> On 15 Mar 2021, at 10:23, smitra <[email protected]> wrote: > > On 14-03-2021 20:03, 'Brent Meeker' via Everything List wrote: >> On 3/14/2021 3:24 AM, Bruno Marchal wrote: >>>> The laws are constructs of the human mind. [Lawrence] >>> The expression of the laws are constructs of the human mind, but I >>> guess you are OK that F=GmM/r^2 was as much approximately true >>> before human life appears on this planet and after. OK? >> I think "approximately true" implicitly assumes someone for whom the >> approximation is good enough. Someone with values and purpose. >> Brent > > There exists an as of yet unknown exact description of gravity. The leading > term of the expansion of that theory for large distances, low energies and > velocities will yield the Newtonian theory. > > It's not much different from saying that sin(x) = x + O(x^3)
I agree. "3,14 is an approximation of PI” is true, independently of any observer, even if it is a vague proposition. Its degree of precision are themselves independent of us, even if the taste for this or that precision might depend on us, and of some context. I used “approximately true” because it is hard to find a law of physics which is not an approximation of such sort, but for the point I was making I was alluding to some such laws, and that would make sense for anyone realist on some physicai reality (fundamental or not). If not, then “the laws is a construct of mind” would be interpreted in an anthropomorphic way, like if the humans are at the origin of the physical reality. The fact that F = GmM/r^2 does not depend on some human thinking about “F= GmM/r^2. Brent might have confuse a law and a human (correct or incorrect) description of that law. This difficulty appears also in arithmetic. The fact that the arithmetical reality run all computations must not be confuse with that fact that we can describe the computations in arithmetic, as a computation is not the same as a description of a computation, even if to prove that Arithmetic is Turing universal imposed *us* to go through those description. There is a complex pedagogical problem here. It is like the difference between the number 1 and the symbol “1”, those are extremely different entities. Nobody knows what the number 1 is, but everybody can handle it very easily, and the symbol “1” is anything you want, even the Mount Everest if you want, although that would not be a practical symbol, for sure. Bruno > > Saibal > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/b04113884b49d4a27415a230620f58c2%40zonnet.nl. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/0D92FF27-7A14-4DFA-A30C-94019C5A2D4F%40ulb.ac.be.
