> They are mapping visual data about gas density Is X-ray data visual data? I suppose it is... but my understanding of this is the data comes from ripples in

> They are mapping visual data about gas density Is X-ray data visual data? I suppose it is... but my understanding of this is the data comes from ripples in the gas. So it's not that removed from sound waves? I mean, sound needs a medium, and if we can measure the ripples in the medium we more or less have something approaching a sonic representation, or "sounds of space".