For questions about or related to the Kardashev scale of technological development.

The Kardashev scale is a way of measuring a civilization's level of technological development. It is based on the amount of energy the civilization in question is able to use (theoretical maximum use not actual use - that's an important distinction).

A civilization's Kardashev level is defined by the formula (as suggested by Carl Sagan):

$$ K = \frac{\log{_{10}}{P - 6}}{10} $$

where $P$ is the civilization's theoretical maximum power use in watts.

The definitions of each type of civilizations are these:

  • Type I
    Able to harness amounts of energy roughly equivalent to that available on a single planet. ($\approx 10^{16}\text{ W}$)
  • Type II
    Able to harness amounts of energy equivalent to the total output of a single star. ($\approx 10^{26}\text{ W}$)
  • Type III
    Able to harness amounts of energy equivalent to the output of an entire galaxy of stars. ($\approx 10^{36}\text{ W}$)

As of 2012, with global energy use at 553 EJ (exajoules) (being equivalent to 17.54 TW), humanity stood at 0.724K.