Submanifolds of a Hilbert Space

If you do software development then you've probably had the misfortune of working with Git as a source control system. Now, those of you who use Git will be aware that it makes very heavy use of branches, and that it's all too easy to end up with a whole pile of them of of which are the one that you actually need.

Well, it turns out it's all very simple after all, as this image that dropped into my work inbox reveals:



You could tell the email's progress around the office by when different people burst out laughing.