Archive for April, 2007

Mirah is Amazing

Posted in Laws by epictetus on April 27th, 2007

[youtube hH-cpZZAUWQ]

This performance is absolutely haunting — when she kicks on the distortion it’s like a heart attack.

I missed her when she was playing a bunch of MA schools recently, I would love to see her some time.

Search rankings

Posted in Laws by epictetus on April 27th, 2007

These are the search rankings for, my wife’s real estate website, on google, for various terms:

weston real estate – #22

weston land — #30 (Community profiles page)

weston ma #53

weston ma real estate – #62

weston – #796

weston mass – Not in results
weston homes for sale – not in results
weston ma homes for sale — not in results
weston massachusetts homes for sale — Not in results

Pi Project Notes

Posted in Laws by epictetus on April 11th, 2007

     I’ve been doing a lot of research on the practice of computing the digits of Pi.  The first question is, “Why?”.  In the great majority of real-world applications, an approximation of few digits (i.e. 3.14) is close enough — it’s hard to imagine any calculation where an approximation to 20 digits would not be accurate enough.
One of the most interesting things about Pi is how much we don’t know — the “state of our ignorance” as Borwein puts it (CHECK).  For instance, in all calculations so far, the frequency of decimal and hexidecimal digits has been very close to what you would expect from a completely random  distribbution of digits (each digit has about 1/10th probability of occurring, or 1/16th for hexadecimal)… but there is no proof that this must be the case for all digits.  In “Contact” by Arthur Clarke he speculated about a binary “message” hidden in the digits of Pi — we currently have no proof that such a message or similar statistical anomaly exists, though of course it seems unlikely.
Also, as an excersize in computability and algorithms, it is somewhat interesting to look at the records for calculating the digits of pi.  The last few records have been set by Professor Kanada, using a number of supercomputers… the current record is about 1.3 trillion digits.  In ASCII format, that’s 1.3TB of digits (or in a more efficient 4-bits-per-digit representation, 650GB).  This means that memory/disk efficiency will be key, and algorithms that calculate digits indiviually will probably be preferred; if at all-possible, the only number of the final precision we want to store/use in our algorithm is our final answer, not a number of intermediate steps.

The algorithms for approximating Pi involve some kind of converging series.

Here are some links to interesting papers on this topic:

* Unbounded Spigot Algorithms for the Digits of Pi — Jeremy Gibbons responds to and improves upon the spigot algorithm proposed by Rabinowitz and Wagon in 1995.

* A Spigot Algorithm for the Digits of Pi — Rabinowitz and Wagon give a great “spigot” style algorithm for computing digits of Pi,

Ramanujan, Modular Equations, and Approximations to Pi OR How to Compute One Billion Digits of Pi .  — Borwein, Borwein, and Bailey evaluate a number of different series and algorithms that converge upon Pi. with a focus on computability and speed of convergence. Expands on Ramanujan’s work.

Cellphone pictures

Posted in Laws by epictetus on April 9th, 2007

I figured I would upload a bunch of cellphone pictures and comment on them.

Dim Sum in Chinatown
Here is our table.. you can see various dumplings and mystery items in front of us.

Dim Sum

Here is a view across the restaurant, the part in the foreground is only about 1/4 of the overall space. The place was HUGE, and basically they bring carts of dumplings and things past and say what they are (in chinese), and you grab what you want.  Unfortunately, as a vegetarian, none of them seemed to know what the word “Meat” meant.

My Computer

Here is the computer I am building. It has a Dallas version of an Intel 8032 as the CPU, and 32K of external memory, a 16 bit address bus (but the upper 32k of addresses are all IO space due to some lazy IO decoding), and an 8-bit data bus. I am building it as part of the engineering sciences E-123: Digital Circuit Design course at Harvard Extension school. Notice the nice hex keypad. Right now I have to manually program it a byte at a time, because I have not yet added a serial port and software to allow me to send data from the serial port into memory.

Kids with Potato Cannon
Here are a couple of the guys with the potato cannon I built. Notice the landern igniter and large cumbustion chamber.

Harvard student Sleep-studying

Here is a typical Harvard undergrad, she has fallen asleep in a common room while studying with her laptop.