User talk:DonaldJLem

proper time
The definition used in the Wikipedia article on proper time reverses proper time with coordinate time. The first diagram mis-labels curves. The vertical coordinate is proper time and coordinate time (in an inertial reference where coordinates are t and x=0). The curve length represents the time measured by the wristwatch moving on the curve (Lorentz coordinates t and x) not proper time (that is the vertical line). I would like to send the author a more detail report (WORD FILE). How should I send it and does the author want it.)DonaldJLem (talk) 22:01, 13 December 2021 (UTC)