The reason this anecdote is so significant is the sequence. It’s easy to discover a new planet and then work up the math proving that it’s there; it’s quite another to mathematically insist a massive undiscovered planet should be precisely where it ends up being. This is a different level of correctness. It’s not interpretative, because numbers have no agenda, no sense of history, and no sense of humor. The Pythagorean theorem doesn’t need the existence of Mr. Pythagoras in order to work exactly as it does.
I have a friend who’s a data scientist, currently working on the economics of mobile gaming environments. He knows a great deal about probability theory,35 so I asked him if our contemporary understanding of probability is still evolving and if the way people understood probability three hundred years ago has any relationship to how we will gauge probability three hundred years from today. His response: “What we think about probability in 2016 is what we thought in 1716, for sure . . . probably in 1616, for the most part . . . and probably what [Renaissance mathematician and degenerate gambler Gerolamo] Cardano thought in 1564. I know this sounds arrogant, but what we’ve believed about probability since 1785 is still what we’ll believe about probability in 2516.”
If we base any line of reasoning around consistent numeric values, there is no way to be wrong, unless we are (somehow) wrong about the very nature of the numbers themselves. And that possibility is a non-math conversation. I mean, can 6 literally turn out to be 9? Jimi Hendrix imagined such a scenario, but only because he was an electric philosopher (as opposed to a pocket calculator).
“In physics, when we say we know something, it’s very simple,” Tyson reiterates. “Can we predict the outcome? If we can predict the outcome, we’re good to go, and we’re on to the next problem. There are philosophers who care about the understanding of why that was the outcome. Isaac Newton [essentially] said, ‘I have an equation that says why the moon is in orbit. I have no fucking idea how the Earth talks to the moon. It’s empty space—there’s no hand reaching out.’ He was uncomfortable about this idea of action at a distance. And he was criticized for having such ideas, because it was preposterous that one physical object could talk to another physical object. Now, you can certainly have that conversation [about why it happens]. But an equation properly predicts what it does. That other conversation is for people having a beer. It’s a beer conversation. So go ahead—have that conversation. ‘What is the nature of the interaction between the moon and the Earth?’ Well, my equations get it right every time. So you can say that gremlins do it—it doesn’t matter to my equation . . . Philosophers like arguing about [semantics]. In physics, we’re way more practical than philosophers. Way more practical. If something works, we’re on to the next problem. We’re not arguing why. Philosophers argue why. It doesn’t mean we don’t like to argue. We’re just not derailed by why, provided the equation gives you an accurate account of reality.”
In terms of speculating on the likelihood of our collective wrongness, Tyson’s distinction is huge. If you remove the deepest question—the question of why—the risk of major error falls through the floor. And this is because the problem of why is a problem that’s impossible to detach from the foibles of human nature. Take, for example, the childhood question of why the sky is blue. This was another problem tackled by Aristotle. In his systematic essay “On Colors,” Aristotle came up with an explanation for why the sky is blue: He argued that all air is very slightly blue, but that this blueness isn’t perceptible to the human eye unless there are many, many layers of air placed on top of each other (similar, according to his logic, to the way a teaspoon of water looks clear but a deep well of water looks black). Based on nothing beyond his own powers of deduction, it was a genius conclusion. It explains why the sky is blue. But the assumption was totally wrong. The sky is blue because of the way sunlight is refracted. And unlike Aristotle, the person who realized this truth didn’t care why it was true, which allowed him to be right forever. There will never be a new explanation for why the sky is blue.
Unless, of course, we end up with a new explanation for everything.
[4]A few pages back, I positioned two scientists—Tyson and Greene—on opposite ends of a continuum of confidence, constructed inside my own mind. But even in the context of this fabricated binary, they agree on things far more than they differ. Since the dawn of civilization, people have argued about (and continually increased) the age of the known universe; when I asked both men if there was any chance the current age of our universe will be recalculated again, they both had the same answer. “It will not happen,” says Tyson. “That number [13.79 billion years, plus or minus 0.2] is actually quite stable,” reiterates Greene. Even on points of conflict, they generally force themselves into alignment: When I told Tyson that Greene was open to the possibility that our understanding of gravity might drastically change, Tyson implied that I may have phrased the question incorrectly.
