Tuesday, May 6, 2008


At the law firm where I’m interning, one of the computers in the upstairs library has a Perpetual Calendar. If you enter a date from any year, it’ll give you the day of the month. Some members of the library staff are fascinated by the program, and yesterday, one of them wanted to show it off to me. I for my part wanted to explain to him the elegant mathematical principles on which it works, but I caught myself just in time.

I refrained because I remembered an incident from my school days. A friend of mine was complaining that her birthday never fell on a Sunday. I told her that this was impossible, but she persisted with her claim, so I tried to prove to her that God or the Gregorian Calendar were not biased against her.

The proposition which I was trying to prove follows directly from elementary principles of modular arithmetic. The proof should be evident to any reader with a basic background in number theory.

But within three minutes of launching into my explanation, I could tell that I had lost her interest. In fact, she was giving me that disconcerting “What a freak you are” look that I sometimes get from people. An exercise book that I was using at the time had a sort of perpetual calendar, so I picked it up and tried to use it as a teaching aid. It was then that she commented that I was spoiling the magic of the perpetual calendar by explaining its working.

Yesterday’s incident made me think about her comment, and I am convinced now that she was wrong. A perpetual calendar is wonderful, but more wonderful still are the principles of modular arithmetic on which it is based. And most wonderful of all is the undying curiosity of the human mind that drives us to take apart cars, radios and atoms to find out what just what it is that makes them tick. As Brutha said about finding an aquifer in the desert, “just because you can explain it doesn't mean it’s not still a miracle.”

1 comment:

Anonymous said...

Doubletake, Doublethink. said...
i understood none of the formula.
i didn't even know my non-understanding was a non-component of basic number theory.


birthdays are a pain. but they must fall on a sunday sometime.

Sroyon said...
@doubletake: It's okay to not understand, as long as you understand what I'm getting at. I think it is one of the besetting flaws of our education system that elementary number theory, perhaps the most beautiful sub-discipline of mathematics, is not taught in schools. I thought of including in the post itself a full explanation that presupposes no prior knowledge of number theory. But that would just have put readers off, and we fledgeling bloggers cannot afford to give a fig for readers' tastes.

Rahul Saha said...
Very nice post Sryon. Really nice. For a coincidence, read the post I'll put up later today. Note: This is not a cheap trick to get you to read my blog.

A Couch-side View said...
I second Saha. But I do not have a post to follow yours up. I have however written something else of my own and this is indeed a cheap trick to make you read my blog.

RC said...
Nice, Sroyon. Very nice. Makes one wonder about something Einstein said:

"There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle."

Hmmmmm ..... :)

Wisps of Randomness said...
Wow,that was a good read. Didn't understand all of it though,but I DID understand what you were getting at,which is the whole point,I guess^.^

Sroyon said...
@saha: Hey, thanks! And (no flattery intended) you'll never need to resort to cheap tricks to keep me coming back to your blog.

@suhrith: And neither will you. :)

@rc: Hey I hadn't heard that quote before! Would probably have included it in my post if I had.

@wisps: That, as you say, was the whole point.

A.K. Visalakshi said...
clap clap clap! And not just because i still use my fingers to count!

little boxes said...
woohoo...makes me feel like an idiot for sure

kroswami said...
“What a freak you are” look that I sometimes get from people."


Indecision Personified!!!!!!! said...
That girl with that look was dead on. Tell me do you know where she is now... i was thinking there would be a nice triumverate of 'partners-in-crime'. :)

btw this is a cheap trick to get you to have a look at my blog.

February 11, 2009 12:33 AM