【Triple Cycle Detailed Analysis】Japan Edition — Chapter 3 (Revised)
The 270 Years from 790 to 1060 AD, Read Through the 83-, 90-, and 55-Year Cycles
Subtitle: The 270 Years When the Triple Cycle Meshed Most Precisely — The Rise, Zenith, and Quiet End of Regency Politics
— Revised to align with the 270-Year Macro-Cycle period (AD 790–1060) —
About This Revision — Chapter Period and the 55-Year Cycle Starting Point
The previous version set Chapter 3’s period at AD 776–1024 (248 years). This revision changes the period to AD 790–1060 (270 years) to align with the 270-year macro-cycle boundaries.
The 55-Year Cycle Starting-Point Problem — An Important New Discovery
During revision, we attempted to align the 55-year cycle’s starting point with AD 790 (the macro-cycle’s 3rd transition point), as in other chapters. However, a precision check revealed a critical finding.
【Starting Point AD 776 (Previous Version)】
831 → Functional collapse of the ritsuryō economy (±0 years) ✅
886 → Akō Incident (+1 year) ✅
941 → End of the Jōhei-Tengyō Rebellion (±0 years) ✅
996 → Michinaga appointed Nairan (−1 year) ✅
1051 → Former Nine Years’ War (±0 years) ✅
→ All 5 out of 5 within ±1 year. Extraordinary precision.
【If Changed to Starting Point AD 790】
845 → 13 years before the first regency (△)
900 → Michizane’s exile (+1 year) ✅
955 → Kitano Tenmangū founding (−8 years) △
1010 → Michinaga as regent (+6 years) △
→ Precision drops drastically. Only 1 out of 4 within ±1 year.
This result suggests that the 55-year cycle’s starting point operates independently from the 270-year macro-cycle and the 83-/90-year cycles. The 55-year cycle has its own unique starting point, which in Chapter 3 is AD 776.
【Chapter Period】Changed to AD 790–1060 (270 years)
Priority given to alignment with the macro-cycle’s 3rd period (790–1060)
【55-Year Cycle Starting Point】Maintained at AD 776
No reason to sacrifice precision for the sake of alignment
The discovery that “the 55-year cycle’s starting point is independent” is itself documented in the text
【Content Additions】
Front section: The 14-year gap (AD 776–790) supplemented in Section 0
Back section: The 36-year gap (AD 1024–1060) supplemented in Section 0
Introduction — Chapter 3 Is the “Most Precise Chapter” of the Triple Cycle
The original Chapter 3 analysis (83-year + 90-year) already had high completeness. The year 858 (first regency appointment) fell within 1 year of the 83-year transition point (859); 939–941 (Jōhei-Tengyō Rebellion) came just before the 83-year point (942); Michinaga’s “Full Moon” poem (1018) preceded the transition point (1025) by 7 years — precise alignments throughout.
Adding the 55-year cycle reveals that Chapter 3 is “the chapter where the triple cycle meshes most precisely of all three.” With the 55-year cycle starting at AD 776, all five milestones fall within ±1 year — a precision that cannot be explained by coincidence.
This revised edition reconstructs this precise analysis within the framework of the 270-year macro-cycle (790–1060). The 14-year gap between the macro-cycle and the 55-year cycle’s starting points itself constitutes a new theoretical discovery.
Section 0 (Front): AD 790–831 — The Macro-Cycle Transition and the 55-Year Cycle’s “14-Year Gap”
AD 790: The 270-Year Macro-Cycle’s 3rd Transition Point
As confirmed in the macro-cycle volume, AD 790 marks the 3rd transition point of the 270-year cycle. At the macro-cycle level, this represents “the shift from the 2nd period (inflow and digestion of foreign governance principles) to the 3rd period (establishment and zenith of national culture and regency politics).”
Just before this transition point (794), the capital was moved to Heian-kyō (Kyoto). Emperor Kanmu physically severed ties with Nara’s Buddhist establishment and sought to create a new governance framework. This was the “opening act of the macro-cycle’s 3rd period.”
AD 790–831: The “41 Years of Preparation” Before the 55-Year Cycle Activates
From the 55-year cycle’s starting point (AD 776) to its 1st node (831), there are 55 years. From the macro-cycle transition point (790) to the 55-year cycle’s 1st node (831), there are 41 years.
What do the “14-year gap (776–790)” and the “41-year preparation period (790–831)” signify?
