The United States has finished constructing a huge physics experiment aimed at recreating conditions at the heart of the Sun.
The US National Ignition Facility is designed to demonstrate the feasibility of nuclear fusion, a process that could offer abundant clean energy.
The lab will kick-start the reaction by focusing 192 giant laser beams on a tiny pellet of hydrogen fuel. To work, it must show that more energy can be extracted from the process than is required to initiate it.
So like a hydrogen bomb. Isn't that dangerous? Professor Mike Dunne, who leads a European venture that is also pursuing nuclear fusion with lasers, says that if NIF was successful, it would be a "seismic event".
I hope that was just an unfortunate turn of phrase.