G: Here are some fundamental fixed numbers in physics:

1. Speed of Light (c): ( 299,792,458 ) meters per second (in a vacuum).
2. Absolute Zero: ( 0 ) Kelvin or ( -273.15^\circ ) Celsius, the lowest possible temperature.
3. Gravitational Constant (G): ( 6.67430 \times 10^{-11} ) m(^3) kg(^{-1}) s(^{-2}).
4. Planck's Constant (h): ( 6.62607015 \times 10^{-34} ) Joule-seconds.
5. Elementary Charge (e): ( 1.602176634 \times 10^{-19} ) Coulombs.
6. Boltzmann Constant (k(_B)): ( 1.380649 \times 10^{-23} ) Joules per Kelvin.
7. Avogadro's Number (N(_A)): ( 6.02214076 \times 10^{23} ) entities per mole.
8. Electron Rest Mass (m(_e)): ( 9.10938356 \times 10^{-31} ) kilograms.
9. Proton Rest Mass (m(_p)): ( 1.67262192369 \times 10^{-27} ) kilograms.
10. Fine-Structure Constant (α): Approximately ( 1/137 ), dimensionless.

These constants are essential for defining the laws of physics and remain unchanged across all experiments and observations.