In other words, does the effect of relativistic length contraction affect all dimension of the moving object or only the direction parallel to the movement?
And if the effect affects only one dimension, then does the observer who aligning with the direction experience time dilation of other dimension?
Suppose I have a spaceship with laser beam bouncing between the parallel mirror inside vacuum chamber perpendicular to the moving of spaceship
Setup as the picture above, the red line is laser in vacuum chamber, should the observer see the length contraction between mirror, making the laser path smaller ?
And also, will the observer see speed of red laser slower than $c$ ?