Who said what

(If you intend to continue this discussion, we should move it to a different place. It is already off topic here.)



I've always thought Special Relativity was fairly easy to
understand, The real problem is that it is hard to believe.

There is a trick to understanding SR. Time "over there" is not a function of relative velocity between here and there. It is a function of relative velocity AND relative position between here and there. Look at SR's Lorentz transformation for time with relative velocity along the x axis to see what I mean.

Suppose the moving frame is a long space ship (1,000 [meters]). The relative velocity of the nose and the tail (and all other parts, of course) are the same when viewed from your frame, but the relative x coordinate (x_here) of the nose and the tail are different. so when you calculate t_overThere for the tail you get a different value than you do for the nose.

In your frame, this changes the calculated length of the space ship because in your frame, time in the other frame is seen to be a function of relative position as well as relative velocity. By the rules of SR you can't find the length of the ship by taking the difference between the nose position and the tail position NOW. You must take the difference between the nose position NOW and the tail position LATER.

Exactly how much later depends on how fast the ship is moving relative to you.

Like I said, easy to understand. And the numbers that you get when do the math will match real world observation to as many decimal places as can stand to crunch.

But this process is reciprocal. An observer on the ship looking at you sees your lab front door at a different time than your lab back door. And you start running into the zoo of paradoxes that SR is famous for.

And <u>that</u> is what makes it hard to believe.

===

SR makes a great mathematical model, but it is a poor physical model. A lot of the confusion surrounding SR comes form not recognizing the difference.

General Realtivity, an otherwise pretty good model in both senses, inherits this mess from SR and thus becomes an overall mess itself.

LB

Sorry if I chose the wrong bucket Larry. Don't know if it is worth moving or not.

I saw the quote and copied it because I am having trouble with the slavish application of Occam's Razor to scientific problems - it almost always results in a wrong answer. I suppose that is better than no answer, and it is a way to move forward (or sideways) I guess. But I think we need to find a better razor - Occam's takes us down too many rat-holes (eg: BB Theory), from which we find it almost impossible to extricate ourselves in a human lifetime.

&gt;&gt; Like I said, easy to understand.

Easy for those who understand to say . Actually, I agree with your comments.