In physics we’re not supposed to talk about how we feel. We are a hard-nosed, quantitative, and empirical science. But even the best of our dispassionate analysis begins only after we have decided which avenue to pursue. When a field is nascent, there tend to be a range of options to consider, all of which have some merit, and often we are just instinctively drawn to one. This choice is guided by an emotional reasoning that transcends logic. Which position you choose to align yourself with is, as Stanford University physicist Leonard Susskind says, “about more than scientific facts and philosophical principles. It is about what constitutes good taste in science. And like all arguments about taste, it involves people’s aesthetic sensibilities.” ...Notice the verbal trickery here. He does not say that no one questions single quark particles.
Quarks are permanently bound together into protons, neutrons, and other composite particles. “They are, so to speak, hidden behind a … veil,” Susskind says, “but by now, although no single quark has ever been seen in isolation, there is no one who seriously questions the correctness of the quark theory. It is part of the bedrock foundation of modern physics.”
Susskind wants you to thing: "No one has ever seen an isolated quark but everyone believes in them anyway."
But that is not right. Lots of physicists do not even believe in particles at all. A quark is a useful fiction that helps to understand the SU(3) theory, but that's all. There is no need to believe that quark particles are real, or that they have colors.
My own research is in string theory, and one of its features is that there exist many logically consistent versions of the universe other than our own. The same process that created our universe can also bring those other possibilities to life, creating an infinity of other universes where everything that can occur, does. ...This is the crazy world view of a string theorist. Their god is the elusive mathematical equation that is going to unify all of physics, even if it explains nothing. They believe so much that they will accept the possibility of essentially infinitely many equations driving infinitely many unobservable universes.
The multiverse explains how the constants in our equations acquire the values they do, without invoking either randomness or conscious design. If there are vast numbers of universes, embodying all possible laws of physics, we measure the values we do because that’s where our universe lies on the landscape. There’s no deeper explanation. That’s it. That’s the answer.
But as much as the multiverse frees us from the old dichotomy, it leaves a profound unease. The questions we have spent so long pondering might have no deeper answer than just this: that it is the way it is. That might be the best we can do, but it’s not the kind of answer we’re used to. It doesn’t pull back the covers and explain how something works. What’s more, it dashes the theorists’ dream, with the claim that no unique solution will ever be found because no unique solution exists.
There are some who don’t like that answer, others who don’t think it even qualifies to be called an answer, and some who accept it. ...
Tasneem Zehra Husain is a theoretical physicist and the author of Only The Longest Threads. She is the first Pakistani woman string theorist.
Gian Giudice, head of CERN’s theory group, speaks for most physicists when he says that one look at the sky sets us straight. We already know our scale. If the multiverse turns out to be real, he says, “the problem of me versus the vastness of the universe won’t change.” In fact, many find comfort in the cosmic perspective. Framed against the universe, all our troubles, all the drama of daily life, diminishes so dramatically that “anything that happens here is irrelevant,” says physicist and author Lawrence Krauss. “I find great solace in that.”Great solace?
Even without the multiverse or even anything cosmological, our lives on the surface of the Earth are infinitesimal compared to just the interior of the Earth. That is already enuf to overwhelm his psychological sense of well-being, and I don't believe that anyone really finds any solace in the multiverse.