Time Dilation and the Speed of Light

[Justatruthseeker]

Tell Einstein.

I would but he's dead.

You don't seem to have the faintest idea what I believe, you're just making it up.

Yet you claimed you didn't believe those galaxies were receding from us with increasing speeed, even if that is a requirement of Hubble's Law relating redshift to distance. Need I go back and link to your posts?

Or was that just so you wouldn't have to consider time dilation? Just throwing anything out in an attempt to avoid the logical conclusion?

 

[FrumiousBandersnatch]

... you claimed you didn't believe those galaxies were receding from us with increasing speeed, even if that is a requirement of Hubble's Law relating redshift to distance. Need I go back and link to your posts?

Yes, link to the post where I said that.

 

[Radrook]

So the issue here, as I understand it, is whether there is indeed an actual creation of space between galactic clusters which is producing voids and causing a general expansion of the universe or whether these clusters are actually moving THROUGH space at the velocities indicated by their red shifts and are therefore experiencing the time dilation effects of doing so.

The present scientific popular opinion favors the former but since scientific opinions seem to suddenly change due to new discoveries one can never be 100% sure of what's coming next. We once thought that all matter in the universe was reasonably accounted for and then suddenly the declaration that most of it was missing came into vogue.

Dark matter - Wikipedia

Then we had the popular concept that our sun was producing a typical bow shock wave as its magnetic field interacted with interstellar incoming radiation. Then it is found that it lacks the velocity to produce such a wave. So there goes the whole concept right out the window.

Sun Is Moving Slower Than Thought
Sun’s shock wave goes missing

So what the future holds in reference to this controversy is anybody's guess.

 

[FrumiousBandersnatch]

So the issue here, as I understand it, is whether there is indeed an actual creation of space between galactic clusters which is producing voids and causing a general expansion of the universe or whether these clusters are actually moving THROUGH space at the velocities indicated by their red shifts and are therefore experiencing the time dilation effects of doing so.

The present scientific popular opinion favors the former but since scientific opinions seem to suddenly change due to new discoveries one can never be 100% sure of what's coming next.
...
So what the future holds in reference to this controversy is anybody's guess.

True enough; and that the apparent expansion is due to galaxies moving through space would be reasonable if the big bang was an explosion that flung matter out into a pre-existing universe, but that is not what the big bang proposes; it says that spacetime itself expanded, and the observations to date are consistent with that model.

Dark energy was invoked not because galaxies are apparently moving apart with speeds proportional to their separation - Einstein's field equations predict an expanding universe; but because that expansion appears to be accelerating.

 

[Radrook]

True enough; but dark energy was invoked not because galaxies are apparently moving apart with speeds proportional to their separation - Einstein's field equations predict an expanding universe; but because that expansion appears to be accelerating.

Dark energy was indeed proposed as an explanation for the acceleration. Dark energy - Wikipedia

 

[Justatruthseeker]

And yet all those who believe in an expanding universe still want to use Hubble's Law to calculate the distance of those galaxies. I just wish you would all make up your minds what you believe.

Is it recessional velocity in which case we can calculate the distance of those galaxies correlated with redshift; or is it not recessional velocity in which case their is no correlation between redshift and distance and the distance to those galaxies can not be determined?

Hubble law and the expanding universe

"Hubble's law is a statement of a direct correlation between the distance to a galaxy and its recessional velocity as determined by the red shift."

If it is recessional velocity then time dilation corrections must be applied. If it is not recessional velocity then the distance of galaxies can not be determined by redshift and therefore the age of the universe since the BB can also not be determined.

 

[Justatruthseeker]

Dark energy was initially proposed in order to explain the discrepancy between the calculated orbits of stars in galaxies and the actual slower velocities that were observed. They expected that the orbits that were more distance from the galactic hubs should be slower just as they are in our solar system where the outer planets have lesser velocities than the ones nearer to our Sun. But the observations didn't fit that model. So they were forced to postulate dark matter in order to make the mathematics make sense again.

Or they are simply using the wrong physics for the wrong state of matter? 99.9% of the universe is plasma which is dominated by the EM physical laws. And right where their Fairie Dust exists, we have plasma galore.

