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An editorial interpretation of Nasir al-Din al-Tusi, distinguished by later stamp iconography, adjusting a two-circle model and linear slider with collaborators in a Maragheh-like research space
AI editorial interpretation

When two circles make a line, one device enters a community of astronomy

No verified lifetime portrait of al-Tusi or record of this exact observing scene survives. The narrow face, high white turban, and pointed beard use later stamp iconography only for recognition, not appearance evidence. The two-circle model and collaborators condense Maragheh's scholars, engineers, books, and instruments rather than a lone invention, a single-handed rescue of Baghdad's books, or a proven direct line to Copernicus.

MathVoyage editorial direction · OpenAI image generation · later stamp iconography reference · no verified lifetime likeness · 2026-08-07

Remember the mind, not only the dates

Nasir al-Din al-Tusi

AD 1201 - AD 1274
Thinking ground · Maragheh
Born · Tus
Islamic Golden AgeFrom two circles to linear oscillationThe Maragheh observing communityA similar diagram and an unproven transmission route

The idea to carry forward

Combine two circular motions and a point can oscillate along a straight line.

Enter through one scene

AD 1256

A new patronage system after Alamut’s surrender

After Alamut surrendered in 1256, he became an adviser to Hulagu. His position in the Nizari fortresses and his choices under Mongol rule are more complex than a simple captivity-and-rescue story.

Questions this person helps open

Concept ports to revisit, not another achievement list

These are reverse projections of existing editorial routes, not claims of direct influence or sole invention.

No concept port has yet been reviewed for this person.

Browse every concept route

PROFILE 02 · DEEP VOYAGE

How Nasir al-Din al-Tusi’s ideas moved

Instead of memorizing more dates, follow the world that shaped this mind, the scenes that changed its direction, and the questions carried onward.

CHAPTER 01 · PERSON AND PERIOD

What questions surrounded Nasir al-Din al-Tusi?

Before the finished achievement, read what this person treated as a problem and where the surviving evidence reaches its limit.

About 1 min read

A Persian scholar who reorganized geometry and observation amid conquest and changing systems of patronage. Born in Tus, al-Tusi spent many years at fortresses of the Nizari Ismailis. Whether different periods of that residence were patronage or confinement remains disputed. After Alamut surrendered to Mongol forces in 1256, he served as an adviser to Hulagu and led the creation of the Maragheh observatory, gathering scholars, instruments, and books from several regions. The story that he personally rescued the last documents of Baghdad’s House of Wisdom in 1258 lacks adequate evidence. His Treatise on the Complete Quadrilateral was an important systematic account of plane and spherical trigonometry. The Tusi couple combines two circular motions to produce linear oscillation and was used to revise Ptolemaic planetary models. A strikingly similar construction appears in Copernicus, but the route of transmission remains debated.

CHAPTER 02 · TURNING SCENES

4 turning scenes

Follow the moments when the idea moved one step further. Every scene continues through an evidenced place or an honestly labelled time context.

  1. Scene 1 / 4

    AD 1256Alamut· Geographic context

    A new patronage system after Alamut’s surrender

    After Alamut surrendered in 1256, he became an adviser to Hulagu. His position in the Nizari fortresses and his choices under Mongol rule are more complex than a simple captivity-and-rescue story.

    Continue from this scene's time

  2. Scene 2 / 4

    AD 1259Maragheh

    Maragheh observatory — organizing observation institutionally

    With Hulagu’s patronage he led a research institution gathering scholars, books, and large observational instruments. Long-term observations bringing together several regional traditions produced the Ilkhanic Tables.

    Continue from this scene's place

  3. Scene 3 / 4

    AD 1260Maragheh

    Shakl al-qatta — a system of plane and spherical trigonometry

    Using the complete quadrilateral, he developed relations for plane and spherical triangles, including the sine rule. It was an important step from astronomical examples toward a general theory of trigonometry.

    Continue from this scene's place

  4. Scene 4 / 4

    AD 1261Maragheh

    Tusi couple — from circular motion to linear oscillation

    When a smaller circle rotates oppositely inside a circle of twice its radius, a point on the smaller circle oscillates along a diameter. Copernicus used a similar construction, but its route of transmission is not established.

    Continue from this scene's place

THOUGHT EXPERIMENT · NOT A FACT CLAIM

Erase Nasir al-Din al-Tusi from the map

This is a thought experiment about influence, not a verified historical fact.

Beginners watch a point move along a line as a small circle rolls inside a larger one. Intermediate learners calculate the radius and angular-speed ratios; advanced learners prove the motion with parametric equations or complex numbers. Experts compare Maragheh manuscripts, Copernican diagrams, and possible routes of transmission to ask how historians distinguish influence from independent rediscovery.

Beyond MathVoyage

Curated sources and problems. Bring one discovery back from OEIS, Project Euler, MathOverflow, or arXiv.