This may be slightly beside the point - but does anybody ever ask themselves the fairly basic question (well, I think it's basic) - space appears to be empty - so just what is curved? I have seen it suggested that space is not empty but a seething mass of virtual particles (or whatever) - how...
Thiru - interesting question. The answer is "yes" and "no". The search for an "infinitely variable gear" is a very old one - Da Vinci being one of the first to have a try (and not a very good try). It is something I have been working on for the last fifty years or so. I think you could...