> On 8 Aug 2019, at 01:56, Bruce Kellett <[email protected]> wrote: > > On Wed, Aug 7, 2019 at 11:40 PM Bruno Marchal <[email protected] > <mailto:[email protected]>> wrote: > On 7 Aug 2019, at 15:08, Bruce Kellett <[email protected] > <mailto:[email protected]>> wrote: >> What exactly is the difference between something that it is impossible in >> principle to detect and something that does not exist? > > It is like the difference between the human existence and the human non > existence, for an alien situated in a very far away galaxy. The fact that > this alien cannot detect us does not make the human disappearing. > > You got that the wrong way round. It is like the supposition that aliens > exist in some remote galaxy where we cannot detect them. Their existence or > non-existence is irrelevant to us,
That leads to solipsisme. > so there is no difference between their non-detectability and their > non-existence. FAPP yes. For theoretical and metaphysical/theological purpose no. You are invoking the instrumentalist position. > We are not asking what the aliens think about our existence -- our existence > is a given for us. > > It is like the other side of the moon before we built rocket. > > The far side of the moon was always observable in principle. Rockets did not > change that. > > It is like taking our theory at fave value, instead of eliminating some terms > in the equation by sheer coquetry. > > Taking any theory at face value is a mistake. We have to test all the > theory's consequences. That is impossible for most theories. > And if we find some consequences to be untestable (causally disconnected from > us, for example), then those consequences remain speculative and not to be > relied on as true — No 3p sharable experience at all can ever make us using “truth” in science. > they can be eliminated from our consideration until such time as direct > evidence is obtained. Physics is about the observable, not the unobservable. We discuss metaphysics, not physics. Bruno > > Bruce > > -- > 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] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAFxXSLQGersUa96pv7u0M%3DqwnQe1FufOHEiON_CzT5ZvRudyLQ%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAFxXSLQGersUa96pv7u0M%3DqwnQe1FufOHEiON_CzT5ZvRudyLQ%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- 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/EDDD6E9C-BDD3-4A4E-B619-A9EE9CDAE9FE%40ulb.ac.be.
