In the ongoing quest to unlock the secrets of the universe, physicists at the European Organization for Nuclear Research (CERN) are looking into the future and thinking big — real big.

After five years of development, the research organization has unveiled conceptual plans for a particle accelerator called the "Future Circular Collider" (FCC) sited under the Swiss-French border. A successor to the group's 27 kilometer-long (16-mile long) Large Hadron Collider, the FCC would feature a circular tunnel spanning an incredible 100 km (62 miles).

"Expanding our understanding of the fundamental laws of nature requires the energy frontier to be pushed much further," CERN said in a statement. "Reaching this goal within the 21st century in an economic and energy efficient way calls for a large circular collider."

A rendering of the Future Circular Collider (FCC) overlapping the Large Hadron Collider (LHC).
A rendering of the Future Circular Collider (FCC) overlapping the Large Hadron Collider (LHC). (Photo: CERN)

What kind of benefits can be achieved with a more powerful particle accelerator like the FCC? For one, its extreme length would allow atoms to build up enough velocity to approach the speed of light, triggering larger collisions that may unveil new particles presently invisible to modern technology.

As CERN outlines in a brochure, the power of the FCC — with an estimated six to 10 times the energy of the Large Hadron Collider — may help to shed light on unexplained phenomena like dark matter and the prevalence of matter over antimatter.

"The search for new physics, for which a future circular collider would have a vast discovery potential, is therefore of paramount importance to making significant progress in our understanding of the universe," the agency added.

A conceptual view within the proposed 100 km-long FCC tunnel.
A conceptual view within the proposed 100 km-long FCC tunnel. (Photo: CERN)

Mining the secrets of the universe, however, isn't cheap. Over two phases covering both the construction of the tunnel and the addition of instruments like an electron-positron collider and a superconducting proton machine, the total cost could approach more than $38 billion.

That high price tag has led some to openly question whether pursuing such a costly project is worth the possible benefits, particularly in the face of more pressing issues such as climate change.

"There is always going to be more deep physics to be conducted with larger and larger colliders," Sir David King, a professor and the U.K.'s former chief scientific advisor, told the BBC. "My question is to what extent will the knowledge that we already have be extended to benefit humanity?"

Should CERN gain approval from its international partners, the costs for the project will be spread over a 20-year period, with the FCC estimated to be fully-functional by the middle of this century.

The Large Hadron Collider, meanwhile, is expected to continue its own groundbreaking research into sub-atomic mysteries until at least 2035.

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.