I had this clever idea that you could do something like [...] only of course the engineering considerations would make it completely impractical: maybe in a century. Obviously you will credit me with the idea.
Oh, yes, we used to do that, but we worked out that [...] would be better. Of course what we do now requires [obviously completely absurd engineering even in theory], but we got it all sorted out in the end.
[gives up science, becomes computer programmer].