the ol' clocks and rods...

[Sarahisme]

hi i can't quite get my head around how this works...

 

or well the way this book does it anyways....

 

the observer on the rod reads the time of the clock to be 5:(L/(gamma*v)) and yes i agree with this but then the book calucaltes the length of the rod (from the point of view of another observer situated on the clock) by using the time seen by the first observer (who is situated on the rod)

 

that is the observer on the clock calcuates the length of the rod by doing this:

 

length of rod = v * L/(gamma*v)

 

but this is uses the value of the clock as seen by the observer on the rod. but wouldnt the oberver on the clock see a different time to the one the observer on the rod sees?

 

and yes i know the rod is seen to be shorter (from the point of view of the observer on the clock) but still...if someone could explain this too me, that'd be great!

 

Thanks

 

Sarah

[Sarahisme]

would both observers agree that the time taken for event A then B to occur be L/(gamma*v)

 

i am pretty sure the answer is no. and since this is the time as mesured by the observer on the rod, then how can the observer on the clock use this time to calcualte the length of the rod?

[Sarahisme]

one other related question....

 

what if there was another clock which was attached to the rod (i.e. in the rods inertial reference frame) then what would it read at event B?

[Sarahisme]

or is that both observers agree that the reading on the clock at even B is L/(gamma*v)

but the time they think it takes to get to event B is different

 

???