Blog June 28 2016
I never liked physics much.
I’m not just talking about the math. I don’t like what modern physics tells us: that time is an illusion, for one thing. That we live in a reality where everything that ever was, and ever will be, always is: static timelines embedded in a “block universe” like threads in amber. I may remember scratching my head before writing this sentence, but that’s just one frozen slice of me with a bunch of frozen memories. An instant further along is another slice at t+1, with memories incrementally more advanced, and because it remembers the past it believes that it is moving through time. But in reality—seen from some higher-dimensioned overhead perspective—we exist on a tabletop where nothing changes, nothing moves, nothing goes away.
I hate that vision. My gut rebels at the grim counterintuitive determinism of it. But I’m no physicist, and we all know how misleading gut feelings can be. I don’t like it, but what do I know? I know nothing.
You can’t say that about Lee Smolin. Eminent theoretical physicist, co-founder of the world-renowned Perimeter Institute, author of the 2013 book Time Reborn. I’ve just read it. It gives me hope. It says my gut was right all along. We do exist from one moment to the next. This flow we perceive is no illusion. Time is real.
It’s space that’s bullshit.
Imagine the universe as a lattice of nodes; the only way to get from one place to another is to hop along the nodes between, like stepping-stones in a stream. The more dimensions the lattice has, the shorter the number of hops required to get between two points: Smolin invokes the analogy of a cell-phone network, which puts you just one step away from billions of “nearest neighbors.”
It takes energy to keep those higher dimensions active, though. In the early, hot universe—right after the Big Bang—there was energy to spare; dimensions were abundant and everything was one cell-phone-hop away from everything else. “Space” didn’t really exist back then. As the universe cooled, those higher dimensions collapsed; the cell network shut down, flattening reality into a low-energy mode where only those few locations adjacent in three dimensions could be considered “nearest”. Now, to get anywhere else, you have to hop myriad low-dimensional nodes. You have to cross “space.”
The point is, space is not a fundamental property of reality; it only emerged in the wake of that energy-starved collapse. This is the story Smolin is selling: There is no time-space continuum. There is only time.
Physics is wrong.
According to Time Reborn, physics went astray at two points. The first was when it started confusing maps with the territories they described. Most physics equations are time-symmetric; they work as well backwards as forwards. They are timeless, these rules that do such a good job of describing our observations of reality; so, physicists thought, maybe reality is timeless too. When we first started drawing graphs of motion and mass on paper—each moment a fixed point along some static axis—we were being lulled into a block-universe mindset.
Smolin describes the second wrong turn as “the Cosmological Fallacy”: an unwarranted extrapolation of the local to the universal. Physics studies systems in isolation; you’re not going to factor in the gravitational influences of the Virgo Supercluster when you’re calculating the trajectory of a bowling ball down the local lane, for example. You ignore trivial variables, you impose boundaries by necessity. You put physics in a box and leave certain universals—the laws of nature, for example—outside. Those laws reach into the box and work their magic, but you don’t have to explain them; they just are.
Physics works really well in boxes. The problem arises when you extrapolate those boxy insights to the whole universe. There is no “outside” when you’re talking about all of existence, no other realm from which the timeless laws of nature can reach in and do their thing. Suddenly you’ve got to explain all that stuff that could be taken as axiomatic before. So you start fiddling around with branes and superstrings; you invoke an infinite number of parallel universes to increase the statistical odds that some of them would turn out the way ours did. If Smolin’s right, a lot of modern physics is an attempt to reimpose an outside on a universe that doesn’t have one. And because we’re trying to apply locally-derived insights onto a totality where they don’t apply, our models break.
Smolin’s alternative sits so much easier in the gut—and, at the same time, seems even more radical. Everything affects everything else, he says; and that includes the laws of physics themselves. They are not timeless or immutable: they are affected by the rest of the universe, just as the universe is affected by them.
They evolve, he says, over time.
Everyone agrees that reality was in flux during the first moments after the Big Bang: universal laws and constants could have taken entirely different values than they did when the universe finally congealed into its present configuration. The strong and weak nuclear forces could have taken different values; the Gravitational Constant could have turned out negative instead of positive. Smolin suggests natural laws are still not set in stone, even now; rather, they result from a sort of ongoing plebiscite. How the universe reacts to X+Y comes down to a roll of the dice, weighted by past experience. Correlations, initially random, strengthen over time; if X+Y rolled mostly snake-eyes in the past it’ll be increasingly likely to do so in the future.
Now we’re 15 billion years into the game. Those precedents have grown so weighty, the correlations so strong, that we mistake them for laws; when we see X+Y, we never observe any result but Hitchhiker’s Guide to the Galaxy, transmuting a missile into a sperm whale or a bowl of petunias.)
So much becomes possible, if this is true. Smolin’s concept of “Cosmological Natural Selection” for one, in which Darwinian processes apply to the universe at large—in which black holes, egg-like, spawn whole new realities, each governed by a different physics (those which maximize black-hole production outcompete those which don’t). Another mind-blowing implication is that if the universe were to encounter some combination of quantum events that had never happened before, it wouldn’t know what to do: it would have to roll the dice without any precedent weighting the outcome. (Something to keep in mind, now that we’re starting to play around with quantum computing in a big way.)
We may even find our way to ftl, if I’m reading this right. After all, the lightspeed limit only applies to our impoverished four-dimensional spacetime. If you pumped up the energy in a given volume enough to reactivate all those dormant cell-phone dimensions, wouldn’t space just collapse again? Wouldn’t every node suddenly get closer to every other?
Of course, all this hypothesizing leaves open the question of how the universe “remembers” what has gone before, and how it “guesses” what to do next. But is that any less absurd than a universe in which a cat is both dead and alive until something looks at it? A universe governed by timeless laws so astronomically unlikely that you have to invoke an infinite number of undetectable parallel universes just to boost the odds in your favor?
At least Smolin’s theory is testable, which makes it more scientific than this multiverse that everyone else seems so invested in. Smolin and his allies seek to do to Einstein what Einstein did to Newton: expose the current model as a local approximation, good enough for most purposes but not truly descriptive of the deeper reality.
And yet I’m not entirely convinced. Even with my poor grasp of physics (or more likely, because of it), aspects of this new worldview seem a bit off to me. Smolin openly derides multiverse models—but where then do the black-hole-spawned “baby universes” of Cosmological Selection end up? And while I can easily imagine two points, three nodes apart, on a 2D lattice, I don’t see how adding a third dimension brings them any closer together (although it certainly opens up access to a whole bunch of new nodes). Also, if the laws of nature are affected by the objects and processes they affect in turn, wouldn’t that feedback follow certain rules? Wouldn’t those rules bring determinism back into play, albeit with a couple of extra complications thrown in?
These are most likely native criticisms. Doubtless Smolin could answer them easily; I’m probably just pushing his metaphors beyond their load-bearing limits. But perhaps the most important reason that I’m not convinced is because I so very dearly want to be. Current physics leaves no room for free will, no room even for the passage of time. Every moment we experience, every decision we think we make, is a lie. It’s not just that nothing happens the way we perceive it; in the block universe nothing happens, period.
Who wouldn’t reject such a reality, given half a chance? Who wouldn’t prefer an uncertain future in which we make our own decisions and influence our own destinies? What I wouldn’t give to live in such a world. Smolin offers it up on a platter. And because it is so tempting, I must counter my desire with an extra dose of skepticism.
Then again, the most basic tenet of empiricism is that any of us could be wrong about anything. “No amount of experimentation can ever prove me right,” Einstein once said. “A single experiment can prove me wrong.”
Maybe, before too long, Smolin will get his single experiment.
Stay tuned.