Category Archives: physics

機遇再生論 1.2.2

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「所有」，就是「場所之有」。

沒有明確的場所，就不知所「有」何物。

「機會再生論」原始版本的邏輯矛盾來源，在於「所有」。論述中，運用「所有」這個詞語時，並沒有講清楚情境，導致它不自覺地，包括了元層次的事物。「機會再生論」原始版本的邏輯矛盾，來自「本層次」和「元層次」（meta level）的矛盾。

「

『機遇再生論』的大概意思是，所有可能發生的事情，例如重生，只要等足夠長的時間，總會發生。

假設『事件甲』不自相矛盾，它發生的機會就不是零；那樣，根據『機遇再生論』，甲終會發生。

但是，除非甲是必然事件，否則，『事件甲不會發生』都不會自相矛盾，它發生的機會都不是零；那樣，根據『機遇再生論』，『事件甲不會發生』終會發生。

機會再生論，會引起邏輯矛盾。

」

留意，「事件甲」是「本層次」的事件。但是，「事件甲不會發生」卻是「元層次」的事件，即是「元事件」。所以，如果把「機會再生論」的原始版本，修正為嚴謹版本，講清楚當中的「所有」，限於「本層件」的事件，原始版中的邏輯矛盾，就可以避免。

留意，暫時的成果，只是透過分清楚語言層次，避開了邏輯矛盾。至於「機遇再生論嚴謹版」正不正確，符不符合實情，則是另一回事，另一個話題。

— Me@2015-03-21 10:07:51 PM

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2015.03.28 Saturday (c) All rights reserved by ACHK

Logical Fatalism

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Logical Fatalism and the Argument from Bivalence

Another famous argument for fatalism that goes back to antiquity is one that depends not on causation or physical circumstances but rather is based on presumed logical truths.

The key idea of logical fatalism is that there is a body of true propositions (statements) about what is going to happen, and these are true regardless of when they are made. So, for example, if it is true today that tomorrow there will be a sea battle, then there cannot fail to be a sea battle tomorrow, since otherwise it would not be true today that such a battle will take place tomorrow.

The argument relies heavily on the principle of bivalence: the idea that any proposition is either true or false. As a result of this principle, if it is not false that there will be a sea battle, then it is true; there is no in-between. However, rejecting the principle of bivalence—perhaps by saying that the truth of a proposition regarding the future is indeterminate—is a controversial view since the principle is an accepted part of classical logic.

— Wikipedia on Fatalism

Quantum superposition can solve logical fatalism:

Macroscopic time is due to quantum decoherence.

The future is a coherent (constant phase difference) superposition of eigenstates.

That’s why classical probability can be regarded as part of quantum theory.

Quantum decoherence gives classically consistent histories.

— Me@2012.04.08

— Me@2015.03.26

2015.03.27 Friday (c) All rights reserved by ACHK

機遇再生論 1.2.1

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而這個「機會再生論」原始版本的邏輯矛盾來源，在於「所有」。

論述中，運用「所有」這個詞語時，並沒有講清楚情境，導致它不自覺地，包括了元層次的事物。「機會再生論」原始版本的邏輯矛盾，來自「本層次」和「元層次」（meta level）的矛盾。

「所有」即是「全部」，意思是「百分之一百」。但是，如果沒有明確的上文下理，講清楚是什麼的百分之一百，「百分之一百」就沒有明確的意思，不太知道所指何物。

相反，如果有明確的上文下理，就自然有明確的意思。例如，「三十元中的百分之一百」，就很明顯是指，那三十元。

又例如，「這間屋的所有人」，都有明確的意思，因為有明確的範圍；有範圍，就可點人數：

凡是在這間屋內遇到的人，包括你自己，你都記下名字，直到在這間屋，再不找到新的人為止。那樣，你就可以得到，有齊「這間屋所有人」的名單。

「所有」，就是「場所之有」。

沒有明確的場所，就不知所「有」何物。

— Me@2015-03-21 10:07:51 PM

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2015.03.21 Saturday (c) All rights reserved by ACHK

Parallel universes

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What do these parallel universes mean?

Let me begin with the term “parallel universes”. It is a term that seems to be exciting for a certain large group of the laymen (and filmmakers) although it creates almost no excitement among most professional physicists. The phrase has been given at least three vastly different meanings:

– different histories that could occur in quantum mechanics interpreted with the many-worlds interpretation

– different stringy vacua that may or may not be connected with ours by bubble nucleation within eternal inflation

– different branes that may be parallel to our, Standard Model brane in our world if it is a braneworld

Again, professionals would never confuse these three concepts but the laymen and filmmakers often do – because what they really understand about these concepts are just the two words, “parallel universes”. With this poor resolution of their wavelets, the very different concepts above may coincide.

