span | 1 span | 2 span | 3 span | 4 span | 5 span | 6 span | 7 span | 8 span | 9 span | 10 span | 11 span | 12 span | 13 span | 14 span | 15 span | 16 span | 17 span | 18 span | 19 span | 20 span | 21 span | 22 span | 23 span | 24 span | 25 span | 26 span | 27 span | 28 span | 29 span | 30 span | 31 span | 32 span | 33 span | 34 span | 35 span | 36 span | 37 span | 38 span | 39 span | 40 span | 41 span | 42 span | 43 span | 44 span | 45 span | 46 span | 47 span | 48 span | 49 span | 50 span | 51 span | 52 span | 53 span | 54 span | 55 span | 56 span | 57 span | 58 span | 59 span | 60 span | 61 span | 62 span | 63 span | 64 span | 65 span | 66 span | 67 span | 68 span | 69 span | 70 span | 71 span | 72 span | 73 span | 74 span | 75 span | 76 span | 77 span | 78 span | 79 span | 80 span | 81 span | 82 span | 83 span | 84 span | 85 span | 86 span | 87 span | 88 span | 89 span | 90 span | 91 span | 92 span | 93 span | 94 span | 95 span | 96 span | 97 span | 98 span | 99 span | 100 span |
earth radius | 3.5881337309685 × 10-8R⊕ | 7.1762674619369 × 10-8R⊕ | 1.0764401192905 × 10-7R⊕ | 1.4352534923874 × 10-7R⊕ | 1.7940668654842 × 10-7R⊕ | 2.1528802385811 × 10-7R⊕ | 2.5116936116779 × 10-7R⊕ | 2.8705069847748 × 10-7R⊕ | 3.2293203578716 × 10-7R⊕ | 3.5881337309685 × 10-7R⊕ | 3.9469471040653 × 10-7R⊕ | 4.3057604771621 × 10-7R⊕ | 4.664573850259 × 10-7R⊕ | 5.0233872233558 × 10-7R⊕ | 5.3822005964527 × 10-7R⊕ | 5.7410139695495 × 10-7R⊕ | 6.0998273426464 × 10-7R⊕ | 6.4586407157432 × 10-7R⊕ | 6.8174540888401 × 10-7R⊕ | 7.1762674619369 × 10-7R⊕ | 7.5350808350337 × 10-7R⊕ | 7.8938942081306 × 10-7R⊕ | 8.2527075812274 × 10-7R⊕ | 8.6115209543243 × 10-7R⊕ | 8.9703343274211 × 10-7R⊕ | 9.329147700518 × 10-7R⊕ | 9.6879610736148 × 10-7R⊕ | 1.0046774446712 × 10-6R⊕ | 1.0405587819809 × 10-6R⊕ | 1.0764401192905 × 10-6R⊕ | 1.1123214566002 × 10-6R⊕ | 1.1482027939099 × 10-6R⊕ | 1.1840841312196 × 10-6R⊕ | 1.2199654685293 × 10-6R⊕ | 1.255846805839 × 10-6R⊕ | 1.2917281431486 × 10-6R⊕ | 1.3276094804583 × 10-6R⊕ | 1.363490817768 × 10-6R⊕ | 1.3993721550777 × 10-6R⊕ | 1.4352534923874 × 10-6R⊕ | 1.4711348296971 × 10-6R⊕ | 1.5070161670067 × 10-6R⊕ | 1.5428975043164 × 10-6R⊕ | 1.5787788416261 × 10-6R⊕ | 1.6146601789358 × 10-6R⊕ | 1.6505415162455 × 10-6R⊕ | 1.6864228535552 × 10-6R⊕ | 1.7223041908649 × 10-6R⊕ | 1.7581855281745 × 10-6R⊕ | 1.7940668654842 × 10-6R⊕ | 1.8299482027939 × 10-6R⊕ | 1.8658295401036 × 10-6R⊕ | 1.9017108774133 × 10-6R⊕ | 1.937592214723 × 10-6R⊕ | 1.9734735520326 × 10-6R⊕ | 2.0093548893423 × 10-6R⊕ | 2.045236226652 × 10-6R⊕ | 2.0811175639617 × 10-6R⊕ | 2.1169989012714 × 10-6R⊕ | 2.1528802385811 × 10-6R⊕ | 2.1887615758908 × 10-6R⊕ | 2.2246429132004 × 10-6R⊕ | 2.2605242505101 × 10-6R⊕ | 2.2964055878198 × 10-6R⊕ | 2.3322869251295 × 10-6R⊕ | 2.3681682624392 × 10-6R⊕ | 2.4040495997489 × 10-6R⊕ | 2.4399309370585 × 10-6R⊕ | 2.4758122743682 × 10-6R⊕ | 2.5116936116779 × 10-6R⊕ | 2.5475749489876 × 10-6R⊕ | 2.5834562862973 × 10-6R⊕ | 2.619337623607 × 10-6R⊕ | 2.6552189609167 × 10-6R⊕ | 2.6911002982263 × 10-6R⊕ | 2.726981635536 × 10-6R⊕ | 2.7628629728457 × 10-6R⊕ | 2.7987443101554 × 10-6R⊕ | 2.8346256474651 × 10-6R⊕ | 2.8705069847748 × 10-6R⊕ | 2.9063883220844 × 10-6R⊕ | 2.9422696593941 × 10-6R⊕ | 2.9781509967038 × 10-6R⊕ | 3.0140323340135 × 10-6R⊕ | 3.0499136713232 × 10-6R⊕ | 3.0857950086329 × 10-6R⊕ | 3.1216763459426 × 10-6R⊕ | 3.1575576832522 × 10-6R⊕ | 3.1934390205619 × 10-6R⊕ | 3.2293203578716 × 10-6R⊕ | 3.2652016951813 × 10-6R⊕ | 3.301083032491 × 10-6R⊕ | 3.3369643698007 × 10-6R⊕ | 3.3728457071103 × 10-6R⊕ | 3.40872704442 × 10-6R⊕ | 3.4446083817297 × 10-6R⊕ | 3.4804897190394 × 10-6R⊕ | 3.5163710563491 × 10-6R⊕ | 3.5522523936588 × 10-6R⊕ | 3.5881337309685 × 10-6R⊕ |
A span is the distance measured by a human hand, from the tip of the thumb to the tip of the little finger. In ancient times, a span was considered to be half a cubit. Sometimes the distinction is made between the great span (thumb to little finger) and little span (index finger to little finger).
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
span | span | ≡ 9 in | = 0.2286 m | Imperial/US |
spans | earth radius | spans | earth radius |
---|---|---|---|
1 | ≈ 3.5881337309685E-8 | 4 | ≈ 1.4352534923874E-7 |
1.5 | ≈ 5.3822005964527E-8 | 4.5 | ≈ 1.6146601789358E-7 |
2 | ≈ 7.1762674619369E-8 | 5 | ≈ 1.7940668654842E-7 |
2.5 | ≈ 8.9703343274211E-8 | 5.5 | ≈ 1.9734735520326E-7 |
3 | ≈ 1.0764401192905E-7 | 6 | ≈ 2.1528802385811E-7 |
Earth radius is the distance from Earth's center to its surface, about 6,371 km (3,959 mi). This length is also used as a unit of distance, especially in astronomy and geology, where it is usually denoted by R⊕.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
earth radius | R⊕ | ≈ 6,371 km | ≈ 6,371 km | Science - Astronomy (Length) |
earth radius | spans | earth radius | spans |
---|---|---|---|
1 | ≈ 27869641.294838 | 4 | ≈ 111478565.17935 |
1.5 | ≈ 41804461.942257 | 4.5 | ≈ 125413385.82677 |
2 | ≈ 55739282.589676 | 5 | ≈ 139348206.47419 |
2.5 | ≈ 69674103.237095 | 5.5 | ≈ 153283027.12161 |
3 | ≈ 83608923.884514 | 6 | ≈ 167217847.76903 |
spans | earth radius |
---|---|
1 | ≈ 3.5881337309685 × 10-8 |
27,869,641.294838 | ≈ 1 |
Symbol | Definition |
---|---|
≡ | exactly equal |
≈ | approximately equal to |
= | equal to |
digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |