# How to prevent the paragraphs to spread out over the page?

I have a problem. I have several large equations within the text. And when LaTeX does not manage to put the equation on the same page and moves it to the next one, he spreads the paragraphs of the text in the first page. How could I prevent this? I know about \pagebreak and \newpage, but I do not want to force the \newpage, as the text may move (if I add something later or so on) and the pagebreaks may not be valid. I would like to make LaTeX not to spread the paragraphs over a page automatically. Is it possible?

I tried to make an example:

\documentclass[a4paper,12pt,twoside]{book}
\usepackage{amsmath}
\begin{document}

LaLaLa\\\

LaLaLa\\\

LaLaLa\\\

LaLaLa\\\

\begin{eqnarray}
123&+&123 \\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
\end{eqnarray}

LaLaLa\\\

LaLaLa\\\

\begin{eqnarray}
123&+&123 \\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
123&+&123 \nonumber\\\
\end{eqnarray}

\end{document}

-
Have a look at the mathmode => \allowdisplaybreaks. –  Marco Daniel Nov 7 '11 at 16:08
–  Stefan Kottwitz Nov 7 '11 at 16:08
You may consider switching from eqnarray to align \eqnarray vs. \align. –  Marco Nov 7 '11 at 16:13

You can prevent this behaviour with using \raggedbottom.
By default the book class uses \flushbottom which fixes the bottom of the text and inserts variable space inbetween the paragraphs.