# It seems we move relative to the medium that propagates light (This might sound abstract. Please bear with me. I promise it's super easy to understand (don't click on the links if you don't feel ready :) - This is the intro to people that might think that talking about the nature of reality is "complicated" or "nor worth their time"; it is not complicated..., it is as easy as buying a loaf of bread). Please bear with me. ## A big deal I would be making a disservice if today I didn't write about our latest experiment where [daily variations of the amplitude of the fringe shifts (were) observed when an air-glass Mach-Zehnder type interferometer is rotated](https://www.researchgate.net/publication/369529273_Daily_variations_of_the_amplitude_of_the_fringe_shifts_observed_when_an_air-glass_Mach-Zehnder_type_interferometer_is_rotated). In my opinion, this is a big deal and please let me explain why:  *[Plot of the daily variations measured](https://siran.github.io/assets/writing/daily-variations.png)* ## What does this mean Put simply, I haven't been able to find any current-physics explanation for: 1. fringe shifts upon rotation in a fixed in-lab interferometer that slowly rotates, 2. daily, periodic variation of the amplitude of such fringe shifts ## What could it be My current explanation is that we are measuring a Doppler frequency shift while we move relative to the medium that propagates light. I haven't yet made the mathematical fit to the data in [Matlab](https://matlab.mathworks.com/) (I've been fixing this blog so I could write), but it seems to me that a Doppler fit to the data is much more appropriate than any dragging effect. --- I have a couple of explanations. So stay tuned.