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Cake day: September 19th, 2023

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  • Vertical farming usually uses LED lighting, not direct sunlight.

    That’s one method of bringing"sunlight" to plants. Another would be to grow them outside.

    And I think the idea is that once the water is present on a given level it gets recirculated and reprocessed there, so it wouldn’t need much additional pumping.

    Even if all you do is pump all the water from the floor of each level to the ceiling of the respective level, you’ve done the exact same amount of work as pumping all the water for the top floor back to the roof in the first place. Only you’ve done it with a hundred pumps and a hundred times the points of failure and repair rate as a single pump for the entire building.

    You’d be so much farther ahead to just install a reservoir on the roof that gets filled by a single pump and let gravity feed the lower floors. Much the way we already do for flat farming.

    And then you’ve got to make up for the inefficiencies lost in planting and harvesting. Vertical farming brings nothing to the table except a smaller footprint in a world where that’s not a real advantage.

    A far better use of empty office buildings would be to convert much of the space into full-time living space.















  • unoriginalsin@lemmy.worldto196@lemmy.blahaj.zoneGlitch in the matrix
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    7 months ago

    What an interesting error to point out in support of pemdas.

    Clearly the formatting of a paragraph of text in a textbook full of clearly and unambiguously written formulas discussing the very order of operations itself compared to the formatting of an actual formula diagram is going to be less clear. But here you’ve chosen to point to a discussion of why the order is irrelevant in the case under question.

    Your example is the conclusion of a review of mathematics.

    First we shall review some mathematics.

    The actual order of differentiation is immaterial:

    The fact that the example formula is written sloppy is irrelevant, because at no point is this going to be an actual formula meant to be solved, it’s merely an illustration of why, in this case, the order of a particular operation is “immaterial”.

    Even if ∂^2f/∂y∂x is clearly written to mean ∂^2f/(∂y∂x), it doesn’t matter because “∂2f/∂x∂y=∂2f/∂y∂x”. So long as you’re consistently applying pemdas, you’re going to get the same answer whether you derive x first or y.

    However, when it’s time to discuss the actual formulas and equations being taught in the example text, clearly and unambiguously written formulas are illustrated as though copied from Ann illustration on a whiteboard instead of inserted into paragraphs that might have simply been transcribed from a lecture. Which, somewhat coincidentally, is exactly what your citation is.