# The Smallest Possible Contribution

The very excellent @minutephysics just put out a video on the ‘everywhere stretch’, otherwise known as the Big Bang.  It needed a small diagram, generated via LaTeX, and it ended up being provided by me.  It appears for about 0.04 seconds of the 5 minute presentation and it looks like this:

By my calculation, if every 0.04 seconds of the video took as much time as I took for the diagram, the video would require about two months non-stop work to make.  Clearly we don’t enough appreciate the free content that Henry and his colleagues provide for us!

It also was a nice example for me of how so-called ‘social media’ allows people to connect by interest and not accidents of geography.

Technical details:

I should have but did not use some clever LaTeX package for drawing this diagram.  I drew it using xFig, exported to a LaTeX picture environment and edited the output by hand to make the equations come out right.  Took 5 or 10 minutes and the code looks like this (embedded in a .tex file so that it can be compiled for test purposes):

\documentclass{article}
\usepackage{color}
\begin{document}
\setlength{\unitlength}{4144sp}%
%
\begingroup\makeatletter\ifx\SetFigFontNFSS\undefined%
\gdef\SetFigFontNFSS#1#2#3#4#5{%
\reset@font\fontsize{#1}{#2pt}%
\fontfamily{#3}\fontseries{#4}\fontshape{#5}%
\selectfont}%
\fi\endgroup%
\begin{picture}(1332,1557)(3136,-3730)
\thinlines
{\color[rgb]{0,0,0}\put(3556,-2581){\vector( 0,-1){810}}
}%
{\color[rgb]{0,0,0}\put(3826,-2446){\vector( 1, 0){495}}
}%
{\color[rgb]{0,0,0}\put(4456,-2671){\vector(-1,-1){697.500}}
}%
\put(3421,-3661){\makebox(0,0)[lb]{\smash{{\SetFigFontNFSS{12}{14.4}{\familydefault}{\mddefault}{\updefault}{\color[rgb]{0,0,0}$U$}%
}}}}
\put(3381,-3031){\makebox(0,0)[lb]{\smash{{\SetFigFontNFSS{12}{14.4}{\familydefault}{\mddefault}{\updefault}{\color[rgb]{0,0,0}$\pi$}%
}}}}
\put(4366,-2491){\makebox(0,0)[lb]{\smash{{\SetFigFontNFSS{12}{14.4}{\familydefault}{\mddefault}{\updefault}{\color[rgb]{0,0,0}$U \times F$}%
}}}}
\put(4276,-3121){\makebox(0,0)[lb]{\smash{{\SetFigFontNFSS{12}{14.4}{\familydefault}{\mddefault}{\updefault}{\color[rgb]{0,0,0}$\textrm{proj}_1$}%
}}}}
\put(3151,-2446){\makebox(0,0)[lb]{\smash{{\SetFigFontNFSS{12}{14.4}{\familydefault}{\mddefault}{\updefault}{\color[rgb]{0,0,0}$\pi^{-1}(U)$}%
}}}}
\put(4001,-2356){\makebox(0,0)[lb]{\smash{{\SetFigFontNFSS{12}{14.4}{\familydefault}{\mddefault}{\updefault}{\color[rgb]{0,0,0}$\phi$}%
}}}}
\end{picture}%

\end{document}