Topic: The recent announcement of the first image of a black hole.
1: First picture of black hole was unveiled in April. It is taken far outside visible wavelengths, at a wavelength of 1.3mm, which is around 100 times the frequency of your microwave oven. The picture is assembled from information collected from antennas at widely separated sites around the globe, including Chile, Arizona, Mexico, Spain, and Hawaii.
2: We don’t actually see the black hole. We see its shadow, the dark spot in the center of the image. The orange donut of emission around the hole is glowing, translucent, hot gas.
3: The university of Illinois was involved. We were leaders in interpreting the image. Part of what we did was building supercomputer models of hot gas falling into the black hole. That hot gas is what we see.
4: Future holds the possibility of much sharper images, with more information about the black hole. New observations will include more telescopes from around the world, in Greenland, the Alps, and in Arizona.