Saturday, March 31, 2012

Aviation Security Debate: Bruce Schneier V. Kip Hawley (Former TSA Boss)
Let us start with the obvious: in the entire decade or so of airport security since the attacks on America on September 11th 2001, the Transportation Security Administration (TSA) has not foiled a single terrorist plot or caught a single terrorist. Its own "Top 10 Good Catches of 2011" does not have a single terrorist on the list. The "good catches" are forbidden items carried by mostly forgetful, and entirely innocent, people—the sorts of guns and knives that would have been just as easily caught by pre-9/11 screening procedures. Not that the TSA is expert at that; it regularly misses guns and bombs in tests and real life. Even its top "good catch"—a passenger with C4 explosives—was caught on his return flight; TSA agents missed it the first time through. 

Dr. Neil deGrasse Tyson's remarks at Senate Commerce hearing on the future of our space program

Sunday, March 25, 2012

Slinky drop physics

If there are a lot of slinky drop questions on my upcoming Linear Algebra test then I'm all set.

Earth, from Saturn
Gotta love earth from space, on any scale. My favorite recent image is taken by Cassini in orbit around Saturn. In this image, Saturn has eclipsed the Sun. And in this view there's a four-pixel sized speck to the left of the ball, outside the ring, barely visible without a zoom. That's Earth.
- Neil deGrasse Tyson

Wednesday, March 21, 2012

Holding a Gun Makes You Think Others Are Too, New Research Shows
The researchers varied the situation in each experiment -- such as having the people in the images sometimes wear ski masks, changing the race of the person in the image or changing the reaction subjects were to have when they perceived the person in the image to hold a gun. Regardless of the situation the observers found themselves in, the study showed that responding with a gun biased observers to report "gun present" more than did responding with a ball. Thus, by virtue of affording the subject the opportunity to use a gun, he or she was more likely to classify objects in a scene as a gun and, as a result, to engage in threat-induced behavior, such as raising a firearm to shoot.

Wednesday, March 14, 2012

Q: Satellites experience less time because they’re moving fast, but more time because they’re so high. Is there an orbit where the effects cancel out? Is that useful?
The original question was: I read that due to time dilation from both gravity and speed, GPS satellites need their clocks adjusted to match Earth’s time or else the whole idea would fall flat on its face. So my question is wouldn’t there be a natural way to match the GPS clocks with Earth by simply having the time dilation from movement offset the time dilation from gravity? How fast would they have to orbit the Earth to cancel out the gravitational time dilation?

Tuesday, March 13, 2012

Not Enough Money Or Time To Defend Detroit's Poor
Critics say Slameka is right. He might sound extreme, but Slameka reflects widespread problems across the country. In New York City, because there aren't enough defenders, overworked lawyers say they show up for trials ready to tell the judge they've done nothing on the case. In Miami, they say the only way they can squeeze in jail visits is if they work every weekend. And in Detroit, public defenders haven't seen a raise in more than 30 years. Slameka has to take on 50 clients at a time to earn a living.
This was linked to via a Slashdot story where there was a discussion about public defenders.  I'll repeat what I wrote there:
I've always thought a good idea would be simply to force lawyers who want to practice criminal law in a state to occasionally serve as a public lawyer. Say every 5 years of private practice they would have to do 1 year of this public service. Both prosecutors and free defense lawyers would be drawn from this pool.

Monday, March 12, 2012

Forecast Accuracy from WeatherSpark

I've mentioned WeatherSpark in the past.  Which is not only my sole source of weather, but makes me compulsively check the weather several times a day.  While their standard graphs remain a great way to present forecasts, I just discovered they provide forecast accuracy reports.  They report four different sources of forecasts, and the accuracy report allows you to compare them (for a particular location).

While it provides an idea of which weather forecast source you should be trusting, it also provides some interesting insights in to forecast accuracy in general.  While temperature forecasts are pretty close, rain forecasts are not that great, and wind direction is basically impossible to predict.  Once you get out past 7 days, forecasts become less accurate than simply taking the average temperature of the past several years.

The averages page is also interesting:

Sunday, March 11, 2012

The Personal Analytics of My Life
Every day — in an effort at “self awareness” — I have automated systems send me a few e-mails about the day before. I’ve been accumulating data for years and though I always meant to analyze it I never actually did. But with Mathematica and the automated data analysis capabilities we just released in Wolfram|Alpha Pro, I thought now would be a good time to finally try taking a look — and to use myself as an experimental subject for studying what one might call “personal analytics.”

Thursday, March 8, 2012

The Nuclear Game - An Essay on Nuclear Policy Making

An interesting set of essays on nuclear policy.
When a country first acquires nuclear weapons it does so out of a very accurate perception that possession of nukes fundamentally changes it relationships with other powers. What nuclear weapons buy for a New Nuclear Power (NNP) is the fact that once the country in question has nuclear weapons, it cannot be beaten. It can be defeated, that is it can be prevented from achieving certain goals or stopped from following certain courses of action, but it cannot be beaten. It will never have enemy tanks moving down the streets of its capital, it will never have its national treasures looted and its citizens forced into servitude. The enemy will be destroyed by nuclear attack first. A potential enemy knows that so will not push the situation to the point where our NNP is on the verge of being beaten. In effect, the effect of acquiring nuclear weapons is that the owning country has set limits on any conflict in which it is involved. This is such an immensely attractive option that states find it irresistible.

Monday, March 5, 2012

Q: Do you need faith to believe in science?
It’s easy to see why science seems like just some wacky new belief system that you have to have faith in to believe.  The difference is, if you don’t believe it (and you’re properly motivated), then you can go out and test it. To be fair, most people do take science on faith.  It’s much harder to test things yourself, than it is to trust that the kind of people who can figure out how to fly around in space and build fancy computers have things pretty well sorted out.  But keep in mind; the option is there.

Friday, March 2, 2012

Bridging the Chasm between Two Cultures
From a vantage point outside the New Age culture, my culture’s disavowal of emotions and the intellect may seem very strange and nearly inexplicable. Nevertheless, it is a very real cultural component that must be understood and considered if any useful communication is going to occur. If we want to successfully communicate with someone, we've got to understand not just their language, but the cultural context from which their language springs. From what I've seen in both the New Age and the skeptical cultures, this understanding is absent. I certainly didn't understand the skeptical culture until I spent real time considering it as a culture—and I know from my reading that most people in the skeptical culture don't understand the New Age culture at all. As a result, the yelling between our cultures just becomes louder while the real communication falls into the chasm that divides us. In all the din, people in my culture hear what they deem to be hyper-intellectual and emotionally charged attacks upon their cherished beliefs, while people in your culture hear what they deem to be wishful thinking, scientific illiteracy, and emotionally charged salvos in defense of mere delusions.

Thursday, March 1, 2012

What facts support evolution?

John Stossel's Illegal Everything

Posting Fox News clips.  So, it has come to this.

Public Key Cryptography Explained With Colors

Imagine you wanted to communicate securely with someone you had never met before.  How could you exchange a private key to use while you assume your communications are being intercepted.  This is the problem of public key encryption.  It is an interesting problem to think about.  This video does a great job of explaining the process that takes place every time you visit a site that starts with https.