12 Answers votes newest views recent 20Video lectures of mathematics courses available online for free (2) 9Covering maps in real life that can be demonstrated to students 42D Problems Which are Easier to Solve in 3D (2) 45What are some examples of colorful language in serious mathematics papers? 15“Modern” proof for the Baker-Campbell-Hausdorff formula 24Motivating the category of chain complexes 37What is the main goal of a paper, really? 15Is there a “knot theory” for graphs? 9What should be offered in undergraduate mathematics that’s currently not (or isn’t usually)? 12What would you want to see at the Museum of Mathematics? 15Propagation of an error in the LMO invariant? (Revision: I don’t think LMO is wrong!) 28Examples of common false beliefs in mathematics.