|
Table \(\PageIndex{1}\): Physical Constants
|
|
Name
|
Value
|
|
speed of light (
c
)
|
2.9979 × 10
8
m/s
|
|
gravitational constant (
G
)
|
6.674 × 10
−11
m
3
/(kg s
2
)
|
|
Planck’s constant (
h
)
|
6.626 × 10
−34
J-s
|
|
mass of a hydrogen atom (
M
H
)
|
1.673 × 10
−27
kg
|
|
mass of an electron (
M
e
)
|
9.109 × 10
−31
kg
|
|
Rydberg constant (R
∞
)
|
1.0974 × 10
7
m
−1
|
|
Stefan-Boltzmann constant (σ)
|
5.670 × 10
−8
J/(s·m
2
deg
4
)
1
|
|
Wien’s law constant (λ
max
T)
|
2.898 × 10
−3
m K
|
|
electron volt (energy) (eV)
|
1.602 × 10
−19
J
|
|
energy equivalent of 1 ton TNT
|
4.2 × 10
9
J
|
|
Table \(\PageIndex{2}\): Astronomical Constants
|
|
Name
|
Value
|
|
astronomical unit (AU)
|
1.496 × 10
11
m
|
|
Light-year (ly)
|
9.461 × 10
15
m
|
|
parsec (pc)
|
3.086 × 10
16
m = 3.262 light-years
|
|
sidereal year (y)
|
3.156 × 10
7
s
|
|
mass of Earth (
M
Earth
)
|
5.974 × 10
24
kg
|
|
equatorial radius of Earth (
R
Earth
)
|
6.378 × 10
6
m
|
|
obliquity of ecliptic
|
23° 26’
|
|
surface gravity of Earth (
g
)
|
9.807 m/s
2
|
|
escape velocity of Earth (
v
Earth
)
|
1.119 × 10
4
m/s
|
|
mass of Sun (
M
Sun
)
|
1.989 × 10
30
kg
|
|
equatorial radius of Sun (
R
Sun
)
|
6.960 × 10
8
m
|
|
luminosity of Sun (
L
Sun
)
|
3.85 × 10
26
W
|
|
solar constant (flux of energy received at Earth) (S)
|
1.368 × 10
3
W/m
2
|
|
Hubble constant (H
0
)
|
approximately 20 km/s per million light-years, or approximately 70 km/s per megaparsec
|
Footnotes
1
deg stands for degrees Celsius or kelvins