When a meter stick travels at the speed of light relative to an observer, it does not appear to retain its original length due to the effects of relativistic length contraction. According to the principles of special relativity, as an object approaches the speed of light, its length contracts in the direction of motion, making it appear shorter to the observer. The question posed is a trick, as no object with mass can actually reach the speed of light. Therefore, the observer would not measure the meter stick as being one meter long. This discussion emphasizes the importance of understanding the implications of relativistic physics in such scenarios.
