This is a red herring. The argument for dark matter/energy need not be inductive. The inductive form is:
o we've defined the set based on the laws of physics we've observed o everything is in this set o gravity seems stronger/weaker than predicted in some contexts .: there are unobserved members of the set: dark matter and energy. A non-inductive argument for dark matter/energy is just as valid: o the model we've induced is not completely consistent with the data o the laws characterize everything we've encountered so far .: there must be something we haven't encountered that will refine the laws. No induction is necessary to motivate a hypothesis for some form of matter that's imprecisely or inaccurately described by the laws we've, so far, induced. But parsimony suggests that a theory that assumes it's complete is more testable than a theory with metaphysical holes in it. So, the argument for dark matter _seems_ inductive, even though it's not. Only someone who assumes our laws are complete (fully refined) would think the argument is inductive. My sample is small. But I don't know of any physicists or cosmologists who think our laws cannot be modified. I.e. it's naive to assume identity between a scientific theory and the reasoning surrounding the pursuit of a scientific theory. Douglas Roberts wrote at 03/24/2012 03:08 PM: > There's also an interesting "dark matter" inference that has found its > way into grudging cosmological acceptance. This time the role of the > inferred substance is to keep galaxies from flying apart, as it has > recently been observed that based on the amount of their measurable, > observable mass and rotational velocities, they should flung their stars > off ages ago. > > --Doug > > > On Sat, Mar 24, 2012 at 3:16 PM, Douglas Roberts <d...@parrot-farm.net > <mailto:d...@parrot-farm.net>> wrote: > > I feel that I am being drawn in to an enemy encampment, but: > > Developing a proof would be far better than choosing to rely > on inference, if the goal is to develop a larger-scale understanding > of a system. > > Take "dark energy" as an example. Its presence is inferred from > having observed that the rate of expansion of the observable > universe began to accelerate relatively recently, on a cosmological > time scale. In response to this, the cosmologists have inferred the > existence of a mysterious energy with magical gravitational > repulsive properties as a means to explain away an otherwise > inexplicable observation. A much more satisfying approach will be > to develop a sufficient understanding of the underlying physics of > our universe from which a rigorous proof of the phenomenon could be > derived. > > But, without that understanding, we are left with cosmological > "magic dust", instead of a real understanding of the observed dynamics. > > --Doug -- glen e. p. ropella, 971-222-9095, http://tempusdictum.com ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
