I Non-homogeneous and anisotropic metric and laws of physics...?

AI Thread Summary
The discussion centers on the implications of a non-homogeneous and anisotropic universe, suggesting that fundamental laws of physics could vary across different regions. However, it is argued that the cosmological principle is merely an assumption for simplifying models rather than a law of physics, indicating that more complex models could still adhere to the same underlying laws. The potential for anisotropy in spacetime to break Lorentz invariance is acknowledged, but it is emphasized that this hypothesis is still in its early research phase and lacks definitive validation. The reliability of popular science articles as sources for understanding physics is also questioned. Overall, the conversation highlights the need for further investigation into these complex concepts.
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Non-homogeneous and anisotropic metric and laws of physics...?
In this popular science article [1], they say that if our universe resulted to be non-uniform (that is highly anisotropic and inhomogeneous) then the fundamental laws of physics could change from place to place in the entire universe. And according to this paper [2] anisotropy in spacetime could break the Lorentz invariance [3]

I know that there are metrics and spacetimes which are non-homogeneous and anisotropic. If our spacetime was highly anisotropic and inhomogeneous would this be possible? Can you think of some specific types of spacetimes or metrics where this could happen? Any examples that you can think of?[1]: https://whatifshow.com/what-if-the-universe-isnt-uniform/

[2]: https://doi.org/10.1038/s41598-021-86355-3

[3]: https://en.wikipedia.org/wiki/Modern_searches_for_Lorentz_violation
 
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Suekdccia said:
In this popular science article [1]
Pop science articles are not good sources for learning physics.

Suekdccia said:
they say that if our universe resulted to be non-uniform (that is highly anisotropic and inhomogeneous) then the fundamental laws of physics could change from place to place in the entire universe.
This is wrong. The cosmological principle is not a law of physics. It's just a simple assumption that allows us to construct simple models. If it turns out that the simple models don't work, we'll just have to construct more complicated models. But those models will still use the same underlying laws of physics.

Suekdccia said:
And according to this paper [2] anisotropy in spacetime could break the Lorentz invariance [3]
This is a proposed hypothesis that is still in the very early research stage. Way too early to make any statements about its validity.
 
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