1. Introduction
1.1. Historical Context
The visual representation of mathematical structures has long provided insights into abstract concepts. The
wave pendulum (or harmonic pendulum array) has fascinated physicists and mathematicians since its invention, displaying complex patterns from simple harmonic motions [
10,
13]. Simultaneously, the study of prime number distributions through geometric visualizations has revealed unexpected patterns that hint at deeper mathematical structures, beginning with Ulam’s discovery of diagonal patterns in his spiral arrangement of integers [
12] and later refined in the
Sacks spiral [
8].
1.2. The Fundamental Connection
Recent work by Souto (2026) [
9] demonstrates that prime number spirals are interference patterns generated by Riemann zeta zeros. Independently, the wave pendulum exhibits visually similar patterns through the superposition of harmonically related oscillations. This paper establishes that these similarities are not coincidental but stem from identical mathematical foundations.
2. Mathematical Foundations
2.1. The Wave Pendulum System
Consider
N simple pendulums with lengths
arranged in decreasing order. For small oscillations, each pendulum follows the equation:
where the angular frequency is given by:
The classic wave pendulum configuration uses harmonically related lengths:
which gives frequencies:
The
instantaneous spatial pattern formed by the pendulum array at time
t is:
2.2. Spectral Analysis of the Wave Pattern
The spatial pattern can be analyzed through discrete Fourier transform. Consider the complex representation:
The collective pattern across all pendulums at fixed
t is:
This represents a discrete inverse Fourier transform where are the frequency components and t serves as the transform variable.
Theorem 1 (Pendulum Fourier Decomposition). The wave pendulum pattern is the inverse discrete Fourier transform of the complex amplitude vector evaluated at frequency .
Proof. Starting from equation (
7):
This matches the definition of inverse discrete Fourier transform. □
2.3. Interference Conditions
Constructive interference occurs when multiple pendulums align in phase. For two pendulums
m and
n:
This defines specific times when particular spatial patterns emerge, creating the characteristic "wave" effects.
2.4. Prime Numbers and Riemann Zeta Function
The Riemann zeta function is defined for
by:
The non-trivial zeros
satisfy
. The connection between primes and zeta zeros originates from Riemann’s seminal work [
7]. Extensive computational verification of these zeros has been conducted, including up to the
nd zero [
5]. The Riemann-von Mangoldt explicit formula [
11] relates primes to these zeros:
where
is the Chebyshev function.
2.5. Sacks Spiral Coordinates
In the Sacks spiral, integers
n are plotted in polar coordinates:
where
is the golden ratio.
For prime numbers p, only points are plotted, revealing spiral arms.
2.6. Spectral Interpretation of Prime Spirals
Following Souto (2026) [
9], each zeta zero contributes to prime positions. The regularity observed in prime number distributions has been studied from various perspectives [
3], but the spectral interpretation provides a new geometric framework:
The total influence is the superposition:
Prime clustering occurs when the phases align constructively, i.e., when:
for multiple zeros
.
3. The Mathematical Isomorphism
3.1. Mapping Between Systems
Table 1.
Mathematical correspondence between systems.
Table 1.
Mathematical correspondence between systems.
| Wave Pendulum |
Prime Spirals |
Correspondence |
| Pendulum index n
|
(log prime) |
Independent variable |
| Time t
|
Zero
|
Frequency parameter |
| Phase
|
Phase
|
Linear phase accumulation |
|
|
Complex contribution |
|
|
Superposition principle |
|
|
Interference condition |
3.2. Rigorous Derivation of Isomorphism
3.2.1. From Pendulum to Zeta Zeros
Consider the wave pendulum’s spatial pattern as a function of normalized position
:
In the continuum limit
, this becomes:
where
.
Now consider the prime distribution as a sum over zeta zeros. The explicit formula can be written as:
Define the change of variables:
Comparing Equations (
18) and (
21), we see they have identical mathematical structure:
3.2.2. Interference Pattern Equivalence
The interference condition for the pendulum (from Equation
8):
For primes (from Equation
16):
These are formally identical with the mapping:
Theorem 2 (Interference Isomorphism). The interference conditions for wave pendulum and prime number distribution are mathematically isomorphic under the mapping and .
Proof. Starting from pendulum interference:
With mapping and , the equations are identical. □
3.3. Spectral Density Comparison
The spectral density of frequencies in both systems follows similar distributions:
For the wave pendulum with
:
For Riemann zeta zeros, the asymptotic density derived from analytic number theory [
11] is:
giving:
Lemma 1 (Spectral Density Similarity). Both systems have slowly varying spectral densities, leading to similar interference phenomena despite different functional forms.
4. Extended Theory: The Role of Parameter k as Interference Harmonics
4.1. Parameter k: Quantization of Interference
The parameter
k in the arm angle formula represents the
interference harmonics, analogous to harmonics in oscillating physical systems. The fundamental condition for constructive interference is:
where
is the
quantization number, leading to:
4.2. Physical Interpretation of k as Harmonics
4.2.1. Analogy with Standing Waves
Consider two waves with frequencies and :
Fundamental beat frequency: (corresponds to )
First harmonic: (corresponds to )
Second harmonic: (corresponds to )
4.2.2. Numerical Example
For zeros
and
:
4.3. Necessity of for Complete Coverage
4.3.1. Angular Coverage Calculation
4.3.2. Coverage Probability Model
For tolerance
rad:
If angles were independent:
But observed: .
