Grant: Discovery Grants Program - Individual

On April 10, 2019, the Event Horizon Telescope (EHT) released the first horizon-resolving images of a black hole, an ominous dark silhouette against the nearby luminous emission. This was followed by the first polarization maps of M87* in 2021, revealing large-scale magnetic structures at the event horizon, and the first images of the black hole at the heart of the Milky Way (Sgr A)* in 2022, detecting the turbulence that drives matter toward the event horizon. The EHT has dramatically confirmed that supermassive black holes live at the centers of nearly all galaxies and, paradoxically, drive some of the most energetic phenomena in the universe. In the coming decade, the EHT will undergo significant expansion in array size and station capability. Already, the EHT has expanded from the 8-station array fielded in 2017 responsible for the first published images of M87* and Sgr A*; observations in 2018, 2021, 2022, and 2023 have all included new sites. All EHT stations detect polarization, have grown more sensitive, and made observations at higher frequencies. The enhancements will culminate in a dedicated array that will be able to map M87* from its event horizon to the stars. Simultaneously, preparation has begun for a space-based array that could have a resolution 300 times greater than that of EHT, capable of seeing an object the size of M87* from across the universe. We will continue realizing EHT's transformative potential to reveal the nature of supermassive black holes, determine how they formed and grew to their gargantuan sizes, and how they influence their galactic and intergalactic environments. Doing so requires dedicated programs to support EHT science utilization by applying well-tested cutting-edge analysis techniques to EHT data (e.g., "imaging with error bars", algorithms that isolate and extract physical features), develop the tools to exploit the rapid enhancement of EHT capabilities (e.g., "moviemaking with error bars", use machine learning to accelerate direct-to-physics analyses), and prepare for future ground- and space-based arrays by assessing their scientific opportunities (e.g., study the evolution of black holes across cosmic time, the implications for Einstein's general relativity, and turn Sgr A* into a laboratory to study its environment). We are poised to empirically understand the origin and inordinate impact of black holes by realizing the extraordinary scientific potential of horizon-scale experiments. The journey of matter from galactic scales to its final plunge across the horizon reveals how objects grow generally, from planets to galaxy clusters; the discovery of horizon-scale deviations from general relativity would drive a revolution. HQP within this program will develop facility with cutting-edge data analysis techniques, the ability to deploy them with large-scale computing, and the leadership skills to conceptualize, organize and execute projects within a distributed, globe-spanning collaboration.