During a trip home, my father challenged me with the question "At what speed, in m/s, would someone have to travel for yellow to look green?" Since I am only in 9th grade high school physics, not even in AP yet, I was wondering what the answer was. I know my dad asked me jokingly, but now I am curious.
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Using the Doppler effect and Einsteins theory of relativity (since light travels so fast).
F = f(1 + v/c)
Where F = observed frequency, f = source frequency, v = speed, c = speed of light
The frequency of yellow light is approximately 520 THz
The frequency of green light is approximately 570 THz
Rearranging the equation for v:
v = 28800000m/s
or 9.6% the speed of light toward the yellow object
F = f(1 + v/c)
Where F = observed frequency, f = source frequency, v = speed, c = speed of light
The frequency of yellow light is approximately 520 THz
The frequency of green light is approximately 570 THz
Rearranging the equation for v:
v = 28800000m/s
or 9.6% the speed of light toward the yellow object
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You have to be moving AWAY from the green light for it to look yellow at sufficiently high speeds because yellow light is of lower frequency. You will have to be receding from the green light at relativistic speeds for this to happen.
Define Green and Yellow by their wavelength and apply the relativistic Doppler Effect. From there you can calculate the necessary speed.
Define Green and Yellow by their wavelength and apply the relativistic Doppler Effect. From there you can calculate the necessary speed.