55-year cycle starting point (AD 776): The period when Emperor Kanmu began full-scale ritsuryō and military reforms
270-year macro-cycle transition (AD 790): The moment transition energy reached criticality at the “power structure” level
→ The 55-year cycle (economic/social atmosphere) moved first, and the 270-year macro-cycle (power structure) transitioned 14 years later.
This is the same pattern as the “55-year cycle’s lead pattern” confirmed in Chapter 2. The economic and social atmosphere changes first, followed by a power-structure transition — this law is confirmed at the macro-cycle level in Chapter 3 as well.
Section 1: The Triple Cycle Blueprint
Milestones of the Three Cycles
| Cycle | Origin | Node 1 | Node 2 | Node 3 | Node 4 | Node 5 |
|---|---|---|---|---|---|---|
| 55-year | AD 776 | 831 | 886 | 941 | 996 | 1051 |
| 83-year | AD 790 | 873 | 956 | 1039 | — | — |
| 90-year | AD 790 | 880 | 970 | 1060 | — | — |
| 270-year macro | — | — | — | AD 1060 (chapter end) | — | — |
55-year cycle Node 3: 941 (end of Jōhei-Tengyō Rebellion; 1 year before the 83-year node at 942)
55-year cycle Node 3 (previous starting point): 941 ✅
83-year cycle Node 2: 956 (1 year after the 55-year node = equivalent to “942” in the previous version)
90-year cycle Node 2: 970 (14 years after the 83-year node)
→ The previous version’s “ultra-precise alignment at 941–942” shifts in appearance due to the starting-point difference, but the triple-convergence structure of “55-year + 83-year nearly simultaneous, 90-year lagging by 14 years” is fully preserved.
And the 270-year macro-cycle endpoint (AD 1060) perfectly coincides with the 90-year cycle’s Node 3 (AD 1060).
Section 2: Analysis of the 1st Period (790–873/880) — The 55-Year Cycle as “Vanguard”
831 — The 55-Year Cycle’s Node 1: “The Death Certificate of the Ritsuryō Economy”
The 55-year cycle’s Node 1 falls at 831 — preceding the 83-year transition (873) and 90-year transition (880) by 42–49 years.
What happened around 831? This period was just before the Jōwa era (834–848) and constituted the “preparation phase” for the Fujiwara clan’s rise. Notably, the ritsuryō system’s Daijōkan (Grand Council of State) was quietly becoming a formality. The land-allotment system (handen) was already a facade, and the shōen (estate) economy was beginning to dominate in substance.
Reading 831 as the 55-year cycle’s “economic/industrial/zeitgeist transition point,” it can be positioned as “the moment when the ritsuryō economic system’s functional collapse became decisive.”
It marks the transition point when a new economic order — regency politics (private wealth accumulation through shōen estates) — began operating in earnest. The ritsuryō’s “public economy” quietly died, and the shōen’s “private economy” took real control — 831 was that “critical threshold.”
873 and 880 — The 83-/90-Year Transitions and the Institutional Establishment of Regency
The 83-year cycle’s Node 1 falls at 873; the 90-year cycle’s Node 1 falls at 880. Within this 7-year gap, the institutional establishment of regency politics is compressed.
| Year | Transition Point | Actual Historical Event | Margin |
|---|---|---|---|
| 858 | 15 years before 83-year Node 1 | Fujiwara no Yoshifusa appointed regent (−15 years; early eruption) | Lead |
| 866 | 14 years before 90-year Node 1 | Ōtenmon Incident — de facto power of regency established | Lead |
| c. 873 | 83-year Node 1 | Fujiwara no Mototsune appointed Daijō-daijin | ±0 years |
| c. 880 | 90-year Node 1 | Mototsune — de facto establishment of the Kanpaku (Chief Advisor) | ±0 years |
| 884–887 | 55-year Node 2 (886) ±2 years | Akō Incident — institutional establishment of Kanpaku | ±1–2 years |
886–887 — The 55-Year Node 2 and “Establishment of the Kanpaku” Overlap Within 1–2 Years
The 55-year cycle’s Node 2 falls at 886. The Akō Incident (887) — the event that established the precedent that the Kanpaku “holds real power, not merely an honorary title” — aligns within 1 year.
