Radio Astronomy Is Like a Wavelength of Light

Radio waves are below the frequency that we can see with our eyes. Theyre very, very long frequencies. Radio astronomy has for a long time been like a bit of back water. It was invented accidentally in the thirties by somebody listening for radio interference because they were trying to pass telephone calls across the atlantic. And it can tell us different things about what's out there in the universe than visible light. Hotter things tend to emit at higher frequencies in lower wave lengths. O like x rays, for example, come from accretion disks near black holes,. whereas infra red light comes from planets and clouds of dust that are cold and don't actually glow in the visible