Derived Planck Units
In any system of measurement, units for many physical quantities can be derived from base units. Table 3 offers a sample of derived Planck units, some of which in fact are seldom used. As with the base units, their use is mostly confined to theoretical physics because most of them are too large or too small for empirical or practical use and there are large uncertainties in their values (see Discussion and Uncertainties in values below).
| Name | Dimension | Expression | Approximate SI equivalent |
|---|---|---|---|
| Planck area | Area (L2) | 2.61223 × 10−70 m2 | |
| Planck volume | Volume (L3) | 4.22419 × 10−105 m3 | |
| Planck momentum | Momentum (LMT−1) | 6.52485 kg m/s | |
| Planck energy | Energy (L2MT−2) | 1.9561 × 109 J | |
| Planck force | Force (LMT−2) | 1.21027 × 1044 N | |
| Planck power | Power (L2MT−3) | 3.62831 × 1052 W | |
| Planck density | Density (L−3M) | 5.15500 × 1096 kg/m3 | |
| Planck angular frequency | Frequency (T−1) | 1.85487 × 1043 s−1 | |
| Planck pressure | Pressure (L−1MT−2) | 4.63309 × 10113 Pa | |
| Planck current | Electric current (QT−1) | 3.4789 × 1025 A | |
| Planck voltage | Voltage (L²MT−2Q−1) | 1.04295 × 1027 V | |
| Planck impedance | Resistance (L2MT−1Q−2) | 29.9792458 Ω |
Read more about this topic: Planck Units
Famous quotes containing the words derived and/or units:
“Jesus wept; Voltaire smiled. From that divine tear and from that human smile is derived the grace of present civilization.”
—Victor Hugo (1802–1885)
“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)