Re: Pioneer anomaly

John Baez wrote:
> Charles Cagle <skybolt99@xxxxxxxxxxxx> wrote:
>>If towards the sun why isn't any one suggesting
>>simple gravitational anisotropy related to the sun ...that more mass
>>might be lying along the solar equator than is believed?
>
> I don't see how that would explain it. The motion of *planets*
> is known quite accurately and fits the usual solar model and
> Newtonian laws of gravity quite well. The motion of the Pioneer
> and Ulysses spacecraft may not. So, one needs to find things that
> the Pioneer and Ulysses spacecraft have in common that are different
> from planets, which might explain this effect.
>
> 1. They are much lighter, hence more susceptible to the effect of
> small forces.
>
> 2. They are manmade entities, hence affected by a variety of similar
> small forces (solar wind, radio transmissions, possible outgassing, etc.)
>
> 3. They are moving quite rapidly away from the Sun.

4. The pioneer spacecraft (but not Ulysses) are much farther from the sun.

> Another key piece of the puzzle: the Viking mission to Mars did
> *not* detect the Pioneer anomaly, and it would have had an acceleration
> of this magnitude (roughly 10^{-9} meters/second^2 towards the Sun)
> been present, since its radio tracking was accurate to about 12
> meters.

A spherical shell of mass would have no effect on the planets inside,
and would not be detectable by Viking either (nor by Ulysses, oh well).

A hollow shell would raise more questions than I am prepared to even ask
right now, but I wouldn't leave it off the list of possibilities unless
someone has a really convincing argument against it.

Even a solid sphere with a radius >=70AU may not be ruled out (at least
not according to http://www.ph.unimelb.edu.au/~foot/pioneer.html). It
would have much more effect on objects at a greater distance
(acceleration proportional to R). A solid sphere only raises one
question, but that is a big one: where the hell is all this stuff, and
why can't we see it? OK, that's two questions :-)

Ralph Hartley

.

Relevant Pages

  • Re: Solar Shell
    ... research goals directed toward making use of the solar environment. ... The sun is more like a candle. ... technology works as advertized, its clearly easiest to pull stuff out ... of the sun compared to controlling the ejection across the whole sun to ...
    (sci.space.policy)
  • Re: OT: Man made hot ice.
    ... Here is a little blurb about that lucky old Sun. ... While solar magnetic ... you get a crash," says Weiss. ... This is hardly the sunspot crash that observations from 1645 to 1715 ...
    (rec.gambling.poker)
  • Re: Dying Earth: the undertakers
    ... as well as give the PCs chinks in the ... Sun is dead, trying to ensure their own existence. ... The world is supposed to be simply far future Earth. ... the solar as a solar deity, ...
    (rec.games.frp.dnd)
  • Surprises from the Suns South Pole (Forwarded)
    ... Surprises from the Sun's South Pole ... Although very close to the minimum of its 11-year sunspot cycle, ... The solar storms, which were confined to the equatorial regions, produced ... it measured the temperatures of the large polar coronal holes. ...
    (sci.astro)
  • Re: Planitary nebula
    ... Stellar Nova of the sun ... Hopefully the solar brightening will run out of steam, ... They claim do it by teleporting hydrogen from the atmosphere into the core ... Since it has been going on for 30 years and if you know the mass of the ...
    (sci.astro)