HubbleSite: News - Hubble Finds Giant Halo Around the Andromeda Galaxy

"But if you could see the huge bubble of hot, diffuse plasma surrounding it, it would appear 100 times the angular diameter of the full Moon! The gargantuan halo is estimated to contain half the mass of the stars in the Andromeda galaxy itself....... Scientists using NASA's Hubble Space Telescope have discovered that the immense halo of gas (read plasma here - my comment) enveloping the Andromeda galaxy, our nearest massive galactic neighbor, is about six times larger and 1,000 times more massive than previously measured. The dark, nearly invisible halo stretches about a million light-years from its host galaxy, halfway to our own Milky Way galaxy."

Now if they apply the correct physics as the dominating physics.......

Galaxy formation - The Plasma Universe theory (Wikipedia-like Encyclopedia)

What was "dark" is dark no longer......

 

[Justatruthseeker]

Yes, link to the post where I said that.

Time Dilation and the Speed of Light

Time Dilation and the Speed of Light

"Since the accelerating expansion of the universe is spacetime itself expanding, the galaxies are not undergoing relativistic acceleration"

If they are not undergoing acceleration, then there is no correlation between redshift and distance which requires their recessional velocity as a correlating factor according to Hubble's Law which is used to correlate their distances...

Hubble law and the expanding universe

"Hubble's law is a statement of a direct correlation between the distance to a galaxy and its recessional velocity as determined by the red shift."

 

[FrumiousBandersnatch]

Dark energy was initially proposed in order to explain the discrepancy between the calculated orbits of stars in galaxies and the actual slower velocities that were observed.

That was dark matter.

... they were forced to postulate dark matter in order to make the mathematics make sense again.

Yes...

But I was talking about dark energy, not dark matter.

 

[Radrook]

That was dark matter.

Yes...

But I was talking about dark energy, not dark matter.

Thanks! Fixed the response.

 

[Radrook]

Or they are simply using the wrong physics for the wrong state of matter? 99.9% of the universe is plasma which is dominated by the EM physical laws. And right where their Fairie Dust exists, we have plasma galore.

HubbleSite: News - Hubble Finds Giant Halo Around the Andromeda Galaxy

"But if you could see the huge bubble of hot, diffuse plasma surrounding it, it would appear 100 times the angular diameter of the full Moon! The gargantuan halo is estimated to contain half the mass of the stars in the Andromeda galaxy itself....... Scientists using NASA's Hubble Space Telescope have discovered that the immense halo of gas (read plasma here - my comment) enveloping the Andromeda galaxy, our nearest massive galactic neighbor, is about six times larger and 1,000 times more massive than previously measured. The dark, nearly invisible halo stretches about a million light-years from its host galaxy, halfway to our own Milky Way galaxy."

Now if they apply the correct physics as the dominating physics.......

Galaxy formation - The Plasma Universe theory (Wikipedia-like Encyclopedia)

What was "dark" is dark no longer......

Thanks for the info and the links. Very interesting subject!
I also found this site which offers basic explanations about the plasma universe. .
TheUniverse

 

[FrumiousBandersnatch]

Time Dilation and the Speed of Light

Time Dilation and the Speed of Light

"Since the accelerating expansion of the universe is spacetime itself expanding, the galaxies are not undergoing relativistic acceleration"

What I said in the first of those quotes contradicts your previous assertion, and is the basis for my later comment:

What you said: "you claimed you didn't believe those galaxies were receding from us with increasing speeed".

What I actually said: "Galaxies are in relative motion due to the expansion of spacetime."

No statements of belief or lack of belief, just a statement of the current consensus in cosmology - which also says that the expansion is accelerating. But although the separation between them is accelerating, the galaxies themselves are not undergoing acceleration because it is the expansion of spacetime itself that is accelerating (which, as previously discussed, is not the same as a boat being carried along by an accelerating river).

If they are not undergoing acceleration, then there is no correlation between redshift and distance which requires their recessional velocity as a correlating factor according to Hubble's Law which is used to correlate their distances...

