The ramifications of being able to focus gravity are mind boggling. For example, we would be able to use the pull of the Moon to launch spacecraft without the use of giant rockets and rocket fuel. I'm sure you can think of other uses...
I think the gravity force is too weak to use it this way. (Or it is sometimes too strong?) But we could use the tides as an energy source (which are caused by gravity between the earth and the moon) ... Maybe?
As you see, I provide more questions than answers.
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