May 02, 2007

Fox Street Journal

Rupert Murdoch's News corp wants to buy Dow Jones for $5 billion. That is 65% more than the Wall Street Journal publisher was worth yesterday.

Murdoch's offer was turned down by the venerable Bancroft family that owns half of Dow Jones.

But "there can be a limit to their ability to say no," say some like Lawurence Haverty: "Dow Jones is a minnow in the shark pool." The issue is that public shareholders have been unhappy that DJ has been down in the dumps. (Murdoch helped that by causing a 55% jump in DJ yesterday without even laying down a dime.)

Murdoch's bid makes me sad. The Wall Street Journal is the best-written newspaper on the planet (discounting the wacky editorial page), and I really do not want it to be controlled by the creator of such wonderful stuff as the Sun, the New York Post, and Fox News.


Posted by David at 05:39 PM | Comments (1)

May 03, 2007

Google's Secret Fortress

Oh no. Today the secret location of Google's Volcano Fortress has been revealed.

Go ahead and click on the map, but before you contemplate infiltrating the island on your gyrocopter, you might want to prepare yourself for a possible encounters with ninjas, pirhanas, sumo wrestlers, and a nefarious rocket base.

Oy vey. The internet. Now anybody can buy the secret map for $13.

Continue reading "Google's Secret Fortress"
Posted by David at 02:11 PM | Comments (1)

May 11, 2007

Where's Dave?

What has Dave been up to since he has not been blogging?

Yes, both being a code monkey and watching "code monkey." (Video via Rod.)

Posted by David at 01:16 PM | Comments (2)

May 16, 2007

Guessing Your Hat

This puzzle has been making the rounds.

Three Google interns go to the cafe, and a hat of a random color (equally likely red or blue) is placed on each of their heads. Nobody can see their own hat, but each can see the hats of their two friends.

For the group to get free tiramisu, each must write down a guess for their own hat color (writing "I don't know" is fine), and the team must make no wrong guesses and produce at least one correct guess. The thing is, once the interns have their random hats, no communication whatsoever is allowed.

The interns discuss this game for a minute before being hatted, and they play in a way that allows them to get free food well over 50% of the time, without any cheating.

What did they do?

And if no intern can possibly have any idea what their own hat color is, where the heck did this better-than-nothing information come from? (Perhaps this is a good way to pretend you know something when you don't?)

Posted by David at 10:13 AM | Comments (6)

May 25, 2007

Hat Hints

Some hints to follow up on the seven-intern version of the red-hat blue-hat puzzle from the last post. The case where there are seven interns is much trickier than the case where there are only three interns, but once you see the solution to seven, you can see the solution for all 2n-1 interns. For numbers of interns that do not line up with powers of two like this, the optimal solution is an open problem (though, using Dominic's construction, you can always use the 2n-1 solution as a lower bound).

So here is the hint. You don't know the seven interns' strategy, but day after day you observe them getting free tiramisu (about 7/8 of the time), and here is what you notice:

  • The interns have apparently worked out a geeky way to distinguish each other, because each shows up at the cafe wearing a name tag with a number from 001 to 111, that is, the numbers one through seven in binary.
  • You notice that, when all seven interns get hats of the same color, they all guess wrong. Sometimes they all guess wrong with other color combinations too.
  • But very strikingly, most days, only one intern guesses. And when only one intern guesses, the guess is always right. The most entertaining days are when only one intern has a hat of a different color. Inevitably the other interns stay quiet and that intern guesses his own hat color correctly.

Yesterday the interns did not get tiramisu. The first three got red hats and the rest got blue hats, and they all guessed their hat color. They were all wrong.

Today, the first four interns got red hats and the last three got blue hats. Intern #4 was the only one to submit a guess and, as happens whenever only one intern guesses, she guessed "red" correctly.

What the heck are they doing, and how often can they get tiramisu doing this?

Tomorrow we will give red hats to interns #3 and #7. Which intern will correctly guess that her hat is "blue" tomorrow?

Posted by David at 11:46 AM | Comments (0)