This installment will be a little light with just three short articles. One is about how having dogs around seems to improve cooperation between humans, one about using a powerful computer to find every possible solution to the classic Rubik’s Cube puzzle, and the last one looks at how people get trampled to death in large crowds.

Dogs make people more social

The first article is from The Economist and covers research by Christopher Honts and his colleagues at Central Michigan University who wondered if having dogs around in the workplace improved collaboration among people. This was because previous research has indicated that dogs help their owners forge intimate relationships with other people.

They organized test subjects into groups of four persons each and instructed each group to come up with ideas for a 15-second advertisement for a made-up product. The team members were all supposed to offer their own ideas on what to do for the advertisement but at the end only one idea would be selected. Some of these groups had a dog underfoot as they worked while the rest did not.

At the end of the task, the team members had to answer questions on what they felt about the team. The researchers found that the members of teams with dogs rated each other more highly on such measures as trust and team cohesion. Similar results were also found when they performed a version of the Prisoner’s Dilemma with subjects. Groups that had a dog around them seemed to be more loyal to each other and were less likely to snitch on their fellow team members.

I particularly recommend going to the website and checking out the website because some of the commentators raised some questions about the methodology used in the study and one of the study’s authors took the trouble to address some of the issues in the comments. Especially interesting are the ideas about using other animals, such as cats and goldfish, to test to see if this effect is unique to dogs.

Solving Rubik’s Cube once and for all

The next article isn’t from magazine or other news source but instead comes directly from the team who claims to have completely solved the classic Rubik’s Cube puzzle in all possible permutations. To do this, they used about 35 years of CPU time donated by Google in order to cover the 43,252,003,274,489,856,000 possible positions that the puzzle can take. What they found was that using the most efficient algorithm, it is possible to solve every configuration of the puzzle in a maximum of twenty moves.

While the actual results might be interesting only to mathematicians and puzzle enthusiasts, I still found the methodology they employed to be fascinating. After all, the number of possible permutations the puzzle has actually exceeds the memory available to modern desktop PCs, so it was necessary to break down the problem into smaller sets so that different computers can attack each part of the problem separately. In order to save CPU time, they also reasoned that symmetrical positions needed to be solved only once and the results appropriately modified for each of the 24 possible orientations.

Even so, they state that they didn’t try to find the optimal solution of every possible permutation and contented themselves with any solution of twenty moves or less. So if any team feels a pressing need to go for perfect solutions, there’s still that milestone to aim for.

Deadly stampedes

The last article is actually a post on the excellent Freakonomics blog by a guest who wrote a book on how panicking crowds can result in deaths. If you’re anything like me, you’d have wondered about how exactly people get killed in stampeding mobs. After all, surely it’s possible to escape or otherwise huddle into a protective ball to save yourself? However, as this article shows, without firsthand experience, it’s hard to appreciate just how terrifying and powerful a panicking crowd can become.

As the article explains, crowds become dangerous when the density approaches about 10 people per square metre, or 2,600 people in an area the size of a tennis court. When this happens, only a very small stimulus is needed to induce a crowd to panic. It may be when two separate crowds merge and panic starts at the point where they merge, or when a moving crowd is suddenly stopped by a barricade. The panic then spreads throughout the mass of people until common sense and rationality gets thrown out the window.

The article cites a paper by Ed Hsu and colleagues at John Hopkins who describes how a panicked crowd can exert sufficient force to bend steel supports and knock down brick walls. Contrary to popular opinion, deaths caused in a stampede usually results in the victims dying while standing upright. The corpses can still be upright once the crowd is dispersed. These people die because the sheer pressure to their rib cages prevent them from being able to breathe, leading to ventilatory failure.

The comments in the article also indicate is curling into a protective ball is one of the worst things you can do as you tend create a temporary gap that the pressure of the crowd around you will then try to fill. This leads to people being pushed to fall over you, crushing and suffocating you in the process. The article recommends that the only way to be safe is to always be mindful of the density of crowds, to be aware of exits, and to be willing to quickly move out of the crowd when it looks like things are getting to be too bad, even if it means missing out on why you were part of that crowd to begin with.