Posted: Apr 20, 2009 10:10 AM

The next big issue which President Barack Obama will have to face is the old problem of illegal immigration.

The second law of thermodynamics (or the third depending upon how you count) has to do with temperatures having a tendency to even out when two systems are touching each other.

An ice cube (system one) will tend to warm up on the floor (system two) in front of your refrigerator where you dropped and then completely forgot about it in your zeal to get a Gin & Tonic mixed and presented to the dinner guest you were trying to impress.

Because of the second law of thermodynamics the ice cube got warmer and the floor got cooler but not cold enough to refreeze the ice (because energy is lost in the transfer of heat) and you ended up slipping on the resulting puddle of water and falling onto your tush while the person you were cooking dinner for pretended not to be laughing his/her's off.

Ok. Here it is: People, like heat, tend to move toward equilibrium, in this case economic equilibrium. Those living in poorer countries often to want to move to richer countries. Having moved, they generally don't totally catch up economically with the rich people, but they are not as poor as they were before.

The 20th century population shift from rural to urban is explained by this same simple notion: People moved from the farms to the cities because that's where the jobs (and, thus money) were.

President Obama has just returned from another kumbaya fest with heads of countries, this time in our very own hemisphere, many of whom have said very bad things about us.

Just about all of them are in much deeper economic trouble than the U.S. and we are in pretty deep economic trouble.

If, as it appears illegal immigration has slowed, it is largely because of an unemployment in the United States at 8.5 percent and growing. It is not as likely that someone crossing into the U.S. will be able to find a job in 2009 as it was in 2006, so the poverty-to-wealth movement has slowed.

Mexico is our third or fourth largest supplier of oil - depending upon how much we've imported from there or Venezuela in any given month. Mexico is running out of oil. According to oilman-turned-alternative-energy-oracle, T. Boone Pickens, within five years Mexico will be a net importer of oil.

Just as the U.S. was the first to dive into this recession, it is likely we will be the first country to emerge. When that happens - to go back to our thermodynamics metaphor - there will be a rush of humanity attempting to move to the United States to find work.

That means that at the same time Mexico's economy will be moving toward utter and total collapse, the economy of the United States of America will likely be once again booming.

Now, while the flow of people across our borders has diminished, is the time for President Obama to find a rational answer to illegal immigration.

At the Summit of the Americas, President Obama promised that our dealings with our neighbors to the south would be as "equal partners."

That will not be true. Words will not change the laws of physics any more than commands and incantations of King Canute could hold back the ocean's tides.

People will move from poverty to prosperity. It is a law of econ-dynamics.