This article on deterministic chaos is a nice introduction to the concepts behind it.

The main point here is that - a system is

The most famous illustration of this is the "butterfly effect" described by Lorentz while studying the equations that determine the weather. The weather is a chaotic system where outcomes are strongly dependent on the initial conditions. The tiniest fluctuations in air pressure in one part of the globe may have the most spectacular effects in another part. Thus, a butterfly flapping its wings somewhere in Chicago may cause a tornado in Tokyo.

I present all of this to suggest that astrology is a predictive model of a chaotic system. They rely on initial conditions (with birth time and location of various planets and constellations) and work on the assumption that small changes in the initial condition can have large effects on the life of the individual.

But there is more to these systems that that. Chaotic systems come in two shapes (source: Sapiens: A brief history of humankind). The weather, for example, is a level one chaotic system. Level one chaos is chaos that does not react to predictions about it. Though it is influenced by myriad factors, we can build computer models that take more and more of them into consideration, and produce better and better weather forecasts.

Level two chaos is chaos that reacts to predictions about it, and therefore can never be predicted accurately. Markets, for example, are a level two chaotic system. What will happen if we develop a computer program that forecasts with 100 per cent accuracy the price of oil tomorrow? The price of oil will immediately react to the prediction and would consequently fail to materialise. (The mere act of predicting affects the outcomes)

Life, like markets are level two chaotic systems and the mere act of knowing your prediction based on horoscope reading immediately alters the system, rendering the prediction meaningless.

The main point here is that - a system is

*deterministic*if its current state completely determines how it will behave in the future. A simple pendulum is not chaotic and its motion can be described by a simple equation. A double pendulum on the other hand is a chaotic system where the motion of the system is extremely sensitive to changes in the initial conditions. This is the essence of non-linearity: effects are no longer proportional to causes and even small causes can produce large effects.The most famous illustration of this is the "butterfly effect" described by Lorentz while studying the equations that determine the weather. The weather is a chaotic system where outcomes are strongly dependent on the initial conditions. The tiniest fluctuations in air pressure in one part of the globe may have the most spectacular effects in another part. Thus, a butterfly flapping its wings somewhere in Chicago may cause a tornado in Tokyo.

I present all of this to suggest that astrology is a predictive model of a chaotic system. They rely on initial conditions (with birth time and location of various planets and constellations) and work on the assumption that small changes in the initial condition can have large effects on the life of the individual.

But there is more to these systems that that. Chaotic systems come in two shapes (source: Sapiens: A brief history of humankind). The weather, for example, is a level one chaotic system. Level one chaos is chaos that does not react to predictions about it. Though it is influenced by myriad factors, we can build computer models that take more and more of them into consideration, and produce better and better weather forecasts.

Level two chaos is chaos that reacts to predictions about it, and therefore can never be predicted accurately. Markets, for example, are a level two chaotic system. What will happen if we develop a computer program that forecasts with 100 per cent accuracy the price of oil tomorrow? The price of oil will immediately react to the prediction and would consequently fail to materialise. (The mere act of predicting affects the outcomes)

Life, like markets are level two chaotic systems and the mere act of knowing your prediction based on horoscope reading immediately alters the system, rendering the prediction meaningless.