Basil Hiley on working together with David Bohm

The following is from an interview with Basil Hiley, who was a collaborator and colleague of David Bohm for over 30 years. My emphasis in italics.

>>Basil Hiley: The quantum domain arises because as we probed into the behavior of matter…we found that the atoms were behaving in a way which we could not understand in terms of classical physics… And then, it was [Werner] Heisenberg who actually spotted…how to change…the classical description into a quantum description…

0:45 …the change in the mathematics was in a way quite dramatic. It changed from simply thinking about particles with positions and momentum and evolving in space time, to something which forbid us to actually talk about positions and or to measure positions and momentum simultaneously… and you then have to have an entirely new way of describing the phenomena. And this occurs not at the macroscopic level, but it becomes very evident as we get down to the molecular, atomic, and subatomic levels. We have to use instruments to see what is going on and therefore we do not directly perceive what is going on, so we have to understand how our instruments are working. …we get into this dilemma that it is not possible to measure the position and the momentum of a particle at the same time… So…we’ve got a question there: “Does it mean that atoms don’t have position and momentum at a given time? Or, is it just simply…that we can’t measure the momentum and position at a certain time?” This gives us the choice [of] the Copenhagen interpretation [which] says, “we don’t know, but there’s nothing we can say about it”. And that left us with a very vague idea that we don’t know, or we can’t even find out what is going on underneath the measurements that we’re getting. And, therefore there is a concentration on what we can measure and how the measurements are related to each other. This is in contrast to people like [Albert] Einstein…who believe that there is something underlying this, and…we can actually try to develop a theory which shows us what is going on beneath this apparent uncertainty.

3:39 …David [Bohm]…showed that even within the Schrödinger equation, by technically splitting it into a real and imaginary part, splitting [it] into two coupled equations, …that one equation looked very much like a classical equation. That it was a particle evolving along a trajectory, but [that] it had a new feature to it and it’s the feature that we have called a quantum potential. It seemed almost as if there was another force being generated from the sub quantum medium, and the question has always been: “What does it mean? And how do we get information about it?”

4:33 [Niels] Bohr had this idea that we could not say anything about the underlying reality, and people have taken that also to mean that there may not be an underlying reality. Einstein completely disagreed with this point of view. He thought there must be an underlying reality, and this underlying reality would produce the effect we actually see in our instruments. Now the question then was: “What is the underlying reality?“

5:45 …what he [David Bohm] did was to take the Schrödinger equation [and]…split it into two equations which were coupled. One equation looked remarkably like a classical equation of motion, but it had a very big difference, and the difference was that there was a new energy [which] seemed to be involved. And this new energy manifested itself in terms of a quantum potential… and this gave rise to a new force which only worked in the quantum domain. …if you go to the classical domain this force becomes zero. So he…then developed his ideas of particles following trajectories, but to do that he did not have to introduce hidden variables. All he used was the variables that were being used in quantum mechanics anyway, but he was using them more like classical variables than abstract operators.

7:44 [Paul] Dirac…said we can’t talk about a trajectory going through in the classical sense, but what we can do is…look at the process of slowly unfolding into one process and then enfolding into another. So, there is a transition between these states, and it’s this transition…which we’ve been focusing on recently.

8:21 Remember, we’re talking about wholeness. We have to have wholeness in here, [and] here we agree with Bohr, [who] pointed out that it [wholeness] was very important. The new features that quantum mechanics introduces is a kind of wholeness, which means we cannot analyze things by cutting them up into little bits as we do in classical physics. But what we can do is if we want to try and cut it up that the way one bit goes into the next bit actually involves unfolding into the whole, and then enfolding back again into a particular region. And so you get this idea of unfolding and folding, unfolding and folding. So what looks like a continuous trajectory is actually a series of folding and unfoldings.

9:10 Dirac essentially had this idea but gave it up. What Bohm has done is to say: “Don’t give it up”. Dirac thought that the uncertainty principle would be violated if you went down this road… What David Bohm did was to show that it would not be violated, that you would still retain the uncertainty principle.