“He’s pointing forward to a time when our understanding of gravity includes our understanding of dark matter,” said Tyson. “That there will be some other understanding of gravity, but it will still enclose Newton’s laws of gravity and Einstein’s general relativity. So he may have presumed your question meant, ‘Is there anything left to be discovered about gravity?’ And that question is not clear to someone who researches gravity.”
This kind of willful, unilateral agreement is not unique to famous scientists—most of the unfamous scientists would agree, too. You’re not really a scientist if you don’t. The core components of science—say, the structure of DNA or the speed of light or the weight of carbon—have to be uniform. This is a card game that can be played with only one specific deck, and that should increase our confidence in what we believe to be true. If everyone is using the same information to do different things and still coming to the same reliable conclusions, there isn’t much room for profound wrongness.
Yet there is something about the depth of this consensus that makes me slightly less confident.
Can I point to a specific example? I can’t point to any specific example. If someone demanded I outline an unambiguous scientific truth that seems dangerously misguided, I could not do it (and if someone else did so, my contradictory inclination would be to immediately disagree). But herein lies the problem. If we’re playing a card game that works with only one deck, we can interrogate only the deck itself. If we assert, “This Queen of Diamonds is actually a Joker,” the rest of the cards will prove the assertion is wrong. What we can’t do is allege that we’re all playing the game wrong, because this is the only game anyone plays. We can’t assert that this card game is actually a board game, because nobody knows what that would mean if we can’t visualize the board. This is the ultimate model for naïve realism: It’s irrational to question any explicit detail within a field of study that few rational people classify as complete.
“There are certainly some ideas that many of us are starting to anticipate will be jettisoned, even if we can’t quite jettison them just yet,” Greene says. “The most basic being that space and time are ingredients that are somehow fundamental, and that space and time will be the starting point for any understanding of physics. Even going back to Aristotle, there is this basic assumption that physics take place in an arena—basically, inside a container. And that container involves some expanse that we call space, and events in the space take place over a duration we call time. Now, it’s certainly the case that our view of space and time has shifted, mostly because of Einstein. We now see space and time as much more malleable. But we still see them as ‘being there,’ for lack of a better term. But some of us anticipate that—in the future—our theories will not start with space and time. They will start with something more fundamental. What that fundamental thing is—we still don’t know. Sometimes we give it names like ‘the atoms of space and time’ or ‘the constituents of space and time.’ We don’t really have a name for whatever this is, because it’s not necessarily a particle
, per se. It’s an even more basic entity. It’s something that—when arranged in a specific way—builds space and time. But if those ingredients were somehow arranged differently, the concepts of space and time wouldn’t even apply.”
Whether or not you take Greene’s position as radical is open to interpretation (some might classify it as inordinately safe). I’m in no position to adequately consider what it would mean if physics were no longer based on space and time, or what that would change about day-to-day life. But his central point is my obsession: the possibility that we are unable to isolate or imagine something fundamental about the construction of reality, and that the eventual realization of whatever that fundamental thing is will necessitate a rewrite of everything else. Here again, I’m not the first person to fantasize about this possibility. It’s the controversial premise of Thomas Kuhn’s 1962 masterwork The Structure of Scientific Revolutions. Kuhn’s take was that science does not advance through minor steps, but through major ones—basically, that everyone believes all the same things for long stretches of time, only to have the entire collective worldview altered by a paradigm shift36 transforming the entire system. Prior to these massive shifts, researchers conduct what Kuhn called “normal science,” where scientists try to solve all the puzzles inside the existing paradigm, inadvertently propping up its dominance. In essence, Kuhn saw science as less coldly objective than scientists prefer to believe.
