No analyst can give precise answers to questions about the future of the stock market or the economy and be right all the time. This is the realm of prophecy or fortune-telling, not scientific analysis. On the other hand, it is not true that the future is completely unpredictable. As I write this sentence in January 2000 the temperature outside is well below freezing. If you were to ask me to predict whether it will be warmer or colder next Tuesday, I would be unable to give a correct answer. However, if you asked me what sort of temperatures to expect on April 9, I could predict warmer than today and almost certainly be right.
You can make this prediction too. How? We can confidently make this prediction because we know that April is a warmer month than January. But what are April and January? They are points in time as marked by our calendar. A calendar is a cyclical model for interpreting time in terms of the seasons. Consider the situation of a farmer. If he plants too early a late frost may destroy his crop. Too late, and he wont get a harvest. It is critical that the farmer properly times his planting with respect to the seasons. In Neolithic times the entire community depended on agriculture, and hence, on the seasonal rhythm of the weather. The entire economy and the livelihood of everyone were determined by seasonality. A model for interpreting time in terms of seasonality that would permit prediction of planting times would be incredibly useful information for any Neolithic society. The development of that model, what we now call the calendar, was one of the seminal accomplishments of Man.
Now what precisely is the calendar? The calendar is a model of the seasonal cycle that uses the positions of celestial objects to measure the current position in the cycle. It has always been apparent that the length of the day and the seasons are correlated. Days are short in the winter and long in the summer. People discovered that the positions of the sun and stars change with the length of the day and the seasons. By making simple celestial observations ancient peoples were able to measure the length of the seasonal cycle (or year) and found it to be about 365 days long.
The actual length of the year is 365.242199 days, so a 365-day calendar year is about 6 hours too short. The ancients were aware of this and so they constructed calendars in such a way that the average length approached the correct length of the year. In a way calendars represent a measurement of the length of the year. The accuracy of this measurement by pre-modern peoples is quite impressive. Most peoples of antiquity used calendars that implied a length of the year of around 365.25 days. For example, the Julian calendar, upon which our modern calendar is based, used the leap year concept in which every fourth year is 366 days long instead of 365 days. This calendar was based on an estimate of exactly 365.25 days for the year, which is 11 minutes too long. Now this seems pretty accurate, but this 11 minute discrepancy adds up over time, making the Julian get ahead of the seasons (what it is supposed to measure) by one day every 130 years. The Julian calendar was introduced in 46 BC. By the sixteenth century it had gotten twelve days ahead of the seasons, which was starting to have an impact on its seasonal timing function. Pope Gregory implemented a new calendar in 1582, which we use today. The Gregorian calendar implies a year of 365.2425 days, which is still 26 seconds too long. The Gregorian calendar represents a measurement of the length of the year to better than one part per million. The ancient Mayan calendar year was even more accurate.
Societies over the millennia have taken their calendars very seriously. They have constructed elaborate observatories (e.g. Stonehenge) for making precise celestial observations in the effort to design accurate calendars. This effort was justified because it was apparent that calendars worked to predict the future of an agricultural economy and more accurate calendars worked better. But no one really understood why calendars worked. The most plausible explanation for correlation between the seasonal cycle and the stars was that the gods caused both. The intent of the gods might be interpreted by study of the stars, and the evidence certainly supported this idea. Since the gods controlled the heavens and earth, it was reasonable that they controlled the lives of mere mortals too. Since the will of the gods for the seasons was revealed by the heavens, surely the will of the gods for the insignificant details of a persons life were revealed by the heavens as well. Thus was born the science of astrology.
The ancients held both astrology and the calendar as equally valid. Then came Copernicus, Kepler and Galileo, and people discovered why there was a linkage between the stars and seasons. The seasons are simply the natural consequence of the fact that the earth revolves around the sun and that the earths axis of rotation is tilted with respect to the plane defined by the earths orbit. All of a sudden, it became clear that the calendar should work and that it is completely natural that it does. However, this mechanical arrangement of the earth and sun did not provide a mechanism for why astrology should work. Furthermore, the track record of astrology had never been as reliable as the calendar. Deprived of the support of the obvious validity of calendrical methods, astrology lost its status as a science.