⊙ Field Notes

The Calculation,
The Lineage,
The Practice.

Essays on the systems, the math, and the mythology behind every reading.

— Updated periodically. Published by Alex Costa. —

2026-08-18·For Practitioners·11 min read
The AI solution for astrologers & energy workers

Chatbots improvise, consumer apps serve themselves, chart software stops at the math. What a working practitioner actually needs from AI — five options compared, with the white-label pricing math.

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2026-05-21·Numerology · Pythagorean·7 min read
What is your Life Path number, actually?

The single number Pythagoras would have written next to your name. It reads your work in this life — not your personality. The nine assignments, the master numbers, and the math you can do by hand.

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2026-05-21·Mesoamerican · Calendar·7 min read
What does your Mayan day-sign actually mean?

The Tzolk'in is older than the alphabet. Daykeepers in Guatemala still count it today, the same way their grandmothers' grandmothers counted it. Why the count is older than your horoscope, and what your day-sign and tone actually read.

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2026-05-21·Position · Brand·6 min read
Co-Star reads one chart. Arcana reads ninety-four.

Twelve traditions read the same person and agree on most of what they see. They disagree on three things. Those three things are usually the most accurate parts of the reading — the precise places your internal contradictions live.

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2026-05-21·Methodology · Jung·8 min read
What is shadow work, really? Jung and the traditions.

Carl Jung named "shadow" in 1917. Diviners had been reading it for three thousand years. Where the Vedic 12th house, the BaZi elemental imbalance, the Mayan day-sign shadow, and the Pythagorean Life Path tension all converge — and why "shadow work" has been diluted into journaling.

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2026-05-21·African · Yoruba·8 min read
Ifa: the Yoruba oracle older than written language

UNESCO Masterpiece of the Oral Heritage of Humanity. 256 chapters, 4,000–6,000 verses, memorized by trained babalawos and passed down for at least two thousand years entirely without writing. The divination system the West almost never reads.

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2026-05-18·Numerology · History·9 min read
Cheiro and the Reconstruction of Chaldean Numerology

The Irish-born society palmist who told fortunes to Mark Twain, Oscar Wilde, and King Edward VII — and whose 1925 Book of Numbers built the foundation of every "Chaldean" numerology reading on the internet today. A look at what the system actually is, what survived him, and what the historical record will and won't support.

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⊙ The Practice

Read your own birth, in full.

One name, one date — and the engine returns a 30-page symbolic portrait drawn from 94 readings across 32 ancient cultures.

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⊙ The next deep-dive

One tradition, read deeply, every other week.

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