This seems very theoretical, just a lower bound on space required, without talking about what is being computed. Does it have any import on real algorithms?
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So it's more like polar star. Maybe not directly practical, but it will lead tons of people in the right direction.
Analogy is thermodynamics says how efficient a heat engine _could_ be. If your engine is way below that you know there how much of an improvement there _could_ be, that it's not an impossible problem. That will get people to build better stuff.