[Harri (OP)]

The universe is expanding everywhere in every direction as a consequence of the so called big bang ... what effect does this have on our solar system?  Is the space between the objects in our solar system expanding too? 

[Halc]

The universe is expanding everywhere in every direction as a consequence of the so called big bang ... what effect does this have on our solar system?

Our solar system (and our galaxy cluster for that matter) is gravitationally bound and will remain so despite expansion of space. So there can be no change to our solar system due to this effect.

For instance, there are essentially four factors altering Earth's orbital distance, two increasing it and two decreasing it.  Expansion isn't any of them.

(Tides, decreasing mass of sun , friction, and gravitational waves

That list is in order of decreasing effect, but in the long run with all object gone completely cold, tide-locked and the solar system free of dust, the order changes to tides, gravitational waves with the other two no longer applying. Notice that tides becomes a negative effect in the long run.  Still no expansion on that list.

[charles1948]

The universe is expanding everywhere in every direction as a consequence of the so called big bang ... what effect does this have on our solar system?

Our solar system (and our galaxy cluster for that matter) is gravitationally bound and will remain so despite expansion of space. So there can be no change to our solar system due to this effect.

But surely, if Space is "expanding", it must be doing so throughout the entire Universe.  Including within the Solar System.

Wouldn't that make planets in the Solar System, get further apart, as the Space between them expands?

I notice that you refer to "Gravitational Binding".  But doesn't Gravitational "binding" , ie "attraction" operate through Space, following the "Inverse Square" law.

So if Space expands, won't the "binding" or "attraction"  correspondingly reduce?

Which would result, in the case of the Solar System,  in reduced gravitational force from the Sun on the planets.
So causing the planets to move away from the Sun.

[Halc]

But surely, if Space is "expanding", it must be doing so throughout the entire Universe.  Including within the Solar System.

It does. Relative to the sun, Earth is not orbiting the same 'space' as it was long ago. That orbit has expanded to closer to where Mars is now, and Earth, not having any additional energy imparted by said expansion, has been pulled back to its original distance from the sun as determined by the mass of the sun and the tangential velocity of Earth, neither of which is effected by said expansion.

Wouldn't that make planets in the Solar System, get further apart, as the Space between them expands?

It only moves away the space through which the planets used to orbit. Gravity keeps the planets at their relatively constant* orbital distance.

* Not including actual changes to orbital energy that I enumerated in my prior post.

I notice that you refer to "Gravitational Binding".  But doesn't Gravitational "binding" , ie "attraction" operate through Space, following the "Inverse Square" law.

Binding refers to things in orbit around each other, which requires them to be within the hill radius of the primary. So the moon is gravitationally bound to Earth, not to the sun, despite the sun exerting a stronger force on it.  But Mars is not gravitationally bound to Earth despite its finite distance from Earth. Yes, our planet does alter the trajectory of the other planets and the stars, but only the one natural object is bound to us.
Earth is bound to the sun. The sun is bound to the galaxy, possibly indirectly.

If the expansion rate increases enough, it can disrupt this binding and pull the planets away. In such a scenaro, the sun exits the galaxy, then the planets get pulled away, you get pulled off the surface of Earth, your arms get pulled off you, and finally the nucleus of every atom gets pulled apart because expansion works quicker than even the nuclear strong force can overcome.  This is the big-rip scenario, and it seems the universe is not headed for such a fate.

So if Space expands, won't the "binding" or "attraction"  correspondingly reduce?

Binding is not a function of what the space is doing. It is a Newton/Kepler concept.

Which would result, in the case of the Solar System,  in reduced gravitational force from the Sun on the planets.

If the gravity didn't keep the planets at a constant distance despite expansion, then yes, it would reduce the force between such objects. They would cease to be bound in that case, and each planet in turn would simply exit the solar system, staring with the outside ones.  This again is the rip scenario where expansion takes place faster (say 10²⁵ times more than the current rate) than forces can compensate over the distances involved.

