"The sphere on top contains a light source."
"The light it emits is reflected by the beam splitter under it and goes straight inside the tube following it."
"Then, it passes through an opening in the wheel and is reflected back here by a mirror nine kilometers away."
"Nine kilometers!"
"The inside of the tube will appear bright when the wheel's rotating slowly, but as it accelerates, the light will eventually be blocked, turning it dark."
"The time it takes for the light to return is equal to the time it takes for the cog to turn a step at that moment."
"Using this method, Fizeau managed to calculate the speed of light with about a five percent error."
"So... could you, with this?"
"...I couldn't."
"You can infinitely increase the gear ratio, spin it ever faster, but the light never gets blocked."
"You can even say that the speed of light is infinite."
"Infinite..."
"Physically speaking, it's impossible."
"I mean, it's a dream. Anything goes, right?"
"If everything is free to be subjectively changed, though..."
"How is it possible that we see anything the same way?"