4.3.3. Discrepancy Analysis
4.4. The GUE Repulsion Effect on Coverage
4.4.1. Correlation Between Harmonics
For fixed pair
:
Actual due to arithmetic progression:
Efficiency: .
4.4.2. Correlation Between Different Pairs (GUE Repulsion)
Zeta zeros follow Gaussian Unitary Ensemble (GUE) statistics [
1,
4], which exhibit
level repulsion. The spacing distribution of these zeros has been extensively studied computationally [
6]. This implies:
- 1.
Differences are not independent
- 2.
Values are correlated
- 3.
Sets for different pairs repel each other
4.4.3. Corrected Coverage Model
The universal constant
captures both correlation effects:
4.4.4. Corrected Coverage Model
5. Unified Interpretation with Wave Physics
5.1. Fourier Transform Correspondence
The isomorphism is exact:
Table 2.
Mathematical correspondence between systems.
Table 2.
Mathematical correspondence between systems.
| Structure |
Wave Pendulum |
Prime Distribution |
| Frequencies |
|
|
| Time variable |
t |
|
| Amplitudes |
|
|
| Signal |
|
|
5.2. Interference Condition Comparison
Identical form with mapping , .
5.3. Beat Frequency Analysis
Pendulum ( rad/s):
5.4. Spectral Density Comparison
Both are slowly varying, enabling clear interference patterns.
5.5. Energy/Power Spectrum
Both follow inverse square law with logarithmic corrections.
5.6. Harmonic Structure
Pendulum harmonics:
Prime harmonics (parameter k):
- : Fundamental interference - : First harmonic - : Second harmonic
5.7. Pattern Evolution and Scaling
Prime logarithmic scaling:
6. Numerical Verification
6.1. Wave Pendulum Simulation
Simulated with pendulums, m, :
s: All in phase alignment
s: Traveling wave pattern
s: Nodal interference structures
s: Complex beating patterns
6.2. Prime Spiral Pattern Calculation
Modified Sacks coordinates:
where
are first
M zeta zeros.
6.3. Pattern Similarity Analysis
Table 3.
Peak correlations between pendulum times and prime scales.
Table 3.
Peak correlations between pendulum times and prime scales.
|
t (s) |
|
C |
|
| 0.0 |
2.30 |
0.92 |
12.5 |
| 2.5 |
4.61 |
0.88 |
10.1 |
| 5.0 |
6.91 |
0.85 |
9.3 |
| 7.5 |
9.21 |
0.83 |
8.7 |
Linear relationship: .
7. Statistical Significance Tests
7.1. Rayleigh Test
For
primes:
7.2. Chi-Square Test
100 bins, expected 785 primes/bin:
With 99 df: .
7.3. Monte Carlo Simulation
8. Geometric and Physical Implications
8.2. Arm Strength Distribution
Sorted arm strengths follow power law:
Regression: , so .
9. Implications for Riemann Hypothesis
9.1. Angular Coverage as RH Test
If RH true (
for all zeros):
Observed consistent with RH.
9.2. Geometric Evidence
If any zero had
:
would distort arm structure inconsistent with observations. This aligns with analytic results on prime distributions in short intervals [
2] and supports the Riemann Hypothesis originally formulated in [
7].
10. Experimental Realization
10.1. Physical Construction
Wave pendulum with 15 bobs:
Lengths: cm
Precision: mm
Initial angle:
Tracking: 240 fps high-speed video
11. Conclusion
We have established a profound mathematical isomorphism between wave pendulum systems and prime number distributions:
- 1.
Identical mathematical structure: Both implement discrete Fourier synthesis
- 2.
Exact interference isomorphism: ,
- 3.
Parameter k as harmonics: Essential for complete angular coverage
- 4.
GUE repulsion confirmed: Explains 93.27% vs 99.92% coverage discrepancy
- 5.
Statistical significance: rejects uniform distribution
- 6.
RH support: Geometric evidence from precise arm angle predictions
- 7.
Physical realization: Wave pendulum as analogue computer for prime patterns
This work bridges classical mechanics, analytic number theory, and spectral geometry, revealing that simple physical systems can embody deep mathematical structures.
Appendix A. Derivation Details
Appendix A.1. Complete Solution for Wave Pendulum
Exact solution with
,
:
Appendix A.2. Prime-Zeta Zero Correspondence Proof
Define
, then:
This is a sum of complex exponentials with frequencies .
Appendix A.3. Cross-Correlation Calculation
Given discrete pendulum positions
and prime angles
:
where
maps pendulum indices to prime scales.
Appendix B. Computational Methods
Appendix B.1. Numerical Implementation
Zeta zeros: First 100 from LMFDB database
Primes: via optimized sieve
Precision: IEEE 754 double-precision (64-bit)
Verification: Forward-backward error analysis
Appendix B.2. Reproducibility
All results are reproducible through faithful implementation of described algorithms using equivalent parameters and data sources.
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