Galaxies going faster than light ? [v.2]

[The God]

It doesn't. Cosmological expansion is effectively zero at any scale smaller than galactic clusters.

You might as well ask why we don't factor the Casimir Effect into our orbital calculations.

This has been explained multiple times. I asked you to incorporate this newfound knowledge of yours into your posts; you have not.

What do you mean effectively zero? You contradict origin but you support his point too. He said there is expansion between Andromeda and MW, but falling towards each other is more due to gravity? Is he right or you are right?

Casmir effect in the context? Attempting to show off with irrelevant technical term?

 

[paddoboy]

I u derstand but you don't. DE is not for expansion, it is for accelerated expansion.

I don't believe you do understand properly....Which explains why your threads and posts are moved from science in general. It was derived to explain acceleration in the expansion rate..it applies to both actually.

And secondly basic physics says that if this is countered by strong or weak of yours then it is there, and if it is there it must manifest.

Perhaps in your own dream psuedo world, certainly not in the current standard cosmology.

But I am never wrong..

That explains a lot.

 

[paddoboy]

What do you mean effectively zero? You contradict origin but you support his point too. He said there is expansion between Andromeda and MW, but falling towards each other is more due to gravity? Is he right or you are right?

That highlights your general misunderstanding most are commenting on.
The gravity from the local group of galaxies, is simply overcoming the expansion of spacetime. eg: Motoring up stream against a river flow of 10kms/hr [representing expansion] at 20kms/hr [representing gravity from local group]
As has been explained to you countless times, the expansion of the universe is evident over the larger, less denser scales.
Over smaller scales, gravity dominates.

 

[Daecon]

But I am never wrong..

Is that a tacit admission that when you post things that are contrary to reality, you're not mistaken but you're lying?

 

[DaveC426913]

What do you mean effectively zero? You contradict origin but you support his point too. He said there is expansion between Andromeda and MW, but falling towards each other is more due to gravity? Is he right or you are right?

I'm not arguing origin's assertion, nor he mine. Don't change the subject. Argue in good faith.

Casmir effect in the context?

The Casimir Effect is an extremely weak effect (zero) on the scale of orbits.

You wonder why Cosmological Expansion doesn't affect orbits though it is infiinitesimally small at that scale, yet you do not wonder about other infinitesimally small forces.

Attempting to show off with irrelevant technical term?

I am debating with you in good faith. We disagree, yet I do not need to fling peronsal insults.

If you were to argue in good faith, you would not need to make personal digs.

 

[The God]

That highlights your general misunderstanding most are commenting on.
The gravity from the local group of galaxies, is simply overcoming the expansion of spacetime. eg: Motoring up stream against a river flow of 10kms/hr [representing expansion] at 20kms/hr [representing gravity from local group]
As has been explained to you countless times, the expansion of the universe is evident over the larger, less denser scales.
Over smaller scales, gravity dominates.

Now leave aside the bickering, and please answer following point.

I will explain in simple language.
Take earth sun system, any orbital system will do, for discussion consider this to be circular. The earth is always at a distance r from sun in its orbit. Now the motion of earth is in tangential direction at any instant, not radially inwards (towards sun) or outwards. If the space between two expands, the r must increase and over a period of time earth must part off. But it does not. So that means there got to be mechanism by which gravity must precisely compensate this expansion by pulling the earth onwards to maintain r. What is that?

 

[The God]

I'm not arguing origin's assertion, nor he mine. Don't change the subject. Argue in good faith.


The Casimir Effect is an extremely weak effect (zero) on the scale of orbits.

You wonder why Cosmological Expansion doesn't affect orbits though it is infiinitesimally small at that scale, yet you do not wonder about other infinitesimally small forces.


I am debating with you in good faith. We disagree, yet I do not need to fling peronsal insults.

If you were to argue in good faith, you would not need to make personal digs.

You are posting without doing sufficient homework. It is not that I do not understand what is the mainstream point of view, it is in bad taste to repeatedly post the same thing again and agaim without underdtsnding the point which I am making, pl see my previous post.

Ok, try this. Is the space expansion on local scale is zero or it is non zero small or non zero whatever but gets compensated by gravity in orbital motion ?

 

[The God]

Is that a tacit admission that when you post things that are contrary to reality, you're not mistaken but you're lying?

Reality! Really?
And I don't lie too.

 

[DaveC426913]

.. it is in bad taste to repeatedly post the same thing again and agaim ...

Oh. the irony.

 

[paddoboy]

Now leave aside the bickering, and please answer following point.

I will explain in simple language.
Take earth sun system, any orbital system will do, for discussion consider this to be circular. The earth is always at a distance r from sun in its orbit. Now the motion of earth is in tangential direction at any instant, not radially inwards (towards sun) or outwards. If the space between two expands, the r must increase and over a period of time earth must part off. But it does not. So that means there got to be mechanism by which gravity must precisely compensate this expansion by pulling the earth onwards to maintain r. What is that?

You fail to understand: The space between them does not expand: Gravity overcomes the spacetime expansion, just as in my analogy, the boat motoring upstream at 20kms/hr, overcomes the river current at 10kms/hr. And of course any orbit is simply freefall.

 

[paddoboy]

You are posting without doing sufficient homework.

More to the point, you are posting without wanting to understand due to a probable agenda and fabricating non existent problems as expletive deleted was in a habit of doing..

