The Rodney Brooks (@rodneyabrooks) Rules for Predicting a Technology’s Commercial Success (via @exponentialview by @azeem)

Building electric cars and reusable rockets is fairly easy. Building a nuclear fusion reactor, flying cars, self-driving cars, or a Hyperloop system is very hard. What makes the difference? 

The answer, in a word, is experience. The difference between the possible and the practical can only be discovered by trying things out. Therefore, even though the physics suggests that a thing will work, if it has not even been demonstrated in the lab you can consider that thing to be a long way off. If it has been demonstrated in prototypes only, then it is still distant. If versions have been deployed at scale, and most of the necessary refinements are of an evolutionary character, then perhaps it may become available fairly soon. Even then, if no one wants to use the thing, it will languish in the warehouse, no matter how much enthusiasm there is among the technologists who developed it. 

Here I present a short list of technology projects that are now under way or at least under serious discussion. In each case I’ll point out features that tend to make a technology easy or hard to bring to market.

• Not Much Needs to Change
• Haven’t Been There, Haven’t Done That
• Obstacles are closer than they appear
• No Component Is Too Hard, but All Together They’re a Bear
• Sometimes, the Possible Just Takes a Little Longer 

In pointing out the differences that make one technology harder than another, I am not preaching technological defeatism. I’m only suggesting that we properly gauge the difficulty of whatever we are told could be the next big thing. If the idea builds on practical experience, then guarded optimism is in order. If not, then not. Hope is a scarce thing; we shouldn’t squander it.