Two days ago, I discussed several theories which call for universes parallel to our own. Brian Greene, writing in Discover Magazine, floats another one even queerer than the three I mentioned. Whereas the other worlds in my last post were causally isolated from our own, this hypothesis posits that all the events in our universe are the “holographic” projection of another distant cosmos. I haven’t given this theory enough benefit of the doubt to even call myself “skeptical” of it yet, but it’s still kind of trippy to think about:
The strangest version of all parallel universe proposals is one that emerged gradually over 30 years of theoretical studies on the quantum properties of black holes. The work culminated in the last decade, and it suggests, remarkably, that all we experience is nothing but a holographic projection of processes taking place on some distant surface that surrounds us. You can pinch yourself, and what you feel will be real, but it mirrors a parallel process taking place in a different, distant reality.
Plato likened our view of the world to that of an ancient forebear watching shadows meander across a dimly lit cave wall. He imagined our perceptions to be but a faint inkling of a far richer reality that flickers beyond reach. Two millennia later, Plato’s cave may be more than a metaphor. To turn his suggestion on its head, reality—not its mere shadow—may take place on a distant boundary surface, while everything we witness in the three common spatial dimensions is a projection of that faraway unfolding. Reality, that is, may be akin to a hologram. Or, really, a holographic movie.
The journey to this peculiar possibility combines developments deep and far-flung—insights from general relativity; from research on black holes; from thermodynamics, quantum mechanics, and, most recently, string theory. The thread linking these diverse areas is the nature of information in a quantum universe.
Physicists Jacob Bekenstein and Stephen Hawking established that, for a black hole, the information storage capacity is determined not by the volume of its interior but by the area of its surface. But when the math says that a black hole’s store of information is measured by its surface area, does that merely reflect a numerical accounting, or does it mean that the black hole’s surface is where the information is actually stored? It’s a deep issue and has been pursued for decades by some of the most renowned physicists. The answer depends on whether you view the black hole from the outside or from the inside—and from the outside, there’s good reason to believe that information is indeed stored at the event horizon. This doesn’t merely highlight a peculiar feature of black holes. Black holes don’t just tell us about how black holes store information. Black holes inform us about information storage in any context.
Think of any region of space, such as the room in which you’re reading. Imagine that whatever happens in the region amounts to information processing—information regarding how things are right now is transformed by the laws of physics into information regarding how they will be in a second or a minute or an hour. Since the physical processes we witness, as well as those by which we’re governed, seemingly take place within the region, it’s natural to expect that the information those processes carry is also found within the region. But for black holes, we’ve found that the link between information and surface area goes beyond mere numerical accounting; there’s a concrete sense in which information is stored on their surfaces. Physicists Leonard Susskind and Gerard ’t Hooft stressed that the lesson should be general: Since the information required to describe physical phenomena within any given region of space can be fully encoded by data on a surface that surrounds the region, then there’s reason to think that the surface is where the fundamental physical processes actually happen. Our familiar three-dimensional reality, these bold thinkers suggest, would then be likened to a holographic projection of those distant two-dimensional physical processes.
If this line of reasoning is correct, then there are physical processes taking place on some distant surface that, much as a puppeteer pulls strings, are fully linked to the processes taking place in my fingers, arms, and brain as I type these words at my desk. Our experiences here and that distant reality there would form the most interlocked of parallel worlds. Phenomena in the two—I’ll call them Holographic Parallel Universes—would be so fully joined that their respective evolutions would be as connected as me and my shadow.
I can’t help but wonder what repercussions this theory would have on our discussions of causality, agency, and “free will” if it were proven plausible, let alone true.
It would be a victory for determinists, no doubt, but I can’t imagine what we would do with it. Most contemporary literature by determinists I’ve read has been less concerned with actually proving the reality of physical necessity (for example their failure to really sieze the Rietdijik-Putnam argument is especially striking) with demonstrating we do not have to abandon commonsense moral intuitions with the specious doctrines of libertarianism. But holographic cosmology would surely inspire some interesting papers. I don’t have a clear enough head right now to imagine what they would contain; but it could be a fun thought exercise for Sunday.
Filed under: causality, cosmology, determinism, indeterminism, inflationary cosmology, libertarianism, metaphysics, philosophy, philosophy of time, physics, quantum physics, relativity, responsibility/agency/"free will", science, the fourth dimension, Uncategorized | Leave a Comment »