B Explaining Distant Time Dilation & Enhanced Gravitation

[doudou]

When we observe distant time dilation effects, usually indicated by redshift, there are three possible explanations:

1) The speed of light, is slower there and then;
2) Space, is contracted for light there and then;
3) The frequency, of specific light is slower there and then.

However, it is difficult to determine, which of these explanations is the most plausible, when we are on Earth. Even if we send a spaceship to the location in question, we may not be able to perceive any above changes, due to potential local flatness.

Similarly, when we observe distant gravitational effects, there are three possible explanations:

1) The value of the gravitational constant, G, is greater there and then;
2) Space is expanded for gravitation there and then;
3) There is extra mass, such as dark matter, present there and then.

Again, it is challenging to determine which explanation is the most plausible.

This raises some questions:

a) Are our theories about the universe limited to this stage, where we have the ability to create theories, such as general relativity, variable speed of light, and theories in which energy and mass are not conserved, or even mixed, and where they are all equally plausible?

b) While there is no limit to time contraction or reduced gravitational effect, according to the above explanations, have we actually observed any instances of this?

c) Dark matter seems to be a result of the practice, that we observe distant enhanced gravitational effect through a specific perspective, it could be also expressed as “dark G” or “dark space curvature”, could this clarify the nature of "dark matter" more clear?

Thank you!

 

[Dale]

When we observe distant time dilation effects, usually indicated by redshift, there are three possible explanations:

1) The speed of light, is slower there and then;
2) Space, is contracted for light there and then;
3) The frequency, of specific light is slower there and then.

I don’t understand these three different explanations. Could you describe any physically possible experiment that could distinguish these possibilities? Such an experiment doesn’t need to be economically or technologically feasible (but it cannot violate known physical laws), it is just to help understand what you mean by these three options.

Similarly, when we observe distant gravitational effects, there are three possible explanations:

1) The value of the gravitational constant, G, is greater there and then;
2) Space is expanded for gravitation there and then;
3) There is extra mass, such as dark matter, present there and then.

Same here.

 

[PeroK]

When we observe distant time dilation effects, usually indicated by redshift, there are three possible explanations:

1) The speed of light, is slower there and then;
2) Space, is contracted for light there and then;
3) The frequency, of specific light is slower there and then.

Physics Forums is here to discuss mainstream science as it is currently understood. It's not a place to present your own ideas, based on a lack of knowldege of the subject.

You ought to try to learn something about the current model of the universe (Big Bang theory etc.).

Redshift generally is a function of the relationship between the source and the receiver - relative motion, gravitational potential, curvature of spacetime. It's not due to any of the things you list.

 

[doudou]

I don’t understand these three different explanations. Could you describe any physically possible experiment that could distinguish these possibilities? Such an experiment doesn’t need to be economically or technologically feasible (but it cannot violate known physical laws), it is just to help understand what you mean by these three options.

Same here.

Thanks for your patience, Dale.

This is a serious discussion about the Philosophy of Physics. I was not trying to break any physics laws, but rather to clarify some longstanding debate problems while also protecting the laws of physics in any local frame.

We all agree that the laws of nature remain the same in a local frame, just like how people on Earth perceive the flatness of the ground everywhere.

However, there is still a problem when it comes to the global frame and the large scale. Do we still have this kind of flatness?

By observing a distant frame, we may PERCEIVE or THINK differently, which could provide more clues on this issue.

Let's take map projection as an example.

In Mercator projection, space is flat, but we may perceive or think that there is "dark land" in Russia or Greenland. (The red dots are Tissot's Indicatrix, which show distortions of a map projection.)

In the Equal-Area projection, we have actual size, but space can be perceived as curved.

Neither projection is incorrect or more valid than the other, but their existence helps guide us towards a closer understanding of the nature.

 

[Dale]

This is a serious discussion about the Philosophy of Physics.

OK, if there is no possible physical experiment which can distinguish these possibilities then there is no physics content to the distinction. It is purely a matter of philosophy, as you say.

We are not philosophy experts here, we are physicists. So this question is off topic and is closed. We will be glad to discuss any actual physics questions you may have later. The key distinction between a physics and a philosophy discussion being whether there is a possible experimental measurement that could unambiguously answer the question.