The spacetime curvature of a body such as the Solar System as experienced from the outside

[geordief]

If we consider  the gravitational effect of the Solar system  upon its nearest neighbours (or upon the gravitational field immediately outside it) does this change as the SS evolves with time?

For example ,as Jupiter moves 180 degrees around the Sun  is there a noticeable (or theoretical) effect on  the gravitational  field as experience by a body outside the SS?

 

I ask this because I have heard that the effect of gravity is not dependent on the interior makeup of a massive body( the Solar System  in this instance)

[Bufofrog]

21 minutes ago, geordief said:

For example ,as Jupiter moves 180 degrees around the Sun  is there a noticeable (or theoretical) effect on  the gravitational  field as experience by a body outside the SS?

I would say yes there is an effect but it is tiny.  The gravity of the sun can can be modeled as a point source corresponding with the center of the sun.  in a case where all the planets are more or less lined up on one side of the sun the point source for the combined gravity would be slightly offset from the center of the sun.

[geordief]

Well I have heard that the gravitational effect of any body is independent of any interior  structure. 

Are there examples where this is so -or  does  my Solar System example show this not to be so?

Does the gravitational  field exerted by the    Solar  System  "vibrate"  ever so slightly as the planets orbit the Sun?

 

Is my understanding of   the saying* that the spacetime curvature  effect of mass is unaffected by any internal  structure  maybe  a bit "half baked "?

 

*I have read this more than a few times

 

[swansont]

2 hours ago, geordief said:

For example ,as Jupiter moves 180 degrees around the Sun  is there a noticeable (or theoretical) effect on  the gravitational  field as experience by a body outside the SS?

To a very good approximation it's given by GM/r^2 where M is the mass of Jupiter.

For the field of the solar system, you'd get a good approximation using the mass of the sun, and the corresponding distance.

The mass of Saturn is less than 0.0003 solar masses, so outside the solar system, the difference would be small. But you are free to calculate how small the effect is.

 

 

[mistermack]

I would say that it depends how far away you are from the solar system. Inside it, you get noticeable variation, like the high tides we get when the Sun and Moon are on opposite sides of the Earth, or in line on the same side. 

But further away, the local effects would dwindle. I'm guessing, but I think it's pretty likely that the centre of mass of the Solar System will not move, or vibrate, (apart from rotation round the Milky Way etc) so once you are away from the local effects, there would be no 'vibration' in the field. 

I seem to remember that the centre of mass of a binary star system doesn't move, so Jupiter/Sun should behave the same way. 

[MigL]

It may not 'vibrate' unless you count the cycles in years or decades, but you will certainly get different effects if you measure the gravity on one side of the Sun, with all the planets lined up towards you radially, than if they were lined up on the opposite side of the Sun ( it does happen ).

Unless you are sufficiently distant, the Solar System can't be regarded as a CoM problem.
The planetary gravitational wells act like small moving depressions along the wall of the much larger depression which is the gravitational well of the Sun.

[Markus Hanke]

8 hours ago, geordief said:

I ask this because I have heard that the effect of gravity is not dependent on the interior makeup of a massive body

That’s right, but the SS isn’t a massive body - it’s a multi-body system. Thus, if you are somewhere close but outside the SS, there will be small variations as the various planets go about their orbits. However these would be tiny, since almost all of the total mass is in the sun.

Once you go far enough away, the SS will behave like a single body, since these variations will be too small to be detectable by any reasonable means.

[geordief]

1 hour ago, Markus Hanke said:

That’s right, but the SS isn’t a massive body - it’s a multi-body system. Thus, if you are somewhere close but outside the SS, there will be small variations as the various planets go about their orbits. However these would be tiny, since almost all of the total mass is in the sun.

Once you go far enough away, the SS will behave like a single body, since these variations will be too small to be detectable by any reasonable means.

So a proton (as a single bodied object of mass) cannot be viewed in the same way as the SS(wrt to its gravitational  field)?

Its constituent quarks are not in motion in the same way as the planets around the Sun and the cog  cannot move around  even if it made any sense to want to measure the its gravitational  field "up close" ?

[MigL]

I don't think the two cases are remotely related.

Almost all of the proton's mass is in the 'field'.
The constituent quantum particles ( quarks ) are 'point-like', and don't have a position/momentum until interacted with.

[mistermack]

2 hours ago, MigL said:

It may not 'vibrate' unless you count the cycles in years or decades, but you will certainly get different effects if you measure the gravity on one side of the Sun, with all the planets lined up towards you radially, than if they were lined up on the opposite side of the Sun ( it does happen ).

But in that case, the centre of mass of the Sun would move, a tiny amount, and nullify the shift of the overall centre of mass. Like the 'wobble' that we see in the light from some distant stars, indicating a sizeable planet orbiting. 

[Markus Hanke]

2 hours ago, geordief said:

So a proton (as a single bodied object of mass) cannot be viewed in the same way as the SS(wrt to its gravitational  field)?

No. You’d have to account for quantum effects, since those can’t be ignored on scales of subatomic particles.