Do Neutrinos Have Evil Twins of Their Own? Part 1: Thus, "Particle" will be redefined.

Ettore Majorana, a 31-year-old scientist, purchased a boat ticket from Palermo to Naples on March 25, 1938. He wrote to Antonio Carrelli, the director of the Naples Physics Institute, that evening prior to boarding:

Dear Carrelli,

I made a decision that has become unavoidable. There isn’t a bit of selfishness in it, but I realize what trouble my sudden disappearance will cause you and the students. For this as well, I beg your forgiveness, but especially for betraying the trust, the sincere friendship, and the sympathy you gave me over the past months.

I ask you to remember me to all those I learned to know and appreciate in your Institute, especially Sciuti: I will keep a fond memory of them all at least until 11 pm tonight, possibly later too.

*— E. Majorana*

He vanished from sight.

“There are several categories of scientists in the world,” said Enrico Fermi, widely referred to as the Pope of Physics. Despite their greatest efforts, those in second or third place never achieve anything. The first group consists of people who produce significant discoveries that are essential to the advancement of science. Then there are the geniuses, such as Newton and Galileo. Among them was Majorana.

Majorana published his final paper a year before he vanished. The majority of scientists at the time disregarded this odd, quiet little work. A particle that is its own antiparticle was described as a speculative possibility. Something that shouldn’t be possible. Something that could potentially open the future of physics if it actually exist.

Ettore Majorana‘s fate is still unknown.

Handwritten notes for the equation in infinite components

And whether he was correct is still unknown to us.

It goes without saying that neutrinos will be the subject of this series. As you may remember from earlier angry diatribes on the topic, neutrinos are terrible. They ruin everything. Before the discovery of the neutrino, we essentially understood every aspect of physics (I’m exaggerating, but you get the idea). It doesn’t act appropriately. It disregards the regulations. It doesn’t give a damn about your fancy mathematics, Nobel medals, or conventional model. The neutrino will simply exist, do its own thing, and be completely content with that.

It would be embarrassing to be laughed out of the room if you proposed the existence of neutrinos, even now, right now, without any supporting proof.

Your emotions don’t matter to neutrinos.

And I’ll tell you exactly how neutrinos violate every single law that matters to us. We’re going to get weird, so please keep your arms and legs within the ride at all times and fasten any loose things. I’ll describe what a particle is in order to accomplish that, possibly in a way you’ve never heard before.

In reality, particles aren’t particles.

Not in the manner we typically consider it, anyway.

We’re used to a simple conception of a particle. Like an electron. It has properties that we can measure. Mass, charge, spin. We can point to it. We can throw them across the room. We can trade them. Even in the quantum field picture, we can still treat an electron as an OBJECT, a thing, a concrete fixture that exists as a unique and independent entity in the universe.

So…that’s wrong.

Think about your hands. Or just look at them. Regard them. Your left hand and your right hand are mirror images of each other. They have the same fingers, the same basic structure, the same everything — except they’re fundamentally, irreducibly different. You can’t rotate your left hand into your right hand. You can flip it, you can twist it, you can wave it around like you just don’t care, and it will always be a left hand. There is no sequence of moves that transforms one into the other.

That property — that built-in handedness that can’t be changed — is called chirality. And it shows up everywhere in nature. Certain molecules are chiral. DNA is chiral. Life itself has a preference: almost every amino acid in your body is left-handed. Why? Nobody really knows. But the universe apparently has opinions about handedness.

So do particles.

A particle moving through space has a direction — it’s going somewhere. And a particle also has spin — it’s rotating, in a quantum mechanical sense that doesn’t map perfectly onto a spinning top but is close enough for our purposes. Like a spinning bullet flying through the air. The relationship between those two things — which way the particle is moving, and which way it’s spinning — gives the particle a handedness. If the spin aligns with the direction of motion, we call it right-handed. If it’s opposite, left-handed.

Now, the picture I just described is called HELICITY, which can change from your point of view. If you race past a speeding, spinning bullet and look behind you, it looks like it’s moving AWAY from you, not TOWARDS you, so its handedness flips.

So for particles we use a different assignment of handedness called CHIRALITY that doesn’t depend on how you look at it. It’s a real physical property, just like mass and charge. A left-handed particle and a right-handed particle are, in a deep sense, different objects, just like your hands. Almost perfectly the same, but different orientations of existence. Mirror images of each other.

For massless particles, the chirality can’t change. Neither can the helicity. In fact for massless particles they’re the exact same thing. Why? Because you can’t race past a photon and look behind you. So once a photon is born with a particular handedness, either left- or right-handed, it stays that way forever.

The same is NOT true for massive particles. Massive particles, as they travel, actually flip their chirality as they move! Left, right, left, right. It’s like if you took a right-handed glove and threw it, and as it traveled it magically switched between right and left hands.

And the thing that causes, say, an electron to flip back and forth? Why, it’s the Higgs field. As an electron moves, it’s constantly interacting with the Higgs. And every time it does, it switches between right- and left-handed. Like someone walking through a crowded room, and every time they reach out for a handshake, it’s a different hand.

The Higgs mechanism is what gives particles mass. The switching BETWEEN left- and right-handed versions IS mass.

When you watch an electron whizz by you, you’re not watching a single, whole, unitary particle. You’re watching TWO of them. A left-hander and a right-hander, constantly flipping back and forth. At one moment, you would see a MASSLESS left-handed particle. Then in the next instant you would see a MASSLESS right-handed particle.

How frequently these particles swap hands is controlled by how easily they interact with the Higgs. Every time they interact, they switch, and that frequency of switching IS THE MASS.

So in other words, what we call the property of “mass” is really a measure of how often twin left- and right-hand particles swap places as they travel.

All massive particles in the universe do this.

Except neutrinos.