Imagine that Bob, at a spaceport, observes Alice flying by to the right in her spaceship at a velocity of 0.9c. When Alice’s ship had been previously docked at the spaceport, Alice had measured its length as 100 meters. Alice has five clocks on her spaceship: one in front (at 0 meters), one at 25 meters, one at 50 meters, one at 75 meters, and one at the rear at 100 meters. All the clocks are synchronized in Alice’s frame of reference. When Alice flies by Bob, Bob uses his lattice of synchronized clocks to take simultaneous photos of Alice’s clocks (simultaneous in Bob’s frame of reference). If Bob’s photos show that Alice’s front clock reads t = 0 at that instant, what equation below would give the time that the clock at 50 meters has in the photos?