5 Things You Won't Believe Math Can Predict

5 How to Write a Successful Pop Song

Music is borderline magic; great songs touch you on a spiritual level, instantly changing your mood or causing stirring memories of your youth to come roaring back. How could you ever predict whether or not people will like a song with some cold computer program? It all comes down to what's in people's hearts.

Or maybe not. We've already explained how your brain secretly loves "Call Me Maybe" due to the way "catchy" pop songs trigger an almost addictive response. You could say, "But what about the meaning of the lyrics, or the passion of the performer?" but then you'd remember that you loved "Gangnam Style" even though you had no idea what it was saying (we looked it up on Google Translate, and it looks like the song is about the time Psy got high on meth and had sex with a transvestite while riding a horse). So if it just comes down to manipulating your brain, we should be able to come up with hard data on what works.

Scientists at the University of Bristol devised an algorithm to do just that: They analyzed songs from the U.K. Top 40 chart from the last 50 years. It takes into account 23 variables -- time signature, duration, tempo, loudness variability, etc. -- and from that they programmed software that could chew up any song and spit out the probability that it would become a hit with the public.

According to the researchers, the software has around a 60 percent accuracy rate for picking out songs that will make it to the top five and ones that won't even go above 30 on the U.K. Top 40 singles chart. That's a stunning figure, considering that it can't account for so many other variables, such as how heavily the label promoted it, or whether there was some other factor in the song's success (i.e., if the song was featured in a hit movie).

The algorithm's accuracy is also dependent on cultural context -- what worked in 1970 won't necessarily work now:

You see the way the blue line is starting to shoot back up? Simplicity is coming back. "Loudness," however, is on the decline after four decades on the rise:

So, if you're a musician, take a look at the numbers and get to work. Before they find a cyborg that can do your job.

4 Which Gang Is Responsible for a Crime

As we've previously mentioned, you'd be surprised to learn that the stupid premise behind Numb3rs, that crime show where a guy solves murders with a calculator, is basically a real thing that exists. Detectives with the LAPD collaborate with math professors to study trends in crime rates and try to predict, for example, which house in a particular neighborhood a criminal will try to burglarize next. Apparently, they can do this by essentially treating criminal behavior like traffic flow patterns, or even weather forecasting, as figuring out where a storm is going to hit apparently uses similar equations to figuring out which liquor store is going to get knocked off next.

But it goes beyond simply following crime trends. That's kids' stuff. Now they've figured out a way to actually pinpoint which specific gang is most likely to have committed a particular crime. The mathematicians, led by Andrea Bertozzi, compiled a ton of data related to gang crime from Hollenbeck, one of Los Angeles' most gang-ridden neighborhoods. They painstakingly went through police records and dug up around a thousand crimes to try to understand how exactly each gang operated.

Remember, while there are a certain number of crimes committed just for the hell of it, most of the time the criminals are doing it for a reason. This is especially true when they're members of an organization. Any organization, even an organization of high school dropouts who call themselves the East Side Skullfuckers, has goals -- they're fighting over territory, taking revenge, and so on. If you figure out what those goals are, and where they are in achieving them, you can predict what they're going to do.

So from there it was simply using the data to map out which gangs/members hated each other, who was in debt to whom, and who was overdue for a retaliation attack. When they plugged in the data for some known crimes (with the identities of the perps left out) to see if the computer could guess who actually did it, it was able to narrow down the suspects to one of three gangs 80 percent of the time (the neighborhood has about 30 gangs operating at any given time).

Holy shit, not even Batman's computer could do that. Although we can think of at least one program Bruce Wayne would find even more useful, which is the one that tells us ...

3 Where Terrorists Are Hiding Bombs

As the last, oh, thousand years of war have taught us, winning isn't necessarily as straightforward as just blowing up all the other guy's tanks and airports. In battlegrounds such as Afghanistan, the military has to deal with guerrilla tactics, where the enemy hides within the general population. It's hard to fight somebody if you don't know who or where they are until something explodes. So how do you predict the behavior of people so desperate and/or crazy that they're willing to strap bombs to themselves if necessary? Once again, with the power of math.

The University of Maryland developed software called SCARE (Spatio-Cultural Abductive Reasoning Engine) that has been consistently able to predict the locations of guerrillas' bomb caches to within half a mile, which isn't perfect, but is infinitely better than the previous "throwing darts at a map" strategy the military was forced to employ.

Because just as we saw with pop music and criminal gang scenes, hiding inside what seems like random chaos are some pretty reliable parameters. For one thing, terrorists are not likely to attack too close to home (they don't want to give away the location of their base of operations, and they're not stupid), but due to physical constraints, they're also not likely to roam too far. So right off the bat, mathematicians have a pretty good idea of what area they need to look at. But that's just the start.

