Posted by
glen ep ropella on
Mar 26, 2012; 5:40pm
URL: http://friam.383.s1.nabble.com/Just-as-a-bye-the-way-tp7397553p7406840.html
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 <
[hidden email]
> <mailto:
[hidden email]>> 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,
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