Voir et Croire

Quand nous ouvrons nos yeux et regarde quelque chose, nous voyons que fichue chose. Quoi de plus évident que, droit? Disons que vous êtes à la recherche de votre chien. Ce que vous voyez est vraiment votre chien, parce que, si vous voulez, vous pouvez atteindre et toucher. Il aboie, et vous pouvez entendre la trame. Si ça pue un peu, vous pouvez sentir. Tous ces indices de perception supplémentaires corroborent votre conviction que ce que vous voyez est votre chien. Directement. Pas de questions posées.

Bien sûr, mon travail sur ce blog est de poser des questions, et jeté des doutes. Tout d'abord, voir et toucher semble être un peu différente de l'ouïe et l'odorat. Vous n'entendez pas strictement votre chien aboyer, vous entendez le son. De même, vous ne sentez pas directement, vous sentez l'odeur, la piste chimique, le chien a laissé dans l'air. Audition et odeur sont trois lieux perceptions — le chien génère son / odeur, le son / odeur se déplace pour vous, vous percevez le bruit / odeur.

Mais en voyant (ou toucher) est une deux places chose — le chien y, et vous ici percevoir directement. Pourquoi donc? Pourquoi nous sentons-nous que lorsque nous voyons ou touchons quelque chose, nous sentons directement? Cette croyance en la véracité de la perception de ce que nous voyons est appelé réalisme naïf. Nous savons bien sûr que de voir implique la lumière (il en va de toucher, mais d'une manière beaucoup plus compliqué), ce que nous voyons est la lumière réfléchie par un objet et ainsi de suite. Il est, en fait, ne diffère pas de quelque chose de l'audition. Mais cette connaissance du mécanisme de la vision ne modifie pas notre naturel, vue de bon sens que ce que nous voyons est ce qui existe. Voir c'est croire.

Extrapolée à partir de la version naïve est le réalisme scientifique, qui affirme que nos concepts scientifiques sont également réel, même si nous ne pouvons pas percevoir directement les. Donc atomes sont réels. Les électrons sont réels. Les quarks sont réels. La plupart de nos meilleurs scientifiques là-bas ont été sceptique à ce sujet extraploation à notre notion de ce qui est réel. Einstein, probablement le meilleur d'entre eux, soupçonnaient même espace et le temps pourraient ne pas être réel. Feynman et Gell-Mann, après avoir développé des théories sur les électrons et les quarks, exprimé leur point de vue que les électrons et les quarks peuvent être des constructions mathématiques plutôt que des entités réelles.

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

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