Convert Furlong per Fortnight to Nautical Miles per Second
Convert Furlong per Fortnight (fur/fn) to Nautical Miles per Second (nmi/s) instantly and accurately.
Conversion Formula
nmi/s = fur/fn × 8.979995886e-8
About Furlong per Fortnight
A furlong per fortnight (fur/fn) is a deliberately archaic unit equal to exactly 201.168 ÷ 1,209,600 m/s ≈ 1.663 × 10⁻⁴ m/s - just slightly faster than a garden snail at full creep. One furlong (one-eighth of a mile = 201.168 m) and one fortnight (14 days = 1,209,600 s) are both perfectly legitimate historical measures, but their combination is cherished in physics teaching as a cautionary example of needlessly exotic unit choices. Expressing kinetic energy in kg·fur²/fn² or force in kg·fur/fn² illustrates instantly why the SI was universally adopted. The unit appears in satirical physics papers, recreational mathematics columns, and Terry Pratchett's Discworld novels as the native velocity unit of magical phenomena. The speed of light expressed in furlongs per fortnight is approximately 1.803 × 10¹² fur/fn. Snails travel at roughly 0.5-1 fur/fn; strong tidal rip currents reach 100-200 fur/fn. 1 fur/fn ≈ 1.663 × 10⁻⁴ m/s ≈ 0.599 km/h ≈ 0.372 mph.
About Nautical Miles per Second
A nautical mile per second (nmi/s) equals exactly 1,852 m/s - squarely in the hypersonic domain at approximately Mach 5.44 (ISA sea level). At this speed, kinetic energy per kilogram is ½ × 1852² ≈ 1.71 MJ/kg, comparable to a small shaped-charge detonation. Ballistic missile re-entry vehicles descend at roughly 3.8-7 nmi/s during the terminal phase; ICBM warheads at peak re-entry travel near 4-6 nmi/s. The US Navy's electromagnetic railgun programme aimed to accelerate 10 kg projectiles to approximately 1.7-2.5 nmi/s in test firings, giving them sufficient kinetic energy to destroy armoured targets without a warhead. Hypervelocity impact experiments at two-stage light-gas gun facilities reach similar speeds to simulate asteroid-impact cratering physics. The speed of sound in beryllium metal (the fastest known bulk acoustic medium) is approximately 12.9 nmi/s. 1 nmi/s = 1,852 m/s = 6,667.2 km/h = 3,600 kn ≈ Mach 5.44.
Quick Reference Table
| Furlong per Fortnight (fur/fn) | Nautical Miles per Second (nmi/s) |
|---|---|
| 1 fur/fn | 8.98 × 10-8 nmi/s |
| 2 fur/fn | 1.796 × 10-7 nmi/s |
| 5 fur/fn | 4.49 × 10-7 nmi/s |
| 10 fur/fn | 8.98 × 10-7 nmi/s |
| 25 fur/fn | 2.245 × 10-6 nmi/s |
| 50 fur/fn | 4.49 × 10-6 nmi/s |
| 100 fur/fn | 8.98 × 10-6 nmi/s |