Study suggests time existed before the big bang!

[beecee]

9 hours ago, michel123456 said:

Physical reason?

Or reason?

There are 2 ways to see things:

1. the Universe comes up, it is young, it gets old and older, then it dies. It is a Universe that looks like a living being. As it gets older, it changes and then yes, an observer in an older Universe will observe something different that what we do observe today. Which means that today in some sense we have the privilege to observe the "true universe" in contrast to future astronomers that will observe only a single galaxy.

2. All observers from any point of it are observing grosso-modo the same thing. From any point in space & from any point in time. That is the Copernican principle.

I support point 2.

I fail to see how point 2, and the Copernican principle contradicts or is in any opposition to point 1. Basically the Copernican principle rightly tells us that the Earth occupies no privileged position. It also encompasses the assumptions  that the universe is isotropic and homogeneous over large scales. It does not say [as you seem to be saying] that the universe today, will be the same as the universe tomorrow, or in a few billion years, or that the same homogeneity and isotropic properties of today, will be the same as it will be in a few billion years. What it does say, is that the isotropic and homogeneous properties over larger scales that we observe today, will also be homogeneous and isotropic in a few billion years, albeit in a different way with the process of time.

https://en.wikipedia.org/wiki/Copernican_principle

extract:

In cosmology, if one assumes the Copernican principle and observes that the universe appears isotropic or the same in all directions from our vantage point on Earth, then one can infer that the universe is generally homogeneous or the same everywhere (at any given time) and is also isotropic about any given point. These two conditions make up the cosmological principle.[7] In practice, astronomers observe that the universe has heterogeneous or non-uniform structures up to the scale of galactic superclusters, filaments and great voids. It becomes more and more homogeneous and isotropic when observed on larger and larger scales, with little detectable structure on scales of more than about 200 million parsecs. However, on scales comparable to the radius of the observable universe, we see systematic changes with distance from Earth. For instance, galaxies contain more young stars and are less clustered, and quasars appear more numerous. While this might suggest that Earth is at the center of the universe, the Copernican principle requires us to interpret it as evidence for the evolution of the universe with time: this distant light has taken most of the age of the universe to reach us and show us the universe when it was young. The most distant light of all, cosmic microwave background radiation, is isotropic to at least one part in a thousand.

[Strange]

9 minutes ago, beecee said:

Basically the Copernican principle rightly tells us that the Earth occupies no privileged position.

There is something called the "perfect Copernican principle" (or something like that), which says that we are not in a privileged place in time, either. This was one of the reasons that people were keen on (quasi) steady state models.

But these are just principles; i.e. working assumptions. The "perfect" Copernican principle is falsified by the evidence.

[beecee]

1 minute ago, Strange said:

But these are just principles; i.e. working assumptions. The "perfect" Copernican principle is falsified by the evidence.

Yep, that's the relevant point.