BurtJordaan » September 23rd, 2019, 3:35 am wrote:bangstrom » 20 Sep 2019, 08:13 wrote:Your observer has no external source of measurement so how is she to tell if the blue lines are getting longer or if the red squares are getting smaller?

To follow up on the above question. Well, if the red cubes are to represent something real, they must be galaxy clusters. Now astronomers do not measure the redshift of the clusters directly, but rather the redshifts of the Ceiphed Variables stars and Type Ia Supernovae in them. Using these as 'standard candles' in the astronomical distance ladder, their distances can be determined and hence we can check out Hubble's law and determine Hubble's constant. Using Hubble's constant we can determine the distance to any distant type 1a supernova detected to a good accuracy.

I have written something on the distance ladder on my website page: http://www.einsteins-theory-of-relativity-4engineers.com/the-expanding-universe.html. For details, read the pdf linked from there.This was written in the late 1990's. Accuracies have improved considerably over the last 2 decades, but the principles remained the same.

Hence real life astronomy rules out the possibility of "red squares getting smaller of redder"...

In the red square model of shrinking matter, the light from 1a supernova becomes redder and the duration of their luminosity becomes longer because the rate of time was slower in the distant past than at present. The red cubes represent something real and that is the entire material world from atomic scales to galaxy clusters. As atoms grow smaller, their spin rates increase resulting in a global quickening of time as demonstrated by the example of the spinning ice skater. The shrinking red square model is one of a quickening rate of time while the lengthening blue bar model is one of expanding space. The Hubble constant based on the measurement of redshifting is equivalent in both models.

If space is expanding while time remains the same, that would make c a variable so time must necessarily quicken as space expands if c is to remain as a given constant in the model. Likewise in the model of shrinking red squares. If time quickens while space remains the same, this would also make c a variable.

These problems in both models can be dealt with mathematically by the use of comoving coordinates which allows us to consider either expanding space or quickening time as single elements of change. Either way, this makes both models appear artificial because the approach lacks symmetry.

A more symmetrical model would be a lattice model where space expands while time quickens in equal proportions. In this case, the blue bars would be growing longer while the red squares contract. This model, like many alternatives to the Standard BB would be a model in which there is no method for accurately determining the size or age of the universe other than by direct observation.

Another consideration can be drawn from Edwin Abbot’s classic book “Flatland” where he mentions the example of a sphere from beyond the 2D plane of Flatland crossing the Flatlander's 2D world and all they see is a circle with an expanding radius that comes from nowhere, expands, contracts, and disappears.

This is analogous to the case of a 4D sphere becoming apparent in our 3D world where we are within the 4D hypersphere but observing only a 3D expansion/contraction with no way of determining whether the change we observe is due to the expansion of space or the contraction of all material within a universe of constant radius- or any combination of the two. The take away from this is that we must not confuse cosmic expansion with the familiar expansion of an explosion in 3D space that throws ejecta into pre-existing space and expands by inertia. In expansion models, the universe expands by space itself expanding and this is a much different scenario and it is not inertia driven.