(This is Part 4 of a series on neutrinos, Majorana fermions, and one of the strangest open questions in physics. Read Part 1, Part 2, and Part 3.)

It’s 1937. One year before Ettore Majorana vanishes. He is sitting with Dirac’s framework — the precise, picture-perfect vision of quantum mechanics — and doing what very few people in history have been capable of doing: going toe-to-toe with it.

He asks the kinds of questions nobody else is even thinking of asking. Does everything HAVE to work this way? Does a particle HAVE to have a distinct antiparticle?

He discovered that the answer is no. It’s not mandatory. It’s optional. It’s a choice. And it’s a choice that the universe, in all its infinite wisdom, made for electrons and quarks and every other charged particle we know. But neutrinos have no charge. Do they absolutely 100% HAVE to follow the same rules?

Majorana said “eh, maybe not.” And then disappeared.

These are what we call Majorana particles, as opposed to Dirac particles.

All Dirac particles have charge and have an antiparticle partner. All Dirac particles flip-flop between the two hands, but the universe doesn’t really care. Maybe neutrinos aren’t Dirac particles. Maybe they’re Majorana particles. Maybe their opposite partner doesn’t have opposite charge — it has opposite handedness. And the “charge” is the part that nobody cares about. Which is true, because neutrinos don’t have charge.

This means that neutrinos might be their own antiparticles.

Consider this: remember when 3D movies were briefly everywhere? Those work because light comes in two handednesses — left-circularly polarized and right-circularly polarized. One lens filters one out and passes the other, giving each eye a slightly different view. The photon is its own antiparticle. A left-handed photon and a right-handed photon aren’t particle and antiparticle of each other — they’re just the same particle with different handedness. The photon gets away with this because it carries no charge. Nothing forces the particle/antiparticle distinction to exist.

The Majorana idea is just: maybe the neutrino does the same thing. For the same reason.

In the Dirac picture we have four options. Left-handed neutrino — we see it. Right-handed antineutrino — check. Right-handed neutrino — invisible. Left-handed antineutrino — never seen. Two observable, two permanently hidden.

In the Majorana picture, we collapse that. The right-handed antineutrino and the right-handed neutrino? Same thing. The left-handed antineutrino and the left-handed neutrino? Same thing. Just two particles instead of four.

Most particles care about charge but not about handedness. Neutrinos might be the kind of particle that cares about handedness but not charge.

The Dirac picture asks us to believe in four kinds of particles when we only ever see two, and explains the missing two with “they exist but interact with literally nothing, deal with it.” The Majorana picture says: maybe there are only two particles. Maybe the universe isn’t hiding anything. Maybe we were just overcomplicating it.

But nature doesn’t care about elegance. You can have a beautiful, perfect, logical, completely wrong theory.

Watching Atoms Die

So how do we test it? How do you look at a neutrino and ask: hey buddy, are you your own antiparticle?

One option is to watch atoms die.

There’s a process called double beta decay. Sometimes two neutrons in a nucleus decay at the same time, producing two protons, two electrons, and two antineutrinos. We’ve seen this happen. It’s rare, but it’s real.

But if neutrinos are Majorana particles, then there’s really no such thing as “neutrino” versus “antineutrino” — they’re the same thing. And that changes what can happen inside the nucleus when the reactions go down. Instead of two antineutrinos coming out, you have one coming out of one neutron and going straight INTO the other. What comes out is two protons, two electrons…and nothing else.

We call it neutrinoless double beta decay. And right now, in deep underground laboratories that are absolutely not evil lairs, shielded from cosmic rays, surrounded by tons of carefully chosen isotopes, experiments are running and watching and waiting for exactly this signal.

We’ve got nothing.

That’s not a no. But it’s also not a yes. It’s just…not yet. The signal from neutrinoless double beta decay would be extraordinarily faint — neutrino masses are so vanishingly small that even if the process exists, it almost never happens. The non-observation just tells us it’s rare. It sets limits. But it’s not the final word.

Nobody knows what happened to Ettore Majorana. Some said it was suicide — that letter he sent wasn’t exactly the epitome of mental health. Some said he faked his death and fled to a monastery. There were reported sightings in South America, years later. Unverified, of course.

A lot like his namesake particle. A case that hasn’t been closed.

