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In 2012, scientists at the European Organization for Nuclear Research, known as CERN, proved the existence of the Higgs boson, the elementary particle that grants other particles their mass. The discovery confirmed a mathematical theory at the core of the Standard Model of physics, which tries to explains why the physical universe works the way it does. And it was only possible thanks to the Large Hadron Collider, a ring of superconducting magnets buried hundreds of feet below CERN’s laboratories in Geneva, Switzerland. The collider accelerates subatomic particles to extremely high speeds and smashes them together to find out what they’re made of.
Peter McIntyre, a physicist and particle accelerator expert at Texas A&M University, and his colleagues think there may be more particles and natural forces in the universe that, like the Higgs boson, can only be discovered through high energy collisions—bigger collisions than the Large Hadron Collider can create. Gizmodo interviewed him about his ambitious proposal for a machine that could make those discoveries: A particle accelerator 2,000 kilometers in circumference floating in the Gulf of Mexico, which McIntyre and his colleagues have dubbed Collider in the Sea.
This interview has been edited for length and clarity.
Todd Feathers, Gizmodo: The Large Hadron Collider is 27 kilometers in circumference. The collider you’ve proposed building in the Gulf of Mexico is about 2,000 kilometers in circumference. Why is bigger better?
Peter McIntyre: The thing that paces what the hadron collider can do is that enormous ring of superconducting magnets that makes the magnetic field that is the racetrack that the proton beam goes around. The magnetic fields in the magnets of the Large Hadron Collider have a field strength of about 8 Tesla; that’s about 80,000 times the field strength of the Earth’s magnetic field.
The dilemma you face in trying to make a higher energy collider is you either have to make a higher magnetic field strength, which is technologically very challenging. It means you have to go to more exotic superconductors than our good old friend niobium-titanium. Or, you have to get out the tunnelers and tunnel a much larger circumference tunnel.
A consortium of scientists in Europe and in the U.S. and in Japan and in China have been working separately and together on projects to try to develop the way to build higher field strength superconducting dipoles, the magnets you would need to do that, with a goal being the 16 Tesla that would be twice the [Large Hadron Collider] field strength. As of today, only one magnet has been operated successfully up to that field and no magnets have been made that would have a geometry appropriate [for a collider].
So that motivated me. It’s why I had my dope dream, so to speak, of a collider in the sea. I’m proposing to go up to 2,000 kilometers in circumference and make a ring that would inscribe the Gulf of Mexico. I set that scale somewhat arbitrarily by what Mother Earth has sitting there available to us. That 2,000-kilometer circumference would enable you to build a collider that’s 500 tera-electron-volt collision energy. [Editor’s note: For comparison, the Large Hadron Collider produces collisions at 14 TeV.]
It would open a range for discovery. If mother nature has new fields of nature that are out there to be found, that would be large enough to make it a gambling man’s good bet [that we could find them].
Gizmodo: What is a particle accelerator and how does it work?
McIntyre: In the case of a hadron collider, you start with a bottle of hydrogen gas. The gas is ionized by putting it into a cell that contains electrodes and an intense radio frequency field.
That is sufficient to strip the electrons off the nuclei of the hydrogen atoms and that gives you a bare proton. The proton is the nucleus of the hydrogen atom. It’s the fundamental building block of all nuclei and it’s the nucleus of every hydrogen atom in our universe and in our world. So it’s a jim-dandy thing to start with if you want to probe the inner structure of nuclear matter.
You then take the stripped protons and accelerate them in an electric field. Typically what you do is you use a pattern of electromagnetic fields, which means they’re rapidly oscillating electric and magnetic fields, to accelerate them to progressively higher kinetic energy and you go through a succession of such accelerators.
When you finally get it up to about as high in energy as you can go with that kind of procedure using a device called a linear accelerator, or LINAC, then you put them into the first of a succession of circular accelerators where the beam is channeled by a strong magnetic field that causes it to go around in a circular orbit.
As they’re going around, in one location or a few locations on the ring, you insert radio frequency cavities that each time they come around it gives them a kick in the pants. You accelerate up as high an energy as your circular ring can support, then you transfer it over to a completely separate ring, a much larger ring, and then you do the same thing again.
And that’s what the [Large Hadron Collider] does today to produce the highest energy collisions ever made by man.
Gizmodo: Building an underwater ring of magnets the size of the Gulf of Mexico seems pretty challenging. How would it be done?
McIntyre: You would install them with remote operable vehicles, ROVs, which are standard operating equipment in the world of marine technology today.
You would operate the ring a hundred meters down under the sea, which is neither on the bottom nor on the top. On the top would be utterly unthinkable because of all of the marine commerce of human society. And near the bottom would be a dubious proposition for a whole bunch of points of view because of the topology of the bottom–it’s not planar.
So you’d be making this neutral buoyancy, like a submarine floating and sustaining it in position using a device, a perfectly standard device, called marine thrusters. It’s basically just like an onboard motor, mounted on a stem at several locations along the ship. And the motor can be turned 360 degrees. You can rotate it in any direction you want to deliver thrust.
An array of those things on this ring of superconducting magnets would control the position, so it won’t drift in the ocean currents. It’s below the level of harm’s way for hurricanes, a hurricane could go right over the top of it and the collider wouldn’t even know it was happening because it’s 100 meters down.
I’ve presented this at international conferences of accelerator builders and no one has come up with a deal breaker in those meetings. The questions I’m typically asked are ‘Well, Dr. McIntyre, you know, this is not the way we build hadron colliders.’ Well, my only answer to that is, yes, I understand that. Indeed, I’ve participated in building a few. And all I’ll say to you is, in my opinion, it’s not likely you’ll build any more in the future unless you learn how to think on a bigger landscape than the way you’ve been building things.
Gizmodo: How much would the collider in the sea likely cost?
McIntyre: It’s very problematic to throw costs out at this stage of such a thing, but somewhere in the neighborhood of 20 to 30 billion dollars. Which is about the same as the public has spent on the entire field of high energy physics in its history in the whole world.
That’s a measuring stick by which one would say it has at least not crossed what in physics we call the unitarity bound. In other words, you’ve not really gone nuts. If you did exceed what in one possible future project would be the sum total of all the expenditures ever made in that whole field in all of time by all people, then, yes, you probably, should just forget it.
But it doesn’t cross that. Most of the other things that people talk about for such a thing, in my opinion, do cross that bound. But again, no one is responsibly talking about a cost number for any of these things because there’s a lot yet to be done to get anywhere with them. I don’t have high hopes that I will manage to get support from our Department of Energy or anyone else to do some of that development toward a collider in the sea, because in their guts, they don’t yet really believe in it.
Gizmodo: How confident are you that there’s something else that could only be discovered with a bigger collider?
McIntyre: I would have to say I am not confident there are other point-like particles even remotely within reach of a terrestrial accelerator or collider to discover them directly. I would say I’m strongly hopeful, but I am not confident.
Gizmodo: If there’s no guarantee we’ll find a new particle, why is it worth spending tens of billions of dollars to build a collider at this scale?
McIntyre: That’s a piece of epistemology. You can’t say why it’s important until you know what it is.
When [Ernest] Rutherford did his experiments—which were just as whimsical in his day—to discover the nature of an atom, it was a completely heretical notion at that time. And when he was asked by people from the press ‘What importance do you see in that?’ He said, well, I’m not sure there’s anything terribly significant or of practical importance, but it’s terribly amusing.
Those were his words, right? But there is almost nothing in our modern technology that would be possible without that understanding of atomic physics and of how the atom is organized and structured. Nothing.
