Arquivo da categoria: Cotações

Esta categoria contém minhas reflexões sobre citações principalmente famosos. Reflexões refletiu especialmente para Blog Unreal.

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. Verdadeiro, 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, I, for one, think that Einstein’s century is behind us now. Eu sei, 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, que é). If the dot was moving faster than light, how would you see it? Bem, 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. Assim, 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? Bem, we see a lot of active symmetric structures in the universe. Por exemplo, 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, não faz isso?” LV being physics talk for Einstein’s insistence that nothing should go faster than light. Now that neutrinos can violate LV, why not me?

Claro, 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, por exemplo, emit radiation in the radio frequency range. De fato, 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. De fato, I managed to publish this model a while ago under the title, “É Rádio Fontes e Gamma Ray Bursts Luminal Booms?“.

Entende, I need superluminality. Einstein being wrong is a pre-requisite of my being right. So it is the most respected scientist ever vs. com os melhores cumprimentos, a blogger of the unreal kind. You do the math. 🙂

Such long odds, no entanto, 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. (De fato, 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.) Mas, 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. Eu sei, 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, por exemplo), 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.

Love of Wisdom

Philosophy means love wisdom. But it enjoys none of the glamor that its definition would imply. Por exemplo, in one of the board games that I played with the kids recently, the chance card that would make you bankrupt actually read, “Turn into a philosopher and lose all your money!” This card was particularly troubling for me because I do plan to take up philosophy seriously, hopefully soon.

The lack of correlation between wisdom and worldly rewards is unsettling, especially to those who are foolish enough to consider themselves wise. Why is it that the love of wisdom wouldn’t translate to glory, riches and creature comforts? The reason, tanto quanto eu posso dizer, is a deep disconnect between philosophy and lifeas a wise (but distinctly unphilosophical) friend of mine put it in one of those hazy late-night stupors of the graduate years, “Philosophy to real life is what masturbation is to sex.” Sim, the masses see the love of wisdom as pointless intellectual masturbation. This view is perhaps echoed in what Russell said once:

Philosophy busies itself with things that seem obvious, to come up with something grandiose. This apparent obsession with trivialities is a false impression. Dispelling this impression is the purpose of this post. Let me start by pointing out one fact. Philosophy is at the root of everything that you do. You live a good, moral life? Or even a lousy, greedy one? Your behavior, choices and reasons are studied in Ethics. You are a quant, or do stuff technical or mathematical? Logic. Into physics and worship Einstein? You cannot then ignore the metaphysical aspects of espaço e tempo. Lawyer? Sim, Rhetorics. Knowledge worker? Epistemology defines what knowledge is. Artist? Fashion designer? Work in the movie industry? We got you covered in Aesthetics. Entende, every avenue of human endeavor has a philosophic underpinning to it.

Pointing out this underpinning is, na realidade, not as big a deal as I make it out to be. It is merely a matter of definition. I define philosophy to be whatever it is thatunderpinsall aspects of life, and then point out this underpinning as evidence of its importance. The real value of philosophy is in structuring our thoughts and guiding them, por exemplo, in perceiving the speciousness and subtle circularity of my underpinning-therefore-important argument. Philosophy teaches us that nothing stands own its own, and that there are structures and schools of thought that illuminate questions that befuddle us. There are scaffolds to support us, and giants on whose shoulders we can stand to see far and clear. Para ter certeza, some of these giants may be facing the wrong way, but it is again the boldness and independence that come with philosophy that will help us see the errors in their ways. Without it, learning becomes indoctrination, and in our quest to assimilate information into wisdom, we get stuck somewhere in betweenperhaps at the level of knowledge.

All this discussion still doesn’t give us a clue as to the disquieting connection between philosophy and bankruptcy. For when a great man voices his existential anguish as, “Eu acho que, logo existo,” we can always say (as we often do), “Good for you mate, whatever works for you!” and go about our life.

Love of wisdom perhaps facilitates its acquisition, and the purpose of wisdom is only wisdom. It is very much like life, the purpose of which is merely to live a little longer. But without philosophy, how do we see the meaning of life? Or lack thereof?

Change the Facts

Há beleza na verdade, e verdade em beleza. Onde é que esta ligação entre a verdade ea beleza vêm de? Claro, a beleza é subjetiva, e a verdade é objetiva — ou assim nos dizem. Pode ser que nós evoluímos de acordo com os belos princípios darwinianos para ver a perfeição em verdade absoluta.

A beleza e perfeição estou pensando são de um tipo diferente — aqueles de idéias e conceitos. Em momentos, você pode ter uma ideia tão perfeito e bonito que você sabe que tem que ser verdade. Esta convicção da verdade resultante da beleza pode ser o que fez Einstein declarar:

Mas esta convicção sobre a veracidade de uma teoria baseada em sua perfeição é quase o suficiente. O gênio de Einstein é realmente em sua tenacidade filosófica, sua vontade de empurrar a idéia além do que é considerado lógico.

Vamos dar um exemplo. Vamos dizer que você está em um avião de cruzeiro. Se você fechar as janelas e de alguma forma bloquear o ruído do motor, será impossível para você dizer se você está se movendo ou não. esta incapacidade, quando traduzido para o jargão da física, torna-se um princípio indicando, “leis físicas são independente do estado de movimento do sistema experimental.”

