I am currently reviewing scientific notation with my Barron's text. I am very pleased so far with this text because it is explaining some totally fundamental things to me that I never learned. I should have started physics directly with this text rather than going to other, more cursory introductory texts. For instance, it has explained to me that some labels of measurements are considered fundamental, like meters and kilograms and seconds, and other measurements are made of ratios of these quantities, like meters per second, square meters, or kilogram per cubic meter. When I first encountered these composite quantities, I was mystified as to why two disparate measurements were being "mixed" together.

Similarly, with scientific notation, though I was already familiar with the concept and had worked with it before, I had wondered how one does addition and subtraction with numbers in this form. When I asked a Friendly Mathematician how this was done, he replied that you "normalize" the numbers and make their exponents of 10 the same. I had no idea how to do this, until the book explained it to me. The decimal point moves back and forth, and you can increase or decrease the ten exponent by moving the decimal point on your number. My mnemonic is one of contrary motion. If the decimal point moves one point to the left, the exponent increases in volume by one. If the decimal point moves to the right, the exponent decreases in volume. If it's a negative exponent, you have to remember that an increase in volume means that the "number" goes down, as in -3 going down to -2. And vice versa. That's how you normalize.

Books are patient, books are kind. They stay up with you all night and never complain that you are taking up too much of their time. They are never too busy to help you. They don't complain about being insulted and they rarely (if they are well-written and helpful books, that is) make you feel belittled or stupid. A book will not condescend or laugh at me because I am doing the most basic things over again. And you can work with a book at your own pace. My own pace, in physics, has been exceedingly slow. I also have a very narrow point of attention; big spreads of information intimidate and frighten me. I once said to a Live Physicist that I am learning physics one electron at a time. He replied that this would mean that the time-span of my learning physics would exceed the projected life-span of the entire universe. Well, it may indeed take me that long to get to any kind of advanced physics. But I might as well start where I am, and keep going.

Posted at 1:40 am | link