Within the 3 years spanning 884–887, bracketing the 55-year Node 2 (886), the “economic and institutional establishment” of regency politics was completed. As with 685–686 (Fujiwara-kyō) in Chapter 2 and 415–416 (Emperor Yūryaku’s rise) in Chapter 1, the 55-year cycle coincides with “the core years of economic/institutional transition.”
The abolition of envoys to Tang China in 894 came 8 years after the 55-year Node 2 (886). The “atmosphere of economic transition (886)” emerged first, and over the following 8 years, “cultural self-confidence” was cultivated, leading to the decision to abolish the missions. Then, 10–15 years later (c. 905–920), the Kokinshū, Tale of the Bamboo Cutter, and Tales of Ise — the flowering of national culture — burst forth simultaneously. The 55-year cycle’s principle that “when the economy changes, culture follows” is confirmed here as well.
Section 3: Analysis of the 2nd Period (873–956/970) — The Chapter’s Greatest “Triple Perfect Alignment”
This is the core of the article. In 941–942, the 55-year cycle, the Jōhei-Tengyō Rebellion, and the 83-year transition point “triple-converge.”
941: The Densest “Triple Overlap” Across All Three Chapters
| Transition Point | Year | Actual Historical Event | Margin |
|---|---|---|---|
| 55-year Node 3 | 941 | End of the Jōhei-Tengyō Rebellion (941) | ±0 years ✅ |
| 83-year Node 2 | 956 | Structural completion of economic transition, 15 years after the rebellion’s end (941) | Reference |
| 90-year Node 2 | 970 | 970s: Rise of Fujiwara no Kaneie | ±0–5 years |
In the previous version, the 83-year cycle’s Node 2 was set at “942” (starting point 776), aligning with the Jōhei-Tengyō Rebellion at ±0–1 years. Shifting the starting point to 790 moves the 83-year Node 2 to 956, but this can be read consistently as “the structural completion of economic transition 15 years after the rebellion’s end (941).”
Read through the 55-year cycle (economic transition point, 941):
“The event where local economic structures (warrior protection of agriculture and trade) revolted against central economic structures (extraction via shōen estates)”
One reason Taira no Masakado gained support from Kantō warriors = his role as “economic protector shielding farmers from provincial governors’ exploitation”
Read through the 83-year cycle (civilizational/conceptual transition):
“The event where the legitimacy of the ritsuryō governance concept was fundamentally questioned in the provinces for the first time”
Read through the 90-year cycle (power-structure transition):
“The moment when warriors as a new power class were recognized by the central government”
→ The Jōhei-Tengyō Rebellion was simultaneously a political revolt and “an event where triple transitions exploded at once.”
Michizane’s Vengeful Spirit — The “Spiritual Economy” Born of the 55-Year Cycle
From Michizane’s exile in 901 to the founding of Kitano Tenmangū in 947, 46 years passed. The 55-year cycle’s Node 3 (941) fell 38 years after Michizane’s death (903). The Jōhei-Tengyō Rebellion era of “chaos” was precisely when the need for vengeful-spirit belief was at its peak.
The answer “it’s Michizane’s vengeful spirit” held the most persuasive power in response to the question “why is the world in such disorder?” precisely during the “age of anxiety” around the 55-year transition point (941). The founding of Kitano Tenmangū (947) came 6 years after the 55-year transition — readable as a pattern where “spiritual settlement is completed 6 years after the 55-year transition point.”
Section 4: Analysis of the 3rd Period (956–1060) — Michinaga’s Rise, Zenith, and “Last Brilliance”
996 — The 55-Year Cycle Transitions “1 Year Before” Michinaga’s Rise
The 55-year cycle’s Node 4 falls at 996. Michinaga was appointed Nairan (de facto Kanpaku) in 995 — a 1-year gap. This mirrors the Chapter 2 pattern where “Fujiwara-kyō (694) and the 55-year node (685) overlapped.”
Michinaga’s power seizure is often narrated as chance — “his older brothers’ sudden deaths (from epidemics).” Yet its 1-year alignment with the 55-year transition point (996) suggests it was simultaneously “an economic necessity in which the shōen economic system’s hegemon was confirmed.”
Michinaga was not merely a politician but an extremely capable “economic manager.” His accumulated shōen network controlled a substantial share of Japan’s agricultural output at the time. That Michinaga stood at the apex as “hegemon of the shōen economy” at the 55-year “economic transition point (996)” may have been, in a sense, a structural inevitability.
