## Tuesday, November 02, 2021

### [quamglvi] scientific units of energy

eV (electron volt) = 1.602e-19 J

attocalorie = 26.1 eV

GeV = 38.3 picocalorie

kilocalorie = 1 food calorie = 1 microton tnt

lb tnt = 500 kilocalorie = 500 food calorie

gigacalorie = mega food calorie = 1 ton tnt (by definition)

megaton tnt = 1.642 oz c^2 = 46.553 gram c^2

9.74 megaton tnt = 1 lb c^2 (one pound of matter becomes energy)

21.48 megaton tnt = 1 kg c^2

19.49 gigaton tnt = 1 ton c^2 (TNT is 19.5 billion times less energetic than matter-antimatter)

teraton tnt = 51.3 ton c^2

exaton tnt = 41.84 attofoe

foe = ten to the Fifty One Erg = 10^51 erg = kilo kilo kilo kilo kilo kilo kilo kilo kilo kilo kilo kilo kilo kilo kilo kilo kilo erg = 10^44 J = 2.39e+34 ton tnt = 1.113e+27 kg c^2 = 1.226e+6 exaton c^2

solarmass * c^2 = 1.787 kilofoe = 1.787e+47 J

100 gigafoe = 1e+55 J = 56 mega solar mass c^2 = AGN outburst MS 0735.6+7421, according to Wikipedia

although calorie, food calorie, and ton tnt are not metric units, they take metric prefixes, and together they cover a usefully large range of energy in exact powers of 10.  it's a pity astronomers didn't choose as an energy unit for supernovae an exact power of 10 of tons of TNT (it would have made sense: things that go boom), then the scale could have continued nicely.  we invent a unit:

forca = ten to the FORty CAlorie = 10^40 calorie = 0.0004184 foe = 10^31 ton tnt = 4.7e+23 kg c^2

femtoforca = 10 petaton TNT

kiloforca = 0.4184 foe ~= foe

foe = 2.39 kiloforca ~= kiloforca

100 gigafoe = 240 teraforca