- #1
A Dhingra
- 211
- 1
hello people...
i have a doubt regarding Lorentz length contraction...
according to what he described, the length of a body measured in a moving frame appears shorter as compared to the one taken by an observer at rest...if a train moving with uniform relativistic velocity , is thought of and its length is measured by the observer outside the train at rest with rest to the ground and the moving one, and compared in cases considering the direction of train or light...
the measurement by the observer in train is taken with the help of a torch in his hand and a mirror placed in the side facing him... that is, same as the direction of motion of the train... in this case light will have to move larger distance as compared to when train was not moving, to get reflected back... but the distance it will have to travel backward would be smaller because the train would have covered some distance in the time it used to complete the first half of the motion and then that during its motion...
so in the two different directions, the length of the train would be different as distance is velocity * time....(here i didn't consider the effect of time dilation... because there again i think it should not just slow down but also speed up...)
so along with contraction , expansion of length is also possible...
if it were not to be possible both the ways then an observer moving in an inertial frame taking measurements of length of , say , a rod with very small diameter, and somehow communicates with someone at rest with respect to ground to compare the values of length... he will be clearly able to note that because his measurements of length are small... then due to length contraction he must be probably moving in the direction of the length element of the rod.....
but this sounds against the principle of relativity... that a moving body is aware that it is moving... with the help of exchange of information about length contraction....
so please tell me, what i have been thinking, does that make sense and is it that length appears to expand too for a moving observer...
and if yes , is it applicable to time as well...
thanks in advance...
i have a doubt regarding Lorentz length contraction...
according to what he described, the length of a body measured in a moving frame appears shorter as compared to the one taken by an observer at rest...if a train moving with uniform relativistic velocity , is thought of and its length is measured by the observer outside the train at rest with rest to the ground and the moving one, and compared in cases considering the direction of train or light...
the measurement by the observer in train is taken with the help of a torch in his hand and a mirror placed in the side facing him... that is, same as the direction of motion of the train... in this case light will have to move larger distance as compared to when train was not moving, to get reflected back... but the distance it will have to travel backward would be smaller because the train would have covered some distance in the time it used to complete the first half of the motion and then that during its motion...
so in the two different directions, the length of the train would be different as distance is velocity * time....(here i didn't consider the effect of time dilation... because there again i think it should not just slow down but also speed up...)
so along with contraction , expansion of length is also possible...
if it were not to be possible both the ways then an observer moving in an inertial frame taking measurements of length of , say , a rod with very small diameter, and somehow communicates with someone at rest with respect to ground to compare the values of length... he will be clearly able to note that because his measurements of length are small... then due to length contraction he must be probably moving in the direction of the length element of the rod.....
but this sounds against the principle of relativity... that a moving body is aware that it is moving... with the help of exchange of information about length contraction....
so please tell me, what i have been thinking, does that make sense and is it that length appears to expand too for a moving observer...
and if yes , is it applicable to time as well...
thanks in advance...