Archives de la catégorie: Citations

Cette catégorie contient mes réflexions sur la plupart des citations célèbres. Réflexions Mused spécialement pour Unreal Blog.

Bye Bye Einstein

Starting from his miraculous year of 1905, Einstein has dominated physics with his astonishing insights on space and time, and on mass and gravity. Vrai, there have been other physicists who, with their own brilliance, have shaped and moved modern physics in directions that even Einstein couldn’t have foreseen; and I don’t mean to trivialize neither their intellectual achievements nor our giant leaps in physics and technology. But all of modern physics, even the bizarre reality of quantum mechanics, which Einstein himself couldn’t quite come to terms with, is built on his insights. It is on his shoulders that those who came after him stood for over a century now.

One of the brighter ones among those who came after Einstein cautioned us to guard against our blind faith in the infallibility of old masters. Taking my cue from that insight, Je, for one, think that Einstein’s century is behind us now. Je sais, coming from a non-practicing physicist, who sold his soul to the finance industry, this declaration sounds crazy. Delusional even. But I do have my reasons to see Einstein’s ideas go.

[animation]Let’s start with this picture of a dot flying along a straight line (on the ceiling, so to speak). You are standing at the centre of the line in the bottom (on the floor, c'est). If the dot was moving faster than light, how would you see it? Bien, you wouldn’t see anything at all until the first ray of light from the dot reaches you. As the animation shows, the first ray will reach you when the dot is somewhere almost directly above you. The next rays you would see actually come from two different points in the line of flight of the dot — one before the first point, and one after. Ainsi, the way you would see it is, incredible as it may seem to you at first, as one dot appearing out of nowhere and then splitting and moving rather symmetrically away from that point. (It is just that the dot is flying so fast that by the time you get to see it, it is already gone past you, and the rays from both behind and ahead reach you at the same instant in time.Hope that statement makes it clearer, rather than more confusing.).

[animation]Why did I start with this animation of how the illusion of a symmetric object can happen? Bien, we see a lot of active symmetric structures in the universe. Par exemple, look at this picture of Cygnus A. There is a “core” from which seem to emanate “features” that float away to the “lobes.” Doesn’t it look remarkably similar to what we would see based on the animation above? There are other examples in which some feature points or knots seem to move away from the core where they first appear at. We could come up with a clever model based on superluminality and how it would create illusionary symmetric objects in the heavens. We could, but nobody would believe us — because of Einstein. I know this — I tried to get my old physicist friends to consider this model. The response is always some variant of this, “Interesting, but it cannot work. It violates Lorentz invariance, il ne est pas?” LV being physics talk for Einstein’s insistence that nothing should go faster than light. Now that neutrinos can violate LV, why not me?

Bien sûr, if it was only a qualitative agreement between symmetric shapes and superluminal celestial objects, my physics friends are right in ignoring me. There is much more. The lobes in Cygnus A, par exemple, emit radiation in the radio frequency range. En fait, the sky as seen from a radio telescope looks materially different from what we see from an optical telescope. I could show that the spectral evolution of the radiation from this superluminal object fitted nicely with AGNs and another class of astrophysical phenomena, hitherto considered unrelated, called gamma ray bursts. En fait, I managed to publish this model a while ago under the title, “Sont des sources radio et Gamma Ray Bursts Luminal Booms?“.

Vous voyez, I need superluminality. Einstein being wrong is a pre-requisite of my being right. So it is the most respected scientist ever vs. Cordialement votre, a blogger of the unreal kind. You do the math. 🙂

Such long odds, cependant, have never discouraged me, and I always rush in where the wiser angels fear to tread. So let me point out a couple of inconsistencies in SR. The derivation of the theory starts off by pointing out the effects of light travel time in time measurements. And later on in the theory, the distortions due to light travel time effects become part of the properties of space and time. (En fait, light travel time effects will make it impossible to have a superluminal dot on a ceiling, as in my animation above — not even a virtual one, where you take a laser pointer and turn it fast enough that the laser dot on the ceiling would move faster than light. It won’t.) Mais, as the theory is understood and practiced now, the light travel time effects are to be applied on top of the space and time distortions (which were due to the light travel time effects to begin with)! Physicists turn a blind eye to this glaring inconstancy because SR “works” — as I made very clear in my previous post in this series.

