Monday, March 14, 2016

Happy Pi Day!

Don't rush to your nearest bakery -- not yet any way!

We are talking about the beautifully enigmatic and irrational number aka pi. Why today? -- given the precision provided by the digits on our calendars, 3.14.16 is the closest you can get to this ever elusive number hermit! So in the spirit of full disclosure it is actually a 'rounded' pi day like the one shown on the right (yum!).  For a more appropriate homage, I enclose the one I spotted at the Stata Center@MIT* below!


Well, as it turns the geeking out with this day does not stop yet. It also happens to be birthday of the most famous physicist ever -- yes it is 137th birthday of Albert Einstein which makes this extra special! In addition, 137 has its own hall of fame in physics ---due to fine structure constant, which is recognized as one of the fundamental constants of nature, and which is very close to 1/137!


As you can see alpha seems to be having its own little party with other constants (including pi), such as e = charge of an electron, \hbar = h/(2 pi) = (reduced) Planck's constant, c = speed of light in vacuum and \epsilon_{0} = permittivity of the free space. One of the reasons which carves \alpha firmly on the throne of geeks (and greeks!**), is that it sets the natural coupling strength of matter (electron) with radiation (photon) in Quantum Electrodynamics***.

Now you maybe wondering why did nature choose something as unexpected as 1/137 in its manifestation -- if you have any clues, you just might be able to solve one of the longest standing puzzles in Physics!

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* It may just be a coincidence but MIT also hands out its decision for admissions today.
**being the first greek letter and all..
***The effective electric charge of the electron actually varies slightly with energy so the constant changes a bit depending on the energy scale at which you perform your experiment. So \alpha is not really a 'constant' as such, but hey it is pretty close and makes QED work so well, so we will let it be!

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