Journey to the supermassive black hole at the center of our galaxy Watch this video footage that zooms in on the black hole (Sgr A*) at the center of our galaxy. After an overview of the Milky Way, we dive into the dense clouds of gas and dust at the center of our galaxy. The stars in it have been observed by ESO's Very Large Telescope and ESO's Very Large Telescope Interferometer for decades, with the black hole's immense gravitational pull distorting the orbits of the largest stars. close to him. Finally, we come to Sgr A*, from which the first image was obtained. The black hole is represented by a dark central region called a shadow, surrounded by a ring of gas and luminous dust. The various observations used here were taken at different times, by different teams and with different facilities, and put together for the purposes of the zoom effect. The images range from early visible wavelengths all the way to infrared, with the very last image taken at radio wavelengths.
Testing a 50 year old mercury arc rectifier A mercury-arc rectifier is a type of electrical rectifier used for converting high-voltage or high-current alternating current (AC) into direct current (DC). It is a type of cold cathode gas-filled tube, but is unusual in that the cathode, instead of being solid, is made from a pool of liquid mercury and is therefore self-restoring. As a result, mercury-arc valves were much more rugged and long-lasting, and could carry much higher currents than most other types of gas discharge tube.