Not sure what you think acceleration has to do with it - Hubble's Law refers to recessional velocity. I already said that "galaxies are in relative motion" and that "their separation velocity can exceed light speed...". If you weren't aware, 'recessional velocity' is separation velocity.

"Hubble's law is a statement of a direct correlation between the distance to a galaxy and its recessional velocity as determined by the red shift."

Exactly; and - as before - if you weren't aware, 'recessional velocity' is separation velocity.

You're welcome to disagree with the current consensus, that's not unusual, but you were trying to contradict a misinterpretation or misunderstanding of what I said. I've explained that, and I'm going to leave it there.

 

[Radrook]

What I said in the first of those quotes contradicts your previous assertion, and is the basis for my later comment:

What you said: "you claimed you didn't believe those galaxies were receding from us with increasing speeed".

What I actually said: "Galaxies are in relative motion due to the expansion of spacetime."

No statements of belief or lack of belief, just a statement of the current consensus in cosmology - which also says that the expansion is accelerating. But although the separation between them is accelerating, the galaxies themselves are not undergoing acceleration because it is the expansion of spacetime itself that is accelerating (which, as previously discussed, is not the same as a boat being carried along by an accelerating river).

Not sure what you think acceleration has to do with it - Hubble's Law refers to recessional velocity. I already said that "galaxies are in relative motion" and that "their separation velocity can exceed light speed...". If you weren't aware, 'recessional velocity' is separation velocity.

Exactly; and - as before - if you weren't aware, 'recessional velocity' is separation velocity.

You're welcome to disagree with the current consensus, that's not unusual, but you were trying to contradict a misinterpretation or misunderstanding of what I said. I've explained that, and I'm going to leave it there.

But it isn't either one or the other. I mean some galaxies are indeed accelerating away from one another as they simultaneously are being separated by the expansion of space itself. So both are contribute the spatial separation. Which brings up the question of how they differentiate between the twain effects if both produce a red shift. I assume that there is a qualitative difference which makes differentiation possible-correct?

 

[Stellar Vision]

So the issue here, as I understand it, is whether there is indeed an actual creation of space between galactic clusters which is producing voids and causing a general expansion of the universe or whether these clusters are actually moving THROUGH space at the velocities indicated by their red shifts and are therefore experiencing the time dilation effects of doing so.

The present scientific popular opinion favors the former but since scientific opinions seem to suddenly change due to new discoveries one can never be 100% sure of what's coming next. We once thought that all matter in the universe was reasonably accounted for and then suddenly the declaration that most of it was missing came into vogue.

Dark matter - Wikipedia

Then we had the popular concept that our sun was producing a typical bow shock wave as its magnetic field interacted with interstellar incoming radiation. Then it is found that it lacks the velocity to produce such a wave. So there goes the whole concept right out the window.

Sun Is Moving Slower Than Thought
Sun’s shock wave goes missing

So what the future holds in reference to this controversy is anybody's guess.

Matt O'Dowd gives a great explanation of the recent Dark Energy news here.

 

[FrumiousBandersnatch]

... some galaxies are indeed accelerating away from one another as they simultaneously are being separated by the expansion of space itself. So both are contribute the spatial separation.

Are you talking about acceleration due to the mutual gravitation of galaxies? If so, it's likely to be relatively insignificant (inverse square law), and because it has effectively random vectors at large scales, and doesn't vary with distance from the observer, it's not likely to be particularly relevant to Hubble red shift. If you mean some other acceleration, please explain.

Which brings up the question of how they differentiate between the twain effects if both produce a red shift. I assume that there is a qualitative difference which makes differentiation possible-correct?

I explained above for gravitational attractions between galaxies. If you have something else in mind, please explain.

Caveat: I'm not a cosmologist, so I'm happy to be corrected by someone better informed.

 

[Radrook]

Are you talking about acceleration due to the mutual gravitation of galaxies? If so, it's likely to be relatively insignificant (inverse square law), and because it has effectively random vectors at large scales, and doesn't vary with distance from the observer, it's not likely to be particularly relevant to Hubble red shift. If you mean some other acceleration, please explain.

I explained above for gravitational attractions between galaxies. If you have something else in mind, please explain.

Caveat: I'm not a cosmologist, so I'm happy to be corrected by someone better informed.

