A symmetry argument for multiverses

Penrose tiles by MonkstoneThe multiverse hypothesis is that what we used to see as the Universe (which is supposed to be all that there is) may be part of something larger, that includes other universes like, or unlike our own. This is not a hypothesis that was proposed to conveniently solve the Anthropic paradox (we don’t know why the Universe can support life at all whereas it could be a lot more hostile and sterile than it already is, as far as we can tell). It does solve that problem, but wasn’t proposed for that reason. It emerges, actually, in four different forms, as a necessary consequence of scientific theories for which we have very good evidence. Some levels of multiverse are more controversial than others, of course, but in this post, I want to bring forward another argument in favor of multiverses, based on symmetry.

Symmetry is central to modern physics, and helped us make some of the most important discoveries of the 20th and early 21st centuries. General Relativity comes from Lorentz covariance, which is the idea that the laws of physics look the same no matter where and when you test them, and no matter how fast you’re moving (physicists will forgive this oversimplification, I hope). Antimatter was predicted by Dirac when he applied Relativity to the Schrödinger equation that rules quantum systems. The discovery that high energy particles can be mapped to interesting mathematical groups helped us understand the fields they are associated with, and in turn, unfilled positions in these symmetry groups led to predictions of new particles, that were later discovered to exist. Pretty much every time that the equations describing a system seemed to be more symmetrical than observation, we’ve discovered that something was missing from our observation.

Another interesting discovery of modern physics is spontaneous symmetry breaking. This phenomenon happens when a system’s potential energy is distributed in such a way that the most symmetrical state of the system is not that of lowest energy, and when there are multiple states of lowest energy, that are in principle equally probable.

Imagine a perfectly round igloo, on top of which you drop a ball. If you place the ball exactly at the top point of the igloo, will the ball fall? If it does, can you predict on what side of the igloo? The answers are yes and no: The ball is going to fall because even the tiniest environmental fluctuation (and quantum mechanics assures us that there will be fluctuations) will push it in one direction or the other. You can’t predict where the ball will fall because the system is perfectly symmetrical except for those perturbations that will cause the ball to fall.

This is a case where the problem is perfectly symmetrical, but none of the solutions are: it’s the set of solutions that has the same symmetries as the problem.

Something similar, but a bit more abstract, happened at a cosmic scale during those events we call the Big Bang. Electromagnetism and the weak interaction used to be one and the same force, perfectly SU(2) x U(1) symmetrical, and then the whole universe decayed in a lower energy state where the symmetry was broken, giving rise to photons, W±, and Z0 bosons, and giving a mass to electrons, protons, and neutrons through the Higgs mechanism. We think something similar happened when the symmetry between the strong and electroweak interactions was broken, and maybe also when those broke up with gravitation.

This raises a question however: in our silly igloo example, there are outside perturbations. In the case of the Universe, no such thing exists, by definition. So why does our universe exhibit those specific symmetry-broken results? More importantly, does the whole set of solutions, which is symmetrical, exist? What makes our particular decayed universe more real than those other solutions?

There is no particular reason why we see this particular symmetry breaking: this tells us more where we are in the multiverse than it tells us anything profound about our particular solution to the equations. The whole set of solutions probably exists just as much as our own, and what makes ours real is that we’re in it, that’s all. A gap in the observed set of solutions that should be filled according to the symmetries of the system is indicative that there is something in there that we haven’t found yet.

So there you have it: there is a multiverse because the laws of physics are more symmetrical than our observable universe is.


Some context about Charlie Hebdo: don’t judge a magazine by its cover

"It's hard to be loved by idiots" The past two days have been nerve wracking for the French, and for friends of freedom of speech. We’ve all been floored by the savagery of the attacks, but it’s been heartwarming to see support messages from all over the world, as well as the extraordinary unity of the French people overall, including the Muslim community and clergy, as well as all other confessions (but of course, let’s not fool ourselves, there are already brain-dead violent reactions against the whole Muslim community, which is exactly the sort of division the terrorists are trying to create).

All this makes it particularly irritating when several voices from supposedly smart people writing in reputable journals start blaming the victim. USA Today even went so far as to publish a commentary from a self-avowed radical extremist, something I find way more offensive than anything Charlie ever put on their front page:

Muslims do not believe in the concept of freedom of expression […] why in this case did the French government allow the magazine Charlie Hebdo to continue to provoke Muslims, thereby placing the sanctity of its citizens at risk?

It is time that the sanctity of a Prophet revered by up to one-quarter of the world's population was protected.

