It's very far from the vision people had in 50-60s. We haven't found yet the gravity fighting mechanism that will allow them. We might find a novel way to figh

It's very far from the vision people had in 50-60s. We haven't found yet the gravity fighting mechanism that will allow them. We might find a novel way to fight gravity tomorrow, in another 50 years, or never. Like AI. We might find a way to build truly intelligent computers tomorrow, in 50 years, or never. However in both cases, it's ridiculous to try to come up with rules for a non existing technology. It will be like people in the 50-60s trying to make rules from the Internet.