deletions | additions       diff --git a/Derive L.tex b/Derive L.tex  index 24461c7..52c5a33 100644  --- a/Derive L.tex  +++ b/Derive L.tex 
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L_c \sim \left[\frac{V}{5\,f_l\, f_i\, f_c}\right]^{1/4}.  \end{equation}  On the other hand our discussion of the Drake equation led to the conclusion that, roughly speaking, $N \sim L$ (meaning the denominator in previous equation is $\sim$ 1) (but see the \href{http://en.wikipedia.org/wiki/Rare_Earth_hypothesis}{rare Earth hypothesis} for a different conclusion). Therefor Therefore  we can further simplify and obtain \begin{equation}  %L_c \sim \left(\frac{V}{L_c}\right)^{1/3} = V^{1/4}