The Event Horizon Telescope: From the First Images to the First Movies of Black Holes

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B20 Auditorium

This lecture explores the Event Horizon Telescope's groundbreaking achievements in imaging supermassive black holes, details the complex global and computational infrastructure enabling these discoveries, and outlines the future transition from static images to dynamic, real-time movies of the universe's most extreme environments.

In 2019, the Event Horizon Telescope (EHT) collaboration unveiled the first image of a black hole, revealing the shadow of the supermassive black hole at the center of the galaxy M87 and opening an entirely new observational window on gravity in its strongest regime. Since then, the EHT has produced the first image of Sagittarius A*, the black hole at the center of our own Galaxy; uncovered the dynamically important role of magnetic fields in powering black hole accretion and relativistic jets; and provided direct evidence that the immediate environment of a black hole evolves on observable timescales.

In this colloquium, I will present the scientific discoveries that have emerged from the EHT and explain the physical processes they reveal, from the behavior of matter and magnetic fields in the immediate vicinity of an event horizon to new tests of Einstein's theory of General Relativity, and black energy extraction processes. I will also describe the observational and computational techniques that make these measurements possible. Because no single telescope can achieve the required angular resolution, the EHT combines radio observatories around the world into a virtual Earth-sized telescope. More fundamentally, it is an intrinsically computational telescope: transforming petabytes of raw data into images requires state-of-the-art algorithms, high-performance computing, and sophisticated statistical inference, making computation an integral part of the instrument itself.

Finally, I will discuss ongoing efforts to obtain the first time-resolved "movie" of a black hole, enabling us to probe the dynamics of matter and magnetic fields at the edge of the event horizon in real time. I will conclude with a look toward the next generation of horizon-scale imaging, including both expanded ground-based arrays and future space-based interferometers, which promise sharper images, faster temporal resolution, and ultimately a deeper understanding of black holes, gravity, and the most extreme environments in the Universe.

Presenters

Laurent Loinard, Professor of Astronomy, Institute for Radio Astronomy and Astrophysics (IRyA), National Autonomous University of Mexico (UNAM)

Brief Biography

Laurent Loinard is Professor of Astronomy at the Institute for Radio Astronomy and Astrophysics of the National University of Mexico (UNAM). A founding member of the Event Horizon Telescope (EHT) Collaboration, he has served as its Director since November 2025. He earned his Ph.D. in astrophysics from Joseph Fourier University in Grenoble in 1998. He is internationally recognized for ultra-precise measurements of astronomical distances and for imaging at the highest angular resolution in astronomy, with research spanning star formation, astrochemistry, radio stars, and supermassive black holes. He has published more than 300 refereed articles, cited nearly 40,000 times. His honors include the Guggenheim Fellowship, the Bessel Prize, the TWAS Prize, and - with the EHT - the Breakthrough Prize and the Einstein Medal. He has supervised more than 30 theses, and his students have earned distinctions of their own, including the IAU Ph.D. Prize. An active science communicator, he has taken part in some 200 outreach activities - many of them talks for students and young audiences of all ages.