So “light” is electromagnetic radiation, or EMR. And the different kinds of light seem different because of their wavelengths (λ). Okay great. But what exactly is waving? And going back to the question, how does it travel through the vacuum of space?
It’s a simultaneous waving of the electric and magnetic fields, at a 90 degree angle to each other. (Hence the name: electro-magentic radiation.) The blue wave (electric field) is going up and down, and the red wave (magnetic field) is going left and right.
These fields exist in the vacuum of space, and require no medium to propagate through. So, light can go anywhere. A very famous experiment called the Michelson-Morley Experiment was conducted at Case Western Reserve University in Ohio in 1887, and proved that light doesn’t propagate through any “stuff.”
