Up in the air, scientifically

Once the initial fascination for planes and flying wear off, air travel turns monotonous. Unlike in train journeys, which are usually day-long affairs, on a flight, you don't get the time to connect with fellow travellers, see the changing landscape or explore numerous stations en route your destination. However, plane journeys can be equally interesting, contends Brian Clegg, author of Inflight Science, which draws attention to the science surrounding air travel. At the security check-in, during take-off, inside the aircraft, and the sights outside among the clouds — there are enough things to keep the mind engaged. Take, for instance, the most basic fact that we encounter while in air — flying. How does the plane manage to stay in the air? The engine is powerful enough to provide acceleration and we vaguely know that wings have something to with it. But exactly what? Clegg suggests an experiment. Fold an A4-size paper first along its length and then its breadth. Tear it into two halves and hold one of the halves at one end so that the paper droops. Now blow over the surface. Instead of drooping further, the paper will rise. The same principle applies to the wings of a plane. The reason, Clegg explains, is that a wing is shaped in a way that it changes the direction of the wind blowing over its surface downwards. As per Newton's third law of motion, every action has an equal and opposite reaction. The downward acceleration of the wind in turn gives the wing a lift, keeping the plane in air. Not every fact Clegg shares has to do with physics. Radars, for example, are crucial for navigation. This technology was deployed by the Royal Air Force during the Second World War, which helped British pilots fly in the night. To keep the technology a secret from the Germans, British authorities spread misinformation that eating a lot of carrots improved their pilots' vision. Then, there are the things you can see outside the aircraft window. Here, the scope of the book expands — from the bottom of the ocean to the distant galaxy. While the facts by themselves hold your attention, the writing is inconsistent. At times, the book reads like a textbook. This is apparent in the part where Clegg explains why rivers meander. No doubt, this is a fascinating question, but a person less inclined towards science will find it difficult to keep up with the discussion on angular momentum. The section on clouds doesn't go much beyond defining each cloud type. You get a feeling that in a bid to cram too many facts, there isn't enough space to get into the details — especially of the more complicated phenomenon. Despite these failings, the book presents science in a scenario you can relate to.