( .. an animated description of "what you see is what you get" .. )
Earth expansion is an observation of how things actually are, contextualised through crustal evolution over geological time since the Mesozoic. Plate Tectonics is a hypothesised denial of this on grounds of "No known mechanism". It is nothing less than a celebration of ignorance.
1. Destruction of the ocean floors. We might (with Earth expansion) say that Plate Tectonics should begin with the creation /extrusion /emplacement of the ocean floors, because after all something must be created before it can be destroyed.
But creation is not where Plate Tectonics begins. Nor does it really begin with the destruction of the ocean floors. It begins with the *perceived need* for their destruction (J.O.) It's a subtle difference that shifts the emphasis from the fact to the perception of the fact. The destruction itself is arguable, but for Plate Tectonics the *perceived necessity* for destruction is very real.
So the case for Plate Tectonics does not rest in the facts themselves, nor exactly in the way they are interpreted (though this is somewhat closer), .. but in the way they could be perceived to be structured in the first place - *IF...* (and it's a very big 'IF' ) in order that they *can* be interpreted as desired.
The way I read it (as outlined in earlier posts), it begins exactly where the website of the USGS says it begins, .. with Harry Hess's *surmise*, .. as follows:-
"..The size of the Earth has not changed significantly during the past 600 million years, and very likely not since shortly after its formation 4.6 billion years ago. The Earth's unchanging size implies that the crust must be destroyed at about the same rate as it is being created, as Harry Hess surmised." [emphasis - df. ] ( http://pubs.usgs.gov/gip/dynamic/understanding.html and scroll down to "Convergent boundaries".)Thus are facts nuanced (by presenting 'surmise' as a stated 'fact' of unchanging size. The foundation is not in the body of the paragraph, but in the last four words - "as Harry Hess surmised" (that the crust must be destroyed at about the same rate as it is being created) - and they are hoping nobody notices the segue. It's quite possible the author him/herself didn't notice, though I doubt it. Syntax like that is a quite slippery thing to construct. The Wikipedia succeeds in being more factual and says it this way :-
"Plate tectonics < ....... > is a scientific theory which describes the large scale motions of Earth's lithosphere. The theory builds on the older concepts of continental drift, developed during the first decades of the 20th century (one of the most famous advocates was Alfred Wegener), and was accepted by the majority of the geoscientific community when the concepts of seafloor spreading were developed in the late 1950s and early 1960s."..which acknowledges that Plate Tectonics was based on earlier ideas of Holmes and numerous others (and not on a surmise of Hess) - that convection was the driver of continental separation. It followed Hess's rejection of the implication of the geological evidence [presented by Carey] that the earth had expanded, which would "solve three of my [Hess's] greatest difficulties regarding the evolution of the ocean basins."
Note that Hess didn't reject the evidence, .. he rejected the implication that followed from it re. enlargement as "philosophically unsatisfying", and therefore substituted the *need* for destruction of the ocean floors to match their creation (creation being all about expansion). No-one has contradicted Carey's case for expansion on geological grounds, only on the claim of "no mechanism".
The underpinning of Plate Tectonics was therefore not based on empirical fact but on Holmes' (and others') theory of convection,. The comment that "crust being destroyed (at subduction zones) at the same rate as it is created means that the Earth is not increasing in size", is entirely hypothesis, and the circular argument is obvious, which incidentally renders Plate Tectonics equivalent to Junk Science. (Junk science is when the initial assumption (not the data) is used as the supporting pillar to reach the conclusion inherent in the assumption.)