[charles1948]

Thanks Halc for your post#3.  Much appreciated.  I'll have to study it carefully, before responding.

[Zer0]

@charles1948

Halc seems to have done a killer job in explaining it all...hence No point in elaboration, no scope or space left for it atall.
👍

Just something to ponder over or think about...if everything was indeed spreading & scattering away from everything else...
Then how come the Andromeda Galaxy is all set to collide with the Milky Way Galaxy.
✌️😊

P.S. - Einstein's Greatest treasure was a Brain...& Guess what, We All have it too.
🙏

[Halc]

if everything was indeed spreading & scattering away from everything else...
Then how come the Andromeda Galaxy is all set to collide with the Milky Way Galaxy.

Both galaxies are part of the local group and are gravitationally bound to each other. Were they point masses, they would orbit each other for quite a while, but they're all spread out and will get close enough on the first pass to lose considerable mutual kinetic energy by their interaction.  So this slows both of them down to where the second pass will be a much more direct hit, cumulating into an eventual merger.  The arms and structure of both galaxies will be destroyed by all this, but will eventually reform after the merger completes.

[Harri (OP)]

Many thanks my question is thoroughly  answered.

Would it be true to say then that at any reference point in the universe light from stars is shifting to the red?

[evan_au]

Would it be true to say then that at any reference point in the universe light from stars is shifting to the red?

No - as mentioned above, the Andromeda galaxy is heading towards a collision with the Milky Way galaxy.
- They way they originally worked this out was that they saw that starlight from Andromeda was shifted towards the blue end of the spectrum, ie Andromeda is moving towards us, as a whole.
- And the Milky Way galaxy is one potential reference point in the universe.

This applies to objects that are fairly close together in the universe
- Once you go past a billion light years, stars and galaxies are red-shifted, as their random local motions are dominated by the general expansion of the universe.

[Harri (OP)]

Okay many thanks, I've got it now. 

[Halc]

But surely, if Space is "expanding", it must be doing so throughout the entire Universe.  Including within the Solar System.

Wouldn't that make planets in the Solar System, get further apart, as the Space between them expands?

I'd like to explain this in a way that doesn't involve gravitational binding.  The solar system is a complex example held together with such binding, so let's simplify it.

Suppose there are two pebbles in space, each in a balanced gravitational field to eliminate any acceleration due to gravity.  They are separated by 1 megaparsec.  The first pebble (X) is stationary relative to the cosmological frame, or relative to 'space' so to speak.  Another way of saying this is that X has zero peculiar velocity.
The second pebble (Y) is stationary relative to X, that is to say, the proper separation between the two pebbles remains the same over time, at least for now.  Since space is expanding at 70 m/sec per megaparsec, that means Y has a peculiar velocity of 70 m/sec towards X, which is cancelled by space expansion, and hence the two remaining at a fixed separation.

Given just normal expansion (no gravity, no dark energy), there are no forces acting on either pebble and the separation between the two of them will remain the same forever.  X will remain stationary forever, and Y's peculiar velocity will drop as the Hubble 'constant' changes over time. Peculiar velocity always goes down over time for inertial objects. Hubble's constant is indeed not a constant, it's just the current value during the entire history of humanity's existence.

But expansion is not linear, but is instead accelerating.  This adds dark energy into the equation which exerts a force between objects.  Due to this force, the proper separation between Y and X will indeed begin to grow despite no change in peculiar velocity of either pebble compared to the non-accelerating case.  This is the force that could potentially pull the planets out of the solar system if it grew powerful enough.  If this happened, it would be a short time (hours?) before the planets themselves could not hold themselves together.

