My main concern, at the moment with understanding SRT is: When working with Lorentz transforms or any mathematical work for that matter, what zero [if zero is relative] are you using to provide the transform or your math work stability? You will find, that even "zero" can not be used as a universal reference frame according to SRT. [as proved by the use of the relativity of simultaneity] It appears that the end result of relative time defeats itself due to the fact that if true, the "zero" that is used to logically prove relative time is uhmmm.. well relative.. Premise: When performing any mathematics absolute zero is implied. With out the constancy of zero the math looses stability and utility. SRT indicates that t=0 or even t/d=0 is relative so it begs the question: What zero are you using when calculating the transforms, the one you started with or the one you finished with or the one somewhere in between? If zero is assumed to be absolutely constant yet derives a relative zero as a result does this not strike you as being a possibe issue? Zero can not be a universal reference frame....if SRT is accepted to be logically consistant [which is a pardoxical statement because it takes the constancy of zero to make any mathematical logic consistant] As I can't discuss this issue in the language required [ unqualified layperson ] it will be very interesting to read how others discuss it. care to discuss?