Comment on Fuck geometry

manucode@infosec.pub ⁨3⁩ ⁨weeks⁩ ago

• blackberrynoseferatu@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

  this is why it is still a theorem

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• suzune@ani.social ⁨3⁩ ⁨weeks⁩ ago

  I’m so angry at people who think that distances can be imaginary.

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  • Xerodin@lemm.ee ⁨3⁩ ⁨weeks⁩ ago

    When talking about AC power, some of the power consumed doesn’t actually produce real work. It gets used in the generation of magnetic fields and charges in inductors and capacitors.

    The power being used in an AC system can be simplified by using a right triangle. The x axis is the real power being used by resistive parts of the circuit (in kilowatts, KW). The y axis is reactive power, that is power being used to maintain magnetic fields and charges (in kilovolt-amperes reactive, KVAR). And the hypotenuse is the total power used by the circuit, or KVA (kilovolt-amperes).

    Literal side note: they’re all the same units, but the different sides of the triangle are named differently to differentiate in writing or conversation which side of the power triangle is being talked about. Also, AC generator ratings are given in KVA, so you need to know the total impedance of your loads you want to power and do a bit of trig to see if your generator can support your loads.

    The reactive component of AC power is denoted by complex numbers when converting from polar coordinates to Cartesian.

    Anyways, I almost deleted this because I figured your comment was a joke, but complex numbers and right triangles have real world applications. But power triangles are really just simplifications of circles. By that I mean phasors rotating in a complex plane, because AC power is a sine wave.

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    • spankmonkey@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

      By that I mean phasors rotating in a complex plane, because AC power is a sine wave.

      I read the entire thing as Air Conditioning and it made me think my tired ass had forgotten something important and then here comes like whiplash when it clicked that you were talking about Alternating Current.

      More coffee needed.

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    • suzune@ani.social ⁨3⁩ ⁨weeks⁩ ago

      Please be careful with two different things. Complex numbers have two components. Distances don’t. They are scalars. The length of the vector (0,1) is also 1. Just as a+bi will have the length sqrt(a^2 + b^2). You can also use polar coordinates for complex numbers. This way, you can see that i has length 1, which is the distance from 0.

      The triangle in the example above adds a vector and a scalar value. You can only add two vectors: (1,0) + (0,1) which results in (1,1) with the proper length. Or you can calculate the length/distance (absolute values) of the complex numbers directly.

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    • muntedcrocodile@lemm.ee ⁨3⁩ ⁨weeks⁩ ago

      Its another classic case of Euler’s Identity

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  • lugal@lemmy.dbzer0.com ⁨3⁩ ⁨weeks⁩ ago

    Never been together with people and still felt alone?

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  • Brainsploosh@lemmy.world ⁨3⁩ ⁨weeks⁩ ago

    They’re about as imaginary as numbers are in general.

    Complex numbers have real application in harmonics like electronics, acoustics, structural dynamics, damping, regulating systems, optronics, lasers, interferometry, etc.

    In all the above it’s used to express relative phase, depending on your need for precision you can see it as a time component. And time is definitely a direction.

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    • kogasa@programming.dev ⁨2⁩ ⁨weeks⁩ ago

      That’s not relevant to what they said, which is that distances can’t be imaginary. They’re correct. A metric takes nonnegative real values by definition

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      • Brainsploosh@lemmy.world ⁨2⁩ ⁨weeks⁩ ago

        Why can’t a complex number be described in a Banach-Tarsky space?

        In such a case the difference between any two complex numbers would be a distance. And sure, formally a distance would need be a scalar, but for most practical use anyone would understand a vector as a distance with a direction.

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  • technocrit@lemmy.dbzer0.com ⁨2⁩ ⁨weeks⁩ ago

    You’re mad at mathematicians for constructing complex valued metrics?

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    • suzune@ani.social ⁨2⁩ ⁨weeks⁩ ago

      Omg, yes. This is horrible. :)

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• Foofighter@discuss.tchncs.de ⁨3⁩ ⁨weeks⁩ ago

  But that’s not the definition of the absolut value, I.e. “distance” in complex numbers. That would be sqrt((1+i)(1-i)) = sqrt(2) Also the triangle inequality is also defined in complex numbers. This meme is advanced 4-4*2=0 Works only if you’re doing it wrong.

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