[WordWhiz]

As an example, the airplane was developed entirely on the free market. It wasn't 25 years before we had commercial airline service. A few more decades, and we have jumbo jets taking hundreds of people to every corner of the globe in less than a day--a trip that used to take weeks by train or ship.

Compare that to the space program, a good example of research that the free market would probably not support. Why not? There's no market! We actual benefits we get from sending shuttles into space--at a cost of billions of dollars and several lives--are quite small, when you discount things such as national pride and the "cool factor." Money would be better spent elsewhere.

But we've finally gotten to the point where the private market is researching private space travel, because of the potential for a market. In ten years, we could have thousands of space tourists.

So even in areas where it looks like the free market would never accomplish a particular end, it ends up happening once there is consumer demand. I doubt there's any particular innovation or technology that is so large, and whose benefits are so diffuse, that it could not be accomplished via the free market.