And please show me one iota of evidence that Einstein might not be the final authority on spacetime.
Naw.
It’s more fun to watch naysayers wallow in their hog wallow of ignorance and pontificate so haughtily therefrom.
Don’t have any great need nor ability to show you anything.
Lots of folks have trouble understanding the nose on their faces.
I can say my close relative worked with a VERY high ranking physicist on some highly classified tests in the famous area in Nev. That physicist did not agree with your assessment of Einstein . . . and if I understood correctly, neither, actually, did Einstein.
Lots of text books are wrong about a lot of things.