[Zer0]

@Halc
Hello there!
😊
🙏

I Clearly Understand that the OP has been answered & clarified completely.
👍

But just a lil example if i may...(Please)
🙂

I imagine a river flowing...
~~~~~~

Two Buoys are floating on the River..
~~~¶~~~¶~~~

Now the rate of flow of the River is increasing, it's speeding up...
~~~~~~¶~~~¶~~~~~~

But the Actual distance between both the Buoys is Not changing...

Now lil questions if i may...?
🙃

1) Are both the Buoys connected to just one Anchor? Or do they have different anchors for each respectively?
~~~¶~~~¶~~~///~~~¶~~~¶~~~
       ⚓      ⚓     ///           \     /
                           ///              ⚓


2) Are the Anchors firmly grounded or they are moving steadily with the Flow?

3) As per my understanding, the Actual distance between both the Buoys is certainly Not changing, irrespective of the rate of flow of the river increasing rapidly as time progresses, Right?


P.S. - *Please Note even thou This ain't my OP, & even thou it's been thoroughly Answered... I'm just putting across an imaginative hypothetical question.
Also, The Question is Directed towards a Specific User..who I Believe is in a perfect position to Answer it, Obviously if they choose to...
Hence, I Request All other Scholars to Please hold on to your Genius Horses & Please do Not try to Attempt to Answer it.
Your Guess works might jyst Confuse the Hell outta Mee!
Even if You are Absolutely Sure You know All the Answers, STILL...
🙏
PLEASE!

[Halc]

I imagine a river flowing...
~~~~~~
Two Buoys are floating on the River..
~~~¶~~~¶~~~

