Archive for October, 2007


Wednesday, October 31st, 2007

In the 1950’s, Alan Turing suggested that artificial intelligence would not truly exist until a machine could pass a particular test, which we today call a “Turing Test.” It goes like this: a human examiner poses a question to two unseen participants, who return typewritten responses. The examiner knows that one of the participants is human and the other is a machine, but does not know which is which. The examiner must determine which is the human and which is the machine based on the responses returned. If the machine can fool the human examiner, it passes the Turing Test.

Today, however, it’s the machines who have much more of a need to make this determination. With automated spam-bots trolling the Internet, many Web 2.0 sites and blogs have had to adopt automated mechanisms for determining if the contributor is a live human being or not. One common method is a CAPTCHA (Completely Automated Turing test to tell Computers and Humans Apart), which shows an OCR-proof graphic image of letters and asks the would-be contributor to type those letters out. Spam-bots can’t read graphic images, at least not yet.

But, as in any arms race, the opposition hasn’t given up just yet. Some enterprising young hacker has put together a program to lure humans into helping crack CAPTCHA codes in the guise of a strip tease program. Type in the correct CAPTCHA code and “Melissa” takes off another article of clothing. Never mind that you’ve just helped give an automated program human bona fides.

Hoping to harness the same energies for good rather than evil, a group working out of Carnegie Mellon has released a program called reCAPTCHA, which has the user demonstrate humanity while also contributing to it. When encountering a reCAPTCHA, the user will enter the text of a word that OCR technology wasn’t able to read, which is meant to speed up the ongoing effort to digitize print books. A known word is included as well, as a human-check.

That sounds like a worthwhile cause, except then the user has twice as much to type to contribute a comment. I haven’t put any CAPTCHA on this blog, yet, because I want to encourage people to post comments freely. But I have to say that I do spend a good amount of time deleting spam, and so when I’m ready to go Turing, maybe reCAPTCHA is the way to go.

The whole reCAPTCHA idea reminds me of the ESP Game, in that it allows users across the Web to contribute to a piece of a mostly automated project that only humans can do. Actually, both of these schemes remind me of the ESP game, except that one is good and one is evil.

And I hope we need no Turing Test to tell us which is which.

The Knowledge Problem

Tuesday, October 30th, 2007

Ro has a thought-provoking post about the relationship between learning something and knowing it. Before I address that question, it might be worth taking a moment to consider what it means to know something.

What do we mean when we say we know something? For the individual, it might be the same as saying we unequivocally believe it. But is that enough? If Iago believes his wife has been unfaithful, and he has no evidence to support his belief, does that count as knowledge? Probably not.

Socrates argued that a belief must be justified to be considered knowledge. Othello might say that he knows his wife Desdemona has been faithful, because he has reason to believe in her love and trustworthiness. His belief is justified. But that doesn’t necessarily make it true, and so that probably doesn’t count as knowledge either. Knowledge must be both true and justified.

When we say someone else knows something, that might mean that they believe it and we believe it too. If Iago uses manufactured evidence to manipulate Othello into believing that Desdemona has been having an affair with Cassio, Othello can say that he knows that Desdemona has been unfaithful, because his belief is justified by evidence that has been presented to him. But we would not say that Othello knows it. He still believes it, but we do not.

Which brings us to the Gettier problem. Imagine that while Othello is being manipulated by Iago, Desdemona has been secretly having an affair with the Duke. Othello makes the statement that he knows Desdemona has been unfaithful. Does he know it? This time, his belief is both true and justified. And yet Gettier would not count this as knowledge, because Othello’s belief, while true and justified, is based on false evidence. He has no knowledge of the actual affair. Robert Nozick would point out that if the statement weren’t true, Othello would still believe it.

Now let’s go back and look at the question originally posed by Ro, which has to do with the relationship between knowledge and learning. If I say I learned something, that means I know it, which means I believe it. If I say you learned something, that means you believe it and I believe it. For example, President Bush got into a bit of trouble for including the following in the 2003 State of the Union address:

The British government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa.

By citing the British government, Bush’s speechwriters sought to insulate the administration from claims they already knew were false. But by using the word “learned” they implied the word “knew” which means that Bush was essentially saying that he also believed that the statement was true. It was later discovered that the statement was not true, and that the Bush administration was aware it was not true at the time the speech was written. Saying “The British government has learned” did not provide the out they were hoping it would.

Ro’s other question was whether knowing something implies that one has learned it. A strict empiricist might say yes, but even John Locke allowed for some a priori knowledge gained through reason alone. The classic example is from René Descartes: Cogito ergo sum. I think, therefore I am. Is this knowledge? Was it learned?

Finally, I can also attest that it is possible to have learned something and not know it. I demonstrate this condition several times every day.

Countdown: 100 Movies

Sunday, October 28th, 2007

And I thought puzzle-making was time-intensive…

A list of the 100 movies represented can be found here.

Conundrum: Pic Tac Toe in 3D, Part II

Saturday, October 27th, 2007

In a normal “Pic Tac Toe” puzzle, there are nine pictures in a 3×3 grid, like Tic-Tac-Toe. In each of the three rows, three columns, and two diagonals, there is a common theme that unites the three pictures. The challenge is to find the eight themes.

