O’Reilly’s recent SOLID conference was all about the intersection of hardware and software, but it also extended and challenged our ideas about what was hardware in a world of new and nano materials, and how software and code becomes tangible. And of course there were robots – lots of them. All the keynotes were excellent and are online, but I found these ones particularly relevant for startups – or anyone who wants to understand why hardware is hard and where it has become easier.