In contemporary physics, quantum mechanics (QM) and quantum field theory (QFT) are hailed as "the most successful theories" — their predictive accuracy reaches an astonishing dozen decimal places, underpinning modern technologies from microchips and lasers to particle colliders and magnetic resonance imaging. However, a sharp yet long-avoided question remains unresolved: Do these theories truly "explain nature," or merely "compute numbers"?

A growing number of physicists, philosophers of science, and reflective engineers have come to recognize that mainstream quantum theories today, due to their systematic abandonment of realism, have fallen into a profound explanatory crisis. Instead of revealing the operating mechanisms of the microscopic world, they have created a host of avoidable cognitive confusions. Without a fundamental realism-oriented reconstruction, physics will gradually lose its scientific essence as a discipline for "understanding the world" and degenerate into an elaborate yet empty metaphysics.

I. Emptiness Behind Success: The "Instrumentalist Trap" of Quantum Theory

The standard formulation of quantum mechanics — particularly the Copenhagen interpretation — explicitly asserts:

"Do not ask where the electron is before measurement; the question is meaningless."

This instrumentalist stance reduces physical theories entirely to "algorithms for predicting observational outcomes," rather than physical pictures describing how the world actually operates. Its direct consequences are:

• The wave function is treated as a purely mathematical tool for calculating probabilities, not corresponding to any physical reality.

• Particles lose definite ontological status: they are point-like entities in some contexts and diffused probability clouds in others.

• The vacuum is depicted as a "boiling sea of virtual particles," filled with constantly appearing and annihilating virtual electron-positron pairs, even though these "virtual particles" can never be directly observed.

• The measurement process requires the artificial introduction of "wave function collapse," yet fails to explain the physical mechanism or conditions for this process.

📊 The result: Theories can make correct calculations, but cannot answer the most basic, naive physical questions such as "Why are atoms stable?" "How is light emitted?" and "What exactly is an electron?"

This is analogous to possessing a black-box model that accurately predicts the weather, yet knowing nothing about atmospheric movements, water vapor cycles, or pressure gradients — this is not science, but advanced divination. The goal of science has never been to "fit data," but to understand causal mechanisms.

II. Five Deep Cognitive Dilemmas Created by Quantum Theory

Instead of explaining nature, the mainstream quantum framework actively generates the following interconnected cognitive dilemmas, which have seriously hindered the further development of physics:

1. The Measurement Problem: The Split Between Classical and Quantum

Why can microscopic systems exist in superpositions (e.g., electrons passing through two slits simultaneously), while macroscopic instruments always yield definite results (e.g., a bright spot on a screen)? The standard theory cannot consistently explain the "quantum-classical transition," forcing the introduction of the vague concept of an "observer," and even invoking alternative explanations such as consciousness, information, or "environmental decoherence." None of these, however, can truly resolve the question of "why only one result emerges."

2. Loss of Reality: Does the World Exist Independently?

If electrons have no definite positions, electromagnetic fields are merely operator-valued distributions, and the vacuum is filled with unobservable virtual particles, what objective reality remains in the physical world? Science has degenerated from "exploring reality" to "manipulating symbols," and students are trained to be "algorithm engineers" rather than explorers of nature.

3. The Vacuum Catastrophe: A Vast Chasm Between Theory and Reality

The vacuum energy density predicted by QFT is 120 orders of magnitude higher than astronomical observations (via cosmic acceleration) — the most severe predictive failure in the history of physics. Its root cause lies in mistaking mathematical divergences for physical reality, and treating intermediate quantities (virtual particles) in path integrals or perturbative expansions as real existences.

4. The Collapse of the Particle Concept

In relativistic QFT, "particle number" is not absolute: a uniformly accelerating observer perceives a thermal bath (the Unruh effect), while an inertial observer perceives a vacuum. This means even the basic question of "what matter is composed of" loses an objective answer. If particles depend on the observer, can "elementary particles" still be considered elementary?

5. Nonlocality and the Crisis of Causality

Quantum entanglement implies spooky action-at-a-distance correlations. While it does not transmit information (thus not violating the signal constraint of special relativity), it fundamentally conflicts with the spirit of local causality emphasized by relativity. Bell's theorem forces physicists to make a painful choice between "abandoning realism" or "abandoning locality" — both cornerstones of modern physics.

❗ These are not "esoteric philosophical questions," but alarms of the theory's internal inconsistency. A truly successful physical theory should eliminate confusion, not institutionalize it.

