What is luminiferous aether?
Q: What is luminiferous aether?
A: Luminiferous aether is a substance once believed to fill the Universe and explain how the transmission of waves of light can happen. People believed that light was a kind of wave, and that it must travel through some sort of medium in order for its speed to be consistent.
Q: What did people believe about this substance?
A: People believed that this substance had to have a very low viscosity so that it would not slow down the movements of planets and cause them to eventually fall into their suns. They also thought it could be used to explain why light travels at such high speeds.
Q: How did physicists attempt to make this question clear?
A: Physicists conducted experiments, such as the Michelson-Morley Experiment, in order to try and determine whether or not there was actually an invisible medium through which light travelled.
Q: What did the Michelson-Morley Experiment show?
A: The Michelson-Morley Experiment showed that there was no medium through which light travelled, indicating that there is no Luminiferous aether.
Q: How can we imagine what happens when an observer travels on a boat moving through an ocean current?
A: If an observer were to travel on a boat moving through an ocean current, then they could observe changes in the rate at which waves appeared to travel depending on their relationship with the current.
Q: What does imagining a spaceship travelling from one star to another tell us about relative speeds?
A: Imagining a very fast spaceship travelling at one half the speed of light from one star to another shows us that both photons are measured at 300,000 km/sec regardless of movement or direction - thereby indicating that speeds do not change relative to the movement of the spaceship.
