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

Question

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 $p$.  
 This is a contradiction.
\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?

Answer 1

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 $p$.  
 This is a contradiction.
\end{proof}
\end{column}
\end{columns}
\end{frame}
\end{document}

Answer 2

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}