Actual vs apparent universal expansion rate

[imatfaal]

I hope you are not kidding. Distance means time.

 

Not kidding - and distance only means time in things like Planck Units (and even then it is not exact).

[michel123456]

 

Not kidding - and distance only means time in things like Planck Units (and even then it is not exact).

A galaxy far away is also seen as it was long ago. The fact that you see something at a distance means you see it as it was in the past. One can transform any distance in light-seconds, or light-years. Hubble's law can be translated in an increase of speed by time. As much the Universe gets older as much it expands.

[imatfaal]

A galaxy far away is also seen as it was long ago. The fact that you see something at a distance means you see it as it was in the past. One can transform any distance in light-seconds, or light-years. Hubble's law can be translated in an increase of speed by time. As much the Universe gets older as much it expands.

 

"One can transform any distance in light-seconds, or light-years." This sounds as if you think the light-second or light-year are measurements of time - they are not, they are measurements of distance. At light speed there are massive connexions - but they are not the same

 

"Hubble's law can be translated in an increase of speed by time." Not really unless you want to confuse yourself even more. Right now the gaps between any two galactic cluster size objects that are not gravitationally bound are increasing at c. 71km/s/Mpc - it is not necessary to tie this into one of the objects observing the other - or even being observed by a third party. You could - this is needless complication - take the geocentric idea of only thinking about objects receding from earth at this moment and then divide the distances by the speed of light to get a calculation with respect to the time past since the light was emitted by the object; but why?

 

And acceleration is the second derivation with respect to time not with respect to distance; whichever way you want to look at it.

[MigL]

Michel's problem is his rather simplistic approach to defining speed and acceleration, and he has the same problem in the other thread about the consistency of the SOL.

He is using rulers and clocks as anyone would, but doesn't recognize the ( not so subtle ) fact that speed is calculated from the translational motion across a 'fixed' ruler, while in the case of expansion, there is no translation across a ruler, the ruler is not fixed, it is variable and actually expands.

This is not a speed.

 

You could get a similar effect by modifying the clock.

Consider two observers watching a well defined event ( a distant rocket moving across a star ) occurring at near c speeds. One observer is in nearly flat space-time and the second is in a deep gravitational well. The second observer will see the 'clock', signals from the event, blue-shifted. The units of the clock he is using to measure the speed have shrunk, and so he will see 'apparent' superluminal speeds during the rocket's transit.

Is this an actual speed ? Of course not. It fails to take into account the modified clock or signal.

 

So it doesn't matter that whole clusters of galaxies have 'moved' farther away. The separation between us and them has grown larger. The 'ruler' has changed and grown larger. The clusters have not moved across a fixed ruler. It is NOT a speed or velocity.

And any change in the rate of expansion cannot be considered an acceleration of the clusters of galaxies.

Edited July 26, 2016 by MigL

[Strange]

So it doesn't matter that whole clusters of galaxies have 'moved' farther away. The separation between us and them has grown larger. The 'ruler' has changed and grown larger. The clusters have not moved across a fixed ruler. It is NOT a speed or velocity.

 

 

Excellent!

[J.C.MacSwell]

 

"One can transform any distance in light-seconds, or light-years." This sounds as if you think the light-second or light-year are measurements of time - they are not, they are measurements of distance. At light speed there are massive connexions - but they are not the same

 

"Hubble's law can be translated in an increase of speed by time." Not really unless you want to confuse yourself even more. Right now the gaps between any two galactic cluster size objects that are not gravitationally bound are increasing at c. 71km/s/Mpc - it is not necessary to tie this into one of the objects observing the other - or even being observed by a third party. You could - this is needless complication - take the geocentric idea of only thinking about objects receding from earth at this moment and then divide the distances by the speed of light to get a calculation with respect to the time past since the light was emitted by the object; but why?

 

And acceleration is the second derivation with respect to time not with respect to distance; whichever way you want to look at it.

 

Michel's problem is his rather simplistic approach to defining speed and acceleration, and he has the same problem in the other thread about the consistency of the SOL.

He is using rulers and clocks as anyone would, but doesn't recognize the ( not so subtle ) fact that speed is calculated from the translational motion across a 'fixed' ruler, while in the case of expansion, there is no translation across a ruler, the ruler is not fixed, it is variable and actually expands.

This is not a speed.

 

You could get a similar effect by modifying the clock.

Consider two observers watching a well defined event ( a distant rocket moving across a star ) occurring at near c speeds. One observer is in nearly flat space-time and the second is in a deep gravitational well. The second observer will see the 'clock', signals from the event, blue-shifted. The units of the clock he is using to measure the speed have shrunk, and so he will see 'apparent' superluminal speeds during the rocket's transit.

Is this an actual speed ? Of course not. It fails to take into account the modified clock or signal.

