WEEK FOUR - POST TWO

Propagation is something relevant to all theories of quantum physics and physics in general. It is the act of certain wavelengths of vibrations and energy traveling on a material medium. An example would be sound traveling in air or vibrations traveling through water. This law was previously thought to also apply to light. Theories stated that an invisible medium that existed everywhere in space allowed for light to travel through it. They called this medium the ether. This theory was widely believed to be reality until the Michelson-Morley experiment was done. It was to prove the existence of ether by showing the effects of light's speed while the earth rotates through ether. Most everyone informed of the experiment expected it show surely show the existence of this ether, yet it came up negative. The results showed no proof that the existence of ether or it having an effect on the propagation of light. After this experiment, Albert Einstein, along with his proposition of the theory of relativity, proposed that light had no medium at all to propagate through, that light traveled through nothingness, and he ended up being correct.
This is another example of humanity's understanding of reality evolving and changing alongside our advancements in technology and knowledge. After realizing that ether either didn't exist, or that light didn't propagate through it, it advanced our knowledge of the universe by discovering that light had no need of a material means of propagation. We had a major breakthrough in our understanding of light, which is an essential piece to the puzzle of understanding.