Population statistics are like crystal balls — when examined closely, they can help predict a country’s future (and give important clues about the past). Kim Preshoff explains how using a visual tool called a population pyramid helps policymakers and social scientists make sense of the statistics, using three different countries' pyramids as exa...

As of 2018, there are around 2.5 billion smartphone users in the world. If we broke open all the newest phones and split them into their component parts, that would produce around 85,000 kg of gold, 875,000 of silver, and 40,000,000 of copper. How did this precious cache get into our phones--and can we reclaim it? Kim Preshoff investigates the s...