The software also takes into account cultural factors such as territorial allegiances. Since different guerrilla groups may not exactly be BFFs outside of their mutual hatred of a foreign military, the areas where insurgents are active tend to be closely linked by culture or religion with the area where they keep their bomb factories.

But this kind of thing isn't just useful for tracking down terrorists. The list of potential applications includes tracking down operating bases for criminals on home soil, as well as medical diagnosis, monitoring political organizations, and presumably tracking down the home of that dog that keeps shitting in your yard.

2 How New Drugs Will Affect People

One reason why it takes so long for new drugs to hit the market is that you have to test the shit out of them -- for instance, Viagra was created in 1989, but didn't come to market until almost a decade later. You just can't predict how a drug is going to react with the insanely complex pile of chemical reactions that make up the human body; you can only test it and hope for the best. What cures cancer in mice may give a human accidental superpowers. You just don't know until you try.

But imagine if we could take everything your body does, from regulating blood to fighting infections and more, and turn all of those into math equations. Theoretically, we could run human trials on new drugs without actually having to dig up volunteers willing find out firsthand if the new flu vaccine causes them to start pissing peanut butter.

Mathematician David Eddy has laboriously gathered all the human medical data that he could and created a theoretical math person that he calls Archimedes. Of course, he needed to see whether it would react like a real human being, so he recreated a real trial for a diabetes drug. When the results came out, it was revealed that Eddy's program, a soulless black box full of hidden equations, was able to predict two of the principal findings from the study exactly. Which means that he was literally able to reduce an expensive and risky seven-year trial to numbers and bypass the whole "feed people drugs and see what happens to them" process.

And in case you're protesting that people can't be replaced by math so easily, Eddy didn't forget the human element. His Archimedes program took into account factors such as age and blood pressure, as well as fickle human flaws, such as the tendency for people to forget their pills once in a while.

Of course, this doesn't mean that we'll be replacing human trials with computers anytime soon, because putting our health in the hands of HAL 9000 is still kind of frightening, and the equation doesn't work well enough to completely replace tests on real people. But, as it stands, Eddy's work is at the very least a supplementary tool for researchers to cut down the cost and risk factor of expensive human trials. And if the occasional person still develops Hulk powers from a routine trial, then more power to them.

1 How to Keep a Crowd of People from Trampling Each Other

OK, imagine the most chaotic situation involving humans possible. You're probably thinking of a riot, or a big panicked crowd in a screaming stampede. You'll see horrific stories on the news of people being trampled every few years, like the 1979 Who concert tragedy, the Hillsborough football disaster of 1989, and more recently, the 2010 Love Parade concert in Germany that failed to live up to its name in a terrible way. How the hell is math going to help you understand the mindless insanity of a mob?

But some math geeks who study crowd dynamics did an intensive investigation of the Love Parade tragedy and found that the culprit wasn't really panic and stampeding at all, but something they're calling crowd quakes. And they are very predictable.

When people are packed into a certain density ("about seven persons per square meter," according to the study), they no longer act as individual, sentient human beings, but as a fluid, or particles in a compressed gas. Remember, when the place is packed that tight, you are in the crowd, but you can't see the crowd -- all you're looking at is the Lynyrd Skynyrd T-shirt of the fat guy six inches in front of you. You are going to move in the direction you are shoved. A guy bumps into you from behind, so you hug the guy in front of you. He edges up, and this series of gentle pushes multiplies until somebody at the front of the crowd is literally being suffocated.

That's what it's all about: pressure. If you build pressure in a container of steam, it tries to escape. If you invade the personal space of thousands of humans, they try to do the same. So managing a crowd is the same as managing steam: You do the math about how many "valves" you need and where to put them to decrease the pressure. Other suggestions include altering the shape of the "container" -- keeping the flow of traffic circular, and going in one direction. When the crowd tries to pass through itself going in opposite directions, that's when you exceed the critical density at which horrible things happen.

So, yeah, it's kind of insulting to know that science calculates our behavior similar to how it would calculate the ability of poop to move through a sewer line. But we suppose it's fine as long as it gets us out of the goddamned concert alive.

For more ways to hone your psychic abilities, check out 7 Bizarre Trends That Predict an Economic Collapse and 6 Eerily Specific Inventions Predicted in Science Fiction.

If you're pressed for time and just looking for a quick fix, then check out 3 Past Box Office Hits That Prove January Movies Suck.

And stop by LinkSTORM to learn how to get a degree from the Xavier School For Gifted Youngsters.

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