• glibg10b@lemmy.zip
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    2 days ago

    Pi can be seen in real life (obviously not with full precision, but close enough). Simply make a 1 cm rod on a lathe and measure its circumference, and you’ll see it’s ~3.141 cm

    The same goes for root 2. Simply measure the diagonal of a 1 cm square

    Not sure where you’d see e in real life, though (excluding as the base of an exponential, because any exponential can be trivially rewritten with any base)

    • @glibg10b @Rugnjr I ran this past my (engineer) SO and, after grumbling at being nerd-sniped, he came up with something you could measure to derive e.

      He said a capacitor filled through a resistor for a time unit equal to “RC” gives you a simple formula that solves for e.

      I think I may have got that right? Most of this is gibberish to me, but he gesticulated wildly and held up random electronic things at me so I think he had something.

      • glibg10b@lemmy.zip
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        18 hours ago

        I’m a computer engineering student and you remembered correctly, it reaches the final voltage times (1 - 1/e) at the time given by the time constant. Though technically e is the base of an exponential in this case

        Mathematically, the thing about e that causes this is the fact that d/dx (ex) = ex. In simpler terms, if a car is driving in a straight line and its speed increases e (2.71) times per second, then its distance travelled always equals its speed (plus some amount that doesn’t change) (ignoring units)

        The other cool property about e that I know of relates to complex numbers, but I don’t think I can explain that in a way that’s easy to understand