LCLS is the world’s first x-ray laser. Short coherent x-ray pulses are one of the most powerful probes of matter available today. It is how we know what proteins look like and how cells operate. It is how we know that various solid condensed matter phenomena and exotic states of matter exist. It is how certain classes of drugs were developed. It is the method of choice for those studying important applications like practical superconductivity, chemical engineering, and semiconductor physics. These applications are all limited by x-ray brightness.

Quoting from Stanford’s LCLS website:

LCLS takes X-ray snapshots of atoms and molecules at work, providing atomic resolution detail on ultrafast timescales to reveal fundamental processes in materials, technology and living things. Its snapshots can be strung together into “molecular movies” that show chemical reactions as they happen.

LCLS and the physics of the free electron laser improved the brightness of x-ray sources by 10 orders of magnitude! There are literally entire branches of research that would not exist without this technology. It is so bright that when they focus the beam they come close to having enough photons in one place to spontaneously pair create electrons/positrons! It is enabling pioneering research in a diverse array of fields – revealing the structure of proteins from nanocrystals, manipulating electric and magnetic fields, probing into nuclear fusion, customizing chemical reactions.

Unfortunately, this type of physics doesn’t get the same press as a LIGO or a Higgs, but it is hard to overstate the impact of this development. Every major region of the world is currently rushing to build their own x-ray laser, because there are parts of nature that you just cannot investigate without it and rumor has it that the originators of the free electron laser are in the running for the Nobel prize.

Think of it like the move from the optical microscope to the electron microscope and the whole world of discovery it unlocked. Think about the first time Galileo looked through his new telescope and saw that Jupiter has moons. This is the stage we are at with x-ray lasers and there’s no telling what we will learn with them in the coming decades.