Many people were working in the new field of geophysics, and framed their results accordingly, thus skewing the emphasis of the findings away from geology. This is the reason why Plate Tectonics (as a theory of convection) supplanted continental drift as something new when it wasn't. The way Hess in his 1962 paper dismissed Holmes's work on convection reads as a classic example of appropriation. The problems he was trying to address in relation to the ocean floors were by no means new :-
"In reality, this question had been solved already by numerous scientists during the forties and the fifties, like Arthur Holmes, Vening-Meinesz, Coates and many others: The crust in excess disappeared along what were called the oceanic trenches where so-called "subduction" occurred." ... (link)What he was doing in adopting this was avoiding having to face the implications of the data of continental retrofits and much else, which supported a smaller Earth as illustrated by Carey. And he was not alone. The complicity of the entire geophysics community in Hess's appropriation is apparent from the reference in the Wikipedia, that Hess's paper was "for a time the single most referenced work in solid-Earth geophysics".
(Continuing the above quote..) :-
" ... Therefore, when various scientists during the early sixties started to reason on the data at their disposal regarding the ocean floor, the pieces of the theory fell quickly into place. Wikipedia ref." http://en.wikipedia.org/wiki/Plate_tectonicsI don't believe the "various scientists" did accept it on the data, because the essential facts on which those pieces of the theory "fell quickly into place" described creation of the ocean floors, which were all about the Earth getting bigger (expansion). Geophysicists were effectively taking the fall-back position of adopting the theory-of-the-day of convection that for nearly two decades had been first-year text-book geology - and (riding on the back of sea-floor spreading) calling it new. I believe *this* was the reason why geologists "adopted it" - because they already accepted it as a norm. They didn't "adopt" it at all (on new data); they already owned it. They must have, because as a theory it had been standard text-book geology for nearly two decades.
"Mid-ocean ridge spreading and convection"
The phrase "quickly falling into place" seems to be designed to gloss over this point, with the purpose of talking up new data of the ocean floors. Media likes to be part of 'new developments' - especially ones related to new fields emerging from prestigious institutions. In today's terms the "falling quickly into place" was a 'media beat-up'.
Thus was laid the track down which the brand new gravy train was about to roll. What was being proposed in principle, in terms of theory at least (convection) was no more than people already knew from the work of Wegener and Holmes. Certainly the facts emerging from the ocean floors were substantial, but that substance, first and foremost, supported expansion. Destruction was a device, an avoidance, a ploy (a cop-out), to avoid having to face what could not be talked about, i.e., everything that the criticism of "no mechanism" could be aimed at. As a result and with a consensus assured, the emphasis was towards shoring up and confirming the meme that people already knew, rather than (as science demands) its falsification.
It was a classic example of the 'meme machine', .. an appeal to people's intuitive understanding of the way tectonics worked using crumpling tablecloths to describe mountain building, and soup in a pot to describe convection :- "Everybody already knows what we mean, so we don't have to explain ourselves very well. In fact we don't even have to explain ourselves at all; all we have to say is, "everybody knows" ". And from then on, slogans will do.
In fact those subduction zones need very close scrutiny, which, in their reference to 'flat subduction' and "overriding" Plate Tectonics is only now beginning to do. "Flat subduction" does not return oceanic lithosphere to the deep mantle. And with no return to the deep mantle there is no convection, only spreading (/"growth") and decoupling of the crust from the mantle, . which is expansion. Sea-floor spreading is the fact. The theory to explain how so much has occurred is still not known, but the geological reality is a powerful incentive to get to know.
Hence the *necessity* of subduction, with all its contradictions, for without it, Plate Tectonics is in the same ("no mechanism") position as Earth expansion. But the 'soup-in-a-pot' convection model has no currency in the exchange with Earth expansion, based on factual evidence in the alternative blog (which Plate Tectonics ignores).
In short, Earth expansion includes facts that Plate Tectonics omits, and explains facts for which Plate Tectonics provides only self-contradictory conundrums. By the very nature of scale and time of parameters in Earth science, predictions are specious. The only valuable prediction is that Plate Tectonics will naturally evolve to Earth expansion as 'observation + logic' trumps theory founded on "philosophical un-satisfaction", denial of evidence, ignore-ance of what can be directly observed, and skewed perceptions of how things could be otherwise - *IF*.
[ See also blog for Earth expansion at :-