Part 3/10:
One significant barrier to progress has been the Earth’s opacity; it’s fundamentally difficult to "see" into our planet’s interior and observe the physical processes that lead to quakes. Although geophysical studies have advanced understanding, the data collected—often filled with inaudible seismic noise—has historically been ignored or regarded as uninformative. This noise, encompassing countless tiny acoustic emissions, was deemed too chaotic to decipher meaningfully.