11:03 What David Bohm was suggesting was that…there is a guidance condition in the mathematics, and that…the real part of the Schrödinger equation is telling us something about the energy distribution in a given system, and what you see is…an energy conservation equation, provided you introduce this new quality of energy called the quantum potential energy. And this quantum potential energy only functions when quantum phenomena appear.

12:49 And nowadays we are beginning to think that [the] underlying process is actually to do with the actual structure of space and time. That [space and time] itself may not be continuous. We don’t have continuous geometries, but we have a non-commutative geometry. And the big question is: “What is the form of that non-commutative geometry? What sort of insights do we get about it? How are we going to think about it? How are we going to reformulate our ideas to find out exactly what non-commutative geometry means in everyday terms”.

13:33 The question of existence is very, very interesting here, because what we see is that in the non-commutative structure there doesn’t appear to be any quantum potential. But when we project it into a phase space, a space-time manifold, a classical quantum potential appears. So now, “does that mean the quantum potential is real or not?” … Let’s go back to gravity. Remember, the gravitational force is not a force. The gravitational force arises because space-time has got a curvature in it, that space-time is not Euclidean — it’s Riemannian. Therefore, what is revealed as a force is actually a feature of the underlying geometry. And…what I feel is [that] the quantum potential is a feature of the underlying non-commutative geometry. Now, in that sense, “is it real or is it artificial?” … It’s pointing to the fact that we need a new geometry, and we’re trying to find out features of that non-commutative geometry. And that’s a very active field at the moment with many speculations about how this would arise.

15:05 The quantum potential is a way of talking about this thing, to take some of the mystery out of the quantum phenomena: With the quantum potential you don’t have schizophrenic cats that are alive and dead at the same time; with the quantum potential the cat is either alive or dead; with the quantum potential you explain the qualities that gives you the interference [pattern] without the need for introducing a wave function. And the wave function has been getting in the way in my view, because we have this…measurement problem in which the wave function is behaving in an evolutionary manner through Schrödinger’s equation, and then when we look at it, it collapses. And we have this collapse problem which has been going on now for…100 years, and it still has no solution. And maybe [it] has no solution because it is not relevant. We have got the thing wrong.

16:16 When I first joined David Bohm, we didn’t talk about his…[19]52 paper. What we were talking about was: “How could we get quantum mechanics and gravity and general relativity into one theory? How could we quantize the gravitational field?” Fortunately, we had Roger Penrose with us at Birkbeck at the time. And David Bohm, Roger Penrose, myself, and some mathematicians, used to meet and talk about this problem. So, we were talking about ideas like pre-space, “how are we going to put quantum mechanics into this pre-space idea…? What is a quantum space-time? … Roger Penrose was talking about his spin networks, which has now become quite a big industry in some areas. He was developing his twisters, and it was developing his twisters that led me into the Clifford algebra approach, which is a non-commutative algebra. … At the time, David Bohm was developing a new idea, which he called structure process. … Basically, we want to start with process, not particles moving in space-time, but a process from which both particles and space-time can emerge. … Very radical ideas. … What we were thinking about was: “How are we going to describe this process?” I think I was reading [about] some work by [Hermann] Grassmann and [William] Clifford way back in the 1850s… And they were talking about process essentially, but they weren’t calling it process. They [Clifford and Grassmann] were talking about activity, about order, and they were saying — and Grassmann in particular was saying — that, really, mathematics was not about material processes, it was about thought.

18:41 So, if we are thinking about underlying processes in terms of some sort of new radical idea, we need to develop the mathematics to actually encompass that. And what was coming to the fore all the time was that we need an algebra. And an algebra is essentially something which has both addition and multiplication. And the multiplication became the order of succession. So, if you had a process unfolding, then multiplication was the way it unfolded; addition was the way it coexisted.

19:25 Leibniz…had this idea of what time was. Time was the order of succession, but…also an order of coexistence. Now, we can actually develop an algebra which will encompass that philosophical idea. And that’s what we were developing, and that’s what I think Penrose was developing with his twister theory…

21:06 I…always had been puzzled, even when I wrote the book Undivided Universe with David Bohm…: “How is it that you can have trajectories in this deeper process?” We told a story, which I think was very good, but it wasn’t the final story. We left the final chapter open where we said we needed more radical ideas. And these were the radical ideas that I was hoping David and I would write about, but unfortunately David’s time came too son. So, since then I have been trying to develop the continuation of these original process based ideas, developing a theory, a structure process in quantum mechanics.

