Tuesday, August 30, 2005

I suppose I shouldn't be surprised...

... at writers of op-ed articles being less than 100% accurate. But something like this always makes me see red. Georgia has a new voting law which requires voters to show valid photo identification at the polls. Critics of the law contend that it discriminates against minorities, who are much less likely to have an acceptable form of ID. Defenders say that it is not discriminatory, but simply intended to reduce fraud. I have no strong opinion either way; I think requiring photo ID is desirable, but efforts should be made to ensure that every citizen can easily obtain a valid form of ID (which apparently is not the case in Georgia now, though the new law will go some way towards addressing this problem).

So what am I worked up about? These sentences in the linked article:
Of Georgia's voting-age population, 2,260,437 more people hold such identification than are registered to vote. Thus the number of voting-age citizens who lack photo identification cannot, as a matter of math, be large.
The phrase "as a matter of math" obviously implies that mathematics shows that the truth of their statement cannot be denied. Unfortunately, mathematics shows no such thing: If the only thing we know is that a set X is larger than another set Y, there is nothing obvious that can be said about the number of elements in Y that are not in X.

Granted that the writers are non-mathematicians, and may know nothing at all about set theory. We could be charitable and assume that they thought it was simply common sense, and would be supported by mathematics. But that doesn't support their assertion. Consider this statement, which is entirely equivalent (with the numbers reduced, but remaining roughly in proportion according to the U.S. Census Bureau):
"Of the 150 students in a high school, 50 more played basketball than baseball. Thus the number of students who play baseball but not basketball cannot be large."
Perhaps we have 30 who play only baseball, 80 who play only basketball, 30 who do both, and 10 who do neither. That sounds plausible, but one-fifth of the students play baseball but not basketball. Certainly any law which disqualifies a fifth of the voting population would be unacceptable. So common sense doesn't really help them.

Ok, so I'm overreacting; this isn't even a particularly egregious example of using 'mathematics' to mislead. But I wish there were a penalty for regular offenders... maybe insist that they take high-school math again?

Friday, August 26, 2005

On Buying Books

Yesterday was the first day of the annual Urbana Free Library book sale. Surplus books are practically given away - one dollar will buy you a hardcover in good condition, or 3 mass-market paperbacks. I bought close to 25 books, including a Graham Greene collection, Richard Adams's Watership Down and Isaac Asimov's Black Widowers mysteries.

There are good reasons I shouldn't have gone to the sale: I don't have sufficient shelf space to store the books I already own, and the more books I own, the less time I spend doing anything besides reading. What's worse, I haven't even read all the books I bought in the last year! Given the abundance of excellent libraries around here, there's no reason for me to actually buy books. And yet... the annual sale of the Champaign Public Library will be held early next month, and I'll be there when it opens.

I'm not normally an acquisitive person, but I make an exception for books. There's ... something about a full shelf, running your finger along the tops of the books and pulling one out, deciding that this is the universe in which you will wander for the next few hours. There's something intensely pleasurable just in opening a book, whether you're trying something completely new or renewing your acquaintance with an old favourite, in the smell of the book, the way the paper feels when you turn a page, the weight of the book in your hands.

When I was young, how much I enjoyed visiting a family often had less to do with the people in it than it did with the books they possessed. (My sister claims this is still partly true!). I suspect this is partly why I buy so many books, especially those I've read and enjoyed in the past, but doubt I'll ever read again. I buy them for kids like me who could never find all the books they wanted, for whom finding a new book to love is a joy like no other.

Wednesday, August 24, 2005


Here's another of my excuses for not blogging: I've been spending a lot of time working on BITS2MSPhD. Essentially, it's a program (run by BITS, Pilani alumni) to help BITSians applying to grad schools. Besides the BITS2MSPhD website which contains application-related information, there's a Yahoo! group where alumni in grad school answer questions and help in any other way they can.

Since the only way to sustain the group is to build a large community, join the Yahoo! group if you aren't already a member. Also, the website needs content! We've got quite a lot of information up there already, but we can do with much more. You could write about your university or department (Who's looking for new students? Who's got funding?), your research area, or anything else that you think might be useful. The site is set up as a wiki, but editing permissions are limited at the moment (we'll soon be shifting the website, probably to a BITSAA server), so please email me any new content, and I'll upload it.

Comments/Suggestions about the group and website are welcome from everyone, whether you're a BITSian or not.

Tuesday, August 23, 2005

And So It Ends

A wonderful holiday, that is. I was away for nearly two months, during which I visited 4 countries, attended 3 weddings and the baptism of a cousin's baby, and generally had a fantastic time with friends and family. As I mentioned earlier, my access to the internet was limited for a while, so that's my lame excuse for not blogging. Of course, that doesn't apply to the last month or so, but who's keeping track?

The new semester begins tomorrow, and I'm looking forward to it. I'm done with all my breadth requirements (though that required counting Complexity Theory as a systems course. I have no clue why the department does that, but I'm not complaining!), so this semester's pure fun: Combinatorics, Randomized Algorithms, Computational Geometry, Expander Graphs, and an independent study with Sariel. Yes, I know I can't do them all, but I want to! Most of them will help with preparation for quals, so that's another reason to take them. Choices, choices...

I'm also TAing the undergrad section of CS 473 (Algorithms) this semester. It's the course I wanted, but since it's also one of the courses most hated by students, it'll be... interesting. At the least, it should be good for a funny story or two.