| light-day | 1 ly | 2 ly | 3 ly | 4 ly | 5 ly | 6 ly | 7 ly | 8 ly | 9 ly | 10 ly | 11 ly | 12 ly | 13 ly | 14 ly | 15 ly | 16 ly | 17 ly | 18 ly | 19 ly | 20 ly | 21 ly | 22 ly | 23 ly | 24 ly | 25 ly | 26 ly | 27 ly | 28 ly | 29 ly | 30 ly | 31 ly | 32 ly | 33 ly | 34 ly | 35 ly | 36 ly | 37 ly | 38 ly | 39 ly | 40 ly | 41 ly | 42 ly | 43 ly | 44 ly | 45 ly | 46 ly | 47 ly | 48 ly | 49 ly | 50 ly | 51 ly | 52 ly | 53 ly | 54 ly | 55 ly | 56 ly | 57 ly | 58 ly | 59 ly | 60 ly | 61 ly | 62 ly | 63 ly | 64 ly | 65 ly | 66 ly | 67 ly | 68 ly | 69 ly | 70 ly | 71 ly | 72 ly | 73 ly | 74 ly | 75 ly | 76 ly | 77 ly | 78 ly | 79 ly | 80 ly | 81 ly | 82 ly | 83 ly | 84 ly | 85 ly | 86 ly | 87 ly | 88 ly | 89 ly | 90 ly | 91 ly | 92 ly | 93 ly | 94 ly | 95 ly | 96 ly | 97 ly | 98 ly | 99 ly | 100 ly |
| metric inch | 6.4755170928 × 1016 in (metric) | 1.29510341856 × 1017 in (metric) | 1.94265512784 × 1017 in (metric) | 2.59020683712 × 1017 in (metric) | 3.2377585464 × 1017 in (metric) | 3.88531025568 × 1017 in (metric) | 4.53286196496 × 1017 in (metric) | 5.18041367424 × 1017 in (metric) | 5.82796538352 × 1017 in (metric) | 6.4755170928 × 1017 in (metric) | 7.12306880208 × 1017 in (metric) | 7.77062051136 × 1017 in (metric) | 8.41817222064 × 1017 in (metric) | 9.06572392992 × 1017 in (metric) | 9.7132756392 × 1017 in (metric) | 1.036082734848 × 1018 in (metric) | 1.100837905776 × 1018 in (metric) | 1.165593076704 × 1018 in (metric) | 1.230348247632 × 1018 in (metric) | 1.29510341856 × 1018 in (metric) | 1.359858589488 × 1018 in (metric) | 1.424613760416 × 1018 in (metric) | 1.489368931344 × 1018 in (metric) | 1.554124102272 × 1018 in (metric) | 1.6188792732 × 1018 in (metric) | 1.683634444128 × 1018 in (metric) | 1.748389615056 × 1018 in (metric) | 1.813144785984 × 1018 in (metric) | 1.877899956912 × 1018 in (metric) | 1.94265512784 × 1018 in (metric) | 2.007410298768 × 1018 in (metric) | 2.072165469696 × 1018 in (metric) | 2.136920640624 × 1018 in (metric) | 2.201675811552 × 1018 in (metric) | 2.26643098248 × 1018 in (metric) | 2.331186153408 × 1018 in (metric) | 2.395941324336 × 1018 in (metric) | 2.460696495264 × 1018 in (metric) | 2.525451666192 × 1018 in (metric) | 2.59020683712 × 1018 in (metric) | 2.654962008048 × 1018 in (metric) | 2.719717178976 × 1018 in (metric) | 2.784472349904 × 1018 in (metric) | 2.849227520832 × 1018 in (metric) | 2.91398269176 × 1018 in (metric) | 2.978737862688 × 1018 in (metric) | 3.043493033616 × 1018 in (metric) | 3.108248204544 × 1018 in (metric) | 3.173003375472 × 1018 in (metric) | 3.2377585464 × 1018 in (metric) | 3.302513717328 × 1018 in (metric) | 3.367268888256 × 1018 in (metric) | 3.432024059184 × 1018 in (metric) | 3.496779230112 × 1018 in (metric) | 3.56153440104 × 1018 in (metric) | 3.626289571968 × 1018 in (metric) | 3.691044742896 × 1018 in (metric) | 3.755799913824 × 1018 in (metric) | 3.820555084752 × 1018 in (metric) | 3.88531025568 × 1018 in (metric) | 3.950065426608 × 1018 in (metric) | 4.014820597536 × 1018 in (metric) | 4.079575768464 × 1018 in (metric) | 4.144330939392 × 1018 in (metric) | 