[Reily]

I am not disputing that. So, what’s your issue?

But there have been attempts to show it breaks down in nonrelativistic domains.

https://www.annualreviews.org/doi/10.1146/annurev.nucl.53.041002.110503

[TexasGator]

“But there have been attempts to show it breaks down in nonrelativistic domains.”

They are using Einstein’s equations.