Galaxies moving at faster than the speed of light!!

[esbo]

I am lead to believe this is the case, if it's not then well I guess I am wasting my time!!

 

So.....if they are how is this possible, we are told this is impossible.

 

It seems to be the case that people will say yes some are moving faster than the speed of light but that is

because space if expanding.

 

That leads to new questions such as, how fast are they really moving.

 

It seems to me that nothing is moving very fast really indeed I think that basically everything

is basically pretty static and that there is a standard time for the universe which I will call 'real-time'.

 

So I think there is a common reference point for time and that any different time of moving objects

are basically due to 'clock error' so we could refer to their time as standard time - clock error.

 

Also what if we tied two galaxies together with a rope?

 

Would they stop moving apart? Or would the rope snap?

 

Basically how strong is the force of expansion?

 

Maybe this is something to do with dark energy?

 

Maybe someone can explain?

[StringJunky]

 

 

That leads to new questions such as, how fast are they really moving.

 

Velocity is always relative to something. There is no place that can be said to be absolutely static, therefore, there can be no preferred frame of reference.

 

 

It seems to me that nothing is moving very fast really indeed I think that basically everything

is basically pretty static and that there is a standard time for the universe which I will call 'real-time'.

What time it is from any given frame of reference is a function of the strength of the gravitational field it resides in and the velocity it moves at relative to some other frame. Again, there is no preferred frame.

 

So I think there is a common reference point for time and that any different time of moving objects

are basically due to 'clock error' so we could refer to their time as standard time - clock error.

It doesn't matter what clock you use -provided it has sufficient resolution for the test to measure any difference- it will agree with the predictions of Relativity.

 

 

Basically how strong is the force of expansion?

Very weak compared to gravity...it occurs between superclusters at distances about 200 million light years apart or more.

 

 

 

Maybe this is something to do with dark energy?

The expansion is a consequence and continuation of the BB...dark energy was postulated to explain the increasing rate of that expansion over time.

Edited July 3, 2013 by StringJunky

[esbo]

 

Velocity is always relative to something. There is no place that can be said to be absolutely static, therefore, there can be no preferred frame of reference.

 

What time it is from any given frame of reference is a function of the strength of the gravitational field it resides in and the velocity it moves at relative to some other frame. Again, there is no preferred frame.

It doesn't matter what clock you use -provided it has sufficient resolution for the test to measure any difference- it will agree with the predictions of Relativity.

Very weak compared to gravity...it occurs between superclusters at distances about 200 million light years apart or more.

 

The expansion is a consequence and continuation of the BB...dark energy was postulated to explain the increasing rate of that expansion over time.

 

 

What evidence is there that there is no absolute reference point of velocity and the same goes for time, where is the evidence?

 

How strong is the force of expansion specifically, can you give a number?

 

Given we do not know what dark energy is it seems there is a lot we do not understand about the universe

[ACG52]

 

 

What evidence is there that there is no absolute reference point of velocity and the same goes for time, where is the evidence?

 

Relativity, which has been experimentally and observationally verified to an amazing degree over the last hundred years tells us that there is no absolute frame of reference.

 

 

 

How strong is the force of expansion specifically, can you give a number?

 

The rate of expansion is about 78 km/sec/megaparsec. This means that the rate of expansion increases by 78 km/sec for every 3.26 million light years. This is a very low expansion rate.

 

 

 

Given we do not know what dark energy is it seems there is a lot we do not understand about the universe

Yes, there's quite a bit we don't yet know. The surprising thing is how much we've been able to learn about the universe in just the last 200 years.

[swansont]

What evidence is there that there is no absolute reference point of velocity and the same goes for time, where is the evidence?

GPS works. GPS is based on relativity, and there is no absolute rest frame in relativity. And all of the other experiments that agree with relativity.

 

Evidence that there is no rest frame also includes the Michelson-Morley experiment, which tried to measure our speed relative to the rest frame, and got a null result. But stellar aberration had already shown that we could not be at rest. The contradiction got an absolute rest frame tossed in the trash.

[esbo]

 

Relativity, which has been experimentally and observationally verified to an amazing degree over the last hundred years tells us that there is no absolute frame of reference.

 

 

The rate of expansion is about 78 km/sec/megaparsec. This means that the rate of expansion increases by 78 km/sec for every 3.26 million light years. This is a very low expansion rate.

 

Yes, there's quite a bit we don't yet know. The surprising thing is how much we've been able to learn about the universe in just the last 200 years.

 

 

Merely saying "relativity" is not evidence, nor is saying "Relativity, which has been experimentally and observationally verified to an amazing degree over the last hundred years tells us that there is no absolute frame of reference."

 

If it has been experimentally verified tell me about the experiment, I mean you must be pretty familiar with the experiment? Yes?

 

I asked how strong the force of expansion was, not the rate of expansion, I can easily look that up, bit harder finding the force of expansion.

 

As there is quite a bit we do not know, that seem to leave a lot of room for error in what we *think* we know.

 

Whilst we think we have learned a lot in the last 200 years we may well learn much if it is wrong in the next 200 years.

[StringJunky]

You are standing on a rock in space and you can’t feel any acceleration To you, you are standing on a stationary rock. You can’t see anything else around you until you see Alice atop another rock getting bigger and bigger. Alice has exactly the same experience as you, looking at you, from her point of view.

 

Who is moving and who is stationary? Which is the absolute/real/correct frame out of the two frames?

 

Answer: They are both correct. There is no such thing as an absolute frame in the real world.

 

 

 

I asked how strong the force of expansion was, not the rate of expansion, I can easily look that up, bit harder finding the force of expansion.

 

 

 

Very weak compared to gravity...it occurs between superclusters at distances about 200 million light years apart or more.

Edited July 3, 2013 by StringJunky

[ACG52]

 

 

Merely saying "relativity" is not evidence, nor is saying "Relativity, which has been experimentally and observationally verified to an amazing degree over the last hundred years tells us that there is no absolute frame of reference."

 

If it has been experimentally verified tell me about the experiment, I mean you must be pretty familiar with the experiment? Yes?

 

Feel free to read for yourself.

http://en.wikipedia.org/wiki/Tests_of_general_relativity

http://en.wikipedia.org/wiki/Tests_of_special_relativity

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980327b.html

Not to mention that GPS, which is used everyday by millions of people, depends on special and general relativity correction for accuracy.

 

 

 

I asked how strong the force of expansion was, not the rate of expansion, I can easily look that up, bit harder finding the force of expansion.

Well, I don't know of any way to directly calculate the force of cosmological expansion.

But since the cut over point between gravity and expansion is about 200 million lys from our galactic supergroup, if we take the mass of the supergroup as 2x10⁴⁵ kg, and r as 1.88x10²⁵ meters and calculate F = GM/r², we would get

 

6.67x10^-11 x (2x10⁴⁵) / 3.53x10⁵⁰ = 3.77 x 10^-16 newtons as the force of expansion. Roughly.

Edited July 3, 2013 by ACG52