On the Deepest Level of Reality, Time and Space Don’t Exist, Physicist Claims

4 min readScientists who have been trying for decades to bridge quantum mechanics and the theory of relativity have come up with a possible solution for quantum gravity.One bold proposal, Group Field Theory (GFT), says that the fabric of spacetime is not fundamental but emerges from the tiniest building blocks of space the way wetness emerges from water molecules.This means “atoms of space” can be thought of as abstract quantum entities that don’t reside in spacetime at all.Physicists have a problem. Einstein’s smooth, continuous theory of spacetime has explained gravity and the large-scale properties of our universe beautifully for over a century, but it doesn’t work on the smallest scales. For that, physicists use quantum mechanics, because of its accurate way of describing the atomic and subatomic particles. The problem occurs when physicists try to use one to describe the other, since the smooth nature of general relativity doesn’t play well with the lumpy, jumpy, and particle-based nature of the quantum world.While both work well alone, the math breaks down when they are combined. General relativity predicts that the center of a black hole and the start of the Big Bang had points of infinite density, which they call singularities, but that doesn’t make sense. Many take it as a sign that the theory has reached its limits.“Some kind of very new way of thinking is needed,” says Christian Wüthrich, PhD, professor of philosophy of science at the University of Geneva. “It no doubt will require mathematical innovations.”Over the past few decades, many radical ideas have been floated for this new way of thinking (string theory is probably the most famous). But a lesser-known approach, if it’s correct, would rewrite how we understand the way the universe formed. Group Field Theory, which borrows concepts from condensed matter physics, is starting to make waves (no pun intended). It proposes that space and time are not fundamental features at all, but “emergent” ones that arise from its building blocks, in a similar way that the property of wetness arises from the collective action of water molecules.Water feels smooth and flowy to the touch, but when you zoom in, it’s made of individual H₂O molecules. Its “wetness” can’t be felt by a single molecule but needs to be experienced by trillions of them interacting. So too is spacetime, says Daniele Oriti, PhD, a theoretical physicist at the Complutense University of Madrid. The universe is made up of individual “seeds” that exist outside space and time, he says. He calls them “pre-geometric, no-spatiotemporal entities.” But when they interact, they collectively give rise to the experience of spacetime.“There are properties that make total sense at the level of the fluid, but not at the more fundamental level of the atoms,” says Oriti, a lead developer of Group Field Theory. “The usual notions of geometry; the distances, curvature, and volumes, only make sense at this collective level. Whatever the fundamental ‘atoms of space’ are, you cannot attribute ordinary spacetime properties to them individually.”Oriti says that the “atoms of space” can be thought of as abstract quantum entities that don’t reside in spacetime at all. This is where the theory gets wild and hard to wrap one’s head around: that these atoms exist in a place with no time and space, yet their interactions when many of them get together and organize are what cause spacetime itself.In Oriti’s view, the universe emerged in what was akin to a phase change in which these atoms of space crystallized into the universe, just like frost condenses and freezes on a window pane.“It’s a very interesting proposal,” says Wüthrich. “It’s also mind-boggling.” Of particular challenge to him is the idea that our universe arises from a place with no space and no time. “I don’t think that in our human imagination we have a template or analogy for that kind of relationship,” he says. “We can describe it mathematically, but to have a picture in mind of how that should look does not seem to be possible.”But if this theory is correct, it could force us to rethink what happens at the center of black holes and how the universe came to be. The Big Bang would be less of a singularity in which the whole universe formed from an explosion, and more like a giant phase shift in which pre-spatial entities crystallized into the fabric of spacetime as we understand it today. It would also mean there was no time or beginning to speak of, and no space for anything to be contained in.But how can this theory ever be tested? Not easily, Wüthrich explains. “How to connect the theory to anything that’s empirically accessible that we can observe or measure is a huge challenge.” He says this problem is not unique to group field theory, but also applies to string theory too, and others.Testing the theory may take decades, if it’s even possible at all. But Oriti thinks he knows what the answer is, and if he’s right, the universe didn’t start with a bang. It crystallized into being.Monique Brouillette is a freelance contributor who writes about biology.