The Event Horizon Telescope: A Revolutionary Tool in Astronomy

The Event Horizon Telescope (EHT) has made headlines around the world with its groundbreaking imaging of a supermassive black hole at the center of galaxy M87. But what is this incredible technology, and how does it work? We spoke to Michael Janssen, a postdoctoral researcher at the Max Planck Institute for Radio Astronomy in Bonn, Germany, who works on the EHT project.

The EHT is an astronomical interferometer that combines data from several radio telescopes around the globe. Instead of being limited by the size of individual telescopes, the EHT's resolution is determined by the distance between pairs of telescopes. This allows it to achieve unprecedented angular resolution - equivalent to reading a newspaper in New York from a sidewalk café in Paris.

The EHT observes black holes at a wavelength of 1.3 millimeters using very-long-baseline interferometry (VLBI). By capturing the shadow caused by gravitational bending and capturing of light, scientists can reveal valuable information about the black hole's mass and size. According to Heino Falcke, chair of the EHT Science Council, if a black hole is immersed in a bright region of glowing gas, it should cast a shadow on this material.

The EHT's imaging capabilities are made possible by the tremendous gravitational influence of supermassive black holes on surrounding material. This material becomes super-heated and glows as it is gradually fed to the black hole, creating an accretion disk around some black holes.

The historic first image of a supermassive black hole ever recorded was captured using the EHT, showing the shadow of the monster black hole at the center of galaxy M87. This achievement has irrevocably shifted the paradigm of astronomy and cosmology, and perhaps even science itself. The EHT's work is a testament to human curiosity and our drive to explore the unknown.

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