street-fighting-mathematics

Table of Contents

Fighting Mathematics

Street Fighting Mathematics

Chapter 1 Dimensions

1.1 Economics: The power of multinational corporations

Read this quote: what is wrong with it?

In Nigeria, a relatively economically strong country, the GDP [gross domestic product] is $99 billion. The net worth of Exxon is $119 billion. “When multi- nationals have a net worth higher than the GDP of the country in which they operate, what kind of power relationship are we talking about?” asks Laura Morosini.

GDP is shorthand for Gross Domestic Product, or the monetary flow of $99 billion a year. The net worth of Exxon is $119 billion, which is the worth of the assets held by Exxon. Comparing Products Created/Year to Assets is an apples to oranges comparison.

Consider if we used GDP/decade, wherein Nigeria would have ~$1 trillion in GDP/decade, and Exxon would still be worth $119 billion, in which case Exxon is much smaller than Nigeria;

If we used GDP/week, then Nigeria would be very small in comparison, at ~$2 billion in GDP vs the $119 billion of Exxon.

A dimension is general, and independent of the system of measurement, whereas a unit is how that dimension is measured in a particular system.

Problem 1.1

Are meters, kilograms, and seconds units or dimensions? What about energy, charge, power, and force?

Meters, kilograms, and seconds are dimensions.

This comparison can be made better by saying that by 2006, Exxon Mobil’s revenues were $350 billion, which is twice as big as Nigeria’s 2006 GDP of $200 billion. Exxon Mobil is definitely larger.

Problem 1.2

Finding bad comparisons:

Look for everyday comparisons—for example, on the news, in the newspaper, or on the Internet—that are dimensionally faulty.

1.2 Newtonian mechanics: Free fall