It’s easy to recognize why The Structure of Scientific Revolutions annoys a lot of people who earn a living trying to figure out why and how the world works. There’s something a little insulting about the term “normal science,” in the same way it’s insulting to describe a woman’s outfit as “basic.” There’s also a high degree of intellectual hopelessness ingrained within this philosophy—it makes it seem like whatever science is happening at any given time is just a placeholder, and that the main purpose of any minor scientific advance is to wait for its inevitable obsolescence. Tyson strongly criticized the book, noting that its main arguments are (again) stuck in the seventeenth century.
“[The Structure of Scientific Revolutions] was hugely influential,” Tyson tells me, “especially on the liberal arts, giving them ammunition to suggest that science was no better way of knowing the truth than any other way of investigating. It made a huge case of scientists gathering around one truth, and then there’s a tipping point and everyone moves away from that truth to gather around another truth. Hence the title of the book. And this left people with the sense that science is just whatever is in fashion. Kuhn used, as his best example of this, Copernicus. That’s half his book . . . almost half of that book describes the Copernican Revolution as an example of the way science works. But that’s not how science works. It’s just not. It’s how things happened until 1600.”
Kuhn died in 1996, so he can’t respond to this accusation. But I assume his response would be something in the neighborhood of “Well, of course you think that. You have to. You’re a scientist.” A philosopher can simultaneously forward an argument’s impregnable logic and its potential negation within the same sentence; a scientist can’t do that. There is no practical purpose to fungible physics. If Tyson were to validate the possibility that his entire day-to-day vocation is just “normal science” that will eventually be overwritten by a new paradigm, it would justify the lethargic thinking of anyone who wants to ignore the work that he does (work that he believes is too important to ignore). It is, in many ways, a completely unbalanced dispute. Tyson (or Greene, or any credible scientist) can present ten thousand micro arguments that demonstrate why our current structure of scientific inquiry is unique and unassailable. A Kuhnian disciple need only make one macro argument in response: Well, that’s how it always seems, until it doesn’t.
My limited brain tells me that ten thousand micro arguments are better than one macro abstraction. My limited sense of reality tells me that Kuhn’s abstraction is reasonable and unavoidable, and that the attacks against it define naïve realism. And it’s that latter sensation that prompts me to pose the following: If we’re destined (as Kuhn would argue) for an inevitable paradigm shift, what would that shift feel like?
[5]Here’s the thing with paradigm shifts: They tend to be less dramatic than cultural memory suggests. There’s a tendency to imagine that all those who upend the nature of existence are marginalized as heretics and crucified by crazed mobs, because drama confirms the importance of what those people thought. But it rarely happens like that, and the last monster shift in science—the Copernican Revolution—was a textbook example.
Nicolaus Copernicus surmised that the Earth rotated around the sun in about 1514, and no one killed him for thinking that. He lived another twenty-nine years and died at the age of seventy. Throughout those final twenty-nine years, his revolutionary description of outer space mostly seemed like an unprovable thought experiment that had the ancillary benefit of making the calendar more accurate, which made it easier to schedule Easter. When Galileo later declared that Copernicus was right (and that the Bible was therefore wrong) in the seventeenth century, he was eventually arrested by the Inquisition and forced to recant—but not before the Catholic Church told him (and I’m paraphrasing here): “Hey, man. We all know you’re probably correct about this. We concede that you’re a wizard, and what you’re saying makes sense. But you gotta let us explain this stuff to the rest of the world very, very slowly. We can’t suddenly tell every pasta-gorged plebeian in rural Italy that we live in a heliocentric universe. It will blow their minds and fuck up our game. Just be cool for a while.” Galileo famously refused to chill and published his Dialogue Concerning the Two Chief World Systems as soon as he possibly could, mocking all those who believed (or claimed to believe) that the Earth was the center of the universe. The pope, predictably, was not stoked to hear this. But the Vatican still didn’t execute Galileo; he merely spent the rest of his life under house arrest (where he was still allowed to write books about physics) and lived to be seventy-seven.
