#2566: Decorative Constants

Transcript

[A small panel only with text. Written as an excerpt from a mathematical text book. Begins with a number for an equation, then follows the equation written in larger letters and symbols. And below are explanations of each term in the equation. The μ has a bar over the top and the D has a double vertical line.]

Eq. 4-15

T = 𝔻m₀(r_out - r_in)^μ̅

T: Net rate

m₀: Unit mass

(r_out-r_in): Flow balance

𝔻, μ̅: Decorative

[Caption below the panel:]

Math tip: If one of your equations ever looks too simple, try adding some purely decorative constants.

(Sourced from explainxkcd.com)

Title text:Arguably, the '1/2' in the drag equation is purely decorative, since drag coefficients are already unitless and could just as easily be half as big. Some derivations give more justification for the extra 1/2 than others, but one textbook just calls it 'a traditional tribute to Euler and Bernoulli.'

Explain Original