An Even Bigger Particle Accelerator than the Large Hadron Collider?

Scientists at CERN are considering it, and Alexis Madrigal gives a partial history of how the super colliders have grown throughout their history:

The particles inside Ernest Lawrence's 1931 cyclotron particle accelerator traveled just 11 inches inside the perimeter of what he called his "proton-merry-go-round." The initial size was tiny, but Lawrence's strategy was, as we might say now, scalable: If atoms could be accelerated a bit inside a device with a diameter of 11 inches, then imagine how fast one could make them fly if a bigger device was built. They quickly built a 27-inch version, then a 60-incher a few years later.

Most simple histories of physics date the birth of Big Science to Lawrence's cyclotron. Physics needed big machines. There were things that a big machine could test that no people working unaided or with a smaller machine could. And that's never stopped being true. Bigger equals more energy equals better atom smashing.

Which is why the Large Hadron Collider opened to such fanfare a few years ago. It's the largest particle accelerator in the world, tucked underground near Geneva. The tunnel through which particles travel is now 27 kilometers (16.8 miles) long. Lawrence's cyclotron could reach energies exceeding one million electron volts. The LHC turns up the dial to 14 trillion electron volts. That's an improvement of seven orders of magnitude.

Of course, the United States was actually building the Superconducting Super Collider (they completed 20% of the tunnel), which would have been almost as big (87 kilometers in circumference) as the one the Europeans are considering building by 2075, but Congress pulled the plug in 1993.  More forward-thinking Congressional leadership for you. I do find that Livermore's 11 inch particle accelerator has grown into a currently 27 kilometer version of the same thing to be fascinating.