The success of models developed by physicists and chemists has led to the rapid development of modern technology, the conquest of much disease resulting in increased life expectancy, and the improvement of human lives on Earth. But over reliance on flawed models can create tragedies of epic proportions. It is crucial to learn from physicists the lesson they term uncertainty.
Comparing the harsh, short lives of feudal peasants of medieval Europe with a typical life in a
developed country today, it is indisputable that science and the resulting technology have radically improved human existence. Much of this occurred because scientists developed models that matched the behavior of the known universe. With confidence supported by successful predictions based on these models, the human race used that understanding to modify our environment to make life better. We molded the materials of our world to improve comfort, transportation, communication, and other human needs.
A bit over two centuries ago Europeans developed a model assuming that the material universe is composed of particles. A century later the model was modified to add that these particles were moving under restrictions termed energy. The various forms of energy, governed by the laws of thermodynamics, describe how particles must behave and provide ways that humans can influence and control our world. For example, if a person expends more energy than their caloric food intake, that person must, at least temporarily, loose weight. Or if sufficient 235U is assembled, a nuclear reaction will occur creating an atomic bomb. The model and their laws require that if certain things are done, there will be known consequences.
No matter how successful a model has been, scientists realize there may be aspects of the world the model fails to explain, or worse, predicts incorrectly. Scientists spend much effort probing the edges of their models to find flaws and make corrections. In addition, typically there are limitations on prediction accuracy due to poor measurements or sometimes fundamental uncertainty required by nature. Scientists and engineers know it is unwise to base life endangering decisions beyond what a model can accurately predict.
baby pictureof the universe using microwave light captured from 380,000 years after the Big Bang: it is the equivalent of taking a picture of an 80 year old person showing the day of their birth. (They used the long known fact that while light travels fast, it still takes some travel time. Light coming the greatest distance carries information from long ago.) the WMAP team found evidence that will require a greatly expanded model of the universe:
start of the Universecalled the Big Bang.
quintessence.But quintessence is not ruled out.
While non-scientists often find understanding science to be difficult and view many new discoveries as controversial, scientists are more likely to find beauty in the simplicity of the models needed to understand the physical universe. But scientists remain aware that those models may be inadequate or contain errors despite their simplicity and beauty.
In the past century it has become increasingly popular to try to develop models for the much more complicated human behavior and the behavior of groups of people. Tragedies occur when life changing or threatening decisions are based on flawed models. Millions died as a result of Hitler's model of human abilities and behavior which predicted the superiority of people from north Europe and the inferiority of people with Jewish ancestry. Cambodia and central Africa provide other recent examples.
While there is increasing evidence that viewing violence encourages some people to behave violently, the United States has hesitated to restrict viewing violence by individuals, even minors. But some groups of people believe that knowing an individual's past behavior and interests allows then to know for certain that individual's future behavior. While current models suggest a person with a habit of past criminal behavior may re-offend, the connection between interests and behavior is less certain.
On a larger scale, the United States government believes it can understand the behavior of foreign governments and their rulers sufficiently so that they can predict future behavior, thus requiring preemptive military actions. There are grave risks in a government believing that their model of human behavior so accurately anticipates future behaviors that it justifies restricting what previously were legal thoughts and behavior of individuals or justifies war with other countries.
Creating and using models is one of the most powerful tools ever developed. But the use of such powerful tools requires a constant reminder of the uncertainty inherent in the tools. History shows that our models often need to be revised and improved as new information is discovered. But powerful models can result in tragedy when people act as if imperfect models are absolutely right.