Another philosophical problem with the theory is that it is not testable. Je sais, I alluded to a large body of proof in its favor, but fundamentally, the special theory of relativity makes predictions about a uniformly moving frame of reference in the absence of gravity. There is no such thing. Even if there was, in order to verify the predictions (that a moving clock runs slower as in the twin paradox, par exemple), you have to have acceleration somewhere in the verification process. Two clocks will have to come back to the same point to compare time. The moment you do that, at least one of the clocks has accelerated, and the proponents of the theory would say, “De, there is no problem here, the symmetry between the clocks is broken because of the acceleration.” People have argued back and forth about such thought experiments for an entire century, so I don’t want to get into it. I just want to point out that theory by itself is untestable, which should also mean that it is unprovable. Now that there is direct experimental evidence against the theory, may be people will take a closer look at these inconsistencies and decide that it is time to say bye-bye to Einstein.

Amour de la Sagesse

Philosophie signifie l'amour sagesse. Mais il bénéficie d'aucun de glamour que sa définition impliquerait. Par exemple, dans l'un des jeux de société que je jouais avec les enfants récemment, la carte de la chance qui vous ferait faillite réellement lu, “Tourner dans un philosophe et perdre tout votre argent!” Cette carte a été particulièrement troublant pour moi parce que je ne prévois de prendre au sérieux la philosophie, bientôt je l'espère.

L'absence de corrélation entre la sagesse et les récompenses du monde est troublant, en particulier à ceux qui sont insensés assez pour se considérer comme sage. Pourquoi est-ce que l'amour de la sagesse ne se traduirait pas à la gloire, la richesse et le confort de créature? La raison, pour autant que je peux dire, est un profond décalage entre la philosophie et la vie — comme un sage (mais nettement antiphilosophique) de mes amis a dit dans un de ces hébétudes tard dans la nuit brumeux des années d'études supérieures, “La philosophie à la vie réelle est ce que la masturbation est au sexe.” Oui, les masses voient l'amour de la sagesse comme la masturbation intellectuelle inutile. Ce point de vue est peut-être un écho dans ce que dit Russell fois:

La philosophie se busies avec des choses qui semblent évidentes, à venir avec quelque chose de grandiose. Cette obsession apparente avec trivialités est une fausse impression. Dissiper cette impression est le but de ce post. Permettez-moi de commencer par souligner un fait. La philosophie est à la base de tout ce que vous faites. Vous vivez une bonne, vie morale? Ou même un moche, avide une? Ton comportement, les choix et les raisons sont étudiés en éthique. Tu es un quant, ou faire des trucs techniques ou mathématiques? Logique. Dans la physique et de culte Einstein? Vous ne pouvez pas alors ignorer les aspects métaphysiques de espace et temps. Avocat? Oui, Rhétorique. Travailleur du savoir? Épistémologie définit ce qu'est la connaissance. Artiste? Fashion designer? Travailler dans l'industrie du cinéma? Nous vous sommes couverts en Esthétique. Vous voyez, tous les moyens de l'activité humaine a un fondement philosophique à elle.

Soulignant ce fondement est, en réalité, non pas comme un gros problème que je fais dehors pour être. Il est simplement une question de définition. Je définis la philosophie d'être quoi que ce soit que “les appuie” tous les aspects de la vie, puis pointez sur ce fondement comme une preuve de son importance. La valeur réelle de la philosophie est dans la structuration de nos pensées et de les guider, par exemple, à percevoir le spécieux et la circularité subtile de mon fondement-donc importante argumentation. La philosophie nous enseigne que des stands de rien posséder sa propre, et qu'il existe des structures et des écoles de pensée qui éclairent les questions qui nous intoxiquer. Il y a échafauds pour nous soutenir, et les géants sur les épaules, nous pouvons supporter de voir loin et clair. Pour être sûr, certains de ces géants peut-être le mauvais sens, mais il est encore une fois l'audace et l'indépendance qui viennent avec la philosophie qui vont nous aider à voir les erreurs dans leurs façons. Sans ça, l'apprentissage devient l'endoctrinement, et dans notre quête pour assimiler l'information en sagesse, nous sommes coincés quelque part entre — peut-être au niveau de la connaissance.

