Istor · a private research notebook that runs entirely on your machine

It shows you what it saw.

Local. Offline. Every claim points at its passage.

ἵστωρ.

Tell me about the cycles.

Thoughts

The Antikythera mechanism incorporated several key astronomical cycles:

The Metonic cycle is an astronomical period of 19 tropical years, almost exactly equal to 235 synodic lunar months or 6,940 days^{1, source 1}.

The mechanism’s gearing incorporated a pin-and-slot mechanism that matches Hipparchus’s lunar theory, replicating the Moon’s variable velocity^{4, source 4, Decoding Antikythera mechanism}.

Who made it?

Thoughts

Your library does not settle that. The ten sources describe the gearing, the dials and the inscriptions in close detail; none of them identifies a maker, and the names they raise are offered as possibilities rather than findings.

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What do the inscriptions say?

Thoughts

The inscriptions are the mechanism’s own manual, cut into the plates rather than printed beside them. The back cover says what each dial does, and the dials label themselves: month names from several Greek calendars ring the Metonic spiral, and the Saros dial is lettered with the eclipses it predicts, down to the hour and the direction of the shadowDecoding Antikythera mechanism“eclipse predictions given to the hour, with the direction of the shadow”.

Most of that text came off the fragments rather than their surface. The surviving lettering is small and partly corroded, and the imaging work is what recovered it. Read together the plates say the machine was meant to be read: the front dial shows where the sun and moon are, and the back is where the mechanism explains itself.

It checks what you already gave it.

Before it looks anywhere else. If the documents in your library already settle the question, Istor answers from them and never goes online: the tool works unplugged, and stays quiet when you ask it to.

The decision is the small model’s. Istor runs two, and the cheap question goes first (is this already answered here?), so the better model can be slow, and can be right.

An Istor answer in the dark theme. The question “How did the Antikythera mechanism predict eclipses?” sits in a bubble at the top right. Under it the Thoughts disclosure is open, showing the app drafting its reply and the reasoning it drew on. Then the answer itself, opening on the 223-month Saros cycle, with small numbered citation chips set into the running text. — Ten sources on this machine, and the app’s own working above the answer. The disclosure is where you can read what it drew on before it wrote anything.

The gate, drawn. The cheap question goes first, and its answer decides everything about what happens next: nothing leaves for a question the library already settles.

Every claim points at a passage.

Every citation resolves to a passage in a source you own or a page it actually fetched. Two failures go away: it will not invent a fact, and it will not tell you something does not exist because it falls outside a training cutoff.

Sometimes the model writes a good answer and forgets to cite as it goes. Istor sends the small model to fit a citation quickly, and marks what it fitted: Unverified, check the source.

That word is not a guess about truth. It names the model that put the number there, and it tells you to go and look.

The same answer, scrolled to a paragraph citing a verified source. The citation chip sits raised in the text, and the source it resolves to, Decoding Antikythera mechanism, is listed in the Library rail at the left with a green status dot. — Hover or tab to the citation chips in the window at the top of this page. The card that opens is the passage behind the claim, the same thing you get by clicking a chip in the app.

The mark the answer carries when the citation was fitted after the fact. It names the model that put the word there, and the dotted line does not end until the passage behind the claim closes it.

You can watch it decide.

Open the disclosure above any answer and read what it did: the reasoning, then the passages it pulled, each with its source. It is the evidence the answer rests on, in the product’s own words.

When the gate sends it to the web, you watch that too, domain by domain, as it fetches each page and reads it.

ἵστωρ. 4 sources

Thoughts

Read en.wikipedia.org, Antikythera Mechanism

Overview
The Antikythera mechanism is an ancient Greek…
discovered in 1901. It is the oldest known example…
Read en.wikipedia.org, Antikythera Wreck

Discovery
Around Easter 1900, Captain Dimitrios Kondos…
Read nature.com

Nature.com
A required part of this site couldn’t load.
Read arxiv.org, 2403

arXiv:2403.00040, An Improved Calendar Ring…
Authors
Graham Woan
Joseph Bayley

The gate sent this one to the web rather than answering from the library, so you watch it read, page by page. Four domains, named as each page came back. One of them refused to load, and the log keeps that too.

It marks what nobody knows yet.

Ask it something genuinely unsettled and it will not tidy it up. Scholars have argued over the calendar ring’s hole count for a century; the app answers with the dispute intact, row by row, rather than picking the likelier figure and moving on.

It is the same discipline as the citation mark, pointed at a different gap. One says here is which model put this number here. The other says here is what nobody knows yet.

