deletions | additions       diff --git a/Now_we_have_some_constraints__.tex b/Now_we_have_some_constraints__.tex  index e3d1a50..437ecec 100644  --- a/Now_we_have_some_constraints__.tex  +++ b/Now_we_have_some_constraints__.tex 
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Ok I know I know, there is \href{http://en.wikipedia.org/wiki/Roswell_UFO_incident}{Roswell}... the \href{http://en.wikipedia.org/wiki/Wow!_signal}{WOW signal}... \href{http://en.wikipedia.org/wiki/List_of_reported_UFO_sightings}{UFO} sightings... Well, I am not going into that. I will just state that the most economical explanations for all the aforementioned cases have nothing to do with E.T. and that at this time there is no clear evidence that prove we had contact with alien life. People let's use the \href{http://bit.ly/KDLFp6}{Occam's razor} and throw away the conspiracy spoon.  Back to us. The Fermi Paradox implies that $N$ is probably a small number\footnote{There are some solutions to the Fermi Paradox that do not require $N$ to be small, for a nice review have a look at this \href{http://waitbutwhy.com/2014/05/fermi-paradox.html}{great post} from Tim Urban's}. post}}.  Our revised version of the Drake Equation then leaves two\footnote{Of course the third option is both $f_i$ and $L$ are small, but that doesn't change the main conclusions} interesting alternatives: \begin{enumerate} \item $f_i$ is a small number. That is\textbf{ life is common in the Universe, but intelligent life is not}.  \item $L$ is a small number. Intelligent \textbf{life do not spend much time in the communicative phase}.  \end{enumerate}