 

So it doesn't matter that whole clusters of galaxies have 'moved' farther away. The separation between us and them has grown larger. The 'ruler' has changed and grown larger. The clusters have not moved across a fixed ruler. It is NOT a speed or velocity.

And any change in the rate of expansion cannot be considered an acceleration of the clusters of galaxies.

Michel can correct me if I am wrong, but he is seeing an increase in the rate of gap increase over time between two distant non gravitationally bound points that are only gap increasing due to the Hubble Expansion. Even with a constant Hubble constant, that effect is there...the increasing distance gives them an increased Hubble effect over time, not just for distance. He might (not sure he still is) be relating the gap increase to a velocity, but I don't think he believes a light year is a measurement of time.

[michel123456]

 

Michel can correct me if I am wrong, but he is seeing an increase in the rate of gap increase over time between two distant non gravitationally bound points that are only gap increasing due to the Hubble Expansion. Even with a constant Hubble constant, that effect is there...the increasing distance gives them an increased Hubble effect over time, not just for distance. He might (not sure he still is) be relating the gap increase to a velocity, but I don't think he believes a light year is a measurement of time.

 

Michel's problem is his rather simplistic approach to defining speed and acceleration, and he has the same problem in the other thread about the consistency of the SOL.

He is using rulers and clocks as anyone would, but doesn't recognize the ( not so subtle ) fact that speed is calculated from the translational motion across a 'fixed' ruler, while in the case of expansion, there is no translation across a ruler, the ruler is not fixed, it is variable and actually expands.

This is not a speed.

 

You could get a similar effect by modifying the clock.

Consider two observers watching a well defined event ( a distant rocket moving across a star ) occurring at near c speeds. One observer is in nearly flat space-time and the second is in a deep gravitational well. The second observer will see the 'clock', signals from the event, blue-shifted. The units of the clock he is using to measure the speed have shrunk, and so he will see 'apparent' superluminal speeds during the rocket's transit.

Is this an actual speed ? Of course not. It fails to take into account the modified clock or signal.

 

So it doesn't matter that whole clusters of galaxies have 'moved' farther away. The separation between us and them has grown larger. The 'ruler' has changed and grown larger. The clusters have not moved across a fixed ruler. It is NOT a speed or velocity.

And any change in the rate of expansion cannot be considered an acceleration of the clusters of galaxies.

J.C. understands me very well. True I have a simplistic point of view.

 

Question: if we have to send a rocket through the "increased gap between gravitationaly not bounded clusters of galaxies", how would we describe its motion? Wouldn't that be a velocity? Isn't the "gap" newly created space, exactly as regular space is? Or is it "other kind of space", lets say "gaps" that the rocket will go through by jumping (like photons are supposed to do I suppose?)

[michel123456]

If it is a question so difficult to answer a mod could split the thread.

[Strange]

Or is it "other kind of space", lets say "gaps" that the rocket will go through by jumping (like photons are supposed to do I suppose?)

 

What evidence do you have for this "other kind of space" you have invented?

And what evidence do you have for photons "jumping through gaps"? (Whatever that means.)

[StringJunky]

Michel

 

I think you've got lost down a rabbit-hole with your journey into this subject and need to go back to the point where what you know matches current thinking and carry on from there. I've had to go back few times myself when I realised I've hung onto a misconception, without realising it at the time, which messes up everything you try to understand after because they don't fit onto that erroneous piece(s) of knowledge. Possibly, it's a bit of 'pet theory' you are hanging onto that's causing the problem.

Edited July 27, 2016 by StringJunky

[michel123456]

 

What evidence do you have for this "other kind of space" you have invented?

And what evidence do you have for photons "jumping through gaps"? (Whatever that means.)

Sorry. It was sarcastic.

Let me re-phrase

 

Question: if we have to send a rocket through the "increased gap between gravitationaly not bounded clusters of galaxies", how would we describe its motion? Wouldn't that be a velocity?

Edited July 27, 2016 by michel123456

[Strange]

Sorry. It was sarcastic.

Let me re-phrase

 

Question: if we have to send a rocket through the "increased gap between gravitationaly not bounded clusters of galaxies", how would we describe its motion? Wouldn't that be a velocity?

 

It would. And it would be a different velocity depending on what you measure it relative to.

 

Also, obviously, if you send it to something that is currently 1 billion light years away at a speed of 0.5c it will take much more than 2 billion light years to reach the destination (you can do the maths, if you are interested).

 

The further away your destination is when you start, the greater the extra travel time will be. At some point, space will be expanding ahead of you faster than you are moving and so you will never reach your destination. Pretty simple.

