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Main positions:Director, High Performance Computing Platform, PKU
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Lei Yian

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Education Level: Postgraduate (Doctoral)

Administrative Position: Associate Professor

Alma Mater: Peking University

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The Pernicious Consequences of Wave-Particle Duality
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Introduction: A Century of Conceptual Disaster

Quantum mechanics's wave-particle duality principle, claiming that all matter is both particle and wave. This seemingly profound concept has actually brought catastrophic consequences to physics. A century later, not only have we failed to resolve the perplexities arising from this "duality," but we have also strayed further down the wrong path, ultimately pushing physics into the abyss of mysticism.

The most fatal consequence is this: wave-particle duality forced us to adopt the point-particle assumption. When we say an electron is "both particle and wave," the "particle" is understood as a mathematical point with no spatial extension. This seemingly harmless assumption has fundamentally destroyed the most basic intuitiveness of physics, turning spin—one of the most important physical properties of particles—into an incomprehensible abstract concept.

I: Spin Becomes Impossible

The Collapse of Rotational Mathematics

Let us conduct a rigorous mathematical analysis. For a spherical electron with radius r, if it rotates with angular velocity ω, its angular momentum is:L = Iω = (2/5)mr²ω

The spin angular momentum of an electron is ħ/2, so:ω = 5ħ/(4mr²)

The linear velocity at the electron's surface is:v = rω = 5ħ/(4mr)

To ensure v < c (not exceeding the speed of light), we require:r > 5ħ/(4mc) = (5/4)λC

where λC = ħ/mc = 3.86×10^-13 m is the electron's Compton wavelength.

This result is extremely profound: the electron must have a scale of at least the Compton wavelength to physically rotate without violating relativity!

The Paradox of the Classical Electron Radius

The classical electron radius is defined as:re = e²/(4πε₀mc²) = 2.82×10^-15 m

This is 137 times smaller than the Compton wavelength (the fine-structure constant α ≈ 1/137):re = αλC

If the electron were truly as small as the classical radius, its surface velocity would be:v = 5ħ/(4mre) = 5c/(4α) ≈ 172c

172 times the speed of light! This is absurd. What was the physicists' solution? To avoid the problem entirely by declaring the electron a point particle and spin an "intrinsic" property.

The Quantitative Disaster of Magnetic Moment

The experimental value of the electron's magnetic moment is:μ = g(eħ)/(2m), g ≈ 2.002

If the electron were a rotating uniformly charged sphere of radius r, its magnetic moment should be:μ_classical = (eωr²)/3 = 5eħ/(12m)

This gives g = 5/6 ≈ 0.83, which is vastly different from the experimental value!

Worse still, for a point particle (r → 0), the magnetic moment should be zero! Quantum electrodynamics (QED) "calculates" the g-factor through complex renormalization, but this is merely a mathematical trick that fails to explain the physical origin of the magnetic moment.

II: Misunderstanding of the Compton Wavelength

The Neglected Physical Scale

The Compton wavelength λC = h/mc pervades quantum mechanics:

  • Compton scattering formula: Δλ = λC(1 - cosθ)

  • Characteristic scale of the Dirac equation: ∇ ~ 1/λC

  • Threshold for electron-positron pair production: E > 2mc², corresponding to λ < λC

The standard interpretation claims this is the scale of "quantum uncertainty." But a more natural understanding is: the Compton wavelength is the actual physical size of the particle!

Mathematical Self-Consistency

Consider the Dirac equation:iħ(∂ψ/∂t) = (cα·p + βmc²)ψ

The energy-momentum relation of its plane-wave solutions is:E² = p²c² + m²c⁴

When p = 0, the rest energy E = mc² corresponds to a de Broglie wavelength of λ = h/p → ∞ (incorrect!).

However, considering Zitterbewegung (trembling motion), the electron is actually undergoing microscopic oscillations at the speed of light, with an amplitude exactly equal to:Δx ~ λC

This is no coincidence! The Compton wavelength is the characteristic scale of the electron's internal motion.

III: Proliferation of Infinities

The Root of Self-Energy Divergence

The electrostatic self-energy of a point electron is:E_self = (1/2)∫[ρ(r)ρ(r')/|r - r'|]d³rd³r'

For a point charge ρ(r) = eδ³(r):E_self = e²/(8πε₀r) | (r→0) = ∞

If the electron has a distribution on the scale of the Compton wavelength:ρ(r) = e / [(πλC²)^(3/2)] * e^(-r²/λC²)

The self-energy becomes finite:E_self ≈ e²/(4πε₀λC) = αmc²

This is precisely equal to the fine-structure energy! This is no coincidence.

The Mathematics of the Vacuum Catastrophe

The vacuum energy density in quantum field theory (QFT) is:ρ_vac = ∫(from 0 to ∞) [d³k/(2π)³]*(ħωk/2)

For a free field ωk = c|k|:ρ_vac = (ħc)/(2π²) ∫(from 0 to Λ) k³dk = ħcΛ⁴/(8π²)

If cut off at the Planck scale Λ = Mpc/ħ, we get:ρ_vac ~ Mp⁴c⁵/ħ³ ~ 10^120 J/m³

This is 120 orders of magnitude larger than the observed value!