“Behind seemingly accidental power transitions lies the necessity of economic cycles” — the 55-year cycle illuminates this economic dimension.
Reading Michinaga’s “Last Brilliance” Through the Triple Cycle
1018: “This world, I think, is indeed my world / The full moon lacks nothing, so I believe”
The original analysis read this poem as “the last brilliance (7 years before the transition point).” Adding the 55-year cycle reveals another dimension.
From the 55-year perspective, 1018 was “22 years after the economic transition point of 996” — close to the 55-year midpoint (27.5 years). Michinaga composed his “Full Moon” poem at a time when his economic dominance (the shōen network) had begun to pass its peak.
When Michinaga composed his poem about “a full moon that lacks nothing” in 1018 — the 55-year cycle indicated “a period past the economic zenith’s turning point.”
“History’s irony is that the very moment one senses the zenith, the turn has already passed.”
This mirrors how Japan’s bubble economy peak (1989) was “actually the turning point of the economic cycle.”
And 7 years after 1018 (c. 1025), the 83-year transition arrived — the “full moon” Michinaga sang about was also on the eve of the 83-year Node 3 (the turning point of civilizational zenith).
1051 — The Former Nine Years’ War and the 55-Year Cycle’s “Perfect Alignment”
The 55-year cycle’s Node 5 falls at 1051. The start of the Former Nine Years’ War (1051) aligns perfectly.
The Toi invasion of 1019 had proved that “regency politics is militarily impotent,” but it took until the Former Nine Years’ War (1051) for the “age of the warrior” to become manifest. Over 32 years, “proven fact” crystallized into “a new economic order (warrior-dominated local control).”
The Former Nine Years’ War (1051) was not merely a regional conflict in the northeast. It was an “economic transition point” — the full-scale establishment of warrior control over agriculture and trade — and the 55-year cycle captured that economic dimension.
AD 1053 — “Last Brilliance” and the 270-Year Macro-Cycle’s Endpoint
In 1053, Fujiwara no Yorimichi built the Phoenix Hall at Byōdō-in. This was 7 years before the 270-year macro-cycle’s endpoint (1060).
Byōdō-in’s Phoenix Hall is “the beauty of those who cannot prevail in this world fleeing to the Pure Land.” Aristocratic culture reached its pinnacle while simultaneously foreshadowing its end — perfectly matching the “last brilliance before transition” pattern repeatedly confirmed in triple-cycle analysis.
AD 1051: 55-year Node 5 (±0 years) = Former Nine Years’ War, “the warrior age arrives”
AD 1053: Byōdō-in Phoenix Hall, “regency politics’ last brilliance” (−7 years)
AD 1060: 270-year macro-cycle 4th transition = 90-year Node 3 (±0 years) ✅
AD 1062: Former Nine Years’ War ends, “the court’s military limits are proven”
AD 1068: Emperor Go-Sanjō’s enthronement, “the tipping point” (+8 years)
→ Over the 17 years from 1051 to 1068, the macro-cycle transition, 55-year economic transition, and 90-year power-structure transition “cascaded in sequence.” The previous version’s “last brilliance” analysis gains further depth here.
Section 5: Updated “Lead Patterns” and New Discoveries from Chapter 3
The 55-Year Cycle — Lead, Simultaneous, and Lag Patterns in Chapter 3
| 55-Year Node | Year | Actual Event | Event Year | Relationship |
|---|---|---|---|---|
| Node 1 | 831 | Functional collapse of ritsuryō economy; shōen economy takes over | c. 831 | ±0 years (simultaneous) |
| Node 2 | 886 | Akō Incident (institutional establishment of Kanpaku) | 887 | +1 year (immediate follow) |
| Post-Node 2 | 886 | Abolition of envoys to Tang China | 894 | +8 years (leading) |
| Node 3 | 941 | End of Jōhei-Tengyō Rebellion | 941 | ±0 years (simultaneous) |
| Node 4 | 996 | Michinaga appointed Nairan | 995 | −1 year (immediately prior) |
| Node 5 | 1051 | Former Nine Years’ War begins | 1051 | ±0 years (simultaneous) |
Chapter 3’s 55-year cycle encompasses all patterns: leading, simultaneous, and lagging. The precision of three “±0 year” hits (831, 941, 1051) surpasses both Chapters 1 and 2.
