# How can I add vertical space to a beamercolorbox to make it align with another one?

I'm doing beamer slides in the 16:9 aspect ratio, so I want to use a more horizontal flow than I was when I had 4:3 slides. For example, I'd like to place a theorem and its proof side-to-side rather than the proof below the theorem. As in:

\documentclass[aspectratio=169]{beamer}
\usepackage{tikz}
\usetheme{Rochester}
\begin{document}

\begin{frame}{There is no largest prime number}
\begin{columns}
\begin{column}[t]{0.45\textwidth}
\begin{theorem}
There are infinitely many primes.
\end{theorem}
\end{column}
\begin{column}[t]{0.45\textwidth}
\begin{proof}
Suppose $p$ were the largest prime number.
Let $q$ be the product of the first $p$ numbers.
Then $q+1$ is not divisible by any of them.
Thus it is prime, but is bigger than $p$.
\end{proof}
\end{column}
\end{columns}
\end{frame}
\end{document}


Here is the result:

As you can see, the theorem box is a lot shorter than the proof box and the effect is kind of ugly. Is there a nice way to add vertical space to the shorter one to make it the same height as the longer one?

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Your proof is wrong ... – Hendrik Vogt Jan 26 '11 at 13:48
@Hendrik: I'm just copying Till's proof from the beameruserguide. Mentally substitute lorem ipsum if you like. :-) – Matthew Leingang Jan 26 '11 at 14:01
If you're coming to tex.sx for your maths knowledge, you're doing it wrong – Seamus Jan 26 '11 at 15:27
@Jimi: I use TeXShop on the Mac. You can select a part of the PDF viewer window and copy it. Then open up Preview and Select File > New. You'll get a PDF of what you clipped. Then save it as PNG. – Matthew Leingang Jan 26 '11 at 20:38
@Jimi: Good, I can give more specific tips. Before you select and copy, make sure you click the dotted rectangle button on the right-hand side of your preview window's toolbar. That will make the mouse select regions, rather than select text or magnify the document. – Matthew Leingang Jan 27 '11 at 1:12

I can provide only a hack ...

\begin{theorem}
There are infinitely many primes.\rule[-5\normalbaselineskip]{0pt}{0pt}
\end{theorem}


and the complete code to visualize the meaning of the \normalbaselineskip

\documentclass[aspectratio=169]{beamer}
\usepackage{tikz}
\usetheme{Rochester}
\begin{document}

\begin{frame}{There is no largest prime number}
\begin{columns}
\begin{column}[t]{0.45\textwidth}
\begin{theorem}
There are infinitely many primes.%
\rule[-1\normalbaselineskip]{10pt}{1pt}\kern-10pt%
\rule[-2\normalbaselineskip]{10pt}{1pt}\kern-10pt%
\rule[-3\normalbaselineskip]{10pt}{1pt}\kern-10pt%
\rule[-4\normalbaselineskip]{10pt}{1pt}\kern-10pt%
\rule[-5\normalbaselineskip]{10pt}{1pt}
\end{theorem}
\end{column}
\begin{column}[t]{0.45\textwidth}
\begin{proof}
Suppose $p$ were the largest prime number.
Let $q$ be the product of the first $p$ numbers.
Then $q+1$ is not divisible by any of them.
Thus it is prime, but is bigger than $p$.
\end{proof}
\end{column}
\end{columns}
\end{frame}
\end{document}


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But thanks for the hack, at least. I hadn't thought about using \normalbaselineskip as a unit of length. That can make guessing-and-checking a quicker process. – Matthew Leingang Jan 26 '11 at 14:48
@Herbert Could you explain how your answer works? As I understand it, it creates a widthless, lengthless rule at a certain position, thus forcing the box to stretch to accommodate it. The rule is moved down (hence the minus sign) 5 times the \normalbaselineskip which is...? A measure of the vertical height of a line of text? Is that along the right lines? – Seamus Jan 26 '11 at 15:52
@Seamus: I have no idea how much it is. It is not interesting because it is one line and in the proof we have 5 additional lines. – Herbert Jan 26 '11 at 15:59
@Herbert but it is a measure of the height of a line, right? That is what's important. – Seamus Jan 26 '11 at 16:01
@Hendrik Yes, you're right. There is a not missing. It should read "this site should not be just about providing code snippets..." – Seamus Jan 27 '11 at 11:22

Introducing a dummy column seems to work for me

\begin{block}{blocktitle}
\begin{columns}
% dummy column
\column{0cm}
~
\setlength{\rest}{0.25\textheight}
\vskip\rest
~
% now real column
\column{\textwidth}
words 123 \\
more words\\
\end{columns}

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