Kategori Arkib: Petikan

Kategori ini mengandungi musings saya pada sebut harga kebanyakannya terkenal. Musings fikir khas untuk 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. Benar, 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, Saya, untuk satu, think that Einstein’s century is behind us now. Saya tahu, 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, yang). If the dot was moving faster than light, how would you see it? Baik, 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. Oleh itu, 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? Baik, we see a lot of active symmetric structures in the universe. Sebagai contoh, 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, tidak ia?” LV being physics talk for Einstein’s insistence that nothing should go faster than light. Now that neutrinos can violate LV, why not me?

Sudah tentu, 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, misalnya, emit radiation in the radio frequency range. Malah, 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. Malah, I managed to publish this model a while ago under the title, “Adakah Sumber Radio dan Gamma Ray Pecah berongga Booms?“.

Anda lihat, I need superluminality. Einstein being wrong is a pre-requisite of my being right. So it is the most respected scientist ever vs. milik anda setia, a blogger of the unreal kind. You do the math. 🙂

Such long odds, Walau bagaimanapun, 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. (Malah, 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.) Tetapi, 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. Saya tahu, 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, misalnya), 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, “Ah, 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. Sebagai contoh, 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? Sebabnya, as far as I can tell, is a deep disconnect between philosophy and life — as 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.” Ya, 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 ruang dan masa. Lawyer? Yeah, Rhetorics. Knowledge worker? Epistemology defines what knowledge is. Artist? Fashion designer? Work in the movie industry? We got you covered in Aesthetics. Anda lihat, every avenue of human endeavor has a philosophic underpinning to it.

Pointing out this underpinning is, pada hakikatnya, 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 that “underpins” all 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, misalnya, 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. Yang pasti, 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 between — perhaps 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, “Saya rasa, Oleh itu, saya,” 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?

Tukar Fakta

Terdapat kecantikan dalam kebenaran, dan kebenaran dalam kecantikan. Di manakah pautan ini antara kebenaran dan kecantikan datang daripada? Sudah tentu, kecantikan adalah subjektif, dan kebenaran adalah objektif — atau supaya kita diberitahu. Mudah-mudahan kita telah berkembang selaras dengan prinsip-prinsip Darwin indah untuk melihat kesempurnaan dalam kebenaran mutlak.

Keindahan dan kesempurnaan saya berfikir tentang adalah daripada jenis yang berbeza — mereka idea dan konsep. Pada masa-masa, anda boleh mendapatkan idea begitu sempurna dan indah yang anda tahu ia adalah benar. Ini disabitkan kebenaran yang timbul daripada kecantikan mungkin apa yang dibuat Einstein mengisytiharkan:

Tetapi ini disabitkan tentang kebenaran teori berdasarkan kesempurnaan adalah tidak cukup. Genius Einstein adalah benar-benar dalam ketabahan falsafah beliau, kesediaannya untuk menolak idea di luar apa yang dianggap logik.

Mari kita mengambil contoh. Katakan anda berada dalam kapal terbang pelayaran. Jika anda menutup tingkap dan entah bagaimana menghalang bunyi bising enjin, ia akan menjadi mustahil untuk anda untuk memberitahu sama ada anda sedang bergerak atau tidak. Ketidakupayaan ini, apabila diterjemahkan kepada fizik jargon, menjadi prinsip yang menyatakan, “Undang-undang fizikal adalah bebas daripada keadaan gerakan sistem eksperimen.”

Undang-undang fizikal Einstein memilih untuk melihat adalah persamaan Maxwell dalam elektromagnetisme, yang mempunyai kelajuan cahaya yang terdapat dalam mereka. Bagi mereka untuk bebas daripada (atau kovarian dengan, dengan lebih tepat) gerakan, Einstein mengandaikan bahawa kelajuan cahaya terpaksa menjadi malar tanpa mengira sama ada anda telah pergi ke arah itu atau diri daripadanya.

Sekarang, Saya tidak tahu jika anda mencari dalil yang sangat cantik. Tetapi Einstein lakukan, dan memutuskan untuk menolak melalui semua akibat yang tidak logik. Kerana ia adalah benar, ruang mempunyai menguncup dan masa terpaksa membesar, dan tiada apa yang boleh pergi lebih cepat daripada cahaya. Einstein berkata, baik, jadi ia. Itulah disabitkan falsafah dan ketabahan yang saya mahu bercakap tentang — jenis yang telah memberi kita Relativiti Khas kira-kira seratus tahun yang lalu.

