deletions | additions       diff --git a/Intelligent Life.tex b/Intelligent Life.tex  index 6ab405a..287929c 100644  --- a/Intelligent Life.tex  +++ b/Intelligent Life.tex 
...
\begin{quote}  $N \approx \, \frac{1}{4}\, f_i \, L $.   \end{quote}  This states that the number of communicative civilizations in our Galaxy is just the product of the chance of emergence of intelligent life times the average lifetime of a civilization's communicative phase. It seems hard to be able to put strong theoretical constraints on both these factors. However, one can turn the problem around, and in the final post \href{https://www.authorea.com/25815}{final post}  of this series I will show how the current search for radio signals from extraterrestrial intelligence (\href{http://www.seti.org/}{SETI}) can be used to put some important constraints on the two factors $f_i$ and $L$, and how this information can be used to make bold predictions about the future of humankind. %\href{http://en.wikipedia.org/wiki/Fermi_paradox}{Fermi}