Particle physicists in Europe invented the World Wide Web.* If you like free porn, thank a physicist. The engineering that goes into designing this type of thing has spin-offs, but the main thing is the search for knowledge. We don't know what we'll be able to get from it until we know what it is. This is pretty much pure science. But then so was the search for the structure of DNA... *Yes, of course it's a little more complicated than this.