erg

erg

Energyexact by definition

The erg is the CGS unit of energy, one dyne centimetre, exactly 10⁻⁷ joules. It is a very small amount of energy, roughly what a mosquito spends on one wingbeat, and it survives almost entirely in astrophysics, where luminosities and burst energies are quoted in ergs and erg per second.

Watch out: A supernova releases about 10⁵¹ erg, a number so entrenched in the literature that it has its own nickname, the foe. That is 10⁴⁴ joules, and the erg figure is the one you will meet in the papers.

1 erg 1.0000000e-07 J
Where the unit came from

From the Greek ergon, work, named in 1873 by the British Association committee that also gave us the dyne.