Posts Tagged ‘Measurement’

TO BE AND NOT TO BE? Is Entangled Physics Thinking, Or Sinking?

April 29, 2016

Frank Wilczek, a physics Nobel laureate, wrote a first soporific, and then baffling article in Quanta magazine: “Entanglement Made Simple”. Yes, all too simple: it sweeps the difficulties under the rug. After a thorough description of classical entanglement, we are swiftly told at the end, that classical entanglement supports the many World Interpretation of Quantum Mechanics. However, classical entanglement (from various conservation laws) has been known since the seventeenth century.

Skeptical founders of Quantum physics (such as Einstein, De Broglie, Schrodinger, Bohm, Bell) knew classical entanglement very well. David Bohm found the Bohm-Aharanov effect, which demonstrated the importance of (nonlocal) potential, John Bell found his inequality which demonstrated, with the help of experiments (Alain Aspect, etc.) that Quantum physics is nonlocal.

Differently From Classical Entanglement, Which Acts As One, Quantum Entanglement Acts At A Distance: It Interferes With Measurement, At A Distance

Differently From Classical Entanglement, Which Acts As One, Quantum Entanglement Acts At A Distance: It Interferes With Measurement, At A Distance

The point about the cats is that everybody, even maniacs, ought to know that cats are either dead, or alive. Quantum mechanics make the point they can compute things about cats, from their point of view. OK.

Quantum mechanics, in their busy shops, compute with dead and live cats as possible outcomes. No problem. But then does that mean there is a universe, a “world“, with a dead cat, happening, and then one with a live cat, also happening simultaneously?

Any serious philosopher, somebody endowed with common sense, the nemesis of a Quantum mechanic, will say no: in a philosopher’s opinion, a cat is either dead, or alive. To be, or not to be. Not to be, and not to be.

A Quantum mechanic can compute with dead and live cats, but that does not mean she creates worlds, by simply rearranging her computation, this way, or that. Her various dead and live cats arrangements just mean she has partial knowledge of what she computes with, and that Quantum measurements, even from an excellent mechanic, are just partial, mechanic-dependent measurements.

For example, if one measures spin, one needs to orient a machine (a Stern Gerlach device). That’s just a magnetic field going one way, like a big arrow, a big direction. Thus one measures spin in one direction, not another.

What’s more surprising is that, later on, thanks to a nonlocal entanglement, one may be able to determine that, at this point in time, the particle had a spin that could be measured, from far away, in another direction. So far, so good: this is like classical mechanics.

However, whether or not that measurement at a distance has occurred, roughly simultaneously, and way out of the causality light cone, EFFECTS the first measurement.

This is what the famous Bell Inequality means.

And this is what the problem with Quantum Entanglement is. Quantum Entanglement implies that wilful action somewhere disturbs a measurement beyond the reach of the five known forces. It brings all sorts of questions of a philosophical nature, and make them into burning physical subjects. For example, does the experimenter at a distance have real free will?

Calling the world otherworldly, or many worldly, does not really help to understand what is going on. Einstein’s “Spooky Interaction At A Distance” seems a more faithful, honest rendition of reality than supposing that each and any Quantum mechanic in her shop, creates worlds, willy-nilly, each time it strikes her fancy to press a button.

What Mr. Wilczek did is what manyworldists and multiversists always do: they jump into their derangement (cats alive AND dead) after saying there is no problem. Details are never revealed.

Here is, in extenso, the fully confusing and unsupported conclusion of Mr. Wilczek:

“Everyday language is ill suited to describe quantum complementarity, in part because everyday experience does not encounter it. Practical cats interact with surrounding air molecules, among other things, in very different ways depending on whether they are alive or dead, so in practice the measurement gets made automatically, and the cat gets on with its life (or death). But entangled histories describe q-ons that are, in a real sense, Schrödinger kittens. Their full description requires, at intermediate times, that we take both of two contradictory property-trajectories into account.

The controlled experimental realization of entangled histories is delicate because it requires we gather partial information about our q-on. Conventional quantum measurements generally gather complete information at one time — for example, they determine a definite shape, or a definite color — rather than partial information spanning several times. But it can be done — indeed, without great technical difficulty. In this way we can give definite mathematical and experimental meaning to the proliferation of “many worlds” in quantum theory, and demonstrate its substantiality.”