Now the rate of flow of the River is increasing, it's speeding up...
~~~~~~¶~~~¶~~~~~~

This is a poor analogy.  Expansion isn't some kind of medium that pushes objects around like water does to buoys.

But the Actual distance between both the Buoys is Not changing.

If the buoys are floating freely and not anchored, then their separation probably does change since one buoy is further downstream and hits the acceleration point before the other one does. Again, this has nothing to do with expansion of space.

1) Are both the Buoys connected to just one Anchor? Or do they have different anchors for each respectively?

I don't know. Your story made no mention until now of anchors or how they're attached.  If they were anchored (together or separately) and in current, then the buoys would remain more or less stationary despite changes to the magnitude of the current.  If the current changed directions, then it would seem that the buoys would adjust.

2) Are the Anchors firmly grounded or they are moving steadily with the Flow?

They wouldn't serve as anchors if they didn't stay put. Again, you didn't tell me.  If it's just a buoy and a brick on rope, then sufficient current will suffice to drag the brick along the bottom.

3) As per my understanding, the Actual distance between both the Buoys is certainly Not changing, irrespective of the rate of flow of the river increasing rapidly as time progresses, Right?

You bring into question if the anchors can be moved, so if they do, then the buoys can move closer or further apart.

This ain't my OP,
... I'm just putting across an imaginative hypothetical question.

The question seems to have no bearing on the topic at hand and thus should be in a thread on its own. Expansion isn't a current. Objects don't float on space nor are they carried by it. There's nothing analogous to an anchor in space.

[Zer0]

🙄
Umm...mmmm.....
☹️
okaay!
😔

@Halc

Can We start over Again?

I'll just blow the balooney question...
🎈
You shoot it down if You wish.
🏹
(no compulsion)

Let's please forget bout the river, buoys & anchors...
🙏

Now...
Considering the Earth & the Moon..
🌍   🌕
Both are locked in, obviously the Earth round the Sun, n the Moon round the Earth.
☀️

     Focusing Just on the Earth & Moon...if the Space between them expands...that does not necessarily drift them apart from each other, considering they are locked into motion by Gravity, Right?

Even if the Space inbetween the whole Solar System keeps expanding, that would Not change distsnces between planetary bodies, Right?

Any accelerated change of expansion of Space will Not necessarily put all the heavenly bodies out of orbits, Correct?

& Does the same analogy apply on the whole Milky Way Galaxy?
Irrespective of the Accelerated Expansion of Space...the Saggitarius A would keep Everything locked into orbits & not scatter or wither away, Right?


P.S. - i wished U would answer & not another Simply because i felt U have a deeper understanding on the Subject matter in question here, based on your responses on the OP.
👍
I did Not challenge U for a duel or debate or a caged death match.
✌️
I Understand with crystal clarity that my previous imaginative exsmple was quite moronically worded, & i Apologize for the same.
🙏
Please Realize..You are at a University Professor level..& I'm a Kindergartner.
🍭
Do Not go on what my profile status says(Senior Member)
It should rather say Newbee or Layman...or even better Dumboo!
💩
Geez!!!

[Halc]

Focusing Just on the Earth & Moon...if the Space between them expands...that does not necessarily drift them apart from each other, considering they are locked into motion by Gravity

Even if the Space inbetween the whole Solar System keeps expanding, that would Not change distsnces between planetary bodies, Right?

Right. Space expansion exerts no force on anything, so it cannot begin to move things apart that were not already moving apart.

Any accelerated change of expansion of Space will Not necessarily put all the heavenly bodies out of orbits, Correct?

Indeed, not necessarily. Something needs to apply a force to accelerate the expansion. That's dark energy, and given enough of it (if it's effect increases without limit), then it can pull otherwise bound things apart. Example: With sufficient force, I can pull the bumper off my car, despite it being bound to the car.
Second example: If you jump into a solar-mass black hole, your legs will be pulled off your body before you get to the event horizon despite being in freefall the whole way.  That's an example of rapid spacetime distortion instead of extreme acceleration of expansion, but the effect is similar. You get pulled apart only in your longest dimension and not the other two directions. With runaway acceleration of expansion, you get pulled apart in all 3 directions at once.

Does the same analogy apply on the whole Milky Way Galaxy?

The same, yes, since any galaxy (or even a supercluser) is a bound thing.

Irrespective of the Accelerated Expansion of Space...the Saggitarius A would keep Everything locked into orbits & not scatter or wither away, Right?

Sgr. A is a tiny mass and unlike our sun with its planets, has little effect holding the galaxy together. It is the collective mass of the galaxy (about 22000 times that of Sgr A) which holds it together.

Do Not go on what my profile status says(Senior Member)

That just means you've made over 100 posts. It speaks nothing of anybody's level of expertise.

It should rather say Newbee or Layman...or even better Dumboo!

That's what the personal text is for. You can make it say what you want. You've instead chosen 'Being human' which I think suits you just fine.

