Thanks for the feedback. I agree that Wikipedia article does need some work (if you are an expert, there’s nothing preventing you from making it better!), but the definition of the Copernican Principle — “humans, on the Earth or in the Solar system, are not privileged observers of the universe” — is correct. For a more “formal” source, refer to page 66 of Cosmological Physics.
As to the multiverse concept just being a “theory”, gravity is just a “theory” (as is evolution) and there are compelling arguments for it (although admittedly no evidence at the moment). These are discussed in Brian Greene’s The Hidden Reality and Max Tegmark’s Our Mathematical Universe. I did not link to these sources because they might be a little dense for the average reader but would be interested in hearing your thoughts on them.
When I referred to the simulation argument, it was with “some thinkers are claiming we live in a simulation” which is not a strong endorsement. Personally, I find it compelling, but I would not present it as “truth”. I am glad there are people thinking about these possibilities as many currently accepted ideas in physics initially started out as thought experiments. Both general and special relativity were conceived of as “thought experiments” (for a more formal source see Einstein: His Life and Universe).
Moreover, the principles of quantum mechanics sounded like science fiction and many prominent physicists refused to accept them until the experimental evidence turned out to agree with the predictions to an astounding degree of accuracy. Now, quantum mechanics is considered the most accurate depiction of reality (even though it is still considered a “theory”). Dismissing the simulation and multiverse arguments as mere “thought experiments” seems short-sighted. Of course, many ideas turn out to be utterly wrong, but just because a concept seems far-fetched is not grounds for dismissal — maybe we can’t “prove” either of these ideas at the moment, but, I’m excited for what the future of physics will reveal.
Thank you for pointing out the issue with the Jupyter Notebook links and I have fixed both of them.
