One of my favorite science-based apps is The Elements in Action, which costs $4 on iOS. You will probably remember the periodic table, where all 118 known elements — like hydrogen and helium, and including weird radioactive elements like einsteinium — are set out in a grid. The elements are the basic building blocks of everything you see around you. This app brings 79 of the elements to life through videos that show some of their more amazing characteristics. For example, strontium is a metal that is soft, easy to cut and is so fiercely reactive in air that it quickly turns into an ashy white powder, as demonstrated in one of the app's videos. Each video is accompanied by clearly written text that gives more details about the element's characteristics. The Elements in Action is easy to navigate and attractively designed. It is not going to bring you to a Ph.D. level in chemistry, but it can definitely teach you about dangerous elements, like mercury, without the risks of experimenting on your own. Physics is sometimes called the mother of all sciences because its grand aim is to explain everything, including chemistry and other sciences. Learn Physics, whose basic version is free on iOS andAndroid, can help people master the basics. The app takes a tutorial approach, breaking down subjects like Newton's laws of motion into smaller parts and explaining them, a bit like an intelligent textbook. There are clear diagrams that accompany the text and you can test your knowledge by trying the interactive quizzes in each section. To help you understand some of the math, there's a built-in calculator that lets you test out different values when you're trying to figure something out. The app is definitely not the prettiest and it does sometimes feel dry, and the embedded ads can get annoying. It also requires you to have at least a working knowledge of math. But it does cover a range of topics, like magnetism and thermodynamics. The full app is $1. To gain an appreciation of how much science goes into everyday things, check out the Journeys of Invention. This is a$10 iPad app that is jammed with information about the workings and history of a long list of inventions, like the telegraph and the lunar landers of the Apollo space program. The idea is that by looking back through the history of science and invention, you can see how earlier ideas led to modern ones. For example, we would not have movie theaters without the magic lantern invention of the 17th century. Journeys of Invention uses photos, text and video to tell its many stories and to bring complex ideas alive in an interactive and modern way. Sometimes the explanations feel a little thin, and you will definitely find that you exit the app from time to time to do some web searches. For a deeper and more traditional educational science app, look no further than Khan Academy. This online learning app uses narrated videos to teach topics like physics and chemistry, with each science broken down into smaller subjects like evolution or nuclear chemistry. Khan Academy contains hour upon hour of high-quality lectures that may feel more approachable than any science lesson. A lot of the ideas in the app are complex and there is, unavoidably, some tricky math involved. But because you can switch among the different lessons at will, and stop the videos to look things up elsewhere, the app doesn't feel overly heavy or intellectual. The app is free oniOS and there's also a free unofficialAndroid viewer app. One great way to get children interested in science is through astronomy; stars are instantly fascinating. The Star Walk Kids app, which is $3 on iOS andAndroid, is an interactive sky map that tells you what you're looking at when you point your phone's camera at the night sky. It's intuitive to use, and you can learn more about sky objects, like planets, by tapping on them when they appear on screen. Star Walk Kids is slick, fun and its cartoony graphics can almost certainly teach little stargazers a thing or two.