Toute cette discussion ne nous donne toujours pas un indice quant à la connexion inquiétante entre la philosophie et de la faillite. Car quand un grand homme exprime son angoisse existentielle, “Je pense, donc je suis,” nous pouvons toujours dire (comme nous le faisons souvent), “Bon pour vous mate, tout ce qui fonctionne pour vous!” et aller sur notre vie.

L'amour de la sagesse facilite peut-être son acquisition, et le but de la sagesse est seulement la sagesse. Il est très semblable à la vie, dont le but est simplement de vivre un peu plus longtemps. Mais sans philosophie, comment nous voyons le sens de la vie? Ou l'absence de?

Change the Facts

There is beauty in truth, and truth in beauty. Where does this link between truth and beauty come from? Bien sûr, beauty is subjective, and truth is objective — or so we are told. It may be that we have evolved in accordance with the beautiful Darwinian principles to see perfection in absolute truth.

The beauty and perfection I’m thinking about are of a different kind — those of ideas and concepts. De temps en temps, you may get an idea so perfect and beautiful that you know it has to be true. This conviction of truth arising from beauty may be what made Einstein declare:

But this conviction about the veracity of a theory based on its perfection is hardly enough. Einstein’s genius really is in his philosophical tenacity, his willingness to push the idea beyond what is considered logical.

Prenons un exemple. Let’s say you are in a cruising airplane. If you close the windows and somehow block out the engine noise, it will be impossible for you to tell whether you are moving or not. This inability, when translated to physics jargon, becomes a principle stating, “Physical laws are independent of the state of motion of the experimental system.”

The physical laws Einstein chose to look at were Maxwell’s equations of electromagnetism, which had the speed of light appearing in them. For them to be independent of (or covariant with, plus précisément) motion, Einstein postulated that the speed of light had to be a constant regardless of whether you were going toward it or away from it.

Maintenant, I don’t know if you find that postulate particularly beautiful. But Einstein did, and decided to push it through all its illogical consequences. For it to be true, space has to contract and time had to dilate, and nothing could go faster than light. Einstein said, bien, so be it. That is the philosophical conviction and tenacity that I wanted to talk about — the kind that gave us Special Relativity about a one hundred years ago.

Want to get to General Relativity from here? simple, just find another beautiful truth. Here is one… If you have gone to Magic Mountain, you would know that you are weightless during a free fall (best tried on an empty stomach). Free fall is acceleration at 9.8 m/s/s (ou 32 ft/s/s), and it nullifies gravity. So gravity is the same as acceleration — voila, another beautiful principle.

World line of airplanesIn order to make use of this principle, Einstein perhaps thought of it in pictures. What does acceleration mean? It is how fast the speed of something is changing. And what is speed? Think of something moving in a straight line — our cruising airplane, par exemple, and call the line of flight the X-axis. We can visualize its speed by thinking of a time T-axis at right angles with the X-axis so that at time = 0, the airplane is at x = 0. At time t, it is at a point x = v.t, if it is moving with a speed v. So a line in the X-T plane (called the world line) represents the motion of the airplane. A faster airplane would have a shallower world line. An accelerating airplane, donc, will have a curved world line, running from the slow world line to the fast one.

So acceleration is curvature in space-time. And so is gravity, being nothing but acceleration. (I can see my physicist friends cringe a bit, but it is essentially true — just that you straighten the world-line calling it a geodesic and attribute the curvature to space-time instead.)

The exact nature of the curvature and how to compute it, though beautiful in their own right, are mere details, as Einstein himself would have put it. Après tout, he wanted to know God’s thoughts, not the details.

Blunder de Dieu

Scriptures tell us, in different ways depending on our denomination and affiliation, that God created the world and everything in it, including us. This is creationism in a nutshell.

Standing in the other corner, all gloved up to knock the daylight out of creationism, is science. It tells us that we came out of complete lifelessness through successive mutations goaded by the need to survive. This is Evolution, a view so widely accepted that the use of capital E is almost justified.

All our experience and knowledge point to the rightness the Evolution idea. It doesn’t totally preclude the validity of God, but it does make it more likely that we humans created God. (It must be just us humans for we don’t see a cat saying Lord’s grace before devouring a mouse!) Et, given the inconveniences caused by the God concept (wars, crusades, the dark ages, ethnic cleansing, religious riots, terrorism and so on), it certainly looks like a blunder.

