Convert Furlong per Fortnight to Speed of Light
Convert Furlong per Fortnight (fur/fn) to Speed of Light (c) instantly and accurately.
Conversion Formula
c = fur/fn × 5.547488583e-13
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 Speed of Light
The speed of light in vacuum (c) = exactly 299,792,458 m/s - the defined SI constant from which the metre is derived (since 1983) and the universal speed limit of causality. Light from the Sun reaches Earth in 8 min 20 s; from the Moon in 1.28 s; from Proxima Centauri in 4.24 years. Mars communication delay 3-22 minutes. In optical fibre (n ≈ 1.467), c/n ≈ 200,000 km/s. GPS clocks must correct for both special and general relativistic effects. c = 299,792,458 m/s.
Quick Reference Table
| Furlong per Fortnight (fur/fn) | Speed of Light (c) |
|---|---|
| 1 fur/fn | 5.547 × 10-13 c |
| 2 fur/fn | 1.109 × 10-12 c |
| 5 fur/fn | 2.774 × 10-12 c |
| 10 fur/fn | 5.547 × 10-12 c |
| 25 fur/fn | 1.387 × 10-11 c |
| 50 fur/fn | 2.774 × 10-11 c |
| 100 fur/fn | 5.547 × 10-11 c |