I don't recall seeing you before, so if you are new, welcome.
Neal K. Roys wrote:
> Jonathan Clarke wrote:
>
> >Science is a very difficult thing to define.
>
> >I have erected the following taxonomy.
>
> [....]
>
> >and the verifiability of results.
>
> The two glaring omissions in Jonathan's taxonomy are the words
> "testability" and "falsifiability."
You are quite right. However I was trying to encapsulate these two useful
concepts in the term "verifiability". If this was clumsy of me, I apologise.
I plead writing before breakfast in a state of hypocaffeinaemia and
hypoglycemia (as I am now).
> Marxism and Freudianism, which came out about the same time as Darwinism,
> were originally thought to be sciences. But when it was realized that they
> weren't testable, they were relegated to the realm of philosophy.
These may be philosophical systems but I think philosophers would be somewhat
irate at the thought that the criteria for something being "only" a
philosophical system was that it was not testable!
> You can know if something is testable or not by checking to see if *both* a
> verification scenario *and* and falsification scenario exist.
We must be very careful with falsification. Explanatory power is of equal or
greater importance. Omnipotent explanatory theories are to be avoided,
however. They explain everything and thereby nothing. It is very easy to use
Popper naively, and its utility declines as the scope of the theory increases.
For example:
hypothesis: this rock is a limestone
test: does it fizz when you put 10% HCl on it?
answer: yes (it is a limestone) OR no (it is not a limestone)
At this level Popper works superbly is falsifiability is a vital winnowing
tool.
More complex theories are pose greater difficulties.
hypothesis: The XYZ formation is a lacustrine shale (based on sythesising a
wide range of evidence)
test: certain marine fossils (sharks, forams) are then found in the XYZ
formation.
Does this falsify the lacustrine hypothesis? In theory yes, in practice on
possibly. The lacustrine hypothesis was formulated (in this case) because of a
considerable body of evidence, there might be ways of getting marine sharks and
forams in lacustrine sediments (bull sharks, a marine species, live in central
american fresh water lakes, a marine foram lives in Lake Eyre in central
Australia). The explanatory power of the lacustrine hypothesis is such that a
certain amount of inconsistencies can be accepted. Only to a point of course.
If more and more evidence for non-lacustrine conditions turn up in the XYZ
Formation then alternative explanations must be sort.
A real example is Newtonian gravity. I understand this was falsified quite
early on by its inability to account for the motions of Mercury. Newtonian
gravitation persisted for several reasons, lack of an alternative (until
Einstein) and it's explanatory power. It explained so much that it had to be
a good approximation and the motions of Mercury were aberrations that needed
further research. Should Newtonian gravity been rejected when the motion of
Mercury falsified it? No. Should it provided an agenda for further research?
Yes. The motion of Mercury was one of the problems that led to relativity and
the success of relativity in explaining it was a major demonstration of it's
success.
> Generally evolution education intoxicates students with verification
> scenarios and never even defines what the falsification scenario looks
> like. Consequently, no test could ever falsify evolution because
> falsification is undefined.
>
> Does anyone here have a *falsification* scenario for the following claim?
>
> "The cambrian explosion was caused by ____________(fill in here your
> naturalistic mechanism of choice)"
>
Easy! "The cambrian explosion was caused by mass extinction of the proceeding
vendobionts, leaving vacant niches". This is testable by looking at the
stratigraphic distribution of vendobionts (Ediacara fauna) and the Cambrian
fauna (I believe this hypothesis has been falsified). or "The cambrian
explosion was caused by changes in global ocean chemistry allowing
biomineralisation". This is more difficult to establish a casual link, but you
would look to see if there are any changes in global ocean chemistry from the
Late Neoproterozoic into the Cambrian, as reflected by its proxies (abundance
of chert, , ironstones, phosphorites, carbonates, carbonate mineralogy and
chemistry, carbon, oxygen isotopes, etc.) etc., etc. etc.
> If no falsification scenario exists then instead of being categorized as
> science, Punctuated Equillibrium is an untestable philosophical claim.
>
> A speculation.
Punctuated equilibrium is a methodologically easily, though labour intensive,
to falsify. You just have to collect enough case studies of the duration of
speciation events vs longevity of the species. As I recall, in the punctuated
equilibrium model, speciation events generally last for only 1-2% of the
species duration. claim. It can also be tested experimentally by ecological
studies of the rate of evolutionary change over successive generations it
takes to adapt to a new niche. I recall reading recently (in New Scientist I
think) that in such studies something like 90% of adaptation occurs within a
1000 generations, followed by very slow and decreasing change thereafter, until
a new niche presents itself.
> Neal Roys
> Math Teacher
> Stevenson High School
> Lincolnshire, IL
> Youth Pastor
> Vineyard Community Church
> Mundelein, IL
God Bless
Jonathan