No wonder Nietzsche said,

D'autre part, if God did create man, then all the stupid things that we do — wars, crusades etc. plus this blog — do point to the fact that we are a blunder. We must be such a disappointment to our creator. Sorry Sir!

Photo par La Bibliothèque du Congrès

Sex and Physics — Selon Feynman

Physique passe par un âge de la complaisance de temps en temps. La complaisance provient d'un sentiment de complétude, un sentiment que nous avons découvert tout ce qu'il faut savoir, la voie est libre et les méthodes bien compris.

Historiquement, ces épisodes de complaisance sont suivis par les développements rapides qui révolutionnent la manière dont la physique est fait, nous montrant comment mal que nous avons été. Cette leçon d'humilité de l'histoire est probablement ce qui a incité Feynman-à-dire:

Un âge de complaisance existait au début du 19ème siècle. Personnages célèbres comme Kelvin remarquer que tout ce qui restait à faire était de faire des mesures plus précises. Michelson, qui a joué un rôle crucial dans la révolution à suivre, a été conseillé de ne pas entrer dans un “mort” domaine comme la physique.

Qui aurait pensé que, dans moins d'une décennie dans le 20ème siècle, nous remplir changer la façon dont nous pensons de l'espace et le temps? Qui, dans leur esprit ne pourrait dire maintenant que nous allons à nouveau changer nos notions d'espace et de temps? Je fais. Puis à nouveau, personne ne m'a jamais accusé d'un bon esprit!

Une autre révolution a eu lieu au cours du siècle dernier — Mécanique quantique, qui a supprimé notre notion de déterminisme et porté un sérieux coup au paradigme du système observateur de la physique. Révolutions similaires se reproduiront. Il ne faut pas tenir sur nos concepts comme immuable; ils ne sont pas. Ne pensons pas de nos anciens maîtres comme infaillible, car ils ne sont pas. Comme Feynman lui-même aurait signaler, physique détient à lui seul plus d'exemples de la faillibilité de ses anciens maîtres. Et je pense que d'une révolution complète dans la pensée est en retard maintenant.

Vous pourriez vous demander ce que tout cela a à voir avec le sexe. Bien, J'ai juste pensé que le sexe serait mieux vendre. J'avais raison, n'étais-je pas? Je veux dire, vous êtes encore ici!

Feynman a également déclaré,

Photo par "Caveman Chuck" Coker cc

Einstein on God and Dice

Although Einstein is best known for his theories of relativity, he was also the main driving force behind the advent of quantum mechanics (QM). His early work in photo-voltaic effect paved way for future developments in QM. And he won the Nobel prize, not for the theories of relativity, but for this early work.

It then should come as a surprise to us that Einstein didn’t quite believe in QM. He spent the latter part of his career trying to device thought experiments that would prove that QM is inconsistent with what he believed to be the laws of nature. Why is it that Einstein could not accept QM? We will never know for sure, and my guess is probably as good as anybody else’s.

Einstein’s trouble with QM is summarized in this famous quote.

It is indeed difficult to reconcile the notions (or at least some interpretations) of QM with a word view in which a God has control over everything. In QM, observations are probabilistic in nature. C'est-à-dire, if we somehow manage to send two electrons (in the same state) down the same beam and observe them after a while, we may get two different observed properties.

We can interpret this imperfection in observation as our inability to set up identical initial states, or the lack of precision in our measurements. This interpretation gives rise to the so-called hidden variable theories — considered invalid for a variety of reasons. The interpretation currently popular is that uncertainty is an inherent property of nature — the so-called Copenhagen interpretation.

In the Copenhagen picture, particles have positions only when observed. At other times, they should be thought of as kind of spread out in space. In a double-slit interference experiment using electrons, par exemple, we should not ask whether a particular electron takes on slit or the other. As long as there is interference, it kind of takes both.

The troubling thing for Einstein in this interpretation would be that even God would not be able to make the electron take one slit or the other (without disturbing the interference pattern, c'est). And if God cannot place one tiny electron where He wants, how is he going to control the whole universe?