— Lubos Motl

2015.03.10 Tuesday ACHK

機遇再生論

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「機遇再生論」的大概意思是，所有可能發生的事情，例如重生，只要等足夠長的時間，總會發生。

假設「事件甲」不自相矛盾，它發生的機會就不是零；那樣，根據「機遇再生論」，甲終會發生。

但是，除非甲是必然事件，否則，「事件甲不會發生」都不會自相矛盾，它發生的機會都不是零；那樣，根據「機遇再生論」，「事件甲不會發生」終會發生。

機會再生論，會引起邏輯矛盾。

— Me@2015-03-02 05:10:07 PM
 
 
 
2015.03.09 Monday (c) All rights reserved by ACHK

Quantum decoherence 7

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There is no room for a physical collapse or, on the contrary, for an ad hoc privileged role of conscious observers; the wave functions only predict the probabilities but they can be calculated for any set of consistent histories, regardless of whether the systems look conscious, unconscious, macroscopic, or microscopic; the only “collapse” that occurs is the rapid diagonalization of the density matrix in the preferred basis by the interactions with the environment; however, the “unrealized” diagonal entries of the matrix (probabilities of outcomes that won’t come true) are never “physically” set to zero because their interpretation always remains probabilistic, even when the classical approximation becomes acceptably accurate[.]

— Decoherence is a settled subject

— Lubos Motl

2015.02.19 Thursday ACHK

Interstellar

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Interstellar is a 2014 space adventure film directed by Christopher Nolan.

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Director Christopher Nolan said influences on Interstellar included the “key touchstones” of science fiction cinema; Metropolis (1927), 2001: A Space Odyssey (1968), and Blade Runner (1982). Nolan said about 2001, “The movies you grow up with, the culture you absorb through the decades, become part of your expectations while watching a film. So you can’t make any film in a vacuum. We’re making a science-fiction film… You can’t pretend 2001 doesn’t exist when you’re making Interstellar.” He also said Star Wars (1977) and Alien (1979) influenced Interstellar ‘​s production design: “Those always stuck in my head as being how you need to approach science-fiction. It has to feel used — as used and as real as the world we live in.” Andrei Tarkovsky’s The Mirror influenced “elemental things in the story to do with wind and dust and water”.

Early in the process, Thorne laid down a couple of guidelines; that nothing would violate established physical laws, and that all the wild speculations would spring from science and not from the fertile mind of a screenwriter. Nolan accepted these terms as long as they did not get in the way of the making of the movie. At one point Thorne, spent two weeks trying to talk Nolan out of an idea about a character travelling faster than light before Nolan finally gave up. According to Thorne, the element which has the highest degree of artistic freedom is the clouds of ice on one of the planets they visit, which are structures that probably go beyond the material strength that ice would be able to support.

— Wikipedia on Interstellar (film)

2014.11.13 Thursday ACHK

Cartesian Dualism 2

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Transcend duality and non-duality

Duality is correct, in the sense that mind (software) and matter (hardware) are independent.

They are independent in the sense that a piece of software inside a computer (hardware) can be transferred or copied onto another computer. It can continue to exist even after that particular computer ceases to. 

Non-duality is correct, in the sense that mind (software) is pattern of matter (hardware).

They are not two “things”. They are two aspects of the same “thing”.

— Me@2014-10-04 11:57:06 AM

2014.11.07 Friday (c) All rights reserved by ACHK

Cartesian Dualism

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In philosophy of mind, dualism is the position that mental phenomena are, in some respects, non-physical, or that the mind and body are not identical. Thus, it encompasses a set of views about the relationship between mind and matter, and is contrasted with other positions, such as physicalism, in the mind–body problem.

— Wikipedia on Dualism (philosophy of mind)

The mind–body problem in philosophy examines the relationship between mind and matter, and in particular the relationship between consciousness and the brain.

The problem was famously addressed by Rene Descartes in the 17th century, resulting in Cartesian dualism, and by pre-Aristotelian philosophers, in Avicennian philosophy, and in earlier Asian traditions. A variety of approaches have been proposed. Most are either dualist or monist. Dualism maintains a rigid distinction between the realms of mind and matter. Monism maintains that there is only one unifying reality, substance or essence in terms of which everything can be explained.

