Ringing of the gas as energy gets pumped into it from the black hole. so it's like with the microphone. when you talk into a microphone, it turns your voice into electromagnetic waves, and then your radio turns it back into sound, but here, you're seeing -- you're hearing the voice of a super massive black hole that's billions of times larger than the sun or more massive than the sub. sun. >> it's all so mind blowing. professor adam frank, thank you very much for explaining it to us. >> thank you, prof sorry. new home sales fell sharply last month in a sign rising prices are taking a toll on...