Part of the problem is that the professor does not want just any invention, he wants us to "change the world". We have to find a major problem in the world, and

Part of the problem is that the professor does not want just any invention, he wants us to "change the world". We have to find a major problem in the world, and invent something to deal with it. His standards seem to be very arbitrary as to what qualifies. Does anyone here knows of a major problem in the world ( other than obvious ones like generically unclean water )? Finding these through web searches is difficult to say the least :-)