Scientific equivalent of running up the down escalator in a way.
Also, it's not entirely right to say this has never been achieved in lab before:
NBC science wrote:
Update for 8 p.m. ET May 19: Any scientific claim that something physically possible has "never been done" will almost surely set off a debate, and that's the case for the light-to-matter trick. In an email, Bruce Schumm makes a strong case that it's been done before:
"I'm a physics professor at UC Santa Cruz and a longtime user of the facilities at the SLAC Linear Accelerator Center on the Stanford campus (where you may recall that quarks were discovered in the late 1960s). It is NOT true that the Breit-Wheeler process has never been discovered before. In fact, at this very moment I happen to be running a little experiment using the very same electron beam that a group headed by Adrian C. Melissinos of the University of Rochester used way back in 1997 to demonstrate this process. ... So while the scientists in the article may be making it much more copiously than in the past, they are not the first to produce matter by colliding beams of light!"
Schumm points to a New York Times article about the experiment, which was described in Physical Review Letters. The 1997 article in the Times said Melissinos and his colleagues "confirmed a longstanding prediction" by Breit and Wheeler about using light to create particles.
One caveat is that the SLAC experiment depended on a complicated interaction with a beam of high-energy electrons — and that's the thread on which Pike and his colleagues hang their claim for the novelty of the proposed photon-photon collider. Their paper in Nature Photonics even cites the earlier work, saying that such experiments don't qualify as pure photon-photon collisions because they "involve massive particles."
