Natural Units
Using dimensional analysis, it is possible to combine dimensional universal physical constants to define a system of units of measurement that has no reference to any human construct. Depending on the choice and arrangement of constants used, the resulting natural units may have useful physical meaning. For example, Planck units, shown below, use c, G, ħ, ε0 and kB in such a manner to derive units relevant to unified theories such as quantum gravity.
| Name | Dimension | Expression | Value (SI units) |
|---|---|---|---|
| Planck length | Length (L) | 1.616 199(97) × 10−35 m | |
| Planck mass | Mass (M) | 2.176 51(13) × 10−8 kg | |
| Planck time | Time (T) | 5.391 06(32) × 10−44 s | |
| Planck charge | Electric charge (Q) | 1.875 545 956(41) × 10−18 C | |
| Planck temperature | Temperature (Θ) | 1.416 833(85) × 1032 K |
Read more about this topic: Physical Constant
Famous quotes containing the words natural and/or units:
“The trenchant editorials plus the keen rivalry natural to extremely partisan papers made it necessary for the editors to be expert pugilists and duelists as well as journalists. An editor made no assertion that he could not defend with fists or firearms.”
—Federal Writers’ Project Of The Wor, U.S. public relief program (1935-1943)
“Even in harmonious families there is this double life: the group life, which is the one we can observe in our neighbour’s household, and, underneath, another—secret and passionate and intense—which is the real life that stamps the faces and gives character to the voices of our friends. Always in his mind each member of these social units is escaping, running away, trying to break the net which circumstances and his own affections have woven about him.”
—Willa Cather (1873–1947)