[Zer0]

@Halc
😊
🙏

Hmm...Your detailed description has allowed me to finally Unwrap my head around that " Aether " hypothesis.
👍

Say...why would you want to pull ur car bumper off even if u could...lol
Anyways, does it have that " sh1t Happens " logo on it?
🤔

And ofcourse, when it comes to jumping inside a blackhole...i gotta do it yes...wow! Ur a meanie!
😏
Anyways, I'm familiar with " Sphaggetification "...is that even a word?
🤔

New stuff i learned...Sgt A does hold on slightly but it's the mass of the whole Mway(22000) times that helps keep it in shape.
👍
Did You know the Earth accelerates  & deaccelerates while moving around the sun in the ecliptical orbit...cool Right!
😎

Anyways, why have such different shades of User levels...perhaps it just encourages a few to keep blabbering n posting randomly inorder to level up.
🤔

& say...just having a nicknamed Zer0 wasn't blunt enough eh!
So perhaps i should change that being human stuff...
Yep!
It might suit me, but it does Not help me...
Tanks 4 d Idea!
😉👍


P.S. - Thank You Very Much for explaining things soo Nicely.
🙏
Next time when you sleep or doze off, go down with a smile on ur face thinking U made a difference in this world...a positive one that is.
🖖
Regards,
0.

[Halc]

I'm familiar with " Sphaggetification "...is that even a word?

Sphaghetification is listed in dictionary.com, but my spell checker still highlights it.  Yes, it's a very known term in the physics community.

Did You know the Earth accelerates & deaccelerates while moving around the sun in the ecliptical orbit

That's the dictionary definition of those terms, which is an increase and decrease of speed, respectively. In physics, acceleration is a vector and means change in velocity. The Earth always accelerates towards the sun due to the pull of the sun. Deceleration is not a physics term. Yes, Earth's speed relative to the sun varies throughout its orbit, and is currently decreasing from its maximum in January.
Fun fact: The moon always accelerates towards the sun as well, even when between Earth and sun. The pull of the sun is stronger, so the path of the moon does not curve towards Earth.

[Zer0]

@Halc
(Wat does it mean newyz, sum sorta biochemoblob compuond name is it?)
🤔

*Spaghettification.
Hmm...Got it.
👍
Tanks!
🍭


Now...hold on...plz go slow...

Acceleration is a Vector, meaning change in Velocity.
The Earth is Always Accelerating(falling) towards the Sun.
But there Is a minute difference in Velocity, Right?
🤔

So...Earth decelerating would make it fall(pulled back) towards the Sun with a greater force, hence change in Velocity, Right?
🤔

But still... Deceleration cannot be considered as a physics term, simply because there is Nothing applying the brakes on Earth's Velocity..instead it's only the elliptical orbit that the Earth takes around the Sun due to which the Velocity decreases, Correct?
🤔

(Listen, if i am confusing U & making U doubt your own Understanding of Laws of Physics, then We can Stop right here Okay)
🙏
I did study Perihelion & Aphelion all by meself.
😇


Now...Your Fun Fact simply flew off right thru the top of my head.
🥴
My mind feels Constipated!
🤕
Yeah! That's a diaper around my peanut sized brain.
(To be Honest, i simply did Not get even a word of it)
🤭
Do You have any personal faculty teaching experience for say nursery or junior school?
🤔


P.S. - Now...I shall give you a fun fact... I'm Not trying to Be(ing) Human anymore...Howzatt!
👻

[Halc]

Acceleration is a Vector, meaning change in Velocity.
The Earth is Always Accelerating(falling) towards the Sun.
But there Is a minute difference in Velocity, Right?

Over a short time, yes, but it accumulates.  The centripetal acceleration of Earth due only to the sun is about 0.006 m/sec² which means that after 2.8 minutes the velocity has changed by 1 m/sec towards the sun. After 6 months, the difference is about 60,000 m/sec², which isn't exactly minute.

So...Earth decelerating would make it fall(pulled back) towards the Sun with a greater force, hence change in Velocity

Deceleration isn't a physics term.  Changing the velocity of Earth without changing its distance from the sun is going to have no effect on the gravitational force between the two. Force is a function of the mass and separation of the two masses, but not a function of the motion of either object.

Deceleration cannot be considered as a physics term, simply because there is Nothing applying the brakes on Earth's Velocity..instead it's only the elliptical orbit that the Earth takes around the Sun due to which the Velocity decreases, Correct?

It isn't a physics term because it refers to scalar speed (which is ambiguous without a reference frame) and cannot specify a change in a velocity vector, making it's effect ambiguous. Deceleration is applicable to something like an automobile where it's frame of reference (the road) is implied and hence speed as measured on a speedometer can be meaningfully expressed as a scalar, and deceleration can mean a reduction in that speed.

[Zer0]

Jeeezuz...Deceleration...Christ!!!
😵

Okaay... Time Out!
🙏

I think i get it...Now!
👍

I just won't use Acceleration & Deceleration Anymore.
👎
Faster & Slower are alot more Appropriate.
✌️

Earth has an elleptical orbit round the Sun.
When Earth is Closest to the Sun, it's Perihelion...Earth moves Faster.
When Earth is Farthest from the Sun, it's Aphelion...Earth moves Slower.

There... I've said it.
😔
Done!
👍

P.S. - scalar speed n vectors n God knows wat else...my brain hasn't evolved to grasp technical jargons, maybe a few more decades of learning is required.
Newyz, Tanks Alot... We're Done here.
😊👍
Njoy!
🍭