The quote 'Data is the sword of the 21st century, those who wield it the samurai.' is a bad metaphor. I'll let the cracked authors explain why.

http://www.cracked.com/article...

Maybe it's an unintentionally good metaphor. Big data is the new useless but symbolic catchphrase that you use to make your company look modern.

Say your car gets 10 L /100 km. Your fuel tube will have cross sectional area of 0.1 mm^2.

The inverse square meter interpretation would say that since 1 car requires a fuel cross section of 0.1 mm^2, then we could power 10 cars with 1 mm^2.

So fuel efficiency of this car can be expressed as 10 / mm^2. It's the number of cars you could power with a 1 mm^2 tube of fuel.

Just like Hz is cycles per second, not just 1/s, this is cars per square millimeter, not just 1/mm^2.

Google is working on this.

It's a win-win-win-win situation. The public wins - not wasting time driving, safer, faster. The city wins - less accidents, less time off work due to accidents, hospital visits, less money spent on infrastructure like overpasses. Those savings will make up for the lost revenue from red light cameras. Oil companies win - due to Jevons paradox there will be more gas consumed. Car manufacturers wins - they sell more cars with this feature. The selling feature is they reduce travel time, which is kind of what they've always tried to sell with bigger engines and higher top speeds. This will actually deliver reduced driving time.

So you're that guy who races up to red lights and then has to slam on the brakes.

Here's what happens. You and I are stopped at a light with you in front of me. There's another light 20 seconds away at 35 mph or 10 seconds way at 70mph. The first light turns green and the second is due to turn green in 20 seconds. You arrive at the second light in 10 seconds and have to come to a complete stop. I arrive in 20 seconds the moment the second light turns green but I have to stop because of you. Everyone behind me also has to stop because of you. Your actions caused us all to decelerate and accelerate unnecessarily.

Actually, I wouldn't stop. I'd slow down giving you enough room to accelerate so to minimize my change in speed, but most people wouldn't apply that forethought.

The concept of aliasing is not applicable to the timing of traffic lights for a number of reasons. First, you're going the wrong way, a more reasonable answer would be 17.5 mph also works for lights timed for 35mph, but that's not true either. The timing is a phase variance, not a change in frequency. There's pretty much nothing you can do to beat the system of lights timed for a given speed other than drive that speed. That's a pretty optimal solution anyway.

BBC had a documentary called Out Of Control where they show this technology.
http://www.youtube.com/watch?v=LM_iiPFkNas&t=52m1s
It's a very interesting hour-long program. It makes me wonder if it is me that's posting this to slashdot or my subconscious overlord inside my brain.

These are all very important points. I think there are some examples of them in the video.

For example at 9:00 the speaker talks about how proud they are that their car didn't run down some pedestrians crossing the street. The car stopped just meters from them while making a left hand turn, blocking an oncoming car. The higher level decision that I'm sure the parent would make in practice is to judge the intentions of the pedestrians on the street and not commit to the turn. Although it's not clear in the video, it looks like the pedestrians didn't even run the light. The speaker doesn't acknowledge that their car blocked the oncoming lane resulting in a fairly dangerous situation. As you can see in the video, the oncoming car eventually swerves around the Google car.

Later on, at 12:00 he jokes about how a car nearly sideswipes him while merging onto the freeway. The speaker doesn't acknowledge the Google car's role in that dangerous situation. It's a simple lack of defensive driving on google's part. Yeah, they are not at fault for driving down the freeway, but it's not hard for a human to anticipate the fact that a car in a merge lane tail-gating behind a big semi-truck is going to change lanes at any moment. The Google car had an empty lane to the other side that it could have changed into at no cost.

I think these driverless cars are an insanely great innovation for our society, and I was really impressed with their TED talk too. But I just wish that now that they have the nerdy computer technical issues resolved, they can work on higher level algorithms, perhaps consulting with defensive driving professionals. I think defensive driving algorithms would be pretty interesting too, involving game theory and optimization. They seem to get it right with their four-way stop video, where they say they had to drive forward a bit to show their intention to proceed.

Wired had a nice article about the motivating power of statistics, and the positive sociological pressure that motives members from feeling they are part of a group. There's five excellent reasons to keep track of your workouts in this article.

Kde's Step is a good basic physics simulator. It is part of kde's education project.
From their description:
Step is an interactive physics simulator. It works like this: you place some bodies on the scene, add some forces such as gravity or springs, then click "Simulate" and Step shows you how your scene will evolve according to the laws of physics. You can change every property of bodies/forces in your experiment (even during simulation) and see how this will change the outcome of the experiment. With Step you can not only learn but feel how physics works !

There's a similar project out there called "Seventeen or Bust" whose goal is to find primes that will eventually prove a conjecture. To date they have eliminated 11 of the 17, leaving only 6 candidates left. I prefer to donate my cycles to them since there's bound to be a big party when the last candidate is eliminated and the goal is completed.