RE: Post-Empiricism Science: A little surprised

From: Brian Harper (
Date: Thu Sep 18 2003 - 16:30:25 EDT

  • Next message: Steve Petermann: "Re: Fragility and tendentiousness"
    At 02:59 PM 9/18/2003 -0400, Alexanian, Moorad wrote:
    The distinction between the theories of Ptolemy and Copernicus was not merely aesthetic.  Simplicity plays a major role.  The behavior of a double pendulum can be predicted, the equations are deterministic. However, long-range predictions are difficult to obtain but can be obtained in principle---deterministic chaos.


    Cosmology is akin to forensic science. It is more deductive than inductive.  Just like evolutionary theory but unlike physics, which is an experimental science. Of course, cosmologists do use all that physicists can provide but there is more to it since one is dealing with a unique event.


    First regarding Ptolemy I could point out that Copernicanism as originally formulated was not really simpler since it also required epicycles to obtain predictions as accurate as Ptolemy. I could also quibble that simplicity is aesthetic. But the main point is that we apparently agree that predictive capability was not the main concern.

    The double pendulum cannot be predicted (for very long) in practice. What happens in principle is of little use. It is like a reductionist arguing that evolution can be predicted in principle. Given enough information and a big enough computer etc. etc. To say that the double pendulum can be predicted long term in principle just begs the question regarding the accuracy (predictive capability) of the model.

    This archive was generated by hypermail 2.1.4 : Thu Sep 18 2003 - 16:32:10 EDT