Is Python changing the world, or Go, or Ruby, or Javascript? If you are asking about "changing the world" that's a big thing to ask for. Simply being useful doesn't make a technology world-changing. I feel very confident that Go will not change the world. People may use Go to make things that change the world, but Go won't change the world. If Python has changed the world – that is the language itself has done so, not just the people using the language – then I'd look mostly to its community, governance, and development process. For Ruby I'd look to its culture, philosophy, and discourse. Javascript actually has a technical claim to changing the world: it's created a programming platform that requires no installation of software, and has brought sandboxed development into the world in a broad and practical way. But if we look at Node.js/IO.js, a Javascript platform with similar scope to Python, then I personally see a generational reinvention: a platform that a new generation of budding developers can call their own, and make their own decisions. Asking a lot of questions that no one actively considers in these older platforms.

But there's lots of other things that can change the world besides programming languages. Are programming languages really the best place to hang your hat? Do you want to compare Python to Ruby or Node.js, or compare Python a web application or wiki or the cloud; i.e., entirely different categories?