<a href="https://en.wikipedia.org/wiki/Penrose_diagram" class="extiw" title="en:Penrose diagram">en:Penrose diagram</a> of the universe.
<a href="https://en.wikipedia.org/wiki/User:Eric_B" class="extiw" title="en:User:Eric B">en:User:Eric B</a>
2005-12-27
<span class="int-own-work" lang="en">Own work</span>