What is the greatest world-changing invention?

I%26#039;m doing a poll for a history class on what people think the most world-changing invention is. It could be the computer, internet, telephone, anything.|||good question....ill go with flying (planes/helicopters etc..). Hundreds of years ago the thought that humans could fly would prob have been unimaginable, and now you can be on the other side of the world in a matter of hours. Its helped make the world a smaller place. Its also beautiful seeing the world from a plane.|||Definitely the internet.|||Guttenberg. The printing press, revolutionized the world and civilization as we know it today.|||The internet, the world are now growing exponentially, thanks to the internet.|||I would say it is the car. Reason: it not only paved the way for roads, bridges, and many other things. It is also the reason for the ozone layer, pollution, gas wars, and nitrogen fuel cells. Plus, much more. So it plays in good and bad.|||I vote for the steam engine. It really allowed industrial processes to be automated in the industrial revolution, clothes to be manufactured etc. Then everyone moved from the country to form massive cities and work in factories. Definetly the steam engine.