If you’re here to indulge in some mind-bending talk about time travel, neuroscientist Dean Buonomano is about to break some hearts. He doesn’t think it’s plausible—but if it were, there is one hypothesis of the universe in which it could theoretically happen. There are currently two main ideas about time: Presentism—the notion is that only the present is real: the past happened, the future will happen, but only the present exists—and Eternalism, in which the past, present, and future are all equally real. If you want to flux-capacitor your way back in time, you’ll want to hope that Eternalism turns out to be the true theory. It’s known to physicists as Block Universe, where all moments of the past, present, and future are already laid out in a continuum—there are places to travel to. “Under Presentism we can pretty much take the possibility of time travel off the table because there’s no other moments to go to—only the present is real,” says Buonomano. See Your Brain Is a Time Machine: The Neuroscience and Physics of Time
Partial transcript and video with more on book below
So there’s two general hypotheses or theories about the nature of time. One of them we’ll call Presentism. And Presentism the notion is that only the present is real. The past was real. The future, some configuration of the future universe, will be real. But for now only the present is real.
In contrast the opposing view is called Eternalism. In Eternalism you have: the past, present and future are all equally real. So that makes the present just an arbitrary point in time or an arbitrary moment in time.
So one way to think about this is: Now is to time as Here is to space. So in the same sense that I happen to be here and some viewers are out at some other point in space (and we’re all comfortable with that notion that other points in space are equally real), in Eternalism you have to be comfortable with the notion that other moments in time are as equally real as this moment in time and this is just an arbitrary moment.
A leading neuroscientist embarks on a groundbreaking exploration of how time works inside the brain.
In Your Brain Is a Time Machine, brain researcher and best-selling author Dean Buonomano draws on evolutionary biology, physics, and philosophy to present his influential theory of how we tell, and perceive, time. The human brain, he argues, is a complex system that not only tells time but creates it; it constructs our sense of chronological flow and enables “mental time travel”?simulations of future and past events. These functions are essential not only to our daily lives but to the evolution of the human race: without the ability to anticipate the future, mankind would never have crafted tools or invented agriculture. The brain was designed to navigate our continuously changing world by predicting what will happen and when.
Buonomano combines neuroscience expertise with a far-ranging, multidisciplinary approach. With engaging style, he illuminates such concepts as consciousness, spacetime, and relativity while addressing profound questions that have long occupied scientists and philosophers alike: What is time? Is our sense of time’s passage an illusion? Does free will exist, or is the future predetermined? In pursuing the answers, Buonomano reveals as much about the fascinating architecture of the human brain as he does about the intricacies of time itself. This virtuosic work of popular science leads to an astonishing realization: your brain is, at its core, a time machine.