research memo
constants
| name |
value |
unit |
| pi |
3.141592653589793238462643383279 |
- |
| light velocity (c) |
2.99792458e+8 |
m/s |
| Planck constant (h) |
6.62606876e-34 |
J.s |
| Dirac constant (hbar = h/2*pi) |
1.054571596e-34 |
J.s |
| elementary charge (e) |
1.602176462e-19 |
C |
| rest mass of an electron (m) |
9.10938188e-31 |
kg |
| Boltzmann constant (k) |
1.3806503e-23 |
J/K |
| dielectric constant (epsilon = e7/4*pi*c*c) |
8.854187817e-12 (vacuum) |
F/m |
| refractive index, 15C 1atm atmosphere (n) |
1.00028 (400nm - 800nm) |
- |
| |
1.00027 (800nm - 1300nm or longer) |
- |
periodic table
pressure
units
1 [mbar] = 100 [Pa]
1 [Torr] = 133.322 [Pa]
1 [atm] = 101325 [Pa]
table (3 significant digits)
|
Pa |
mbar |
Torr |
atm |
| 1 [Pa] |
1 |
0.01 |
7.50e-3 |
9.87e-6 |
| 1 [mbar] |
100 |
1 |
0.75 |
9.87e-4 |
| 1 [Torr] |
133 |
1.33 |
1 |
1.32e-3 |
| 1 [atm] |
1.01e+5 |
1.01e+3 |
760 |
1 |
calculator
Temperature
units
- C: Celsius
- K: Fahrenheit
- K: Kelvin
K = 273.15 + C
F = 1.8*C + 32
calculator
Optical power
relation between [mW] and [dbm]
If
A: optical power in [mW]
B: optical power in [dbm]
then
B = 10 * log10 A
or
A = 10 ^ (B/10)
calculator
Weight
units
1[lb] = 0.45359237[kg]
1[oz] = 1/16[lb] = 28.3495[g]
table
|
kg |
lb |
oz |
| 1 [kg] |
1 |
2.2046 |
35.274 |
| 1 [lb] |
0.45359237 |
1 |
16 |
| 1 [oz] |
0.0283495 |
0.0625 |
1 |
force
g ~= 9.8[m/s^2]
g: gravitational acceleration on earth
therefore
1[kg] <--> 9.8[N] = 1[kgf]
calculator
electromagnetic wave
Hartree unit
hbar = e = m = 1
| kind |
value |
note |
| unit length |
5.291772083e-11[m] |
Bohr raduis of hydrogen atom |
| unit time |
2.4188843e-17[s] |
(the period in Bohr orbit)/2*pi |
| unit mass |
9.10938188e-31[kg] |
rest mass of an electron |
| unit charge |
1.602176462e-19[C] |
elementary charge |
| unit energy |
27.211383[eV] |
(ionization energy of hydrogen atom)*2 |
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