DNUEarlier this year, Mathematician Ian Stewart came out with an excellent and deeply researched book titled "In Pursuit of the Unknown: 17 Equations That Changed the World" that takes a look at the most pivotal equations of all time, and puts them in a human, rather than technical context.

We asked Professor Stewart why he decided to do this book:

"Equations definitely CAN be dull, and they CAN seem complicated, but that’s because they are often presented in a dull and complicated way. I have an advantage over school math teachers: I’m not trying to show you how to do the sums yourself. You can appreciate the beauty and importance of equations without knowing how to solve them..... The intention is to locate them in their cultural and human context, and pull back the veil on their hidden effects on history. Equations are a vital part of our culture. The stories behind them --- the people who discovered/invented them and the periods in which they lived --- are fascinating."

This should be particularly relevant to anybody affected by the financial crisis.

Click here to see the 17 equations >

Black Scholes, a derivative pricing equation and number 17 on this list helped cause it. 

From an email exchange with Professor Stewart:

"It’s actually a fairly simple equation, mathematically speaking. What caused trouble was the complexity of the system the mathematics was intended to model.... You don’t really need to be a rocket scientist to understand that lending hundreds of billions of dollars to people who have no prospect of ever paying it back is not a great idea...."

People took a theoretical equation too seriously, overreached its assumptions, used it to justify poor decisions, and built a trillion dollar house of cards on it. This made the crisis inevitable:

"I think that the crisis became inevitable once the financial instruments being traded in gigantic quantities became so complex that no one could understand either their value or the risks they entailed. When markets trade real goods for real money, excesses can only grow to the limits of what is actually out there. When they trade virtual goods (derivatives) for virtual money (leverage), there’s no real-world limit, so the markets can gallop off into Cloud Cuckoo Land."

You can buy the full book here.