Brights Lights, Big Cities

Light pollution and earthbound constellations

Growing up in northern San Diego county, I had the unique opportunity to be only 30 minutes from the Pacific Ocean and 60 minutes from Mt. Palomar. For my money, I preferred treks up the 5,600 foot peak more than to the beach. One reason was the Mt. Palomar Observatory, which was once the largest telescope in the world and is still used today to track down objects in outer space.

Proximity to the Palomar Observatory was good for me, it was bad for astronomers. Widespread light pollution from nearby growing cities in San Diego county reduced the ability of Palomar to capture as crisp as pictures as it might have otherwise. It's a problem facing telescopes all over the world.

Although that stray city light obfuscates views of the heavens, it has proved useful in illuminating (no pun intended) things down here on Earth. Just as starlight is a telltale of the powerful thermonuclear engines at work inside stellar bodies, so Earth-observing scientists at NASA found that shining lights from Earth gives clues about the engines driving the world's economy. They found that city lights very good indicators of urbanization.

We're not talking about population, mind you. China and India combined have ten times the number of citizens as the U.S., but those countries are far dimmer at night thanks to fewer modern, electrified cities. When analyzing what I'll call "ground constellations" across the U.S., the scientists found great concentrations of light.

The brightest groupings came from those (pesky) cities that leave their lights on all night long. And it became quite evident that cities formed clusters that didn't fit neatly into city, county, state or national boundaries. The U.S. Census has no official term to describe large urban complexes beyond combined statistical areas, consisting of metropolitan areas that are economically interlinked, and, consequently, no way of measuring them. Clearly there was something that needed measurement, however.

These mega cities were not limited to just the U.S. There appeared to be as many as 20 supersized metropoli across the face of the planet. Obeservers of census data also were discovering evidence for such uber-urban areas. Robert Lang, a professor at the Metropolitan Institute at Virginia Tech, explains that as far back as the 1960s, Jean Gottman pointed out the existance of a "megapolitan" centered on New York City and surrounding metros in the Northeast. Although distinct cities, they could also be thought of as a single mega city.

Lang decided to use the same term to describe the supercities he discovered through his own research, which he encountered working through Census data from the ground up. He initially discussed 10 megapolitans in the U.S., but has since refined his list to 20. He's even written a book on the subject, due out the summer of 2007. Alternatively, the America 2050 initiative has adopted its own criteria to describe America's megas, based on the Regional Planning Association's (RPA) defintions. It has ten, very similar to, if not the same as, Lang's original list. The two systems are now pretty much integrated, with Lang's 20 megapolitans forming the constituents of the RPA's 10 mega regions.

The lone exception may be that the RPA includes Minneapolis-Saint Paul as part of the Great Lakes mega region, and Lang does not. Having lived in the Twin Cities for many years, I believe that they do indeed belong to a Great Lakes mega. Chicago represents the hub of the Midwest. In fact, the state of Minnesota's Department of Transportation studied air cargo transport (important for high-value manufacturers such as the medical device makers that dominate the Twin Cities business landscape). They found that 90% of air cargo in the region is shipped to Chicago's O'Hare Airport, rather than from MSP International.

This concept of megapolitans and mega regions is taking off. There's an increasing number of organizations looking into "megas" to see how to leverage them to enhance the economic productivity and performance of local areas. .:.