4.20908611032 × 1018 in (metric) | 4.273841281248 × 1018 in (metric) | 4.338596452176 × 1018 in (metric) | 4.403351623104 × 1018 in (metric) | 4.468106794032 × 1018 in (metric) | 4.53286196496 × 1018 in (metric) | 4.597617135888 × 1018 in (metric) | 4.662372306816 × 1018 in (metric) | 4.727127477744 × 1018 in (metric) | 4.791882648672 × 1018 in (metric) | 4.8566378196 × 1018 in (metric) | 4.921392990528 × 1018 in (metric) | 4.986148161456 × 1018 in (metric) | 5.050903332384 × 1018 in (metric) | 5.115658503312 × 1018 in (metric) | 5.18041367424 × 1018 in (metric) | 5.245168845168 × 1018 in (metric) | 5.309924016096 × 1018 in (metric) | 5.374679187024 × 1018 in (metric) | 5.439434357952 × 1018 in (metric) | 5.50418952888 × 1018 in (metric) | 5.568944699808 × 1018 in (metric) | 5.633699870736 × 1018 in (metric) | 5.698455041664 × 1018 in (metric) | 5.763210212592 × 1018 in (metric) | 5.82796538352 × 1018 in (metric) | 5.892720554448 × 1018 in (metric) | 5.957475725376 × 1018 in (metric) | 6.022230896304 × 1018 in (metric) | 6.086986067232 × 1018 in (metric) | 6.15174123816 × 1018 in (metric) | 6.216496409088 × 1018 in (metric) | 6.281251580016 × 1018 in (metric) | 6.346006750944 × 1018 in (metric) | 6.410761921872 × 1018 in (metric) | 6.4755170928 × 1018 in (metric) |
The light-day is a unit of length useful in astronomy, telecommunications and relativistic physics. It is defined as the distance that light travels in free space in oneday, and is equal to exactly 2.59020683712×1013 metres.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| light-day | ly | ≡ 24 light-hours | ≡ 2.59020683712×1013 m | Science - Astronomy (Length) |
| light-days | metric inches | light-days | metric inches |
|---|---|---|---|
| 1 | = 6.4755170928E+16 | 4 | = 2.59020683712E+17 |
| 1.5 | = 9.7132756392E+16 | 4.5 | = 2.91398269176E+17 |
| 2 | = 1.29510341856E+17 | 5 | = 3.2377585464E+17 |
| 2.5 | = 1.6188792732E+17 | 5.5 | = 3.56153440104E+17 |
| 3 | = 1.94265512784E+17 | 6 | = 3.88531025568E+17 |
A metric inch is a nickname for a preferred 1⁄4 subdivision of an ISO 2848 basic module, or 1⁄12 of a metric foot measuring 25 millimetres (0.984 in). A metric inch is 0.4 millimetres (0.016 in) shorter than an inch.
The term was similarly used to refer to the historical Soviet Bloc practice of spacing integrated circuit pins at 1⁄10 of a 25 mm "metric inch" length, instead of the western practice of 1⁄10 of an imperial inch.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| metric inch | in (metric) | = 0.016 in | = 0.0004 m | Metric system SI |
| metric inches | light-days | metric inches | light-days |
|---|---|---|---|
| 1 | = 1.54427821851E-17 | 4 | = 6.1771128740399E-17 |
| 1.5 | = 2.3164173277649E-17 | 4.5 | = 6.9492519832948E-17 |
| 2 | = 3.0885564370199E-17 | 5 | = 7.7213910925498E-17 |
| 2.5 | = 3.8606955462749E-17 | 5.5 | = 8.4935302018048E-17 |
| 3 | = 4.6328346555299E-17 | 6 | = 9.2656693110598E-17 |
| light-days | metric inches |
|---|---|
| 1 | = 6.4755170928 × 1016 |
| 1.54427821851 × 10-17 | = 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 …) |