Critical Mass, Length, Temperature Many systems and processes—whether in nature or society—can appear unchanging until they reach a certain transition point, after which their behavior shifts dramatically. Think of disease outbreaks, the spread of information in a network, or battery failures in electric vehicles. Let’s go through some examples. ...
Do you trust your calculations? This book review is about The Los Alamos Primer, the first lectures on how to build an atomic bomb, by Robert Serber. The review focuses on the basic calculations and physics knowledge of the Manhattan Project scientists. Since the Primer is a collection of 1943 lecture notes combined with Serber’s hindsight commentary, it corrects some of the original calculations and measurements by comparing them with modern values. This makes it fascinating to see how close—or off—the physicists were at the time. For anyone interested in the topic, I highly recommend reading both the Primer and The Making of the Atomic Bomb by Richard Rhodes, one of my all-time favorite books. ...
Unexplainable Differences? This book by Daron Acemoglu and James A. Robinson, published in 2012, explores why living standards and prosperity differ so much across societies that seem to share common geography or culture. Many theories, such as those based on geography, culture, or ignorance, suggest these differences should not be so large. Yet, as the authors show, a simple fence can separate success from failure. A key example in the book is Nogales, a city split by the border between the USA and Mexico. In the northern section, Nogales, Arizona, people enjoy a higher standard of living, better life expectancy, and strong property and voting rights. Just across the fence in Nogales, Sonora (Mexico), people face weak education, higher child mortality, political corruption, and average household incomes that are about a third of those in Arizona. Further similar examples from the book include the difference between North and South Korea, the United States and Russia, or parts of Europe and sub-Saharan Africa. ...
What is it? Why is it interesting? Consider a toy example of a gamble. Someone offers you a game where a fair coin will be tossed: you will win 70% of the money you bet when heads comes up and lose 60% of the money you bet when tails comes up. Furthermore, you are offered the opportunity to play this game many times, although not arbitrarily often, say just once a day. Intuitively, this gamble seems favorable, especially when you are allowed to play it repeatedly. However, it becomes trickier when you ask yourself questions like, “How much of my total wealth should I bet?” and “What is the best strategy to maximize my long-term wealth, say over 10 years?” The Kelly Criterion provides the answer to these questions! ...