A closer look
We like to think of light as an untouchable cosmic speedster, but in 1851, Hippolyte Fizeau proved you can actually drag it. By shooting a beam of light through tubes of rapidly flowing water, he demonstrated that the water's movement physically pulled the light along, altering its speed. This "Fresnel drag" was a massive headache for classical physics and ended up being a crucial stepping stone for Einstein's theory of special relativity. Turns out, even the universe's ultimate speed limit gets caught in the current.
