% geek_clock.tex
% by pts@fazekas.hu at Thu Oct 22 14:24:35 CEST 2009
\documentclass[a4paper]{article}
\usepackage{tikz}
\usepackage[latin2]{inputenc}
\usepackage{t1enc}
\usepackage{lmodern}

\pdfpagewidth=\paperwidth
\pdfpageheight=\paperheight

\newenvironment{fullpage}{%
  \shipout\vbox\bgroup\kern-1in\moveleft1in\vbox to\paperheight\bgroup
  \parindent0pt\hsize\paperwidth
}{%
  \vfil\egroup\egroup
}

\begin{document}

% Define a few constants for easy configuration
\def\framehalf{9.2cm}
\def\radius{8.8cm}
\def\onedegrad{8.6cm}
\def\fivedegrad{8.5cm}
\def\tendegrad{8.2cm}
\def\labelrad{8.3cm}

\begin{fullpage}
  \vfil\noindent\hfil
  \begin{tikzpicture}[scale=1]
    \draw (-\framehalf,-\framehalf) --
          (\framehalf,-\framehalf) --
          (\framehalf,\framehalf) --
          (-\framehalf,\framehalf) -- cycle;
    \draw (0,0) circle (\framehalf);
    \draw (0,0) circle (\radius);
    \draw[fill=black] (0,0) circle (2.5mm);
    \node[draw, circle, inner sep=.2mm] (a) at (0,0) {};
    % main lines
    \foreach \x in {0, 6,...,360}
        \draw[line width=1.5pt] (\x:\onedegrad) -- (\x:\radius);
    % labels and longer lines at every 6 degrees
    \foreach \x in {30, 60, ...,  360} {
        \draw[line width=4pt] (\x:\tendegrad) -- (\x:\radius);
    }
    \node[scale=3,anchor=north east] at (450-1*30:\labelrad)
      {$B'_L$\kern-1ex};
    \node[scale=2.5,anchor=east] at (450-2*30:\labelrad)
      {\lower8ex\hbox{$\displaystyle \sum_{i=0}^{\infty}1/2^i$\kern-2ex}};
    \node[scale=3,anchor=east] at (450-3*30:\labelrad)
      {$7\odot-5$};
    \node[scale=3,anchor=south east] at (450-4*30:\labelrad)
      {$\lceil\pi\rceil$};
    \node[scale=3,anchor=south east] at (450-5*30:\labelrad)
      {$(2\varphi-1)^2$\kern-4ex};
    \node[scale=3,anchor=south] at (450-6*30:\labelrad)
      {$3!$};
    \node[scale=3,anchor=south west] at (450-7*30:\labelrad)
      {$\!6.\overline{9}$};
    \node[scale=4,anchor=west] at (450-8*30:\labelrad)
      {\raise1ex\hbox{${\bullet}{\circ}{\circ}{\circ}$}};
    \node[scale=2.5,anchor=west] at (450-9*30:\labelrad)
      {$\lfloor(7\cdot.1\!-\!.7)^{\textrm{-6e-2}}\rfloor$};
    \node[scale=2.5,anchor=west] at (450-10*30:\labelrad)
      {\lower6ex\hbox{$\displaystyle{5\choose2}$}};
    \node[scale=2.5,anchor=north west] at (450-11*30:\labelrad)
      {\lower3ex\hbox{\kern-3ex$7^5\mathop{\mathrm{mod}} 13$}};
    \node[scale=3,anchor=north] at (450-12*30:\labelrad)
      {$\sqrt[3]{1728}$};
  \end{tikzpicture}
\end{fullpage}

\end{document}