Sparsity Memes

For those who slept through linear algebra, this is peak math humor. The Japanese flag normally features a red circle on white background, but in the L0 norm, we don't care about magnitude—only whether something is non-zero. So that perfect circle becomes a cross because the L0 norm essentially counts the number of non-zero elements. It's basically what happens when mathematicians try to be efficient: "Why use many pixels when few pixels do trick?" Next time someone asks why math matters, just show them how it can transform international symbols with a single notation change.