In this “Pic Tac Toe” puzzle, however, there are twenty-seven pictures in a 3x3x3 grid, like a Rubik’s Cube. In each of the nine rows, nine columns, nine pillars, eighteen lateral diagonals, and four cross-cube diagonals, there is a common theme that unites the three pictures. The challenge is to find the forty-nine themes.

Imagine stacking the three levels below on top of one another. For reference, and notation guidelines, check out my last 3D Pic Tac Toe, including the comments. The rules here are identical to that puzzle.

You can click on each image to see a larger version:

Top Level – Level A

Middle Level – Level B

Bottom Level – Level C

Please post whatever you come up with in the comments section.


UPDATE: Correct themes provided by Neel Mehta (35). Alternate themes suggested by Neel Mehta (6) and K-Lyn (1). See comments for discussion, or click here to skip right to the answers.

Six Degrees of Sir Francis Bacon: Jessica Alba

Friday, October 26th, 2007

First, read the rules of the game.

For some reason, this week saw an unprecedented number of visitors to the blog. It seems that there was a combination of words that matched common search terms. People may have come here for a variety of reasons, but some chose to stay, and I’m glad they did. I’m about to reach 7,000 hits, which last week seemed like a goal to shoot for by the end of December.

But while I’m glad for all of the new traffic, I’m not going to suddenly adjust the content of the blog to pander to the masses in a pathetic attempt to snag the random passerby. That’s not what this blog is about.

Anyway, this week’s challenge is actress Jessica Alba.

Jessica Alba has managed to maintain a professional career at a young age, without getting herself into trouble, unlike such stars as Vanessa Hudgens, Lindsay Lohan, or Britney Spears. Perhaps one day we will see her playing Texas Hold ‘Em on television, or on Dancing with the Stars. If I had to invest in the stock market of the famous, I’d go with the World Series champ of celebrities, Jessica Alba.

Well, that ought to do it.


Okay, I’m done now.

I actually was able to link Jessica Alba to Sir Francis Bacon in six degrees or fewer, though that shouldn’t stop you from posting a longer response, or looking for a shorter one. Entries will be accepted until midnight on Thursday, November 1.

Good luck!

And congratulations to Neel Mehta for winning last week’s challenge by linking Sir Karl Popper to Sir Francis Bacon in three degrees:

Sir Karl Popper > Bertrand Russell > Georg Cantor > Sir Francis Bacon

Sir Karl Popper addressed the problem of induction in a way that was commented on by Bertrand Russell, who studied the work of Georg Cantor, who believed in the Shakespearean authorship of Sir Francis Bacon.

Thursday Morning Riddle

Thursday, October 25th, 2007

I’m a story of structures; allow you to walk;
I’m the place of a meeting; permission to talk;
I’m a minimum wage, though employers may balk;
And the bottom of oceans, all covered with chalk.

Who am I?

UPDATE: Riddle solved by Neel Mehta. See comments for answer.

Question of the Week

Monday, October 22nd, 2007

This blog has recieved an unprecedented amount of traffic over the last 48 hours (about 200 hits), despite the fact that nobody new seems to have linked here. So this week’s question is this:

How did you find this blog?

Six Degrees of Sir Francis Bacon: Sir Karl Popper

Friday, October 19th, 2007

First, read the rules of the game.

This week’s challenge is science philosopher Sir Karl Popper.

I was able to link Sir Karl Popper to Sir Francis Bacon in six degrees or fewer, though that shouldn’t stop you from posting a longer response, or looking for a shorter one. Entries will be accepted until midnight on Thursday, October 25.

Good luck!

And congratulations to DeLisa for winning last week’s challenge by linking Benjamin Franklin to Sir Francis Bacon in a record two degrees:

Benjamin Franklin > Thomas Jefferson > Sir Francis Bacon

Benjamin Franklin was one of the Founding Fathers along with Thomas Jefferson, who was heavily influenced by Sir Francis Bacon.

Thursday Morning Riddle

Thursday, October 18th, 2007

I suggested that science make claims falsifiable;
I’m a fried cheesy snack; and make popcorn snacks viable;
A harmonica player with skills undeniable;
And a safe fun explosive (though don’t hold me liable).

Who am I?

UPDATE: Riddle solved by Brian. See comments for answer.

Conundrum: Primary Colors

Tuesday, October 16th, 2007

You may want to use a map for this one…

Imagine the 2008 Republican primaries are over, and only four candidates won any states. (DC, which is not a state, went to Ron Paul.)

1. Mitt Romney won more states than any other candidate.

2. Rudy Giuliani’s states included Massachusetts and Washington.

3. John McCain won all of the states beginning with one particular letter, and only those states.

4. Fred Thompson’s states included New Mexico.

5. Strangely enough, no two bordering states went for the same candidate. (Four Corners does not count as a border.)

Who won in Michigan? How do you know?

UPDATE: Puzzle solved by David. See comments for solution.