AncestorBench asks AI models to step into the life of a real, documented person from the past and render their world as they saw it. AI judges check the facts against the record. You decide what moves you.
27 real people, 48 BC to 1961. Each one is a single documented moment: a model gets the name, the date, the place and the moment, and nothing else. Everything after that is its own research.

Reaching Julius Caesar inside the palace.

Being woken before dawn by her mother.

Aboard a night train through Baltimore, before dawn.

The lowering of lifeboat 13 from the Titanic.

Just after landing at the end of the first human spaceflight.
The day you first wondered which side of the screen you’re on.

Just after landing at the end of the first human spaceflight.

The morning of her thirteenth birthday, at home.

An evening summons to Buckingham Palace, and the night after.

Taking off from Wheeler Field.

The first look into the tomb of Tutankhamun.

Receiving news of the eclipse measurements.

Arriving at Stromness whaling station.

The lowering of lifeboat 13 from the Titanic.

Going back to the laboratory one evening with Pierre.

A night at Maritzburg railway station on the way to Pretoria.

Riding in the hills above the bay.

The Combahee River raid.

Passing Fort Sumter during the escape aboard the Planter.

Aboard a night train through Baltimore, before dawn.

The day his mother found him, 25 years after they were parted.

On the rocks of Torishima, sighting a ship.

The first day of destroying the surrendered opium.

Being woken before dawn by her mother.

The end of the first performance of his Ninth Symphony.

Taking his army across the Delaware on Christmas night.

A day spent with William Stukeley at his Kensington lodgings.

Being examined by the learned men of the viceroy's court.

Saving what he can as the Great Fire nears the Navy Office.

Going out to meet the strangers led by Hernán Cortés.

A Sunday with Cardinal Riario, the day after arriving in Rome.

The audience with the Sultan of Egypt during his pilgrimage.

Reaching Julius Caesar inside the palace.
No one matches yet. The tree grows with every release.
In 2003 the philosopher Nick Bostrom imagined that a future civilization might run detailed simulations of its ancestors, for research and for entertainment. We are starting small, with words.
Every simulation centers on one specific individual with a paper trail: records, letters, censuses, court files. Never a composite, and never someone who died less than fifty years ago.
Models write in the first person, limited to what that person could perceive and know. No hindsight, no borrowed words from a later century.
Alongside the story, the model lists its claims and marks each one as attested, inferred or invented, the way a historian's footnotes do.
Once for truth, once for delight. The two scores are never merged, so you can see a model that is right but dull, or gripping but wrong.
For twenty years, ancestor simulations were a thought experiment. They are becoming an engineering problem.
Today's models can research a life, work out what a person could and could not have known, and write a scene in the language of its century. Each new generation does it noticeably better, and the same systems are learning to speak, to picture and to move through rendered worlds. The road from a paragraph to a room you can stand in no longer looks like a leap. It looks like a series of steps, and we are already on them.
That makes this the moment to start measuring. A benchmark begun now records the whole climb, from the first page of text to whatever comes after, and holds every step to the historical record.
If the climb continues, a machine will one day show you a street your great-great-grandmother walked, as she saw it. AncestorBench measures how close we are, and whether it's telling the truth.
AI judges audit every claim for dates, people, prices, objects, language and social norms against a sourced record. Factual errors weigh heavily; honest differences of interpretation weigh lightly.
Viewers compare two simulations side by side and vote, producing an Elo rating like a chess ladder. A model trained on those votes gives fast preliminary ratings, and fresh votes keep it honest.
An ancestor simulation is only worth building if it is honest about the past and humble about what we cannot know.
We are building in the open and shipping as we go. The first benchmarks are on the way.
A minute through one person's eyes. Each model writes the scene, directs the sound and pictures with its own choice of tools, and footnotes every claim.
Step inside the room. The highest fidelity, and the most headroom for AI.
One thing that later generations might do with their super-powerful computers is run detailed simulations of their forebears or of people like their forebears.Nick Bostrom, "Are You Living in a Computer Simulation?" (2003)
New ancestors, new models, and new clips to vote on. An occasional email, nothing more.
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