First posted 29 March 2005 - Bohm's eastern influence was primarily Indian / Hindu, but I see strong parallels now with Taoism as well. An amazing man trying to unite worlds that we too easily assume are distinct, incommensurate and irreconcilable.
At the end of my post on Tim Palmer, I related his model to that of David Bohm. There's a lot more to say about Bohm, and this post will be my attempt to pull it together.
David Bohm's name is associated with many things these days - his communist ideology (which cost him his academic post and nearly his freedom during the McCarthy witch hunts), his turn to Indian mysticism and close relationship with an Indian guru, his development of a new technique of dialogue for reaching more creative group solutions to problems and his call for a new scientific order. He did ground-breaking work in plasma physics and made important contributions to quantum theory (proposing the first EPR experiment, for instance), yet most of his work in quantum physics is viewed as outside the canon, ignored or embarrassingly dismissed by the physics community.
Bohm always wanted to understand EVERYTHING, and not just in its details but also in its WHOLENESS. His scientific, mystic and social views were inextricably linked.
The most useful metaphor for his model of the universe is that of the hologram. A hologram is sort of like a photograph, in that it is a visual representation of reality. But while a photograph captures only two dimensions, a hologram captures all three. When light is shone through a holographic plate, a three dimensional image is projected into the space before it. As you move around the image, you capture it from a different perspective, just as if it were the original object it represents. If the holographic image is of a person, you stand in front of it to see the face and chest; from the side you get a profile view; from the rear you see the back.
Yet there is something I think is even more interesting: if you drop the holographic plate and break it, EACH resulting piece of the former plate still can serve to project the entire image. Shine light through a small piece, and you'll still get the full three-dimensional image, just at a lower resolution. The smaller the piece of plate, the less well-defined the projected image. Contrast this with what happens when you rip a photograph in half: each half only shows you half of the image.
So, each piece of a holographic plate contains information about the ENTIRE three-dimensional image. How does this relate to the universe as a whole? Bohm believed that each particle in the universe contained information about the universe as a whole. I've put this sloppily, so let's look in greater detail at what he said.
One of the greatest (perhaps the greatest) mystery in science is demonstrated by the double slit experiment. I've explained the experiment elsewhere, so I won't go further into it here. Suffice it to say that the experiment suggests that particles fired individually through the test apparatus 'know' how they would have interacted (interfered) with one another had they been sent through together.
Physics has twisted itself into some amusing contortions (including the well-known ostrich head-in-the-sand trick) to account for this. Bohm believed that the particles themselves only 'knew' this because they were guided by a new field that he introduced, called the quantum potential. This quantum potential was holographic in its effects in that at any point in the universe, it contained information about the entire universe. Unlike other forces and fields in physics, its effects did not diminish with distance, so even very remote particles were in a sense linked by it. (Those steeped in quantum theory will recognise the link to the phenomenon of entanglement.) This potential was essentially a source of active information, intricately and infinitely enfolded (per chaotic non-linear dynamic systems) into scales below our ability to detect it.
This enfolded order that lay under the seemingly random behaviour of sub-atomic particles, Bohm called the implicate order, which he differentiated from our observable universe, the explicate order. The implicate order was deeper and more fundamental than the explicate one, but only bits of it could ever be unfolded at one time (hence Heisenberg's Uncertainty Principle).
In a later, quantum field theoretical version of the same basic thinking, Bohm added another, yet deeper order, the super implicate order. In this model, the particle was replaced by the quantum potential as the fundamental building block of nature. Particles were just focused knots within the quantum potential itself, and the evolution of the quantum potential over time was guided by the super-quantum potential. In fact, Bohm reckoned there could be (and probably were) an infinite number of these levels. Since the super-quantum potential was sensitive to pseudo-particle-level phenomena, a feedback loop arose, and this calls for another metaphor.
If you think of a video game, the screen images themselves are the explicate order (the particles, etc that we see in our world), the computer programme that dictates how the screen image alters as the game is played is the implicate order (the quantum potential) and the person playing the game and sending signals to the computer programme is the super-implicate order (the super-quantum potential). The loop is completed as the player adjusts his actions based on his perceptions on the screen. This super-implicate order is now the home of active information (but please don't see it, because of its analogy with the human player above, as an actual conscious thing).
Bohm was able to express all of this mathematically and to relate it to the more conventional mathematical formulae of quantum mechanics. His theory predicts observed behaviour just as well as the conventional methods. Yet it never caught on.
There are aesthetic grounds for this rejection, in that Bohm's interpretation gave a certain prominence to a particle's position (as opposed to its momentum). Penrose has said that Bohm's model essentially assumes that every measurement is a measurement of position. But the simplest explanation is that since the conventional view was already operationalised in the scientific community, and since Bohm's model made no different predictions than the conventional view, they should just stick with what they had. More cynically, you could say that physicists no longer cared about the ontological implications of the theories that provided their predictions.
One thing that strikes me as odd is that Bohm himself did NOT view his system as mechanical (deterministic). He felt that the feedback loops (per the video game metaphor) opened room for contingency. I just cannot square this. Feedback loop or not, the dynamics are deterministic, even if non-computable. Palmer's approach, which arrives at much the same place (active, holograph-like information enfolded minutely and hidden from view) albeit with a bit less metaphysical baggage, does not shirk from this.
What IS attractive about both - and let's remember that they are entirely consistent with experimental results - is the holism they bring to the universe. This holism brings nearly common-sensical answers to most of quantum theory's mysteries, and it does so in a way that does not violate the spirit of Einstein's relativity.
Everything is connected, not in some new-age way but ACTUALLY inter-related. Doesn't this just seem to FIT well with the notion of everything having started with the Big Bang? If the entire universe started in a quivering instability the size of a dime, it would be hard to imagine bits that were NOT related to the rest. We are all connected - to one another, to all living things, to everything that exists. A universe undivided.