I have a blog post that gives a little more context: https://adaptive-machine-patterns.com/blog.html#einstein [alt. link: http://archive.today/381Pl] I am new to blogging, so advice welcome.
The preprint is hosted at CULA repository (many thanks) https://www.repository.cam.ac.uk/handle/1810/398349 and it has a DOI: https://doi.org/10.17863/CAM.127224