Hi Frederico,
You write, "Try to read the equation F=ma. In the context of classical mechanics you would say the total force equals to the product of the mass and the acceleration. But out of context, or better, without any interpretation, you cannot say it."
If you mean only that I have to expand the shorthand symbols to natural language, such that I should write, "Force equals mass times acceleration," then I don't really think that constitutes either context or interpretation. The symbols, after all, mean the same things whether one's native language is Portuguese or English, or any other. Mathematical symbols are universal; we learn this "alphabet" of symbols in learning the artificial language of math, yet the symbols are themselves derived from natural language.
Suppose you mean, though, that to understand how to interpret the way in which these symbols correspond to personal experience, such that we are assured the symbols are indeed universal -- we resort to comparing the symbols to objects, exactly the way one learns natural language. "Mass" one can understand as identical to weight, by balance measurement. "Acceleration" is exactly why Newton invented the calculus, to explain acceleration as the rate of change of the rate of change -- can this be explained by direct comparison to an object? -- yes, if one sees the difference between uniform motion described by a straight line, and acceleration described by a curved line, which is the visual basis of the calculus. Then corresponding experience informs one that a hammer head "weighs" more when accelerated toward the nail head, than when resting on it uniformly. We call that increase of mass-energy by the name "force."
"The problem of natural language is that it is not as precise as math, and there are too undefined concepts or open concepts. For example, define reality? Define proposition? Define truth? These concepts are very hard if not impossible to define in natural language. I cannot prove you it is impossible to define these concepts in natural language, but if you look to a dictionary you will see that some definitions are at most circular and you cannot remove the circularity.'
Sure. However, I *can* prove that it is possible to express every mathematical statement in natural language, even though it is impractical, unnecessary and exceedingly tedious. Formal proofs rely on logical judgments derived from a given set of axioms -- they do not necessarily tell us what is true; in fact, the common way of conveying the meaning of Godel's theorem is in the statement: "Truth is stronger than proof." In other words, there exist true statements derived from any set of axioms that cannot be proven from that set, no matter how many or how few axioms the set comprises.
A dictionary is no help here, and in fact we can prove it! Your set of questions above asking to define terms can be reduced to "Define definition." The answer: "Definition is defined by the set of all definitions in the dictionary." Is that useful? -- it is, if one is a mathematical realist (Platonist) as Godel was. Roger Penrose is another example of a modern Platonist. To such a mathematician, there exists a universal "dictionary" -- pure perfect mathematics, in fact, is only a set of self consistent statements. In fact, Godel used to refer to proofs he found particularly elegant as having come straight "from the Book."
Science as a whole, though, conventionally follows the logic of Tarski (correspondence theory of truth) adapted by Popper to correspondence between logically closed mathematical judgments (theory) and experimental results. That's an even longer discussion.
"Really, I was not aware of Chaitin's work." Try his site . I know you'll be interested.
"I liked the way you characterized a closed theory, although we need to take with the meaning of mathematically complete, because if it is understood in the sense Godel then we have a problem with his incompleteness theorem."
I hope I covered that sufficiently above. "Mathematically complete" I take from the EPR definition: every element of the mathematical theory corresponds to every element of the physical reality.
"I've read his book but I'm not a specialist on Wittgenstein philosophy, and so I cannot really answer how my ideas are in relation to his philosophy. If you have something more specific ..."
This is a longer discussion still. Maybe later.
"I'll visit you essay. Thanks for visiting mine, and pleas rate me if you haven't! I wish you all the best in this contest, and that we could keep our talks beyond this scope."
I'd be delighted to engage further ... and of course will award your essay a deservedly high rating.
All best,
Tom