Earlier this week, there was a mind-bending New York Times article on gravity that also touched on the possibility that we live in a holographic universe. Here is one of the key passages from the New York Times article explaining the so-called holographic principle, and how it derives from physicists working out what black holes are:
Over the last 30 years gravity has been “undressed,” in Dr. [Erik] Verlinde’s words, as a fundamental force.
This disrobing began in the 1970s with the discovery by Jacob Bekenstein of the Hebrew University of Jerusalem and Stephen Hawking of Cambridge University, among others, of a mysterious connection between black holes and thermodynamics, culminating in Dr. Hawking’s discovery in 1974 that when quantum effects are taken into account black holes would glow and eventually explode.
In a provocative calculation in 1995, Ted Jacobson, a theorist from the University of Maryland, showed that given a few of these holographic ideas, Einstein’s equations of general relativity are just a another way of stating the laws of thermodynamics.
Those exploding black holes (at least in theory — none has ever been observed) lit up a new strangeness of nature. Black holes, in effect, are holograms — like the 3-D images you see on bank cards. All the information about what has been lost inside them is encoded on their surfaces. Physicists have been wondering ever since how this “holographic principle” — that we are all maybe just shadows on a distant wall — applies to the universe and where it came from.
Put another way, you can explain a black hole—that is, you can account for all the information that it contains—by just describing its two-dimensional surface. The third dimension is an epiphenomenon of the two-dimensional surface. And what is true of black holes may be true of the universe as a whole. If you can account for all the information in the universe in two-dimensions, without resort to the third-dimension, then it is not fundamental:
In one striking example of a holographic universe, Juan Maldacena of the Institute for Advanced Study constructed a mathematical model of a “soup can” universe, where what happened inside the can, including gravity, is encoded in the label on the outside of the can, where there was no gravity, as well as one less spatial dimension. If dimensions don’t matter and gravity doesn’t matter, how real can they be?
Is your mind blown yet?
It should be because, in simple terms, it means this: the three-dimensional universe that we experience may be a holographic projection emanating from the two-dimensional cosmological horizon (about 13.7 billion light-years away). In other words, we should think of the cosmological horizon as a “skin” or “canvas,” with all of the universe’s fundamental information “tatooed” or ”painted” on its two-dimensional surface, and possibly projecting from there. Stripped of appearances, the reality may be that we are two-dimensional beings, 13.7 billion light years away from where we think that we are, imagining that the three-dimensional projection of ourselves is the essential one.
Talk about missing the off-ramp!
Here’s how an article in New Scientist explains the holographic principle:
The idea that we live in a hologram probably sounds absurd, but it is a natural extension of our best understanding of black holes, and something with a pretty firm theoretical footing. It has also been surprisingly helpful for physicists wrestling with theories of how the universe works at its most fundamental level.
The holograms you find on credit cards and banknotes are etched on two-dimensional plastic films. When light bounces off them, it recreates the appearance of a 3D image. In the 1990s physicists Leonard Susskind and Nobel prizewinner Gerard ‘t Hooft suggested that the same principle might apply to the universe as a whole. Our everyday experience might itself be a holographic projection of physical processes that take place on a distant, 2D surface.
The “holographic principle” challenges our sensibilities. It seems hard to believe that you woke up, brushed your teeth and are reading this article because of something happening on the boundary of the universe. No one knows what it would mean for us if we really do live in a hologram, yet theorists have good reasons to believe that many aspects of the holographic principle are true.
And here’s Wikipedia on the holographic principle:
In 1995, Susskind, along with collaborators Tom Banks, Willy Fischler, and Stephen Shenker, presented a formulation of then new M-theory using a holographic description in terms of charged point black holes, the D0 branes of type IIA string theory. The Matrix theory they proposed was first suggested as a description of 2branes in 11 dimensional supergravity by Bernard de Wit, Jens Hoppe, and Hermann Nicolai. The later authors reinterpreted the same matrix models as a description of the dynamics of point black holes in particular limits. Holography allowed them to conclude that the dynamics of these black holes give a complete nonperturbative formulation of M-theory. In 1997, Juan Maldacena gave the first holographic descriptions of a higher dimensional object, the 3+1 dimensional type IIB membrane, which resolved a long-standing problem of finding a string description which describes a gauge theory. These developments simultaneously explained how string theory is related to quantum chromodynamics, and afterwards holography gained wide acceptance.
And this is also from the Wikipedia entry on the holographic principle:
The physical universe is widely seen to be composed of “matter” and “energy”. In his 2003 article published in Scientific American magazine, Jacob Bekenstein summarized a current trend started by John Archibald Wheeler, which suggests scientists may “regard the physical world as made of information, with energy and matter as incidentals.” Bekenstein quotes William Blake and questions whether the Holographic principle implies that seeing “the world in a grain of sand,” could be more than “poetic license”.
Seeing “the world in a grain of sand” may be more than “poetic license.” Isn’t that wonderful? Here are the famous lines from Blake:
To see a world in a grain of sand,
And a heaven in a wild flower,
Hold infinity in the palm of your hand,
And eternity in an hour.
If the holographic principle is true, it would mean that, ultimately, and in accord with Blake’s intuition, the divisions between people and things are illusory (for each piece that projects a holographic image contains the whole, and so can never really be divided).
In other words, we are unbreakable.
The Blake lines quoted above come from his poem, “Auguries of Innocence.” Here are the lines that immediately follow his reflection on seeing “a world in a grain of sand”:
A robin redbreast in a cage
Puts all heaven in a rage.
A dove-house fill’d with doves and pigeons
Shudders hell thro’ all its regions.
A dog starv’d at his master’s gate
Predicts the ruin of the state.
A horse misused upon the road
Calls to heaven for human blood.
Each outcry of the hunted hare
A fibre from the brain does tear.
A skylark wounded in the wing,
A cherubim does cease to sing.
The game-cock clipt and arm’d for fight
Does the rising sun affright.
Every wolf’s and lion’s howl
Raises from hell a human soul.
The wild deer, wand’ring here and there,
Keeps the human soul from care.
And I also can’t help but think of Bell’s Theorem and quantum entanglement, in which no system can be explained fully by local effects. The holographic universe might explain why physicists observe quantum entanglement.
And the idea that we live in a holographic universe also has me wondering how it fits with physicist Garrett Lisi’s idea that the universe “hangs” on the E8 geometrical lattice. Below is what the E8 geometrical lattice looks like in two dimensions—but it is, by Lisi’s reckoning, a 248-dimensional object. Is this the hologram that is being projected from the cosmological horizon, and that we imagine ourselves to be residing in (even as we’re really 13.7 billion light years away from where we think we are, and living in two dimensions)?:
Okay, now my head is spinning. I’ll stop there.