Читать книгу Physics I For Dummies - Steven Holzner - Страница 41

Richard Feynman was a famous Nobel Prize winner in physics who had a reputation during the 1950s and ’60s of being an amazing genius. He later explained his method: He attached the problem at hand to a real-life scenario, creating a mental image, while others got caught in the math. When someone would show him a long derivation that had gone wrong, for example, he’d think of some physical phenomenon that the derivation was supposed to explain. As he followed along, he’d get to the point where he suddenly realized the derivation no longer matched what happened in the real world, and he’d say, “No, that’s the problem.” He was always right, which mystified people who, awestruck, took him for a supergenius. Want to be a supergenius? Do the same thing: Don’t let the math scare you.

In physics, the ideas and observations of the physical world are the things that are important. Math operations are really only a simplified language for accurately describing what is going on. For example, here’s a simple equation for speed:

In this equation, v is the speed, s is the distance, and t is the time. You can examine this equation’s terms to see how this equation embodies simple common-sense notions of speed. Say that you travel a larger distance in the same amount of time. In that case, the right side of the equation must be larger, which means that your speed, on the left, is also greater. If you travel the same distance but it takes you more time, then the right side of this equation becomes smaller, which means that your speed is lower. The relationship between all the different components makes sense.

You can think of all the equations you come across in a similar way to make sure they make sense in the real world. If your equation behaves in a way that doesn’t make physical sense, then you know that something must be wrong with the equation.

Bottom line: In physics, math is your friend. You don’t need to get lost in it. Instead, you use it to formulate the problem and help guide you in its solution. Alone, each of these mathematical operations is very simple, but when you put them together, they’re very powerful.