Mauro Lacy wrote: >> Mauro Lacy wrote: >> >> >>> By the way, I have a question for you, in the form of a zen koan: "We >>> > know the sound of two hands clapping, but what is the sound of one hand > clapping?" We can reformulate it for the ocassion as: "We know the > interference pattern produced by two streams of light, but what is the > interference pattern of one stream of light?" > >> A diffraction pattern. >> > > A diffraction pattern in a medium, and depending on that medium. That is, > the effect is the result of an interaction. >
I don't know what you mean by this. No "medium" is required. A single beam of light traveling through vacuum diffracts with itself (or interferes with itself, if you prefer; it's really the same effect). That's why lasers can never be perfectly collimated; the beam always spreads. Or have you discarded the usual meaning of the word "medium" in favor of something else? > >> >>> Or better yet: >>> "We know the gravitational effect between two material bodies, but what >>> > is the gravitational effect of one material body?" > >> Curves the metric. >> >> But without any other body in the universe there's nobody there to >> > measure it. > > So, an effect again arises as a result of an interaction. > > >> If a tree falls in a forest and there's nobody there to hear it, does it >> > make a sound? > >> Same question wearing different clothes. In both cases it's just >> > semantic games with an undefined term. In the question regarding the > tree, the phrase "make a sound" was never defined and so the issue > appears debatable. In your example, the word "effect" was never > defined, and so the question appears debatable. > > The question is debatable. Although only semantically, if you like. If you > define sound as "something audible" then it only occurs when someone hears > it, by definition. But if you define "sound" as something that has the > possibility of being audible, then there's sound even when nobody hears > it, again by definition. And this is the right way to define it, IMO, > because if not, you're left in the dark regarding the real nature of > things. The specific phenomena of sound manifests when somebody hears it, > but while nobody is hearing it, there's something there that, when someone > heards it, manifests itself as sound. > > But I was pointing to another direction: trying to show that the specific > form of things we perceive or phenomena that occurs in the world, are the > result of an interaction. > Obviously. That's the heart of the Copenhagen interpretation of quantum mechanics: The observer is part of the system, and the act of observing is an interaction. Without the presence of the observer, it's a different system. > In the same venue, gravity only makes sense as a result of the interaction > of two or more massive bodies. What does it mean for something to "make sense"? Without a precise definition of that phrase the sentence is meaningless. For that matter, you haven't said what *you* mean by "interaction" or "massive" or "body". Is a photon "massive"? Is a neutron star one body, or is it a whole bunch of bodies, one for each neutron? Does a ray of light which is bent by a massive star constitute an "interaction" of that star with another "massive body", or not? Everything is debatable when nothing is defined. > In a sense, gravity phenomenologically IS > the result of that interaction, that is, gravity is different when there's > an interaction, This sounds kind of meaningless, frankly. "Different" how? What do you mean by an "interaction"? More fun with undefined terms. > to when there's none, and that difference depends also on > the interacting bodies, in the same way as a diffraction pattern depends > on the medium, No it doesn't, as I already pointed out.
