Explore the colorful world of electrons! As you approach the speed of light, your perceivable reality begins to shift.
Nothing can surpass the speed of light, but what happens when you get close? Subatomic particles such as electrons or an atomic nucleus can approach speeds close to that of light. If they were able to visually perceive reality, the colors that they see would be vastly different than the colors we see!
Light can act as both a particle and a wave, but the wave behavior of light is what causes a color shifting phenomenon when objects begin to approach light speed.
Each light wave has a wavelength that determines its energy and color. Our eyes pick out the wavelength of light and tell us if it is blue or red. Blue light has a short wavelength and red light has a very long wavelength. As you approach a wavelength of light at a speed significant enough to compare to the speed of the light ray traveling toward your eyes, the wavelength appears to be “squished” according to you, shifting the color of the ray toward blue. This “squishing” is based on the idea of relativity.
As you and the wave are moving toward each other at a constant speed, it is possible to shift the reference frame to show only the wave moving toward a stationary you. In order for each aspect of the wave to reach you at the same time as in the original scenario, the wavelength of the light must be shortened, changing the color of the light according to stationary you. Since in your reality, you are always technically at rest, this is why you would perceive a color change.
The same phenomenon occurs when you attempt to escape the beam of light by moving away from it at near light speeds. Since the light is catching up to you, the waves are reaching you more slowly than they would if you were stationary. Due to this, the wavelength is “stretched” according to you and the light appears red.