:oops: He! He! typo, at least I got it right half the time. As to those who think I'm ignorant just because someone thinks so, doesn't make it so. I won't go into who I am, but if anyone that comes here that thinks I'm wrong with my post check it out in any science or math book on the subject and see if I'm wrong---then come back here is show everyone who is ignorant at this thread. 8-) Solitary AKA Bill

You wrote: "These are all "aparent" dilations, not actual, as so many writers claim."

Tell that to the physicists working in Argentina, where you get the most particles from cosmic radiation. When you calculate the half-life of the cosmic muons, compared to the lab muons, their half-life difference matches exactly what Special Relativity predicts. Time dilation is real, not apparent as you have claimed.

You wrote: "Which Sabrina riding on the broom will not notice anthing different about her broom or herself, but will "observe" one at rest in your frame of reference shrink in the direction of its motion."

No, it doesn't work that way. You need to know about proper time. To do that you need to know who will measure two events with one clock. Example: you send someone to Alpha Centauri at near the speed of light. The person in the rocketship will measure the departure and arrival (two events) with the same clock. That's the proper time. The observer on earth will need two clocks, one for the departure on earth, and a second clock on Alpha Centauri to measure the second event, the arrival. For the earth observer that is the improper time. The two times are related by,

T(proper time) = t(improper time) ( 1 - v[sup:3jzoyzva]2[/sup:3jzoyzva]/c[sup:3jzoyzva]2[/sup:3jzoyzva])[sup:3jzoyzva]-1/2[/sup:3jzoyzva]

Otherwise you get the ridiculous claim: "the guy on the rocketship sees the earth moving so he thinks the people on earth are experiencing time dilation". Noboby "feels" like their experiencing time dilation. It's only when they will compare notes that they will realize that their clock was ticking differently, or that one looks younger than the other. The effect is real, even though the people on the rocketship don't feel it, they will experience time dilation, not the people on earth.