Sounds impressive, but the reasons are either well-known or then those reasons use a sleight of hand.

Explicitly: “take both of two contradictory property-trajectories into account”: just read Feynman QED, first chapter. Feynman invented the ‘sum over histories’, and Wilczek is his parrot; but Feynman did not become crazy from his ‘sum over history’: Richard smirked when his picturesque evocation was taken literally, decades later…

And now the sleight of hand: …”rather than  [gather] partial information spanning several times. But it can be done — indeed, without great technical difficulty.” This nothing new: it is the essence of the double slit discovered by that Medical Doctor and polymath, Young, around 1800 CE: when one runs lots of ‘particles’ through it, one sees the (wave) patterns. This is what Wilczek means by “partial information“. Guess what? We knew that already.

Believing that one can be, while not to be, putting that at the foundation of physics, is a new low in thinking. And it impacts the general mood, making it more favorable towards unreason.

If anything can be, without being, if anything not happening here, is happening somewhere else, then is not anything permitted? Dostoyevsky had a Russian aristocrat suggests that, if god did not exist anything was permitted. And, come to think of it, the argument was at the core of Christianism. Or more, exactly, of the Christian reign of terror which started in the period 363 CE-381 CE, from the reigns of emperor Jovian to the reign of emperor Theodosius. To prevent anything to be permitted, a god had to enforce the law.

What we have now is way worse: the new nihilists (Wilczek and his fellow manyworldists) do not just say that everything is permitted. They say: it does not matter if everything is permitted, or not. It is happening, anyway. Somewhere.

Thus Many-Worlds physics endangers, not just the foundations of reason, but the very justification for morality. That is that what is undesirable should be avoided. Even the Nazis agreed with that principle. Many-Worlds physics says it does not matter, because it is happening, anyway. Somewhere, out there.

So what is going on, here, at the level of moods? Well, professor Wilczek teaches at Harvard. Harvard professors advised president Yeltsin of Russia, to set up a plutocracy. It ruined Russia. Same professors made a fortune from it, while others were advising president Clinton to do the same, and meanwhile Prime Minister Balladur in France was mightily impressed, and followed this new enlightenment by the Dark Side, as did British leaders, and many others. All these societies were ruined in turn. Harvard was the principal spirit behind the rise of plutocracy, and the engine propelling that rise, was the principle that morality did not matter. because, because, well, Many-Worlds!

How does one go from the foundations of physics, to the foundations of plutocracy? Faculty members in the richest, most powerful universities meet in mutual admiration societies known as “faculty clubs” and lots of other I scratch-your-back, you scratch-my-back social occasion they spend much of their time indulging in. So they influence each other, at the very least in the atmospheres of moods they create, and then breathe together.

Remember? It is not that everything is permitted: it’s happening anyway, so we may as well profit from it first. Many-Worlds physics feeds a mood favorable to many plutocrats, and that’s all there is to it. (But that, of course, is a lot, all too much.)

Patrice Ayme’

REALITY: At Your COMMAND, FASTER Than LIGHT

September 11, 2015

Feynman:”It is safe to say that no one understands Quantum Mechanics.” 

Einstein: “Insanity is doing the same thing over and over and expecting different results.”

Nature: “That’s how the world works.”

Wilzcek (Physics Nobel Prize): “Naïveté is doing the same thing over and over, and always expecting the same result.”

Parmenides, the ancient Greek philosopher, theorized that reality is unchanging and indivisible and that movement is an illusion. Zeno, a student of Parmenides, devised four famous paradoxes to illustrate the logical difficulties in the very concept of motion. Zeno’s arrow paradox starts and ends this way:

  • If you know where an arrow is, you know everything about its physical state….
  • The arrow does not move…

Classical Mechanics found the first point to be erroneous. To know the state of a particle, one must know not only its position X, but also its velocity and mass (what’s called its momentum P). Something similar happens with Quantum Physics. To know the state of a particle, we need to know whether the state of what it has interacted with before…  exists, or not. According to old fashion metaphysics, that’s beyond weird. It’s simply incomprehensible.

The EPR Interaction: Zein Und Zeit. For Real.

The EPR Interaction: Zein Und Zeit. For Real.