However, if particles have extensions on the Compton wavelength scale, the cutoff should be Λ ~ 1/λC:ρ_vac ~ mc²/λC³ = m⁴c⁵/ħ³

For the electron, this gives a reasonable energy density. The point-particle assumption has led to a 120-order-of-magnitude error!

IV: Fundamental Flaws of Field Theory

Propagator Divergence

The Feynman propagator is:D_F(x - y) = ⟨0|Tψ(x)ψ̄(y)|0⟩

In momentum space:Ṽ_F(p) = i / (γ^μ p_μ - m + iε)

As p → ∞, Ṽ_F ~ 1/p, leading to divergent loop integrals.

If particles have a form factor F(p²):Ṽ_F(p) = [iF(p²)] / (γ^μ p_μ - m + iε)

where F(p²) = e^(-p²λC²/4), all divergences disappear automatically!

The Physical Meaning of the Running Coupling Constant

In QED, the fine-structure "constant" varies with energy:α(Q²) = α(0) / [1 - (α(0)/(3π))ln(Q²/m²)]

Standard interpretation: Vacuum polarization.

But if the electron has spatial extension, different momentum transfers probe different charge distributions:ρ_eff(Q) = ∫ρ(r)e^(iQ·r)d³r = e·F(Q²)

The "running" is merely the momentum dependence of the form factor!

V: Misuse of Symmetry

The Mathematical Game of Gauge Invariance

The QED Lagrangian is:ℒ = ψ̄(iγ^μ D_μ - m)ψ - (1/4)F_μνF^μν

where D_μ = ∂_μ + ieA_μ ensures gauge invariance.

But why do we need gauge invariance? The standard answer: It is a "fundamental principle."

The real answer: If the electron has spatial extension, the phase at different points can be chosen independently:ψ(x) → e^(iα(x))ψ(x)

The gauge field A_μ compensates for this phase gradient:A_μ → A_μ - (1/e)∂_μα

Gauge invariance arises from the spatial extensibility of particles! Point particles have no need for gauge fields.

Chiral Symmetry Breaking

In the Standard Model, left-handed and right-handed fermions have different gauge interactions:ψ_L → SU(2) doublet, ψ_R → SU(2) singlet

Why? "It is an experimental fact."

But if particles rotate on the Compton wavelength scale, left-handed and right-handed correspond to different helical structures:

  • Left-handed: Helix where the magnetic moment is parallel to momentum

  • Right-handed: Helix where the magnetic moment is antiparallel to momentum

Different spatial structures lead to different interactions!

VI: The Illusory Precision of Calculations

The "Success" of Quantum Electrodynamics

QED calculates the electron's g-factor to 12 decimal places:g/2 = 1.001159652180(73)

This is hailed as the most precise prediction in physics. But the calculation requires:

  • 12,672 Feynman diagrams

  • Numerical integration of thousands of divergent integrals

  • Renormalization to remove infinities

If an extended electron model were used from the start, the same result could be obtained with only a few diagrams!

The 19 Parameters of the Standard Model

The Standard Model has 19 free parameters that must be input from experiments:

  • 3 gauge coupling constants

  • 9 fermion masses

  • 3 mixing angles + 1 CP phase

  • 2 Higgs parameters

Why so many? Because point particles have no structure, making it impossible to explain the origin of properties like mass and charge.

If particles have internal structures on the Compton wavelength scale, these parameters could potentially be derived from geometry and dynamics.

VII: A Dead End for New Physics

The Failure of Supersymmetry

Supersymmetry predicts that every particle has a superpartner: e.g., electron ↔ selectron.

The LHC has found no superpartners. Why?

Because supersymmetry is based on point particles! If particles have structure, the distinction between bosons and fermions may merely reflect different internal motion modes, eliminating the need for new particles.

The Predicament of String Theory

String theory attempts to replace zero-dimensional points with one-dimensional strings:X^μ(τ,σ) = x^μ + p^μτ + Σn α_n^μ e^(-inτ)cos(nσ)

It requires 10 or 11 spacetime dimensions to be consistent.

But if particles are acknowledged as three-dimensional extended objects from the start, no extra dimensions are needed! The Compton wavelength provides a natural scale.

Conclusion: A Quantitative List of Disasters

Wave-particle duality, and its core—the point-particle assumption—has led to the following quantitative disasters:

  • Electron surface velocity: 172 times the speed of light (using the classical radius)

  • Vacuum energy density: 120 orders of magnitude error

  • Magnetic moment g-factor: Requires 12,672 Feynman diagrams to calculate accurately

  • Standard Model parameters: 19 unexplainable constants

  • Supersymmetric particles: All predictions unfulfilled

  • Extra dimensions: 6-7 invisible dimensions required

All these problems point to the same root cause: Particles are not points!

The Compton wavelength λC = h/mc is not "quantum fuzziness" but the real size of particles. Acknowledging this, physics can return from a mathematical labyrinth to physical reality.

Mathematics should serve physical understanding, not replace it.

Postscript: The mathematical analysis in this paper shows that almost all quantum "mysteries" can be traced back to the point-particle assumption. The Compton wavelength, as a natural scale running through the entire quantum theory, strongly suggests that it is the physical size of particles. It is time to reconstruct physics based on extended particles.