ἵστωρ. 10 sources

It tracks the Metonic cycle (19 solar years, about 235 lunar months)
It incorporates the Egyptian calendar alongside the Greek zodiac

Historical attribution:

Associated with either Archimedes or Hipparchus

What Is Still Disputed

Issue	Status
Exact date of construction	Only a range (150-100 BC) is known
Exact number of gears	“At least 30”: the exact count is uncertain
Exact number of holes in the calendar ring	354 or 355 (354 is far more probable than 360)
Identity of the inventor	Archimedes or Hipparchus, both candidates
Whether it qualifies as a “computer”	The term is debated
Whether it qualifies as a “calculator”	The term is debated
Whether it qualifies as a “clock”	The term is debated
Whether it qualifies as a “calendar”	The term is debated
Whether it qualifies as a “planetary calculator”	The term is debated
Whether it qualifies as a “solar calendar”	The term is debated
Whether it qualifies as a “lunar calendar”	The term is debated
Whether it qualifies as a “solar-lunar calendar”	The term is debated

The device is widely regarded as a technological marvel, but the precise classification and attribution remain subjects of scholarly debate.

Twelve rows, each printed with a status rather than a settled answer. The hole count is the row the next section is about.

On your machine.

Nothing leaves, and what you write stays yours. Those are two consequences of the section above rather than two separate promises, and both are settings you can open and read.

Settings, on the Research panel. Web research and outbound network fetches are switched off. Inbox watching is on, importing new files from the Istor inbox. Search backend is set to a keyless scrape chain, and the row notes that a SearxNG backend without a URL falls back to it.

Settings, on the Models panel, in the light theme. The backend is a local model server, chosen between Ollama and llama.cpp, and the server URL points at localhost on port 11434. A row below reports nine models already installed on it, and a second row picks which one handles the fast work of summarizing, routing and rewriting.

Web research is off until you turn it on, and there is no account and no key to enter. The model is one you install and point at. Istor does not ship with one. Both panels are the app, unaltered, at the size it draws them.

The library is the interface.

Sources on the left, notes on the right, the answer in the middle. Everything Istor knows is a document you put there, and everything it says can be traced back to one.

The Library rail in full view, in the dark theme and at the size the app draws it. Ten sources are listed under a filter field, each with a status dot at its right, and an Add source control sits at the foot of the rail. — The library in full view, at the size it runs. Ten sources, every one of them a document on this machine.

The Notes rail in full view, in the light theme and at the size the app draws it. Ten notes are listed under a filter field, each named after one of the ten sources, with a New note control at the foot of the rail. — Ten notes, one for each source it read. A note stays after the question is done.

The library, as a list of documents rather than a picture of one. Each row is a source it read, named as the app names it, and the dot is the app’s status mark. Everything the answers on this page cite resolves into these ten.

Where it stops.

Where it refuses. It does not guess. If your sources do not cover your question, it says so. The refusal is deliberate.

Where it genuinely ends. It is not a frontier model and it will not out-reason one. It needs sources, and local means your machine is part of the deal.

354 holes are 1.0169° apart. 355 are 1.0141°. At this size the two rings are the same ring, which is why the app prints both numbers and picks neither. The two counts part by less than a hole’s width, a distance no scale on this page can show.

What it did, and how well.

Ask it something measurable and it reports the measurement, including the part that is wrong. These are the figures from one question about the calendar ring.

354.08: holes in the calendar ring, as fitted from the X-ray data, not a whole number, because the ring is not one.
68%: how much confidence the app attaches to that count. It prints the figure it reached, and 68 percent is not certainty.
0.028 mm: how far the holes wander from a perfect circle, measured on a ring that was cut by hand.
4: citations in the answer at the top of this page. Every claim in it resolves to a passage in one of ten documents.

The disputed count, drawn twice on the same radius and anchored at the same hole. The ring of 354 runs its holes at 1.0169 degrees apart, the ring of 355 at 1.0141; by the far side the two streams are one hole’s width apart, which is the whole argument. The lens magnifies the drawing twelve times to show the parting; the drawing itself is not exaggerated.

The parapegma, the machine’s star almanac^{1, source 1}. Two pinned slabs, one above the dials and one beneath, keyed by Greek letters: each key marks a peg hole, each row a star or a season arriving. The bracketed gaps are the stone’s damage, kept in the drawing because a register that has holes should be drawn with its holes.

The coincidence the rear face stands on. 235 synodic lunar months and 19 tropical years, on one dial: the months as beads outside, the years as divisions inside, both counts starting together at 12 o’clock. After nineteen years the lunar count is about two hours ahead^{1, source 1}. The exeligmos below is the correction a smaller mismatch demands; this is the big one, the one that works.

The two settled dials of the rear plates. On the Metonic spiral, five turns carry 235 lunar months, the 19-year cycle; on the Saros spiral, four turns carry 223, the eclipse cycle. Each radial tick is one month, and the scarlet dot sits where each count ends.