Ingin mendapatkan untuk Relativiti daripada sini? Mudah, hanya mencari kebenaran lain yang indah. Di sini adalah satu… Jika anda telah pergi ke Magic Mountain, anda akan tahu bahawa anda tanpa berat semasa jatuh bebas (terbaik cuba dengan perut kosong). Jatuh bebas adalah pecutan 9.8 m / s / s (atau 32 kaki / s / s), dan ia menangkis graviti. Jadi graviti adalah sama dengan pecutan — bertudung, prinsip lain yang indah.

World line of airplanesDalam usaha untuk menggunakan prinsip ini, Einstein mungkin dianggap dalam gambar. Apakah pecutan bermakna? Ia adalah berapa cepat kelajuan sesuatu berubah. Dan apa yang kelajuan? Fikirkan sesuatu yang bergerak dalam garis lurus — kapal terbang pelayaran kami, misalnya, dan hubungi talian penerbangan paksi X-yang. Kita dapat melihat dengan kelajuannya dengan memikirkan paksi-T masa pada sudut tegak dengan paksi X-supaya pada masa = 0, pesawat tersebut adalah di x = 0. Pada masa t, ia adalah pada titik x = v.t, jika ia bergerak dengan kelajuan v. Jadi garis pada satah X-T (dipanggil garis dunia) mewakili gerakan pesawat. Sebuah kapal terbang yang lebih cepat akan mempunyai talian dunia yang cetek. Sebuah kapal terbang mempercepatkan, Oleh itu,, akan mempunyai garis melengkung dunia, berjalan keluar dari dunia yang perlahan untuk satu puasa.

Jadi pecutan adalah kelengkungan dalam ruang-masa. Dan begitu juga graviti, kerana apa-apa tetapi pecutan. (Saya dapat melihat rakan-rakan ahli fizik saya merasa jijik sedikit, tetapi ia adalah pada dasarnya benar — hanya yang anda meluruskan dunia talian memanggil ia satu geodesi dan atribut kelengkungan kepada ruang-masa bukan.)

Sifat dari kelengkungan dan bagaimana untuk mengira ia, walaupun cantik dalam hak mereka sendiri, adalah butiran semata-mata, sebagai Einstein sendiri akan meletakkannya. Lagipun, dia ingin tahu fikiran Allah, tidak butir-butir.

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!) Dan, 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,

Sebaliknya, 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!

Gambar oleh Perpustakaan Kongres

Seks dan Fizik — Menurut Feynman

Fizik akan melalui zaman puas hati sekali-sekala. Puas hati berasal dari rasa kesempurnaan, perasaan bahawa kami telah menemui segala-galanya ada tahu, jalan yang jelas dan kaedah yang difahami.

Dari segi sejarah, serangan ini puas hati diikuti oleh perkembangan pesat yang merevolusikan cara fizik yang dilakukan, menunjukkan kepada kita bagaimana salah kita telah. Ini pengajaran kekerasan hati sejarah mungkin apa yang mendorong Feynman untuk mengatakan:

Seperti zaman puas hati wujud pada awal abad ke-19. Persona terkenal seperti Kelvin mengatakan bahawa semua yang perlu dilakukan adalah untuk membuat ukuran yang lebih tepat. Michelson, yang memainkan peranan penting dalam revolusi untuk mengikuti, telah dinasihatkan supaya tidak memasukkan “mati” bidang seperti fizik.

Siapa sangka bahawa dalam tempoh kurang sedekad ke dalam abad ke-20, kami akan melengkapkan mengubah cara kita berfikir tentang ruang dan masa? Siapa dalam fikiran hak mereka akan mengatakan sekarang bahawa kita sekali lagi akan mengubah tanggapan kami ruang dan masa? Saya buat. Kemudian lagi, tiada siapa yang pernah menuduh saya fikiran hak!

Satu lagi revolusi berlaku sepanjang abad yang lalu — Mekanik Kuantum, yang telah menghapuskannya tanggapan kami dan penentuan pukulan serius kepada paradigma sistem-pemerhati fizik. Revolusi yang sama akan berlaku lagi. Mari kita tidak berpegang kepada konsep kita sebagai tidak berubah; mereka tidak. Mari kita tidak fikir tuan-tuan lama seperti ma'sum, kerana mereka tidak. Sebagai Feynman sendiri akan menunjukkan, fizik sahaja memegang lebih contoh-contoh kesilapan dari tuan lama. Dan saya merasakan bahawa revolusi yang lengkap dalam pemikiran adalah tertunggak kini.

Anda mungkin tertanya-tanya apa semua ini mempunyai kaitan dengan seks. Baik, Saya hanya fikir seks akan menjual lebih baik. Saya adalah betul, bukan saya? Maksud saya, anda masih di sini!

Feynman juga berkata,

Gambar oleh "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. dalam QM, observations are probabilistic in nature. Iaitu, 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, misalnya, 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, yang). And if God cannot place one tiny electron where He wants, how is he going to control the whole universe?