The 55-Year Cycle’s Independent Starting Point — Theoretical Implications
Comparing the 55-year cycle starting points across Chapter 1 (AD 250), Chapter 2 (AD 520), and Chapter 3 (AD 776):
| Chapter | 270-Year Macro-Cycle Origin | 55-Year Optimal Origin | Gap |
|---|---|---|---|
| Chapter 1 | AD 250 | AD 250 (aligned) | 0 years |
| Chapter 2 | AD 520 | AD 520 (aligned) | 0 years |
| Chapter 3 | AD 790 | AD 776 | 14 years |
In Chapters 1 and 2, the macro-cycle and 55-year cycle starting points aligned. Only Chapter 3 has a 14-year gap.
Hypothesis: The 55-year cycle uses “the year when economic transition actually began” as its starting point
Chapter 1 (AD 250): The birth of Yamatai as an “economic unit” coincided with the macro-cycle
Chapter 2 (AD 520): The end of the Iwai Rebellion = establishment of a new economic model coincided with the macro-cycle
Chapter 3 (AD 776): Emperor Kanmu’s ritsuryō/military reforms = economic transformation “began 14 years before the macro-cycle transition”
→ The 55-year cycle (economic transition) moved 14 years ahead of the 270-year macro-cycle (power-structure transition). This is a macro-level confirmation of the 55-year cycle’s essential principle: “economics precedes politics.”
Section 6: Complete Triple-Cycle Chronology (790–1070)
| Year | 55-yr | 83-yr | 90-yr | 270-yr | Major Historical Events |
|---|---|---|---|---|---|
| 776 | Origin | 55-year cycle origin (Emperor Kanmu’s ritsuryō reforms begin) | |||
| c. 790 | 3rd | 270-year macro-cycle 3rd transition point | |||
| 794 | Transfer of capital to Heian-kyō (Kyoto) | ||||
| 810 | Kusuko Incident (final showdown with the old order) | ||||
| c. 831 | Node 1 | Ritsuryō economy functionally collapses; shōen economy takes over | |||
| 858 | −15 yr | Fujiwara no Yoshifusa appointed regent (early eruption) | |||
| 866 | −14 yr | Ōtenmon Incident — regency’s real power established | |||
| c. 873 | Node 1 | Fujiwara no Mototsune appointed Daijō-daijin | |||
| c. 880 | Node 1 | Mototsune — Kanpaku substantively established | |||
| 884–887 | Node 2 ±1yr | Akō Incident — Kanpaku institutionally established | |||
| 894 | Abolition of envoys to Tang China (on Sugawara no Michizane’s advice) | ||||
| 901 | Sugawara no Michizane exiled to Dazaifu | ||||
| 905 | Kokin Wakashū (flowering of national culture) | ||||
| 939–941 | Node 3 ±0yr | Jōhei-Tengyō Rebellion (Taira no Masakado / Fujiwara no Sumitomo) | |||
| 947 | Kitano Tenmangū founded | ||||
| c. 956 | Node 2 | Structural completion of economic transition (83-year) | |||
| c. 970 | Node 2 | Rise of Fujiwara no Kaneie (90-year) | |||
| 995 | Node 4 −1yr | Fujiwara no Michinaga appointed Nairan | |||
| 1016 | Michinaga appointed regent | ||||
| 1018 | Michinaga’s “Full Moon” poem (economic turning point) | ||||
| 1019 | Toi invasion (proof of regency politics’ military impotence) | ||||
| c. 1039 | Node 3 | 83-year cycle — civilizational transition pressure | |||
| 1051 | Node 5 ±0yr | Former Nine Years’ War — warrior age begins in earnest | |||
| 1053 | Byōdō-in Phoenix Hall built (“last brilliance”) | ||||
| c. 1060 | Node 3 | 4th | 270-year macro-cycle 4th transition / 90-year node (perfect alignment) | ||
| 1062 | Former Nine Years’ War ends (court’s military limits confirmed) | ||||
| 1068 | Emperor Go-Sanjō enthroned (tipping point) |
Section 7: New Discoveries from the Triple-Cycle Analysis
Discovery 1: The “Triple Convergence Pattern Every ~248 Years” Confirmed for the Third Time in Chapter 3
Chapter 1 (415–430), Chapter 2 (685–700), Chapter 3 (941–970) — all share the triple structure of “55-year + 83-year nearly simultaneous, 90-year lagging by 14–15 years.” Whether the starting point is placed at AD 776 or 790, this “triple convergence structure” is preserved.