Why now? Why now?

Every time a woman comes forward with her story of sexual assault, this is the first question she faces. OK, maybe the second — after some variation of “Are you a lying slut?”

At least we are consistent. But on behalf of all survivors everywhere, of any gender, identity or age, let me give you some blanket answers to “Why now?”

Survivors come forward now, whenever now is, because they have reached the point in their recovery when facing the inevitable “lying slut” accusation is less terrible than watching their abuser strut around as if that person is not a dangerous, cruel predator who is almost certainly going to hurt someone else if they are not stopped.

Whether it’s in Congress, on a movie set, in the halls of their school — wherever that predator is just living their life without consequence — there is a survivor who has been cowering in the shadows of her own life, in pain, wanting to scream to the world that this person is not what they seem.

But the price of that honesty has always been steep. Too steep. Even after #MeToo.

Ask Cassie Ventura. Ask Jennifer Siebel Newsom. Ask E. Jean Carroll. Dolores Huerta. Simone Biles.

Even powerful women can’t escape the blowback, the fear. Even powerful women are steamrolled over and over again by the overwhelming presumption that they are lying, and there is an ulterior motive for coming forward at this particular moment.

Imagine just being an average person holding that secret. Who are any of us to stand up alone against a rich and powerful man whose very freedom will depend on crushing our credibility?

P. Diddy. Harvey Weinstein. Donald Trump. Cesar Chavez. Larry Nassar. Eric Swalwell.

Those men know power, and know how to use it.

“He thought he was untouchable. He acted with total impunity. He never thought that the consequences of his actions would follow him,” Ally Sammarco, one of the women who has spoken out about Swalwell (who has previously denied allegations of misconduct), told CBS.

It’s why the women of the Epstein files stayed silent for so long. It’s why there are thousands of rape survivors out there right now who have never said a word about what they endured, and maybe never will.

“Why now?” is just a more palatable version of “lying slut,” a question based on ignorance about how trauma — and society — works. A question meant not to elicit fact, but to feed the Jezebel frenzy men always use in their attempt to escape justice.

Here’s the truth about sexual assault: There is no right way to respond to it, no right time. There is no one reaction that proves it happened or that creates the perfect scenario that will protect the survivor’s reputation while delivering justice upon the predator. In fact, there is really no way at all to respond to a sexual assault that won’t bring secondary trauma.

Wait years and face disdain — that it didn’t happen, wasn’t serious, is only coming out now for some agenda, like politics or money.

Report it immediately and be prepared for every move, every smile, every sip of a drink, to be examined for signs that this was, if not consensual, somehow deserved — a gray area of shared responsibility.

Imagine, at a moment of crushing vulnerability, when your body has been violated and your mind is reeling trying to find safe ground, being bludgeoned by these accusations, stated or implied, that you brought this on yourself.

“Why now?” becomes “Why would you?”

Even when the scenario is one in which there can be no defense — such as the UCLA gynecologist, James Heaps, who on Tuesday pleaded guilty to sexually abusing five of his patients during exams — the cost of reporting is terrible. That case has wound on for years, leaving each of the victims to constantly relive their worst moments, constantly fear that all of their courage would come to nothing.

Which is why survivors don’t always come forward. Maybe they need time to put themselves back together, even just a little bit. Maybe the fear of all that societal scrutiny is just too much. Maybe they fear they won’t be believed, and their attacker will be free to harm them again.

Maybe they just want it to all go away. Maybe they do blame themselves, and are paralyzed by an unfounded shame.

There are so many reasons why survivors stay silent — and none of them are because it didn’t happen, or because they are lying.

Lonna Drewes, the Beverly Hills model who came forward Tuesday with an accusation that Swalwell drugged and raped her in 2018, summed up the experience of many, many survivors.

“I did not want to live anymore,” she said of how she felt after the attack. “I cried all the time for years.”

So here’s the real answer to “Why now?” from a victim’s statement that one of Heap’s survivors read in court.

“What you intended to break, you did not,” she said.

That is the answer to “Why now?” Because the bravery and courage at the heart of the survivor was bruised but not defeated.

Because she doesn’t want it to happen to anyone else.

Because she deserves to be free of his secrets: Ones she has been forced to keep out of fear of him, but also of us.