WEEKLY WHINE

Historic day

An important day is coming up on TUE 14 MAR 2000. That day is the next π Day, and it is the next Einstein's Birthday. If you like, you may combine the two by naming it e^π Day. This is probably the best combined holiday the world ever saw.

Why is this? The most obvious reason is that it brings together all sorts of knowledge. In all fields, not only mathematics, π is an important number. The value of π continually crops up in electrodynamics, computer science, mechanical engineering, and even literature. Similarly, the work of Albert Einstein was not restricted to physics. His contributions were most important to physicists and astronomers of course, but non-scientists also hold him in high regard. Most people recognize the formula E = mc² even if they can't tell you what it means.

The occurrence of e^π Day is a great opportunity to find out that energy and mass are equivalent: if you multiply mass by the square of the speed of light, you get energy. The result of this equivalence is that photons can create matter in particle-antiparticle pairs. This is fortunate, as otherwise the Universe would still be just radiation and no matter.

This wonderful day is also a splendid time to think about the meaning of π. To twenty decimal places, it is π = 3.14159265358979323846. If you want it to more digits, you can find that in large numbers of places. In addition to being the ratio of a circle's circumference to its diameter, π shows up again if you are considering complex exponentials. What is the natural logarithm of -1? It just happens to be the product of two of the most interesting numbers that you'll ever find: ln -1 = iπ.

GoobNet's Links contain a few resources related to the number π, as well as one related to the movie. If you want even more, just go to Go2Net's "The Uselessness of π and Its Irrational Friends". And be sure to visit the Exploratorium on π Day 2000.

On the other side of the holiday, some facts about Al Einstein are here [except everything that looks like a link isn't!]. Nova had a program called "Einstein Revealed". If you'd like to see what the interior of a black hole really looks like, this is a great place not to go. Some folks at Boston University are in the midst of the Einstein Papers Project and have already published seven volumes of his works. And of course, what would e^π Day be without a visit to "Einstein, Image and Impact", an exhibit assembled by none other than the American Institute of Physics.

The only unanswered question is What do we do on e^π Day, anyway?. You can do things that other people have done. For example, partygoers at the Exploratorium always join hands and circumambulate three and a seventh times, sing happy birthday to Al, and eat pie. But the fun part is making up new stuff. After all, that is how Al made his living, and if you do stuff like that, you may well find yourself arriving back at π or the cosmological constant, which many cosmologists are now resurrecting in Al's honor [and because it fits the data better].