Semantic web on the Today programme

Turning on the radio this morning, I was surprised to hear someone discussing data on the Today programme on BBC Radio 4. It turned out to be Sir Tim Berners Lee talking about the semantic web; he even managed to mention RDF and HTML without confusing the interviewers too much. The interesting 8 and a half minute discussion is available via the BBC iPlayer.I'm quite keen on understanding better how the semantic web might relate to science data. When people talk about data in relation to the semantic web, they often seem to be thinking the sort of relatively unitary facts or simple relationships that RDF triples are quite good at expressing, such as the population of China is 1,330,044,605. It's certainly not clear to me how this generalises to express the changing population, let alone how it could express the data from a spectrometer ora crystal structure determination or remote-sensing data. If anyone can point me to a good resource discussing this, I would be grateful!