As leis físicas Einstein escolheu para olhar eram equações do eletromagnetismo de Maxwell, que tinha a velocidade da luz aparecendo nelas. Para eles, para ser independente de (ou covariantes com, para ser mais preciso) movimento, Einstein postulou que a velocidade da luz tinha que ser uma constante, independentemente de você estavam indo em direção a ele ou fora dele.

Agora, Eu não sei se você achar que postulado particularmente bonita. Mas Einstein fez, e decidiu empurrá-lo através de todas as suas conseqüências ilógicas. Para que isso seja verdade, espaço tem para contratar e tempo teve para dilatar, e nada poderia ir mais rápido do que a luz. Einstein disse, bem, que assim seja. Essa é a convicção filosófica e tenacidade que eu queria falar sobre — o tipo que nos deu Relatividade Especial cerca de uma centena de anos atrás.

Quer chegar a Relatividade Geral de aqui? Simples, apenas encontrar uma outra verdade bonita. Aqui é um… Se você tiver ido para a Magic Mountain, você sabe que você é sem peso durante uma queda livre (melhor tentou com o estômago vazio). queda livre é a aceleração na 9.8 m / s / s (ou 32 ft / s / s), e anula a gravidade. Assim, a gravidade é a mesma como a aceleração — voila, outro princípio bonita.

World line of airplanesA fim de fazer uso deste princípio, Einstein talvez pensado nisso em fotos. O que significa aceleração? É o quão rápido a velocidade de algo está mudando. E o que é a velocidade? Pense em algo se movendo em linha reta — nosso avião de cruzeiro, por exemplo, e ligue para a linha de voo do eixo X. Podemos visualizar a sua velocidade de pensar de um eixo de tempo T-em ângulos rectos com o eixo X de modo a que no tempo = 0, o avião está em x = 0. No tempo t, ele está em um ponto x = v.t, Se ele está se movendo com uma velocidade v. Assim, uma linha no plano X-t (chamado a linha do mundo) representa o movimento do avião. Um avião mais rápido teria uma linha rasa mundo. Um avião acelerando, portanto,, terá uma linha curva mundo, correr a partir da linha mundial lento para o rápido.

Assim, a aceleração é curvatura no espaço-tempo. E assim é a gravidade, ser nada, mas a aceleração. (Eu posso ver meus amigos físico encolher um pouco, mas é essencialmente verdadeiro — só que você endireitar a linha de mundo chamando-o de uma geodésica e atributo a curvatura de espaço-tempo ao invés.)

A natureza exacta da curvatura e como calcular-lo, apesar de bela, por direito próprio, são meros detalhes, como o próprio Einstein teria colocá-lo. Afinal, ele queria saber os pensamentos de Deus, não os detalhes.

God’s Blunder

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!) E, given the inconveniences caused by the God concept (wars, crusades, the dark ages, limpeza étnica, religious riots, terrorism and so on), it certainly looks like a blunder.

No wonder Nietzsche said,

Por outro lado, 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!

Foto por A Biblioteca do Congresso

Sex and Physics — De acordo com Feynman

Física passa por uma época de complacência de vez em quando. Complacência origina de um sentimento de completude, um sentimento que descobrimos tudo o que há para saber, o caminho é claro e os métodos bem-entendido.

Historicamente, essas crises de complacência são seguidas por uma rápida evolução que revolucionam a forma física é feito, mostrando-nos o quão errado temos sido. Esta lição humilhante da história é, provavelmente, o que levou Feynman dizer:

Tal era da complacência existia na virada do século 19. Personas famosas como Kelvin observou que tudo o que restava a fazer era fazer medições mais precisas. Michelson, que desempenhou um papel crucial na revolução a seguir, foi aconselhado a não entrar em uma “mortos” área como física.

Quem teria pensado que em menos de uma década no século 20, que iria completar mudar a forma como pensamos de espaço e tempo? Quem no seu perfeito juízo iria dizer agora que vamos voltar a mudar as nossas noções de espaço e tempo? Faço. Então, novamente, ninguém nunca me acusou de um juízo!

Outra revolução teve lugar no decorrer do século passado — Mecânica Quântica, que acabou com a nossa noção de determinismo e desferiu um duro golpe para o paradigma do sistema-observador da física. Revoluções similares vai acontecer de novo. Não vamos segurar nossos conceitos como imutável; eles não são. Não vamos pensar em nossos velhos mestres como infalível, pois eles não são. Como o próprio Feynman recorda, física, sozinha, detém mais exemplos da falibilidade de seus antigos mestres. E eu sinto que uma completa revolução no pensamento está atrasado agora.

Você pode estar se perguntando o que tudo isso tem a ver com sexo. Bem, Eu apenas pensei que o sexo iria vender melhor. Eu estava certo, não fui eu? Quero dizer, você ainda está aqui!

Feynman também disse,

Foto por "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. em QM, observations are probabilistic in nature. Isto quer dizer, 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 theoriesconsidered 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, por exemplo, 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, que é). And if God cannot place one tiny electron where He wants, how is he going to control the whole universe?