I was referring to proper motion through space as opposed to the creation of space between galaxies caused by space expansion. What I am saying is that those two motions can occur simultaneously and reinforce one another. Which brings up my quandary of just exactly how are their red shifts distinguished from each other in order to give each one its accurate value. Let me illustrate in order to clarify.

We have two galactic super clusters at diametrically opposed sides of a great void where the universal expansion is occurring. Simultaneously we have the proper motion of the galaxies of those clusters moving THROUGH space away from each other. So we have two things contributing to the creation of distance, the expansion of space itself within the voids and the proper motion of the galaxies themselves which might be moving away from one another on their own.

How do we sort them out via red shift in order to give each its proper value?

BTW
I an aware that time dilation at these galactic locations would not be caused by the expansion of space itself. The time dilation would affect a galaxy only if it is itself moving THROUGH space and not just having space created between itself and other objects.

 

[FrumiousBandersnatch]

I was referring to proper motion through space as opposed to the creation of space between galaxies caused by space expansion. What I am saying is that those two motions can occur simultaneously and reinforce one another. Which brings up my quandary of just exactly how are their red shifts distinguished from each other in order to give each one its accurate value. Let me illustrate in order to clarify.

We have two galactic super clusters at diametrically opposed sides of a great void where the universal expansion is occurring. Simultaneously we have the proper motion of the galaxies of those clusters moving THROUGH space away from each other. So we have two things contributing to the creation of distance, the expansion of space itself within the voids and the proper motion of the galaxies themselves which might be moving away from one another on their own.

How do we sort them out via red shift in order to give each its proper value?

OK, this is how I see it: a galaxy would only have proper motion through space relative to other galaxies if some force was, or is, acting on it. The only significant force that is effective over galactic and supra-galactic scales is gravity, which is attractive - it's why galaxies congregate into (super)clusters in the first place.

So the galaxies, overall, will tend to be moving through space towards large centres of mass by the mutual attraction of gravity (and yes, there will be galaxies moving away from each other due to 'overshoot' or because they're attracted to different centres of mass). But there will be no preferred direction of movement overall; galaxies will be gravitationally attracted towards superclusters from all directions. So we should expect a roughly equal number of red-shifted and blue-shifted galaxies - and all shades in-between - overall due to this motion; although if we are in a supercluster, we might expect a few more blue-shifted galaxies close to our supercluster (as they will be more likely to be moving toward us).

The expansion of space is analogous to a repulsive force, tending to increase the separation between galaxies or reduce their relative closing speeds. So it will tend to counter the proper motion due to gravitational attraction rather than reinforce it.

Since the overall proper motion of galaxies through space has no preferred direction (being the result of gravitational attraction), and has no relation to the distance from any observer over cosmological scales, it will not be relevant to calculations of the Hubble red-shift if a reasonably sized sample is taken.

BTW
I an aware that time dilation at these galactic locations would not be caused by the expansion of space itself. The time dilation would affect a galaxy only if it is itself moving THROUGH space and not just having space created between itself and other objects.

Cool

 

[RDKirk]

To be perfectly honest, I'm not even sure what "time" is. Does it exist or is it just a handy way to think about things?

Time is the effect of the change of properties of entities that exist and measurable only as an effect of the change of properties of entities that exist. If there are no entities that exist, or if those entities do not change, then there is no time.

 

[FrumiousBandersnatch]

Time is the effect of the change of properties of entities that exist and measurable only as an effect of the change of properties of entities that exist. If there are no entities that exist, or if those entities do not change, then there is no time.

Yes. But if there is an observer, there will always be time - if only because the observer must change. This complicates conceptualizing the absence of time.

 

[RDKirk]

Yes. But if there is an observer, there will always be time - if only because the observer must change. This complicates conceptualizing the absence of time.

However, as Believers one of our beliefs is that God does not change (being extemporarily simultaneous), so if God is the only existing observer with nothing else in existence, then there is no time. Time would begin only when God created something that would begin changing.

A ramification of quantum mechanics appears to be that all events, from the subatomic to the macro-cosmic, requires an observer capable of judging whether the event actually occurred.