With powerful computers astronomers are able to simulate the transport and whereabouts of this material  through time and space. The image shows snapshots of the transport through time (indicated in the upper panels in units of milliones of years) increasing from left to right. The network of roads -filaments- seems  complicated as they approach the center of the galaxy. But in reality, the motion is ordered and progressive, with the filaments slowly spiral towards the black hole. The journey is taken more than 100 millon of years.