Forget the warp drive—there's a new far-out physics concept in town.
Two scientists from Duke University and the Geneva, Switzerland-based European Organization for Nuclear Research (known internationally as CERN) have proposed earnest new plans for a massive particle collider that would wrap around the moon.
In their preprint paper, submitted to the arXiv server earlier this month, the researchers suggest that such a megastructure could enable particle acceleration that reaches 14 quadrillion electron volts, or about 1,000 times more energy than the Large Hadron Collider (LHC)—the most powerful particle collider on Earth—can produce. It's important to take these findings with a grain of salt, though, as the work has not yet gone through the rigorous peer-review process.
Considering that the moon's circumference is about 11,000 kilometers, and the LHC's circumference at CERN is only about 27 kilometers, a particle accelerator of this size would also be an immense undertaking. Literally.
So, what's the point of even considering a gigantic lunar particle collider? It's akin to the reasons why earthly particle accelerators, like the LHC, exist. These vast structures propel charged particles (like protons and electrons) together at high speeds, to the point where the energy from the collisions transform into matter "in the form of new particles," according to CERN.
These collisions create some of the largest particles we know of, including the Higgs boson and the top quark. So, the next logical step would be to create an even bigger particle collider that could potentially lead scientists to the discovery of even bigger particles. It's obviously a fun thought experiment, but the physicists explain in their paper that it really could take scientists to one of the critical "next steps" in particle physics:
[H]igh-energy particle physics finds itself with two main goals for the future. The first is to accomplish a high-precision study of the Higgs and other Standard Model particles and parameters. The second is to attain higher center-of-mass collision energies with hadrons, to explore unexplored parameter space and open up the prospect of new particle discoveries.
Coincidentally, the legendary science fiction author Isaac Asimov wrote an article for the March 1988 issue of Popular Mechanics, in which he proposes building a particle accelerator on the moon. He agrees that the moon could be the perfect laboratory for uncovering the mysteries of particle physics.
"Turning to the heavens, special detectors would analyze rays from astrophysical sources, and moon-based particle accelerators would give new insight into the nature of matter," Asimov wrote.
As for the more practical orders of business—like how to actually build this thing—the physicists also have suggestions.
First, like CERN and other particle colliders on Earth, the scientists would need to build the moon collider inside a tunnel (in this case, inside the lava tubes just below the moon's surface). Experts need to study this concept in-depth to come up with solid excavation plans, though. For instance, which is more suitable for digging up lunar regolith: a tunnel-boring machine, or a process that could promote shallow ditch construction?
Next, we have to consider where we should place the collider on the moon. Your mental impression of "circumference" might be a tape measure wrapped around the moon's equator, but of course you can take the circumference of a spheroid at any point or location. The scientists say there are great circle routes around the moon that avoid changing elevation, for example.
How could scientists power the particle collider? This is a key question facing every proposed moon project, let alone the most colossal particle collider ever imagined. It will require so much energy, the physicists explain, that even all of the existing nuclear fission power on Earth wouldn't be enough.
It's estimated that the moon collider will use tens of terawatts of energy. Here, the scientists suggest a true moonshot idea: a solar-powered superstructure like "a small patch of a Dyson sphere around the sun" or moon. Of course, even if we did build such a thing, the moon is locked into its orbit with Earth and doesn't have a surface that's always exposed to the sun. So, it's hard to imagine building a Dyson sphere for part-time exposure only.
Where do all of these hypotheticals leave us? Well, thinking about a gigantic particle collider like this is "primarily for fun," the physicists told Science News. But thinking through the wild limitations and possibilities is good practice, especially since NASA is planning to put people on the moon again for the first time in decades.