Important update, Jan. 17 at 18:00 UTC: There have been a lot of objections raised about the video mentioned below and the way I describe the math therein. It’s more than I can simply add or update ...

GEOMETERS are wont to speak (it seems to me) somewhat laxly of “the line at infinity” as if there were only one such line in a plane; in a certain but not in the most obvious sense this is true—viz.

Jenae is an editor at CNET covering all things deals. She lives in Queens, New York, where she enjoys playing video games, cooking and hanging out with her two cats. Before coming to CNET, Jenae was ...