Flying 3D printers like this one could handle just about any job we throw at them.
Until we can manage to make renewable energy sources pay off, nuclear power is arguably (and feel free to argue this) one of the cleanest and safest methods of energy generation there is. One of the biggest problems is the dangerous spent fuel, but there may be a solution to that: particle accelerators.
We're not really sure what the future is going to be like and sadly we don't have John Connor dropping from the sky to give us any clues. We'll probably need to tell future Earthlings a thing or two, but how do we do we make sure the information remains intact? Sapphires.