After [[Albert Einstein]]'s [[special relativity]], length can no longer be thought of being constant in all reference frames. Thus a ruler that is one meter long in one frame of reference will not be one meter long in a reference frame that is travelling at a velocity relative to the first frame. This means length of an object is variable depending on the observer. |
After [[Albert Einstein]]'s [[special relativity]], length can no longer be thought of being constant in all reference frames. Thus a ruler that is one meter long in one frame of reference will not be one meter long in a reference frame that is travelling at a velocity relative to the first frame. This means length of an object is variable depending on the observer. |