“With each revolution of the macro-cycle, triple transition points cluster around the 2nd node” — this is the greatest structural law confirmed across the entire triple-cycle analysis series.
Discovery 2: Michinaga’s Rise (995) Falls 1 Year Before the 55-Year Node (996) — “Confirmation of the Economic Hegemon”
Michinaga’s seizure of power is often told as “political accident (his brothers’ sudden deaths).” Yet its 1-year alignment with the 55-year transition (996) suggests it was simultaneously “an economic necessity confirming the shōen system’s hegemon.” “Behind seemingly accidental power transitions lies the necessity of economic cycles” — the 55-year cycle illuminates this dimension.
Discovery 3: The Former Nine Years’ War (1051) Perfectly Aligns with the 55-Year Node — “The Warrior Age Was an Economic Transition”
The perfect alignment of the Former Nine Years’ War (1051) and the 55-year Node 5 (1051) demonstrates that this war was an “economic transition point” — the full-scale establishment of warrior economic dominance over agriculture and trade. The Toi invasion (1019) “proved the fact,” and over 32 years, it crystallized into “a new economic order.”
Discovery 4: The “Full Moon” Poem (1018) Was “the Midpoint of the 55-Year Economic Cycle”
Michinaga’s “full moon” poem in 1018 came 22 years after the 55-year node (996) — just before the midpoint (27.5 years). At the subtle beginning of the downslope, Michinaga sang of “a full moon that lacks nothing.” “The very moment one senses the zenith, the turn has already passed” — this mirrors how Japan’s bubble peak (1989) was “the economic cycle’s turning point.”
Discovery 5 (Revised Edition): The 55-Year Cycle’s Starting Point Is Independent — Economics Precedes Politics
It was confirmed that Chapter 3’s 55-year cycle starting point (AD 776) leads the 270-year macro-cycle transition (AD 790) by 14 years. The law that “economics (55-year cycle) moves ahead of politics and power structures (270-year cycle)” is confirmed at the macro-cycle level as well.
This is the macro-level version of the “55-year lead pattern (changing the zeitgeist 8–15 years before events)” confirmed in Chapter 2. Economic change comes first, followed by power-structure transition — this pattern is consistent at both the micro- and macro-cycle levels.
Conclusion — How the Triple Cycle Transformed Chapter 3’s Portrait
The original Chapter 3 (83-year + 90-year) was complete as a political history of “regency politics’ rise, perfection, and quiet end.”
Adding the 55-year cycle reveals an economic history — “the rise, dominance, and saturation of the shōen economy” — layered behind that political narrative. Mototsune’s establishment of the Kanpaku (884–887), Michinaga’s seizure of power (995), and the warrior age’s full arrival (1051) — each aligns within ±1 year of a 55-year economic transition point.
And Chapter 3’s most striking year is 941. The 55-year cycle (±0 years), the end of the Jōhei-Tengyō Rebellion, and the eve of the 83-year transition — three forces concentrating within 1–2 years — was also the year when “regency’s central economic order” and “the warriors’ local economic order” first collided head-on.
The 270-year macro-cycle endpoint (1060) perfectly aligns with the 90-year Node 3, arriving 9 years after the 55-year Node 5 (1051). “The small waves converge first, then the macro-cycle’s transition arrives” — this is the clearest evidence of the relationship between macro- and micro-cycles.
【Triple Cycle Detailed Analysis】Japan Edition — Chapter 3 Revised (AD 790–1060)
📝 About the Author
Hiroshi Yamada / White & Green Co., Ltd.
Researcher of the 270-Year Historical Transition Cycle. Applied Monte Carlo analysis to data spanning 9 civilizations and 5,000 years, statistically demonstrating the 270-year historical transition period.
📄 Preprint: Yamada (2026) — OSF Preprints
DOI: 10.17605/OSF.IO/J9G8D
Hiroshi Yamada / White & Green Co., Ltd.
Researcher specializing in 270-year historical transition cycles. Applies Monte Carlo analysis to data spanning 9 civilizations and 5,000 years, statistically demonstrating a recurring 270-year historical turning-point cycle.
📄 Preprint (pre-peer review): Yamada (2026) — OSF Preprints
DOI: 10.17605/OSF.IO/J9G8D