22:11 There’s no such thing as a vacuum, being empty of everything. …even [James Clerk] Maxwell didn’t think of the vacuum as being empty. He defined the vacuum as being everything that we can take out of it, that we know how to take out of it. … Now, in quantum field theory, we have inequivalent vacuum states. So, these are states in which there is still activity present. So, we never get to the stillness of nothingness. All is in flux. It’s not a plenum of particles buzzing backwards and forwards. … This idea of energy is a very interesting concept. We always think that energy goes with particles…, but does energy have to be concentrated on particles? Quantum field theory tells us [that]…there is a field, this field carries energy, and it carries energy in a non-local way.

23:44 The problem is for us, we’re trying to describe the universe by getting outside it… It’s the God-like view of reality. Unfortunately, we’re right in it. I’m saying there’s no hill that we can climb up — that’s the illusion. When we do that we fragment everything. We are in it right at the beginning, irreducibly in it. [We] can’t separate ourselves out, …we depend upon it, …and then we have the arrogance to say: “Oh, I’m important on top of the hill. You’re not”. And so we get into this conflict which is going to go on and on.

25:00 One thing that I want to emphasize when I’ve been talking here [is that] I have not got a theory which is complete and ready to solve all the problems of the universe. I’m on a journey, …the journey is a process. What I’ve and what David and I have done is to open up the discussion… I find, when I’m talking to young people that they’re very interested in trying to proceed further with these ideas. In other words, some of them have actually got it… They know..this is an interesting way to go.

28:07 My daughter is a primary school teacher and she is always complaining that the curriculum is killing off any creativity in youngsters. She believes that…their creativity should be encouraged at the primary level, but it is not. It is being stifled…at the moment, and…[it] doesn’t matter whether it’s physics, history, philosophy, or anything. We’ve got to be an educational system going which allows people to be creative. And in that creativity they’re going to make mistakes, but if you don’t make mistakes you will never learn anything. So there is a problem with the whole educational system. … I hope there are people out there…working on it so that we allow for creativity to develop naturally, but sometimes [I] look at the political situation and I’m very concerned.

30:12 He [David Bohm] was making proposals as to how we can begin to be more creative and look at different aspects, and bring them into a more coherent structure. Coherence was all important to him. Order, [was] the thing that he was interested in — not chaos — but actually trying to find the right orders in order, to express the physical phenomena.

30:45 David Bohm’s contribution was immense, not only in the narrow field of physics, but in terms of society in general. … When I started joining him, it was so refreshing. We would talk about all sorts of things if it was relevant for the particular problem that we were dealing with. And David Bohm was dealing with general ideas. He would be dealing with philosophical ideas. We would go into language: “Is…language limiting the way we can express these ideas?”

31:26 He would go into biology and say: “Look, this is the way biological systems develop”. …nature is surely more organic and yet we’re trying…to make it mechanical. Perhaps…there is a more organic way of thinking about life in general. And then, ultimately, he became very fascinated with the role fo consciousness. In all of this: “Where is consciousness? Where does consciousness come in? What is thought? What is thinking?” And he would be discussing those [questions] and writing very profoundly about those ideas. But he never got into a school, and that was because he would make proposals, and then explore these proposals… He was very puzzled by this whole thing.

32:53 It’s very each for us physicists to go back into the mechanical picture. People have done that with David Bohm. They’ve taken him and said, “look it’s Bohmian mechanics”. And David said to me: “Why are they calling it by me in case they haven’t read what I’ve said? It should be called non-mechanics.” … It’s so much easier to talk in term of classical mechanical ideas.

33:26 What I feel is that the universe is organic. With the organic, it’s not the parts that determine the whole, it’s the whole which determines the parts. Wholeness plays a key role in it. And the way we talk about it is through process, and not through particles…