# (Roughly) Daily

## “I know numbers are beautiful. If they aren’t beautiful, nothing is”*…

Euler’s identity: Math geeks extol its beauty, even finding in it hints of a myste­rious connected­ness in the universe. It’s on tank tops and coffee mugs [and tattoos]. Aliens, apparently, carve it into crop circles (in 8-bit binary code). It’s appeared on The Simpsons. Twice.

What’s the deal with Euler’s identity? Basically, it’s an equation about numbers—specifically, those elusive constants π and e. Both are “transcendental” quanti­ties; in decimal form, their digits unspool into infinity. And both are ubiquitous in scientific laws. But they seem to come from different realms: π (3.14159 …) governs the perfect symmetry and closure of the circle; it’s in planetary orbits, the endless up and down of light waves. e (2.71828 …) is the foundation of exponential growth, that accelerating trajectory of escape inherent to compound interest, nuclear fission, Moore’s law. It’s used to model everything that grows…

Now, maybe you’ve never thought of math equations as “beautiful,” but look at that result: It combines the five most fundamental numbers in math—0, 1, e, i, and π—in a relation of irreducible simplicity. (Even more astonishing if you slog through the proof, which involves infinite sums, factorials, and fractions nested within fractions within fractions like matryoshka dolls.) And remember, e and π are infinitely long decimals with seemingly nothing in common; they’re the ultimate jigsaw puzzle pieces. Yet they fit together perfectly—not to a few places, or a hundred, or a million, but all the way to forever…

But the weirdest thing about Euler’s formula—given that it relies on imaginary numbers—is that it’s so immensely useful in the real world. By translating one type of motion into another, it lets engineers convert messy trig problems (you know, sines, secants, and so on) into more tractable algebra—like a wormhole between separate branches of math. It’s the secret sauce in Fourier transforms used to digi­tize music, and it tames all manner of wavy things in quantum mechanics, electron­ics, and signal processing; without it, computers might not exist…

More marvelous math at “The Baffling and Beautiful Wormhole Between Branches of Math.”

[TotH to @haarsager]

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As we wonder if Descartes wasn’t right when he wrote that “everything turns into mathematics,” we might spare a thought for Persian polymath Omar Khayyam; the mathematician, philosopher, astronomer, epigrammatist, and poet died on this date in 1131.  While he’s probably best known to English-speakers as a poet, via Edward FitzGerald’s famous translation of the quatrains that comprise the Rubaiyat of Omar Khayyam, Omar was one of the major mathematicians and astronomers of the medieval period.  He is the author of one of the most important works on algebra written before modern times, the Treatise on Demonstration of Problems of Algebra, which includes a geometric method for solving cubic equations by intersecting a hyperbola with a circle.  His astronomical observations contributed to the reform of the Persian calendar.  And he made important contributions to mechanics, geography, mineralogy, music, climatology, and Islamic theology.

Written by (Roughly) Daily

December 4, 2014 at 1:01 am

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## It’s all about the ink…

Called “the most remarkable formula in mathematics” by Richard Feynman, Leonhard Euler‘s Identity, as the equation in the tattoo is known, was named in a reader poll conducted by Mathematical Intelligencer as the most beautiful theorem in mathematics. Another reader poll conducted by Physics World named it the “greatest equation ever.” *

One can find other mathematical and scientific tattoos here…  and if one wishes to design one’s own, well…

As we steel ourselves for the needle, we might recall that on this date in 1947, George C. Marshall, a former general serving as Secretary of State, gave the speech at Harvard that laid the foundation for what became known as The Marshall Plan– the program under which the U.S. provided around \$12 Billion (a fraction of the sum that the Federal government is “investing” in G.M, but real money in those days… ) to help finance the economic recovery of Europe in the wake of World War II.

Oh, and lest we forget, June is Accordion Appreciation Month.

* Why is Euler’s Identity considered beautiful?  Three basic arithmetic operations occur exactly once each: addition, multiplication, and exponentiation. The identity also links five fundamental mathematical constants:

-The number 0.
-The number 1.
-The number π, which is ubiquitous in trigonometry, geometry of Euclidean space, and mathematical analysis (π ≈ 3.14159).
-The number e, the base of natural logarithms, which also occurs widely in mathematical analysis (e ≈ 2.71828).
-The number i, imaginary unit of the complex numbers, which contain the roots of all nonconstant polynomials and lead to deeper insight into many operators, such as integration.

And the equation is “balanced,” with zero on one side.

Written by (Roughly) Daily

June 5, 2009 at 12:01 am