How high is that ash cloud?
When a cloud of hot dust is thrown high into the sky by a big mountain of hot rock, it can be a problem for air ships that fly people around. Right now, we use space machines and special computers to work out how high the hot dust cloud is and to guess where it will go. This way can take too long for people who fly the air ships around. In our paper, we show a really quick way of working out how high the hot dust is. When the big mountains of hot rock throw the hot dust into the sky, they make a sound that we cannot hear but our special machines can. We can use this sound to work out how fast the hot dust is being thrown into the sky. With this, and a special number machine, we can work out how far they will go into the sky. Using the sound from a real hot mountain that threw out hot dust in 2009, we show that our way can very quickly work out how high the hot dust will go. Our way of working out how high the hot dust goes will better help the people who fly air ships around, and help ...