...that it isn't limited by how 'smart' we are. That's the cheap answer to your question of course. The more expensive answer relates to the role of creativity

...that it isn't limited by how 'smart' we are. That's the cheap answer to your question of course. The more expensive answer relates to the role of creativity in scientific advance, and how creativity is limited by experience. When you look at the history of scientific advance, very rarely are discoveries made out-of-time. They occur when the conditions are right. They rarely occur sooner because they are meaningless without the context of the times in which they were developed. So, scientific advance is essentially limited by us humans and the rate that we progress as a race. In other words, the rate of scientific advance is just about optimal, or approaching a limit set by us. :-)