Quantum Reality: Beyond the New Physics

by Nick Herbert

How does quantum theory describe a quantum entity?

How does quantum theory describe a physical attribute?

How does quantum theory describe a measure...

QUANTUM ENTITIES

Most important for quantum theory, the wave function by virtue of the synthesizer theorem can be expressed as the sum of members of numerous waveform families.

One way in which Ψ differs from ordinary waves is that it carries no energy.

For a quantum wave, the square of its amplitude (at location x) represents not energy but probability, the probability that a particle—a localized packet of energy—will be ...

Since Ψ stands for probability, the wave function is often called a probability wave. However, it is Ψ, not Ψ2 which actually represents a quantum entity.

The relationship between quantum possibility and probability is simple: probability = (possibility)2 The amplitude of a quantum wave is its possibility. The square of a possibility is a probability.

Einstein called Ψ a Gespensterfeld or ghost field. Since it carries no energy, the wave function is also referred to as an empty wave. In France, the Ψ wave is called by a beautiful name—densité de présence, or “presence density.”

Because quantum possibilities add like waves, not like things, physical possibilities can vanish if their representative waves happen to meet out of phase.

One of Glashow’s best arguments for the charmed quark’s existence was the nonexistence of a particular decay mode of the K-particle.

Glashow tailored the properties of the new quark so that its possibility wave was opposite in phase from the strange quark’s wave.

Today quark theory is a cornerstone of particle physics. Theorists see a need for two more quark flavors (top and bottom), making six flavors in all.

This destructive interference of a quark’s physical attribute (its ability to decay into muons) represents a routine application of quantum concepts at the frontiers of present knowledge.

How does quantum theory describe a quantum entity?—is this: quantum theory does not “describe” entities at all; it represents them.

QUANTUM ATTRIBUTES

The most significant word in the quantum vocabulary is the term “attribute.”

Because M already stands for mass, the dynamic attribute linear momentum (often shortened to momentum) is symbolized by the letter P. A quon’s momentum measures how fast it is moving and in what direction. Like position, momentum has three components, symbolized Px, Py, Pz, which tell how fast the quon’s moving in the x, y, z directions.

QUANTUM MEASUREMENT

“soft prisms,”

Step one

Step two

Step three:

Step four:

Step five

Quantum theory’s representation of attributes as waveforms gives us a new way to look at the Heisenberg uncertainty principle (HUP). According to HUP, every attribute A possesses a conjugate attribute V. For any quon, try as you will, you cannot reduce the mutual measurement error associated with these two attributes below a certain natural limit.

HEISENBERG’S PRINCIPLE FOR TWO-VALUED ATTRIBUTES

Each molecule is a heavenly octopus with a million floating jeweled tentacles hungry to merge. Timothy Leary

Quantum theory—the math that describes these facts—likewise reflects each quon’s double identity by representing an unmeasured entity by a particular waveshape—whose form encodes the probability of observing a particle-like event with definite location and attributes.

we take quantum theory seriously as a picture of what’s really going on, each measurement does more than disturb: it profoundly reshapes the very fabric of reality.

In terms of the whale/wasp analogy, the quantum reality question divides into two parts: 1. what is the nature of the whale? 2. how does the whale change into a wasp? The quest to describe the whale is called the “quantum interpretation question.”

The matter of how whale becomes wasp is called the quantum measurement problem: what does the quantum representation of a measurement—as a soft prism splitting a proxy wave into waveforms—tell us about what actually goes on in the measurement act?

the quantum interpretation question. What is the nature of quon unmeasured? Can we describe the world’s unseen whales in words or must we remain silent? In between observations a quon is represented by its proxy wave: the wave function is the best clue we have concerning the real nature of the unmeasured universe.

Feynman’s method, called the sum-over-histories approach, is useful not only for computations but for the insight it gives into what the wave function might mean.

To calculate the electron’s proxy wave Ψ, Feynman postulates that the wave amplitude on the screen is equal to the sum of the amplitudes of all possible ways that an electron can get there from the quon gun. Furthermore all paths are equally important, none better than any other. Feynman implements this quantum democracy of possibilities in his scheme by assigning the same amplitude to every path. Each path differs from its fellows only by its phase. A path’s phase at any location depends on its history, the route that brought it there.

FIG. 7.1 Feynman’s sum-over-histories approach to quantum theory. In Feynman’s scheme, a quon acts as though it takes all paths at once. These paths, unlike classical trajectories, possess phases which add wavewise to produce the system’s proxy wave—a representation of the probability pattern of a large number of quons prepared in the same state.

Feynman’s idea of getting probabilities by adding up possible paths has much in common with classical statistical reasoning.

Feynman’s method works: summing up all paths gives the same wave function as solving Schrödinger’s equation.

The sum-over-histories approach suggests that the quantum proxy wave represents the totality of possibilities—plus mutual phases—open to a quantum entity.

The central postulate of the orthodox ontology is this: All quons represented by the same proxy wave are physically identical. Two quons represented by the same proxy wave are said to be “in the same state.” In terms of quantum states, this postulate reads: “All quons in the same state are exactly alike.”

But because of the orthodox identity postulate, the wave function describes a single quon as well. If all quons are physically identical, the distinction between a statistical description and an individual description vanishes.

The orthodox ontology explains the fact that unmeasured electrons are identical in being but different in behavior by appealing to quantum randomness. The essence of quantum randomness is simply this: identical physical situations give rise to different outcomes.

Critics who object that this theory does not explain the observably different outcomes of electrons in the same state fail to appreciate the nature of quantum randomness: identical situations give different results. That’s all there is to it. If the orthodox ontology is a true vision of things, there’s absolutely nothing in the unmeasured electron’s physical situation that tells where it’s going to strike the screen.

Summing up the orthodox ontology: All quons in the same quantum state are physically identical. The wave function gives a complete account of the physical situation of a single quon. The relationship of the experimenter to an unmeasured quon is one of quantum ignorance: the knowledge he lacks is simply not there to be known. A single unmeasured quon takes all paths open to it. Measured differences between identical unmeasured quons arise from quantum randomness.

neorealism.

these heretics from the orthodox view are sometimes called “hidden-variable” physicists.

In a typical hidden-variable model of reality, the world is described in the same manner whether observed or not. The

Bell’s theorem shows that all efforts to eliminate the superluminal character of these waves must fail. Bell proves (among other things) that it is impossible to construct a hidden-variable model which explains the facts without including something that goes faster than light.

The quantum interpretation question is concerned with the nature of unmeasured reality: what is the relationship between reality and its representation, the fictitious proxy wave Ψ?