The exeligmos, the small dial in the Saros spiral’s eye^{1, source 1}. A Saros prediction is right to the month but lands eight hours late; the next one, sixteen hours; the next, a whole day. The three divisions say how many hours to add, and 8 + 8 + 8 is 24: after 54 years the count comes back to the calendar.

The Callippic cycle, the fourth named cycle: four turns of the Metonic are 76 years^{4, source
4, Decoding Antikythera mechanism}. Each quarter of the ring is one Metonic cycle of 19 tropical years; where the Metonic spiral counts months across five turns, the Callippic counts cycles across four, and the product sits in the middle of the dial it belongs to.

The games dial, the sub-dial that rode with the Metonic spiral^{1, source 1}. Four sectors, one per year of the four-year cycle: Isthmia and Olympia, then Nemea and Naa, then Isthmia and Pythia, then Nemea and Halieia. The arrow marks its pointer, the only one on the mechanism that runs anticlockwise.

The front face, the one that shows where the sun and moon are^{1, source 1}. The inner ring is the zodiac, twelve signs in thirty-degree sectors. The outer ring is the calendar the page’s ring question is about, its holes left uncounted here on purpose; the three month names the imaging recovered (Pachon, Payni, Epiphi) are the ones the source can still read. The sun’s mark stands at the ram, an arbitrary day; the face is drawn, not read.

One answer, two live possibilities. 354 to 355 holes

The app reports 354.08 at 68 percent confidence. It keeps 355 visible instead of rounding uncertainty away.

Istor answering the question “How many holes did the calendar ring have?” in the dark theme, with a Thoughts disclosure above the answer showing the app drafting its reply. The answer says the ring held either 354 or 355 holes rather than the previously assumed 365. The estimate is 354.08 at 68 percent, from high-resolution X-ray measurements, with a radial variation of only 0.028 millimetres between holes. — The capture behind the first three figures. It is answering a question about the same ring the arc above is drawn from.

Questions

Four of the seven answers below are the same answer, and this is it.

Does anything leave my computer?

No. The model and the search run on your machine, and so does the reading. Web research is off until you turn it on in Settings, and when you do turn it on there is no account and no key to enter.

What hardware do I need?

It depends on the model you choose, which is why we do not print a number. A small model runs on a modest graphics card; a larger one wants more. Because the requirement follows the model, there is no single floor we could publish that would be true for everyone, so we would rather say that than pick one and be wrong for half the people reading it.

Which models can it use?

A small model running on your own graphics card, and you choose which. Istor needs Ollama or llama.cpp installed; if it finds Ollama it will suggest a model, and you can run any other one instead.

Does it work with no internet at all?

Yes, and that is the case it is built for. If the documents in your library already settle your question, Istor answers from them and never goes online. With no connection at all, the library still works in full.

Is it open source?

Not yet. The repository is public and empty. It is where the code lands, and it has not landed. What we can tell you today is what is on this page: the app is local and makes no outbound requests unless you switch web research on. Every claim it makes is traceable to a document you gave it. When there is code to read, this page will say so.

When does it come out?

Windows first, with Linux and macOS after. There is no date we are ready to put on it. The installer is the next thing.

Who builds it?

Thoria builds Istor. You can find them at thoria.fyi.

ἵστωρ

It is the old Greek word for a witness, and it comes from a root that meant to see. The same root reached English, and the plate below shows how far it travelled.

One root and three of its descendants. The asterisk is what a reconstructed word is marked with: nobody wrote that one down, and the act’s whole argument is that this tool does not pretend to more certainty than its sources.

A witness is someone who was there and can say what they saw, rather than the person who knows most.

That is the whole design of this tool. It does not know about the Antikythera mechanism. It read ten documents about it, and it can show you which one said what.

ἵστωρ.

ἵστωρ. 10 sources · 10 notes

Tell me about the cycles.

Thoughts

The Antikythera mechanism incorporated several key astronomical cycles, the first of which is the Metonic cycle, nineteen tropical years, almost exactly 235 lunar months^{1, source 1}.

Istor is not finished.

There is no installer yet, and the repository is public and empty. What exists today is the app on this page, running on Windows.

Follow the build

Search all seventy-five pages

There are seventy-five other pages about local AI on this site. These are the ones to start with, or see all seventy-five.

It shows you what it saw.

It checks what you already gave it.

Every claim points at a passage.

You can watch it decide.

It marks what nobody knows yet.

On your machine.

The library is the interface.

Where it stops.

What it did, and how well.

Questions

ἵστωρ

Istor is not finished.

The vocabulary

Running it yourself

Answers you can check

For your research