— Wikipedia on Mind–body problem

2014.10.10 Friday ACHK

Heisenberg

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My first query is why does he claim the position and period of an electron to be unobservable “in principle”? There was theoretically no reason (at THAT time) to doubt that these quantities could be measured, though certainly they were indeterminate practically.

Werner Heisenberg obviously disagreed with this assumption of yours and it just happened that his ability to disagree made him a founder of quantum mechanics.

He has spent several years by trying to develop “quantized planetary” models of the helium atom etc. before he understood that this failing project is failing for fundamental reasons. Such a helium with well-defined positions would be described by a chaotic 3-body problem and there would be no way how it could be consistent with the known regular behavior of the helium atom (and other atoms and other coherent systems), including the sharp spectral lines.

So Heisenberg was able to see in 1925 something that you can’t see now: that the electrons can’t be going along any particular trajectories while they’re in the atoms. Instead, what is observed is that they have a totally sharp energy from a possible list, the spectrum – something we can really observe via the photons that atoms emit or absorb. To conclude that electrons can’t be going along particular classical trajectories in the atoms, he didn’t have to wait for measuring apparatuses that would be sufficiently accurate. He was able to make this conclusion out of the available data by “pure thought”, and he was right.

— Lubos Motl

2014.10.04 Saturday ACHK

String theory rivals

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Does string theory have rivals? The answer by the most cited theoretical physicist (and perhaps scientist) is that there are not any interesting competing suggestions. Be sure that people attending my popular talks (and sometimes radio hosts etc.) often ask the same question and I give the same answer. One reason, as Witten reminds us, is that ideas that actually have something good about them, like twistors and noncommutative geometry, are gradually identified as aspects of string theory itself and absorbed by string theory. It’s just how the things are.

— An interview with Edward Witten at a bizarre place

— Lubos Motl

2014.10.01 Wednesday ACHK

Liouville equation

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Quantum Liouville equation

The analog of Liouville equation in quantum mechanics describes the time evolution of a mixed state. Canonical quantization yields a quantum-mechanical version of this theorem, the Von Neumann equation. This procedure, often used to devise quantum analogues of classical systems, involves describing a classical system using Hamiltonian mechanics. Classical variables are then re-interpreted as quantum operators, while Poisson brackets are replaced by commutators.

— Wikipedia on Liouville’s theorem (Hamiltonian)

2014.09.28 Sunday ACHK

Higgs boson

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The Higgs mechanism explains only a small fraction of the mass in the universe.

Most popular science articles give the Higgs model broad credit for lending mass to everything in the universe. However, the Higgs field gives mass only to elementary particles such as quarks and electrons. Most of the visible universe is made of composite particles such as protons and neutrons, which contain quarks. Just as a loaf of raisin bread weighs more than the sum of its raisins, protons and neutrons get their mass from more than just the quarks inside them. The strong nuclear force that holds those quarks together does most of the mass-giving work.

— Ten things you may not know about the Higgs boson

— Kathryn Jepsen

2014.09.16 Tuesday ACHK

Physical information

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Information itself may be loosely defined as “that which can distinguish one thing from another”. The information embodied by a thing can thus be said to be the identity of the particular thing itself, that is, all of its properties, all that makes it distinct from other (real or potential) things. It is a complete description of the thing, but in a sense that is divorced from any particular language.

— Wikipedia on Physical information

2014.09.12 Friday ACHK

Extreme physical information

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In a theory developed by B. Roy Frieden, “physical information” is defined as the loss of Fisher information that is incurred during the observation of a physical effect. Thus, if the effect has an intrinsic information level J but is observed at information level I, the physical information is defined to be the difference I − J. This defines an information Lagrangian. Frieden’s principle of extreme physical information or EPI states that extremalizing I − J by varying the system probability amplitudes gives the correct amplitudes for most or even all physical theories. The EPI principle was recently proven. It follows from a system of mathematical axioms of L. Hardy defining all known physics.

— Wikipedia on Physical information

2014.08.31 Sunday ACHK

Integrating factor

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In mathematics, an integrating factor is a function that is chosen to facilitate the solving of a given equation involving differentials. It is commonly used to solve ordinary differential equations, but is also used within multivariable calculus when multiplying through by an integrating factor allows an inexact differential to be made into an exact differential (which can then be integrated to give a scalar field). This is especially useful in thermodynamics where temperature becomes the integrating factor that makes entropy an exact differential.

— Wikipedia on Integrating factor

2014.08.26 Tuesday ACHK