{
  "name": "Light-distance ladder, 1 nanosecond to 1 astronomical unit",
  "desc": "How far light in a vacuum travels in 1 nanosecond, 1 microsecond, 1 millisecond, 1 second and the light time for 1 astronomical unit, in meters, inches, feet and miles. Metric values are exact; values that do not terminate are rounded as stated in the rounding column.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "The Yardstick Almanac",
  "url": "https://theyardstickalmanac.com/scale/grace-hopper-nanosecond/",
  "from": [
    "BIPM, The International System of Units (SI Brochure), 9th edition, V4.01 (June 2026): defining values of c and the cesium frequency, SI prefixes (Table 7)",
    "BIPM, SI Brochure, 9th edition, V4.01, Table 8 and note (j): 1 au = 149,597,870,700 m (IAU 2012 Resolution B2)",
    "NIST Handbook 44-2026, Appendix C: 1 inch = 2.54 cm, 1 foot = 0.3048 m, 1 yard = 0.9144 m, 1 mile = 1.609344 km, exactly (24 FR 5348, 1959)"
  ],
  "how": "Compiled by The Yardstick Almanac from the data listed",
  "data_by": [
    "Defined values from the BIPM SI Brochure, 9th ed. V4.01 (CC BY 4.0; adapted: values used in new calculations) and NIST Handbook 44-2026, Appendix C; computed 2026-11-01, CC BY 4.0"
  ]
}