… but there is a way, and it has been proven.

One of the more memorable physics classes I’ve had went into the history of discoveries that led to our understanding of relativity. The relevant story here, starts with how sound travels though air.

Let’s say you’re standing at the bottom of a building shouting to your friend peeking out a window on the 5th floor. On a calm day, that friend will hear you at pretty much the same time as someone standing the same distance away, but on the street. However, if it’s windy, the wind pushes around the air through which the sound of your voice is traveling, the friend up in the window will have a slight delay in receiving that sound. This can of course be verified with more scientific rigor, like a sound sent in two perpendicular directions activating a light.

Scientist at the time thought that light, like sound, must travel though some medium, and they called this theoretical medium the Aether. Since this medium is not locked to Earth, they figured they must be capable of detecting movement of this medium, an Aether wind, if you will. If somehow the movement of this medium caused the speed of light in one direction to be faster than another due to the movement of this medium, measuring the speed in two directions perpendicular to each other would reveal that difference. After a series of experiments of increasing distances and measurement sensitivities (think mirrors on mountain tops to measure the time for a laser beam to reflect), no change in the speed of light based on direction was found.

Please enjoy this wikipedia hole: https://en.m.wikipedia.org/wiki/Michelson–Morley_experiment , and please consider a bit of caution before you refer to things as facts in the future!