[The Nazi philosopher Heidegger, an ex would-be priest, wrote a famous book “Being And Time“. However, rather than a fascist fantasy, the EPR is exactly about that level of depth: how existence and time come to be! And how those interact with our will…]

With that information, X and P, position and momentum, for each particle, classical mechanics predicts a set of particles’ future evolution completely. (Formally dynamic evolution satisfies a second order linear differential equation. That was thoroughly checked by thousands of officers of gunnery, worldwide, over the last five centuries.)

Highly predicting classical mechanics is the model of Einstein Sanity.

Aristotle had ignored the notion of momentum, P. For Aristotle, one needed a force to maintain motion (an objective proof of Aristotle’s stupidity; no wonder Aristotle supported, and instigated, fascist dictatorship as the best system of governance). Around 1320 CE, the Parisian genius Buridan declared that Aristotle was completely wrong and introduced momentum P, calling it “IMPETUS”.

May we be in a similar situation? Just like the Ancient Greeks had ignored P, is Quantum Wave Mechanics incomplete from an inadequate concept of what a complete description of the world is?

Einstein thought so, and demonstrated it to his satisfaction in his EPR Thought Experiment. The EPR paper basically observed that, according to the Quantum Axiomatics, two particles, after they interacted still formed JUST ONE WAVE. Einstein claimed that there had to exist hidden “elements of reality”, not yet identified in the (Copenhagen Interpretation of) quantum theory. Those heretofore hidden “elements of reality” would re-establish Einstein Sanity, Einstein feverishly hoped.

According to Einstein, following his friend Prince Louis De Broglie (to whom he had conferred the Doctorate) and maybe the philosopher Karl Popper (with whom he corresponded prior on non-locality), Quantum Mechanics appears random. But that randomness is only because of our ignorance of those “hidden variables.” Einstein’s demonstration rested on the impossibility of what he labelled “spooky action at a distance”.

That was an idea too far. The “spooky action at a distance” has been (amply) demonstrated in the meantime. Decades of experimental tests, including a “loophole-free” test published on the scientific preprint site arxiv.org last month, show that the world is like that: completely non-local everywhere.

In 1964, the physicist John Bell, CERN’s theory chief, working with David Bohm’s version of Einstein’s EPR thought experiment, identified an inequality obeyed by any physical theory that is both local — meaning that interactions don’t travel faster than light — and where the physical properties usually attributed to “particles” exist prior to “measurement.”

(As an interesting aside, Richard Feynman tried to steal Bell’s result, at a time when Bell was not famous, at least in the USA: a nice example of “French Theory” at work! And I love Feynman…)

Einstein’s hidden “elements of reality” probably exist, but they are NON-LOCAL. (Einstein was obsessed by locality; but that’s an error. All what can be said in favor of locality is that mathematics, and Field Theory, so far, are local: that’s the famous story of the drunk who looks for his keys under the lamp post, because that’s the only thing he sees.)

Either some physical influences travel faster than light, or some properties don’t exist before measurement. Or both

I believe both happen. Yes, both: reality is both faster than light, and it is pointwise fabricated by interactions (“measurement”). Because:

  1. The EPR Thought Experiment established the faster than light influence (and that was checked experimentally).
  2. But then some properties cannot exist prior to “EPR style influence”. Because, if they did, why do they have no influence whatsoever, once the EPR effect is launched?

Now visualize the “isolated” “particle”. It’s neither truly “isolated” nor truly a “particle”, as some of its properties have not come in existence yet. How to achieve this lack of existence elegantly? Through non-localization, as observed in the one-slit and two-slit experiments.

Why did I say that the “isolated” “particle” was not isolated? Because it interfered with some other “particle” before. Of course. Thus it’s EPR entangled with that prior “particle”. And when that “particle” is “measured” (namely INTERACTS with another “particle”), the so-called “isolated” “particle” gets changed, by the “spooky action at a distance”, at a speed much faster than light.

(This is no flight of fancy of mine, consecutive to some naïve misinterpretation; Zeilinger and Al. in Austria, back-checked the effect experimentally; Aspect in Paris and Zeilinger got the Wolf prize for their work on non-locality, so the appreciation for their art is not restricted to me!)

All these questions are extremely practical: they are at the heart of the difficulties in engineering a Quantum Computer.

Old physics is out of the window. The Quantum Computer is not here yet, because the new physics is not understood enough, yet.

Patrice Ayme’