b, using the mass of Formalhaut a as > the value of M. > > Kepler could look at only the planets in our solar system, out as far > as Saturn. So all his examples had the same value of M, namely the > sun's mass. He empirically found an accurate relation between T and a, > but had no reason to include a variable M in  it. Don't blame him for > that! What he did, with the few tools available to him, was brilliant. > And his relationship between T and a works for objects in our solar > system far beyond Saturn, not only Uranus and Neptune, but all the > Kuiper Belt objects out to Eris, about 100 AU from the sun, and comets > that go even further. > >      dow It even works nicely for our solar system being fully dominated by the nearby Sirius star/solar system, especially the case when Sirius ABC was worth 12.5 Ms, better yet was the original molecular cloud of 12.5e6 Ms. ~ BG |