After a good three years of maintenance and improvement work, the largest research machine in the world is started up again: the particle accelerator of the European Organization for Nuclear Research (CERN) in Geneva.
This Friday, the first two proton beams are to be chased in opposite directions through the 27-kilometer underground ring.
It takes six to eight weeks for the machine to be up to speed.
Only then can proton collisions take place again, which should reveal knowledge about the basic laws of the universe.
The particle accelerator is used to simulate the time when the universe came into being around 14 billion years ago.
Researchers observe the decay processes during the collisions and gain insights into the smallest components of matter, the elementary particles.
Among other things, the Higgs boson, which was theoretically described 40 years earlier, was detected for the first time at CERN in 2012.
It contributes to the fact that elementary particles have a mass.