1. The problem statement, all variables and given/known data Paraphrase: A Transporter can reduce a person to data and transmits the data by light or radio signal to another location. A person is beamed from Earth to the planet Zircon orbiting a star in the Andromeda Nebula, two million light-years from Earth. Neglect any relative motion between Earth and Zircon, and assume : (1) transmission produces the person identical to the original in every respect except that he/she has traveled two million light-years and (2) the time required for disassembling and assembling the person is negligible as measured in the common rest frame of the Transporter and Receiver. a. How much does the person age during her outward trip to Zircon? b. The person spends one Earth-year on Zircon, then beams back to Earth. How much has the person aged during her entire trip? 2. Relevant equations Interval^2=(ct)^2 - (s)^2 3. The attempt at a solution The question's wording seems too vague and confusing to me. Am I supposed to assume that the first part of the question, "how much has the person aged during the outward trip", wants me to find the time elapsed from the beamed person's (or her data's) reference frame? If the person is moving at c, then wouldn't that be 0, as the Lorentz interval is 0? If so, then the answer to the second part of the question would be 'one Earth year', as the entire trip from the frame of the person being transported would be just one Earth year, correct? This is question 1-10 from the second edition of Spacetime Physics by Taylor and Wheeler.