Quand nous ouvrons les yeux et regardons quelque chose,,en,nous voyons cette fichue chose,,en,Quoi de plus évident que ça,,en,Disons que vous regardez votre chien,,en,Ce que tu vois est vraiment ton chien,,en,si tu veux,,en,vous pouvez tendre la main et le toucher,,en,Il aboie,,en,et tu peux entendre la trame,,en,Si ça pue un peu,,en,tu peux le sentir,,en,Tous ces indices perceptifs supplémentaires corroborent votre conviction que ce que vous voyez est votre chien,,en,Directement,,en,Aucune question posée,,en,mon travail sur ce blog est de poser des questions,,en,et jette des doutes,,en,voir et toucher semblent être un peu différents de l'ouïe et de l'odorat,,en,Vous n'entendez pas strictement votre chien aboyer,,en,tu entends son son,,en,vous ne le sentez pas directement,,en,tu sens l'odeur,,en,la trace chimique que le chien a laissée dans l'air,,en,L'ouïe et l'odorat sont des perceptions à trois endroits,,en,le chien génère des sons / odeurs,,en, we see that damn thing. What could be more obvious than that, right? Let’s say you are looking at your dog. What you see is really your dog, because, if you want, you can reach out and touch it. It barks, and you can hear the woof. If it stinks a bit, you can smell it. All these extra perceptual clues corroborate your belief that what you are seeing is your dog. Directly. No questions asked.
Of course, my job on this blog is to ask questions, and cast doubts. First of all, seeing and touching seem to be a bit different from hearing and smelling. You don’t strictly hear your dog bark, you hear its sound. Similarly, you don’t smell it directly, you smell the odor, the chemical trail the dog has left in the air. Hearing and smelling are three place perceptions — the dog generates sound/odor, le son / l'odeur vous voyage,,en,vous percevez le son / l'odeur,,en,Mais en voyant,,en,ou toucher,,en,est une chose à deux endroits,,en,le chien là-bas,,en,et vous ici le percevez directement,,en,Pourquoi ressentons-nous cela quand nous voyons ou touchons quelque chose,,en,nous le sentons directement,,en,Cette croyance en la véracité perceptive de ce que nous voyons s'appelle le réalisme naïf,,en,Nous savons bien sûr que voir implique la lumière,,en,toucher aussi,,en,mais d'une manière beaucoup plus compliquée,,en,ce que nous voyons est la lumière réfléchie par un objet et ainsi de suite,,en,pas différent d'entendre quelque chose,,en,Mais cette connaissance du mécanisme de la vue ne modifie pas notre,,en,point de vue de bon sens que ce que nous voyons est ce qui existe,,en,Voir c'est croire,,en,Extrapolé de la version naïve est le réalisme scientifique,,en,qui affirme que nos concepts scientifiques sont également réels,,en, you perceive the sound/odor.
But seeing (or touching) is a two place thing — the dog there, and you here perceiving it directly. Why is that? Why do we feel that when we see or touch something, we sense it directly? This belief in the perceptual veracity of what we see is called naive realism. We of course know that seeing involves light (so does touching, but in a much more complicated way), what we are seeing is the light reflected off an object and so on. It is, in fact, no different from hearing something. But this knowledge of the mechanism of seeing doesn’t alter our natural, commonsense view that what we see is what is out there. Seeing is believing.
Extrapolated from the naive version is the scientific realism, which asserts that our scientific concepts are also real, même si nous ne pouvons pas les percevoir directement,,en,Donc les atomes sont réels,,en,Les électrons sont réels,,en,Les quarks sont réels,,en,La plupart de nos meilleurs scientifiques ont été sceptiques quant à cette extraploation de notre notion de ce qui est réel,,en,Einstein,,en,probablement le meilleur d'entre eux,,en,soupçonné que même l'espace et le temps pourraient ne pas être réels,,en,Feynman et Gell-Mann,,en,après avoir développé des théories sur les électrons et les quarks,,en,ont exprimé leur point de vue que les électrons et les quarks pourraient être des constructions mathématiques plutôt que des entités réelles,,en. So atoms are real. Electrons are real. Quarks are real. Most of our better scientists out there have been skeptical about this extraploation to our notion of what is real. Einstein, probably the best of them, suspected that even space and time might not be real. Feynman and Gell-Mann, after developing theories on electrons and quarks, expressed their view that electrons and quarks might be mathematical constructs rather than real entities.
What I am inviting you to do here is to go beyond the skepticism of Feynman and Gell-Mann, and delve into Einstein’s words — space and time are modes by which we think, not conditions in which we live. The sense of space is so real to us that we think of everything else as interactions taking place in the arena of space (and time). But space itself is the experience corresponding to the electrical signals generated by the light hitting your retina. It is a perceptual construct, much like the tonality of the sound you hear when air pressure waves hit your ear drums. Our adoption of naive realism results in our complete trust in the three dimensional space view. And since the world is created (in our brain as perceptual constructs) based on light, its speed becomes an all important constant in our world. And since speed mixes space and time, a better description is found in a four dimensional Minkowski geometry. But all these descriptions are based on perceptual experiences and therefore unreal in some sense.
I know the description above is highly circular — I talked about space being a mental construct created by light traveling through, get this, space. And when I speak of its speed, naturally, I’m talking about distance in space divided by time, and positing as the basis for the space-time mixing. This circularity makes my description less than clear and convincing. But the difficulty goes deeper than that. You see, all we have is this cognitive construct of space and time. We can describe objects and events only in terms of these constructs even when we know that they are only cognitive representations of sensory signals. Our language doesn’t go beyond that. Well, it does, but then we will be talking the language, for instance, of Advaita, calling the constructs Maya and the causes behind them Brahman, which stays unknowable. Or, we will be using some other parallel descriptions. These descriptions may be profound, wise and accurate. But ultimately, they are also useless.
But if philosophy is your thing, the discussions of cognitive constructs and unknown causations are not at all useless. Philosophy of physics happens to be my thing, and so I ask myself — what if I assume the unknown physical causes exist in a world similar to our perceptual construct? I could then propagate the causes through the process of perception and figure out what the construct should look like. I know, it sounds a bit complex, but it is something that we do all the time. We know, for instance, that the stars that we see in the night sky are not really there — we are seeing them the way they were a few (or a few million or billion) years ago because the light from them takes a long time to reach us. Physicists also know that the perceived motion of celestial objects also need to be corrected for these light-travel-time effects.
In fact, Einstein used the light travel time effects as the basis for deriving his special theory of relativity. He then stipulated that space and time behave the way we perceive them, derived using the said light-travel-time effects. This, of course, is based on his deep understanding that space and time are “the modes by which we think,” but also based on the assumption that the the causes behind the modes also are similar to the modes themselves. This depth of thinking is lost on the lesser scientists that came after him. The distinction between the modes of thinking and their causation is also lost, so that space and time have become entities that obey strange rules. Like bent spoons.
Photo by General Press1