 

If you try to reach

[michel123456]

Michel

 

I think you've got lost down a rabbit-hole with your journey into this subject and need to go back to the point where what you know matches current thinking and carry on from there. I've had to go back few times myself when I realised I've hung onto a misconception, without realising it at the time, which messes up everything you try to understand after because they don't fit onto that erroneous piece(s) of knowledge. Possibly, it's a bit of 'pet theory' you are hanging onto that's causing the problem.

Thank you String.

But I am tired of trying to absorb so many things that do not make any sense.

I won't tell you the story of my life but a long time ago I thought I simply had to inform myself in order to understand the world around me. Since then, I have come to the conclusion that you must be very stupid (or shy) to accept what is being told. During my inquiry I have lost any respect for people who after being explained what is going on say "oh yes you are right I understand now". These are imbeciles.

Relativity makes sense only as a theory of observation. IOW observation, measurements, are distorted and Relativity tells us how. This is my starting point.

From there on, there is a lot of BS.

 

It would. And it would be a different velocity depending on what you measure it relative to.

 

Also, obviously, if you send it to something that is currently 1 billion light years away at a speed of 0.5c it will take much more than 2 billion light years to reach the destination (you can do the maths, if you are interested).

 

The further away your destination is when you start, the greater the extra travel time will be. At some point, space will be expanding ahead of you faster than you are moving and so you will never reach your destination. Pretty simple.

 

If you try to reach

Oh. For a rocket it would be a velocity? but not for a photon?

Why?

[Strange]

Oh. For a rocket it would be a velocity? but not for a photon?

 

I didn't say that.

 

 

Relativity makes sense only as a theory of observation. IOW observation, measurements, are distorted and Relativity tells us how.

 

That's it. That is all there is to it.

[michel123456]

 

I didn't say that.

 

Then what did you say?

[Strange]

Then what did you say?

 

Exactly what is in the post you quoted.

[michel123456]

 

Exactly what is in the post you quoted.

Sybillic answer.

 

Is the motion of the rocket described by velocity?

[Strange]

Sybillic answer.

 

Is the motion of the rocket described by velocity?

 

 

Of course.

[michel123456]

 

 

Of course.

Is the motion of a photon described by velocity?

[Strange]

Is the motion of a photon described by velocity?

 

 

Of course.

[michel123456]

So you mean the rocket will travel through "regular space"?

IOW , at exactly half-way, the rocket will not be pushed by the creation of space behind it?

[Strange]

So you mean the rocket will travel through "regular space"?

IOW , at exactly half-way, the rocket will not be pushed by the creation of space behind it?

 

 

Nothing is "pushed by the creation of space". (There is no such thing as "the creation of space".)

 

But, as I already said, the time taken for the rocket to get to its destination will be increased by the expansion of space between its current position and the destination. At some point, that may make it impossible to reach its destination. Just like photons.

It would be much easier if you actually learned some science instead of making things up.

[michel123456]

 

 

Nothing is "pushed by the creation of space". (There is no such thing as "the creation of space".)

 

But, as I already said, the time taken for the rocket to get to its destination will be increased by the expansion of space between its current position and the destination. At some point, that may make it impossible to reach its destination. Just like photons.

It would be much easier if you actually learned some science instead of making things up.

You are full of contradictions. Take a rest and rethink your answers.

[Mordred]

Nothing Strange said is a contradiction. It seems to me your having difficulty understanding how light can reach us. When the recessive velocity of expansion is greater than c.

 

Recessive velocity. Is not a true velocity the only observers who will measure a greater than c velocity of a galaxy are observers at greater than 4400 Mpc plus or minus 400 Mpc.

 

Any observers less than that distance will measure the Galaxy at recessive velocity of less than c. This is just due to the formula used to calculate recessive velocity.

 

[latex]v=H_od [/latex] this recessive velocity is an "Apparent or peculiar " velocity. Not a true velocity. A true velocity involves Newtons laws. An apparent velocity does not as it varies due to observer.

Edited July 28, 2016 by Mordred

[michel123456]

Nothing Strange said is a contradiction. It seems to me your having difficulty understanding how light can reach us. When the recessive velocity of expansion is greater than c.

 

Recessive velocity. Is not a true velocity the only observers who will measure a greater than c velocity of a galaxy are observers at greater than 4400 Mpc plus or minus 400 Mpc.

 

Any observers less than that distance will measure the Galaxy at recessive velocity of less than c. This is just due to the formula used to calculate recessive velocity.

 

[latex]v=H_od [/latex] this recessive velocity is an "Apparent or peculiar " velocity. Not a true velocity. A true velocity involves Newtons laws. An apparent velocity does not as it varies due to observer.

So the photon has a true velocity or a false velocity?

The rocket that goes from one galaxy to the other has a true velocity or a false velocity? As seen from Earth, will it be recessed also? (I mean "transported by expanding space" as the galaxies are supposed to be, or will it remain a dumb rocket that must travel like you & me only through regular space?. Sorry for being sarcastic again.