Show HN: What if the speed of light was 5 km/h?

	Show HN: What if the speed of light was 5 km/h?(rivendell.dmitrybrant.com)
	515 points by dmitrybrant 14 hours ago \| 217 comments
	tl;dr: An interactive browser demo simulates walking through a park where the speed of light is set to 5 km/h, making relativistic effects visible at ordinary walking speeds. Users can move with WASD/arrow keys and toggle effects like length contraction, time dilation, Terrell rotation, and Doppler shifting (blueshift ahead, redshift behind).
	HN Discussion: ↑Praises the demo as more accurate than the prior MIT slower-speed-of-light game ↑Reflects on how slow light actually is at cosmic scales, reinforcing the demo's premise ~Questions whether the simulation correctly models Thomas rotation from non-parallel boosts •Points to prior/similar works like Mr. Tompkins, MIT's game, and Velocity Raptor ↓Criticizes lack of mobile support and controls