III. Science Must Be Realist: Otherwise, It Is Metaphysics

The fundamental distinction between science and metaphysics lies in:

Science describes an objective world independent of observers and provides testable, intervenable causal mechanisms; metaphysics offers logically consistent but unfalsifiable narratives.

History has repeatedly proven that realism is the engine of scientific progress:

• James Clerk Maxwell firmly believed that electromagnetic fields are real physical entities, daring to predict electromagnetic waves, which were ultimately confirmed by Heinrich Hertz's experiments.

• Albert Einstein questioned "why the speed of light is constant for all inertial frames," leading to the establishment of relativity and reshaping our understanding of space and time.

• Louis de Broglie hypothesized that "particles are accompanied by real pilot waves," giving birth to Erwin Schrödinger's wave mechanics.

• Schrödinger himself lamented in his later years: "We have never truly solved the quantum problem; we have only learned to live with it."

In contrast, today:

• Students are taught "not to imagine electron orbits."

• Researchers are warned "not to ask if the wave function is real."

• Any attempt to construct a physical picture of the electron is often labeled as "outdated," "pseudoscientific," or even "anti-quantum."

🚫 When physics forbids asking "what the world is," it ceases to be science and becomes a ritualized computational religion.

IV. The Way Forward: Reconstructing the Realist Foundation of Quantum Theory

Fortunately, the realist path has not been severed. In recent years, the global approximation interpretation can reanchor quantum theory in classical realism, realizing the "classical origin of quantum phenomena."

1. Quantum Mechanics as a Spectral Image of Classical Physics

• The electron is a real charged entity (or a stable electromagnetic structure), primarily undergoing high-frequency radial oscillations in the Coulomb field of the atomic nucleus, rather than orbiting it.

• The wave function ψ is not a physical field, but a mathematical representation of this complex oscillatory spectrum (similar to Fourier analysis).

• |ψ|² is the long-time average density of the charge distribution, naturally explaining the origin of "probability."

• Energy levels correspond to the eigenmodes of electromagnetic resonators, and quantization is an emergent result of boundary conditions and stability constraints, requiring no "quantum postulates."

2. Quantum Field Theory Should Be Reduced to Classical Field Dynamics

• "Electron fields" and "photon fields" are not fundamental entities, but collective spectral descriptions of the high-frequency behavior of many-particle systems or continuous classical fields.

• "Particle creation/annihilation" is the transfer of energy between different oscillatory modes, analogous to a guitar string being excited from one harmonic to another.

• "Virtual particles" are merely intermediate terms in perturbative calculations, similar to imaginary currents in circuit analysis, with no physical reality.

• The vacuum is the classical ground state with no real excitations, which may contain a static zero-point field but is by no means a "boiling sea of particles."

• Intrinsic properties such as spin and magnetic moment should be understood as rotational or circulatory degrees of freedom of the electron as a classical electromagnetic structure, rather than mysterious "intrinsic quantum numbers."

3. Measurement as a Natural Nonlinear Interaction Process

• Detectors (e.g., photomultiplier tubes, cloud chambers) are themselves macroscopic nonlinear systems.

• Microscopic perturbations are amplified into macroscopically distinguishable signals through initial-value-sensitive (chaotic) or positive-feedback mechanisms (e.g., avalanche breakdown).

• "Collapse" is the result of the system entering a certain dynamic attractor, a natural phenomenon of classical nonlinear dynamics that requires no artificial intervention or mysterious postulates.

✅ This framework retains all the successful predictions of quantum theory (e.g., energy levels, scattering cross-sections, interference patterns) while completely discarding its metaphysical baggage, restoring the intelligibility, causality, and realism of physics.

V. Conclusion: Returning to the Original Aspiration of Science

The mission of physics has never been "Shut up and calculate!" but to understand how nature truly operates.

The brilliant achievements of current quantum theory have masked its deep philosophical crisis. It resembles a magnificent palace without a foundation — barely held up by constantly adding "interpretations," "effective theories," and "renormalization schemes." A true scientific edifice must be built on the cornerstones of reality, causality, and intelligibility.

Realism is not nostalgia, but scientific discipline; reconstruction is not subversion, but redemption.

As Einstein put it:

"The most incomprehensible thing about the universe is that it is comprehensible."

If we actively abandon understanding and embrace mystery, it is not a failure of nature, but a betrayal of science.

Now is the time to bring quantum theory back to realism, back to physics, and back to science — only then can we continue to pursue that oldest and greatest question: What exactly is the world?