In a new experiment a sample was excited with an #XrayPulse and then probed with another, all in under a #femtosecond. When they tried using it with liquid #water, their results had more to say about water’s equilibrium structure than about its subfemtosecond dynamics.

https://pubs.aip.org/physicstoday/article/77/4/12/3279737/Attosecond-analysis-illuminates-a-watery