I don’t mention this to negate what these guys learned, the adversity they faced, or what they accomplished. But it does serve to illustrate the pace at which ideological transformations actually occur: This revolution took over one hundred years, invisible to the vast majority of the planet. Granted, a revolution within our accelerated culture would happen far faster. The amount of human information exchanged is exponentially different, as is the overall level of literacy. But that still doesn’t mean a transformative period would be transparent to the people actually experiencing it; this is why I ask how a modern paradigm shift would feel, as opposed to what it would look like or how it would operate. Like a fifteenth-century monk, my perspective is locked by fixed boundaries. I cannot depict a transformation I don’t have the ability to visualize. But I can envision the texture of how such an experience might feel. I can imagine the cognition of my current worldview slowly dissolving, in the same way certain dreams dissolve within the same instant I wake up and realize that I was not experiencing my actual life.
Every so often, minor news stories will surface suggesting something major about science is already shifting. “NASA successfully tests engine that uses no fuel [and] violates the laws of physics,” read an August 1, 2014, headline in the citizen-journalist-run Examiner. Nine months later, the Silicon Valley–based Tech Times proclaimed, “NASA may have accidentally discovered faster-than-light travel.” Both articles were about the EmDrive, an experimental rocket thruster that supposedly violates Newton’s Third Law (the conservation of momentum). By the time any reader reached the conclusion of these articles, it was clear that the alleged breakthroughs were more interesting than practical. But if a series of similar stories kept appearing in greater depth, and if they ran in places like The Guardian and Scientific American and Wired, there’d be a general sense that a rethinking37 of how we viewed space and time was necessary. This is not the type of paradigm shift I try to imagine, however. To me, this feels closer to a typica
l conversation about technology (which is, obviously, always advancing). Instead, I tend to think about two distinct varieties of potential shifts: the world beyond us, and the world around us.
What I classify as “the world beyond us” are notions like the aforementioned multiverse—the possibility of a cosmos that is way more complicated than the cosmos we conceive. Does such a cosmos seem plausible? Sure. It almost seems likely. I cautiously suspect there are universes beyond our universe, the laws of which might contradict the most basic things we believe. But what is the feeling that would accompany the validation of this hypothesis?
Nothing.
There would be no feeling at all. It would just be an interesting thing to know. I mean, even if NASA did “accidentally” invent faster-than-light travel, it wouldn’t even be a useful tool for exploring these particular possibilities. Depending on what estimate you use, Earth is somewhere38 between 24,000 and 94,000 light-years away from the edge of the Milky Way galaxy. Even if EmDrive technology allowed us to travel at the improbable top speed of the USS Enterprise from Star Trek: The Next Generation (1.04 light-years per hour), and even if we used the low end of the distance estimate, it would still take 2.6 years just to reach the Milky Way’s edge. The distance to the next major galaxy is another 2.5 million light-years, so that would be a 26-year trip. Most critically, the known universe is over 90 billion light-years in diameter (and that’s just the observable part, which—even in a non-multiverse theory—might be one-thousandth of its actual size). Even if we irrefutably knew39 there was a cosmos beyond our cosmos, it could never be reached by anything except a wormhole, the likes of which have been found only in fiction. The multiverse could not be seen or described, and certainly not visited. Which means incontrovertible proof of an infinite multiverse would be like incontrovertible proof of purgatory—we’d just have to dogmatically accept it, with no functional application to our daily lives. For non-scientists, the same could be said for a similar super-discovery in quantum mechanics: If we realized something profound and insane about atomic structure, happening on a level so microscopic that it could never be touched or observed or manipulated, the only thing it would really change is the language of textbooks. Here again, the (very real) paradigm shift would feel like nothing at all. It would mirror the reaction of a seventeenth-century shepherd who had just been told we live in a heliocentric universe: “Oh.”