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John,
You wrote in your most recent post, �gRate-and-state theory predicts a nucleation phase lasting weeks or longer.�h

No, it does not �gpredict�h anything, because no observable phenomena allow us to check whether or not that is indeed happening. Rate-and-state ideas are speculation that is not testable.

According to your own words, �gwe scientists generally deal only in what we know�c we scientists try not to go off in untestable directions.�h

Just because the speculation is consistent and plausible does not make it a theory. As you noted, �gSome seismologists don't think such a phase even exists.�h

Your reasoning upon the Rate-and-state, as I mentioned, is consistent:
�gThe lack of a strong earthquake-tide correlation indicates there is some precursory deformation, as suggested by rate-and-state-friction, that is more important than the tectonic loading and tidal stresses in the last few days before failure.�h

However, it is meaningless, because there is no possibility of determining whether or not �gsuch a phase even exists.�h We could say just as consistently (and meaninglessly) that there IS a tide correlation, and the tide is affecting the Rate-and-state movements.

You claim that �gfew who are familiar with rock mechanic would argue�h but this just makes me wonder what kind of science rock mechanics is. Why do scientists in this field enjoy the luxury of contemplating untestable speculation and calling it theory?

Some people have posted regarding semantics of the word theory, but I thought we were talking about science and scientists. So here is a review of the basic lesson for those who have forgotten:

http://teacher.nsrl.rochester.edu/phy_labs/AppendixE/AppendixE.html
I. The scientific method has four steps
1. Observation and description of a phenomenon or group of phenomena.
2. Formulation of an hypothesis to explain the phenomena.
3. Use of the hypothesis to predict the existence of other phenomena, or to predict quantitatively the results of new observations.
4. Performance of experimental tests of the predictions by several independent experimenters and properly performed experiments.

If the experiments bear out the hypothesis it may come to be regarded as a theory or law of nature�c If the experiments do not bear out the hypothesis, it must be rejected or modified. What is key in the description of the scientific method just given is the predictive power (the ability to get more out of the theory than you put in; see Barrow, 1991) of the hypothesis or theory, as tested by experiment�c There is always the possibility that a new observation or a new experiment will conflict with a long-standing theory.
Getting back to John�fs most recent post, he wrote, �gOur precise measurement of the lack of correlation between earthquakes and tides in California supports rate-and-state theories.�h

No, it does not support anything, no matter how precise it is. There is no observable evidence to show what kinds of rate-and-state movements there might be. In fact, your measurements merely allow you to indulge in further speculation as to what unobservable movements might be going on.

�gTherefore our result gives some hope to those who think earthquakes might be predictable days or weeks ahead of time.�h

How does that follow? Is this what you call a chain of logic? You still do not even know whether or not rate-and-state movement exists, and you have no proposed method of finding out. You yourself have said that even if it does, �gthe same theory says that all of the thousands of tiny earthquakes occurring every day probably nucleate in a way indistinguishable from the way large earthquakes nucleate.�h

Clearly, rate-and-state and your result give absolutely no hope to anyone who wants to predict earthquakes (of course, hope is not taken away, either).

�gWhich part of this chain of logic do you not understand? �g

From the beginning, to the end.

{Or are you claiming comparison of observations of the time of earthquakes with the tides at those times to test a specific model of the nucleation of earthquakes is "not a hypothesis, let alone a theory"?}

This is the first time you have said you are �gtesting�h anything, and it is the first time you mentioned �ga specific model�h. Neither of these was a part of your so-called chain of logic. Neither was mentioned in the original article that Don posted, either, or in any of your posts. The article merely states, {Vidale's research supports the theory that earthquakes are preceded by a "preparatory phase"�c}, but does not say that this was your intention or objective.

So now you are saying that you had a hypothesis about a specific model of rate-and-state and that your results bear out the hypothesis? I find it pretty hard to believe that you did not say so right from the start. However, note the definition of hypothesis above, �gFormulation of an hypothesis to explain the phenomena.�h You are not proposing to explain phenomena; you are proposing to support untestable unobservable speculations about phenomena.

�gThis is the kind of data-theory comparison by which science progresses.�h

Again, there is no theory. Apparently there is a model derived from untestable speculation. Also apparently your results do not contradict that model. But you are left with nothing but consistency and plausibility. That is not how science progresses.

Ara