USA Today is not quoting an opposing view, in an article meant to give context to the attacks: they actually gave an unrestricted tribune to a dangerous extremist who misrepresents his own religion, and advocates against freedom of speech, in favor of blasphemy laws, without comment. It’s hard to fathom why USA Today would do that, but at least one can understand what this guy is saying and why. And it’s chilling.

Harder to understand is the chorus of reasonable journalists who attempt to paint Charlie Hebdo as a racist, islamophobic journal. Before I go into the details of the accusations, and why they don’t hold water, I want to point out what should be very obvious: this is the equivalent of showing up at a funeral and telling the family that the deceased had really looked for it. Only insensitive, tasteless assholes do that.

Case in point, David Brooks writes in the NY Times:

let’s face it: If they had tried to publish their satirical newspaper on any American university campus over the last two decades it wouldn’t have lasted 30 seconds. Student and faculty groups would have accused them of hate speech. The administration would have cut financing and shut them down.

Notice the subtext here: in America, this wouldn’t stand, not because speech is less free, but because the French agree with “hate speech”? Give me a break and watch Fox News for 10 minutes to realize what Americans allow (which is fine, of course, just pointing out the hypocrisy of an article that aspires itself to denounce hypocrisy). It also takes about 30 seconds to find direct counter-examples of American campus newspapers that are nothing but racist hate speech

I’ll also point out that nobody but their readership can “cut financing and shut them down” in the case of Charlie: it’s completely independent, has no ads, and is not part of a large corporation. Imagine that: really free press. Now that’s something you don’t see every day.

So is Charlie hate speech? Of course not, but if your knowledge of it is limited to a few of the most provocative covers that you’ve seen on the Internet, it may seem to be.

Charlie Hebdo is one of the last journals in a long tradition of lampooning, political caricature, irreverence, humanism, secularism, and freedom that goes all the way back to the French Revolution. If you go beyond the cover and look inside, you’ll find something a lot different from what Brooks describes: the articles are about raising awareness on social issues, about defending the defenseless, such as immigrants, and the homeless, about culture, about the struggles of the Third World, the environment, and generally about fighting oppression in all its forms. Most articles aren’t even funny ;)

The authors of those articles and drawings who died in the attack were not immature 13 year-olds trying to “stick a finger in the eye of authority” and who belong at the “kids’ table”. They were very smart, respected and beloved journalists and cartoonists whom people of my generation have seen on TV and read in newspapers since our childhood. We know they are all the kindest, funniest, and smartest folks. They were also resolutely at the “adults’ table”, even by Brooks’ standard that “you must read Le Monde or the establishment organs”: they were not just reading those, they were writing and drawing in them.

Cabu drew on Antenne 2 (French TV), in Paris-Match, Le Journal du Dimanche, France-Soir, Le Figaro, Le Figaro Littéraire, Le Nouvel Observateur, Le Monde, Politique Hebdo, Jours de France, and many more.

Wolinski has drawn in France-Soir, L’Humanité, Paris-Match. In 2005, Jacques Chirac gave him the Légion d’honneur, the highest decoraration in France.

Tignous was drawing in Marianne, and Charb in Télérama and l’Humanité. He even drew illustrations in Le Petit Larousse, the most popular French dictionary. Bernard Maris was a PhD-holding University Professor of economy and “agrégé” who wrote for Marianne, Le Nouvel Observateur, Le Figaro Magazine, Le Monde, and France Inter.

This puts the front pages that created such controversy under a much different light: those were not racist caricatures reminiscent of the darkest anti-Semitic propaganda of the second quarter of the twentieth century. Rather, they were funny, courageous, and deliberate, if provocative, pieces from well-respected and well-understood humanist authors who thought that one should be able to laugh of anything, that it was an essential part of Democracy.

There’s also this weird perception that Charlie was going after the Muslim minority. In reality, they were going after all fundamentalisms, not after communities. In fact, over the years they got 14 lawsuits from Catholic organizations, but only one from Muslims (and Charlie won them all). It’s also worth mentioning that they were able to gather 173,000 signatures against Front National, the extreme right French party that is the real voice against the Muslim community in France, and that attacked the journal several times with lawsuits. During the Mohammed caricature controversy however, the F.N. weirdly supported Charlie, for their own partisan reasons. “It’s hard to be appreciated by idiots”, indeed.

Wolinski said in an interview that what they were doing was in fact to treat Muslims like the adults they are, with whom it’s possible to joke and laugh. Fundamentalists, on the other hand, are like bratty children who can’t stand contradiction. Brats with guns. They are the criminals here, let’s not be confused about that, and they are attacking us all, by assassinating journalists and policemen. They’re the ones we shouldn’t allow at the grownups’ table.