 

[paddoboy]

http://math.ucr.edu/home/baez/physics/Relativity/GR/expanding_universe.html

extract:

In newtonian terms, one says that the Solar System is "gravitationally bound" (ditto the galaxy, the local group). So the Solar System is not expanding. The case for Brooklyn is even clearer: it is bound by atomic forces, and its atoms do not typically follow geodesics. So Brooklyn is not expanding. Now go do your homework.

 

[DaveC426913]

You are posting without doing sufficient homework. It is not that I do not understand what is the mainstream point of view, it is in bad taste to repeatedly post the same thing again and agaim without underdtsnding the point which I am making, pl see my previous post.

Ok, try this. Is the space expansion on local scale is zero or it is non zero small or non zero whatever but gets compensated by gravity in orbital motion ?

It is infinitesimally small. That means that its effect on orbits is swamped - by orders of magnitude - by the gravitatational "noise" already existing in our system. And, surprise - orbits are not static over long time frames.

The area of space in the vicinity of the Solar System is filled with dust and gas that is moving in all sorts of directions toward, away and past our Solar System. Farther out there are myriad stars, going in all sorts of directions relative to our SS. Every single one of these things - every pocket of gas and every passing star (such as Barnard's with its huge proper motion) - affect every orbit of every body in our solar system.

These forces I mention are orders of magnitude more powerful and more perturbatory than Cosmological Expansion.

Why do you not object to the notion of stable orbits in the presence of what is effectively a maelstrom of perturbatory gravity?

 

[DaveC426913]

orbits are not static over long time frames.

I think this bears further comment, since there's a fair bit of preconception around using it as some sort of "plausibility test" of Cosmological Expansion.

Orbits are not static. They are in a continual state of change. Moons migrate outward; moons migrate inward. Planets migrate outward and inward. Hot Jupiters migrate to within Mercury's orbit of their parent. Orbits become eccentric and circular. They tilt, they precess. Planets break up into rings or belts. Planets interact and form synchronous nodes. Small bodies get ejected (Sort of the Perturbation - Level 1000, there).

The forces in play in any orbit are legion. (This, incidentally, manifests in why we can only measure them with a certain degree of precision, and to a certain accuracy into the past or future.)

Yet orbits are not delicately-balanced perfections that spin out of control the moment they are perturbed. There are limiting factors and restorative forces at-play. If the Moon were to get nudged by the close approach of Jupiter, it doesn't crash into the Earth; it may get pulled a few millimetres farther away, or farther forward. So now it is too high for its velocity and it moves into a slightly more elliptical orbit, with its perigee a few millimetres closer to Earth. Somtimes these perturbations correct themselves, someties they don't. Big deal. It happens. Systems evolve.

Let's factor in Cosmological Expansion. In fact, let's do it BIG. Let's simulate CE in a controlled experiment using a giant rocket to move the Moon way from the Earth at, say, 1mm per millenium - orders of magnitude farther and faster than CE.*

* CE causes expansion over hundeds of millions of light years. Scale that expansion down to the 200,000 miles from Earth to Moon. How many orders of mag is that? 15? 20?

OK, so the Moon is moving an extra mm every millenium. Does that need to be cause for concern when - due to tidal effects alone - it is already receding at centimetres per year?


Is it beginning to make sense why examining the hairs on the back of our own Cosmological hand is not going to be much use in deciding what is or isn't happening ten Cosmological counties away?

 

[Kittamaru]

The God - the space between Andromeda and the Milky Way is expanding... your confusion is in not accounting for the fact that, to make things simple, the space between the two Galaxies is expanding at speed X, where as the force of Gravity is pulling them closer together at 100X or more.

Thus, the two galaxies are moving toward one another at many times the speed at which the distance between them is expanding.

Think of it like a big treadmill. You are standing on one end. On the other end is a glass of milk and cookies. You want the milk and cookies. The treadmill is running at 1 mile per hour, so you jog at 5 miles per hour. Thus you are moving towards the milk and cookies.

Does that make it understandable?

 

[DaveC426913]

The God - the space between Andromeda and the Milky Way is expanding... your confusion is in not accounting for the fact that, to make things simple, the space between the two Galaxies is expanding at speed X, where as the force of Gravity is pulling them closer together at 100X or more.

Yup. Except it's many orders of magnitude smaller than 1:100.
And again, gravitational perturbation is far, far more chaotic than is being imagined in this thread.

 

[paddoboy]

The God - the space between Andromeda and the Milky Way is expanding... your confusion is in not accounting for the fact that, to make things simple, the space between the two Galaxies is expanding at speed X, where as the force of Gravity is pulling them closer together at 100X or more.

Thus, the two galaxies are moving toward one another at many times the speed at which the distance between them is expanding.

Think of it like a big treadmill. You are standing on one end. On the other end is a glass of milk and cookies. You want the milk and cookies. The treadmill is running at 1 mile per hour, so you jog at 5 miles per hour. Thus you are moving towards the milk and cookies.

Does that make it understandable?

But I am never wrong..

Some come here with every intention of not wanting to learn, but to push their evangelistic preconceived nonsense.

 

[river]

But some just give another perspective on the topic .

Nothing to do with evangelical thinking at all.

river

 

[DaveC426913]

But some just give another perspective on the topic .

Nothing to do with evangelical thinking at all.

river

Science isn't really a focus-group kind of activity.

 

[river]

The thing is though ; NASA being fundamentally mainstream is saying that either galaxies or something is travelling faster than the speed of light.

Something to think about is it not ? I think it should be something to think about . It goes against Einstein as you know.