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Precession betrays Nemesis position?

  1. May 2, 2003 #1
    In 1995 Richard Muller et al proposed the existance of a twin star of the sun, Nemesis. This would expain the cyclic mass extinctions. To date there seems to be little substantiation for the existance of Nemesis and the only remaining option is: find it.

    That may be happening here:

    http://newfrontiersinscience.com/Members/v02n01/a/NFS0201a.shtml#fnB2

    Apparantly the precession of the Equinoxes is not caused by gravity of the sun and moon but by the orbit of the sun in space, as it must be influenced by a twin star. Is this Nemesis? And can we calculate it's position from the apparant precession?
     
    Last edited: May 2, 2003
  2. jcsd
  3. May 2, 2003 #2

    russ_watters

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    No. Precession is caused by the gravity of the sun and Relativity AFAIK.

    Sounds like another Planet X hoax.

    a quickie:
    The length of a day and the length of a year have nothing at all to do with each other.
     
  4. May 2, 2003 #3

    LURCH

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    Does sound somewhat crackpotish. It would appear that what these fellows are basing their theory on is the need for some explaination of precession other than the Sun and Moon. However, I was allways under the impression that precession is a natural result of gyroscopic forces and occurs ni nearly all rotating objects. Not only would Earth's gyroscopic precession take place without another star, it would take place even without the Sun and Moon, wouldn't it?

    Also, I believe the mass extinctions in the Earth's past have been chronologically linked to the Solar system's orbit around the Milky Way. Currently, we are "above" the plane of the gallaxy, but moving down towards it (I think), which means that at the point in our orbit opposite from where we are now, we will be "below" that plane. It also means that, twice in each orbit, we must pass through the most thickly populated part of the gallactic plane. IIRC, the mass extinctions appear to take place at about these times.
     
  5. May 3, 2003 #4

    russ_watters

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    There are two different kinds of precession. The precession of the earth's rotation axis is indeed a gyroscopic effect. But the earth's ORBIT is also undergoing precession. The positions of perihelion and apahelion are moving.

    In any case, I'm pretty sure thats a well known limitation of Newtonian physics which has been explained by Relativity.
     
  6. May 4, 2003 #5
    Russ, You said
    Right, I was under the impression that this was to be contributed to the gravity of the other planets, mostly Jupiter. However, if there was an alleged twin to the sun, that would yield enough gravity pull to move the sun in orbit, then what would its effect be on the Earths orbit?

    Moreover, (this is difficult to put in words), if I understand correctly, the scholar view is that Earth spin axis "precesses" due to sun and moon differential gravity on the equatorial bulge. We think we recognise precession because there is a difference between the sidereal year and the tropical year. The sidereal year is the time measured for a completed 360 cycle of the Earth in relation to the stars. While the tropical year (about 20 minutes shorter) looks at the time difference for the sun for reaching the equinoxes. Again this is attibuted to a physical change in the spin axis direction of the Earth.

    If I understand correctly, Cruttenden and Dayes assume that the sun moved position in relation to the fixed stars due to the gravity of a twin. So, it is at another position after the completion of a sidereal year. Since we assume that it is not moving, and we measure the position of the fixed stars in relation to the sun, we make an error in our own Earth position. This would seem to cause the sidereal year to happen actually before the completion of the orbit. Now, suppose Earth is only appearing to precess and is not actually changing its spin axis direction. This would mean that the tropical year must resemble a full orbit and the difference in position with the fixed stars tells the movement of the total solar system.

    IMHO there is a simply way to establish if the Earth is actually precessing or only apparantly. The direction of the spin axis should affect the north/south position of the polar star areas. If there is real precession that position would change relatively fast, if there is only apparent precession, that position would remain about static, only accounting for the parallax caused by the orbit of the solar system.


    --------------------------------
    The trouble with most folks isn't so much their ignorance. It's know'n so many things that ain't so.
    Josh Billings
     
    Last edited: May 4, 2003
  7. May 4, 2003 #6
    Lurch
    As far as I understand precession, you need a torque force on the spinning object to change the direction of its spin axis. This torque force is thought to be exerted by the gravity of sun and moon on the oblique turning equatorial bulge of the Earth.

    http://www-istp.gsfc.nasa.gov/stargaze/Sprecess.htm

    Consequently, we seem to need the sun and moon for the precession.
     
  8. Feb 18, 2009 #7
    i was looking at this subject today and i couldn't find an answer i could understand.
    is this premise a silly idea or something that needs more research?
    do we need to wait for the ir sky mapping satellite to do its thing in november 09?
     
  9. Feb 18, 2009 #8

    russ_watters

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    No, this is just crackpottery. Note also, the thread is 5 years old...
     
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