“Never look down to test the ground before taking your next step; only he who keeps his eye fixed on the far horizon will find the right road.” -Dag Hammarskjold
One of the great discoveries of the past few decades was that of a supermassive black hole at the center of our Milky Way. No longer was it mere conjecture or unverified theory; observations in the X-ray, infrared, radio, and of stars orbiting a central, non-luminous point all indicate the presence of a 4 million solar mass black hole at a location known as Sagittarius A*.
At a distance of 26,000 light years, an object as small as this black hole’s event horizon — even at 23 million km in diameter — would be unresolvable to a telescope the size of an entire country. But thanks to the very clever technique of very long baseline interferometry, the proposed Event Horizon Telescope has the capabilities, for the first time, of imaging a black hole’s event horizon directly.