In a superconductor crystal, electrons sometimes arrange themselves into charge waves, like ripples on water, but made of the particles themselves. Some waves stretch far, while others live only over short stretches. Scientists took the material YBa$_2$Cu$_3$O$_{6.67}$ and hit it with short X-ray pulses to observe both types of waves.
After the flash, the large charge waves disappear almost instantly, while the small ones stay put. The large ones recover in 0.6 picoseconds — trillionths of a second, faster than a firefly blinks. The small waves barely notice the light: they are sturdier and hold up even under intense irradiation.
The difference in behavior shows that two distinct types of charge waves coexist in the material. One is destroyed by an electronic process, the other is not. This X-ray method helps disentangle intertwined quantum phenomena that previously merged into a single picture.
A picosecond is one trillionth of a second. If one second lasted as long as 30 years, a picosecond would be shorter than a single heartbeat.