There are several different ways to prove that the “Twin Paradox” isn’t really a paradox at all. In this explanation, we focused on the arrival time of light signals from both twins. Besides measuring the time interval of these signals, Terra and Stella could measure changes in the properties of the light they receive. Let’s assume that Terra and Stella send each other a light signal of the same color (wavelength) and they are sending this light constantly (not yearly as described in the animation). a. What change in the color of light (change in wavelength) would Terra measure while Stella is moving toward the destination star? (It is helpful to remember that the speed of light is the same regardless of the speed of it source.) b. During that same time, what change in color (change in wavelength) of light would Stella measure coming from Terra? c. What do these changes mean for how time is passing where the light was emitted? d. How can you use just information about the change in the wavelength of the received light (not the arrival time of light) to prove that the “Twin Paradox” isn’t a paradox at all?