Einstein would be proud of this public transit demonstration. Inside the tram, passengers sit in their relative rest frame, casually contemplating their existential dread. Meanwhile, outside the window, spacetime appears to warp as everything zooms by at ludicrous speed. It's the perfect visual proof that motion is indeed relative to the observer. The passengers experience themselves as stationary while the universe rushes past them at 40 mph. This is basically how I explain physics to freshmen before crushing their spirits with the math behind it.