There is no scientific theory that could lead us from a detailed map of every single neuron in someone's brain to a conscious experience. We don't even have the beginnings of a theory whose conclusion would be "such a system is conscious.

Some people think that, inevitably, every robot that does any task is a bad thing for the human race, because it could be taking a job away. But that isn't necessarily true. You can also think of the robot as making a person more productive and enabling people to do things that are currently economically infeasible. But a person plus a robot or a fleet of robots could do things that would be really useful.

What AI could do is essentially be a power tool that magnifies human intelligence and gives us the ability to move our civilization forward. It might be curing disease, it might be eliminating poverty. Certainly it should include preventing environmental catastrophe. If AI could be instrumental to all those things, then I would feel it was worthwhile.

It's very hard to predict what kind of uses we'd make of assistants that could read and understand all the information the human race has ever generated. It could be really transformational.

You're able to use a search engine, like Google or Bing or whatever. But those engines don't understand anything about pages that they give you; they essentially index the pages based on the words that you're searching, and then they intersect that with the words in your query, and they use some tricks to figure out which pages are more important than others. But they don't understand anything.

Some PhD physicists write software or work for hedge funds, but physics still has a problem with having very smart people but not enough opportunities.

Leg locomotion was, for decades, thought to be an incredibly difficult problem. There has been very, very painstakingly slow progress there, and robots that essentially lumbered along at one step every 15 seconds and occasionally fell over.