1. The document describes an experiment measuring the length of a moving object using two synchronized clocks, one stationary and one moving with the object.
2. As the moving clock moves away from the stationary clock at a constant velocity, it emits an image of itself at the starting time to the observer.
3. By the time the image reaches the observer, both clocks have ticked forward in time, but the image remains fixed at the starting time.
4. Comparing the times on the clocks and the distances traveled allows calculating the observed length as contracted from the true rest length by a factor related to the object's velocity.