Sorry English is not my first language tense often gives me issues you will often see me use you instead of your as well because of the way it comes out when I translate what I want to say.

Carlip wrote that as teaching aid as part of his lecture duties if I recall. It became part of various discussions on the old sci.physics forum or was it sci.maths man that was a long time ago.

It looks like it got a facelift I am not sure why possibly part of the online coarse details that many universities are pushing these days.

If you are the pmb I think you are you date to way back in that era as well and the term "relativistic mass" would have special meaning to you smile

I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.