David Bohm

David Bohm
Occupations	Physicist; philosopher
Nationality	American-British
Born	1917
Known for	Pilot-wave theory (Bohmian mechanics); quantum nonlocality; implicate order
Notable works	Wholeness and the Implicate Order (1980)
Fields	Quantum theory; philosophy of science
Died	1992

David Bohm (1917–1992) was an American–British theoretical physicist who offered bold new ways to understand quantum mechanics and reality as a whole. He is best known for a pilot-wave or hidden-variable interpretation of quantum physics and for proposing that the universe is an undivided, “implicate” whole underlying the visible world. Bohm’s ideas were controversial in his lifetime but have since influenced many areas from physics to philosophy, consciousness studies and dialogue theory. His work challenged the orthodox view of quantum mechanics and urged that matter, mind and society be seen as interconnected rather than fragmented.

Early Life and Education

David Bohm was born on December 20, 1917, in Wilkes-Barre, Pennsylvania, to an immigrant family. He showed an early aptitude for science and attended Pennsylvania State College (now Penn State), earning a B.S. in 1939. Bohm then did graduate work in physics at the University of California, Berkeley. He was discouraged by the heavy coursework and lack of intellectual freedom at Caltech (where he had briefly studied), but found Berkeley invigorating. Under the supervision of Robert Oppenheimer, Bohm earned his Ph.D. in 1943. He began a postdoctoral career at Berkeley, working on plasma physics and other topics.

During and immediately after World War II, Bohm worked on the Manhattan Project at Berkeley’s Radiation Laboratory (1943–45). There he became acquainted with leading physicists including Oppenheimer and Albert Einstein. After the war he took a position as an assistant professor at Princeton University (1946–51), joining a vibrant theory group. In 1949 Bohm was subpoenaed by the House Un-American Activities Committee because of past associations with Marxist student groups. He refused to name names, was briefly jailed, and ultimately lost his Princeton appointment. At that point Bohm left the United States, moving first to the University of São Paulo in Brazil (1951–55), and later to research posts in Israel and the UK. From 1961 until retirement he was Professor of Theoretical Physics at Birkbeck College, University of London. He became a British subject and continued his research on quantum theory, the nature of reality, and the foundations of physics. In 1990 he was elected a Fellow of the Royal Society. David Bohm died in London on October 27, 1992.

Pilot-Wave Theory and Nonlocality

One of Bohm’s major contributions was a new interpretation of quantum mechanics based on hidden variables. In 1952 he published two papers in Physical Review introducing a causal interpretation (also called Bohmian mechanics or the de Broglie–Bohm theory). This approach offers a concrete picture of quantum phenomena by supplementing the usual wave description with definite particle positions. In Bohm’s picture each quantum particle has a well-defined trajectory at all times, guided by a real wave. The wave in question is the ordinary quantum wave function (a mathematical object that evolves according to Schrödinger’s equation). Bohm showed that the wave function by itself gives only a probabilistic description, but if one also specifies hidden variables (namely the actual positions of particles), quantum statistics can be reproduced without any randomness at the fundamental level.

In practice, this works as follows. The particle’s velocity is given by a guiding equation that depends on the wave function, and the wave obeys the standard Schrödinger equation. Together these two equations determine a unique, deterministic evolution for the particle and wave. For example, in the famous double-slit experiment a Bohmian electron always goes through one specific slit, not both. However, the guiding wave passes through both slits and interferes with itself. The resulting interference pattern in the wave then steers the particle to land on the bright fringes of the detector screen. In this way Bohm’s theory produces exactly the same interference checkerboard as ordinary quantum mechanics, but with a classical-like picture of one particle following one path. The usual quantum probabilistic predictions (given by the Born rule: probability = |wave function|²) emerge naturally in Bohm’s theory if one assumes the particles’ initial positions are distributed according to that same rule.

A key feature of Bohm’s theory is the introduction of a quantum potential. When one inserts the wave function (in polar form) into the Schrödinger equation and separates real and imaginary parts, one finds one equation for probability conservation and another that looks like Newton’s law of motion but with an extra term: the quantum potential. This potential depends on the curvature of the guiding wave, not on local fields. It can be very small for obvious cases but can also dominate behavior in delicate quantum systems. Importantly, the quantum potential is not a local force: it depends on the global form of the wave function. For an entangled pair of particles, for example, the potential linking one particle to the other is immediate, no matter how far apart they are. In other words, nonlocality is built into Bohm’s picture from the start.

“Nonlocal” here means that what happens at one point in space can be instantaneously affected by something happening far away. In Bohm’s interpretation, two particles in an entangled quantum state are connected by a single guiding wave. Measuring one particle changes part of the wave function and thus instantly affects the other, even light-years apart. This was controversial: Einstein famously objected to “spooky action at a distance,” a phrase often used about this kind of connection. Einstein liked the idea of determinism (no fundamental randomness) but could not accept the nonlocal influence that Bohm’s theory implied. Bohm agreed that relativity’s strict locality was violated by his model, but he argued that this nonlocality was not incompatible with observations – it only becomes a problem when one tries to extend the theory to relativistic fields. Indeed, shortly after Bohm’s work, John Bell proved that any hidden-variable model reproducing the predictions of quantum mechanics must involve nonlocal correlations. In that sense Bohm’s theory anticipated Bell’s theorem: it is explicitly nonlocal but otherwise reproduces all of nonrelativistic quantum physics. Bohm simply embraced the nonlocality as real. As one physicist put it, Bohmian mechanics “makes explicit the nonlocality implicit” in the standard quantum formalism.

Because Bohm’s interpretation yields all the same results as conventional quantum mechanics, it makes no different experimental predictions. Its advantage (according to Bohm and some supporters) is conceptual clarity: it removes the mystery of wavefunction collapse and provides a picture of definite reality. The standard (“Copenhagen”) interpretation simply says that before measurement a quantum particle has only probabilities for different outcomes, and that the act of measuring “collapses” the wave function into one result. Bohm instead showed that the collapse is not a fundamental process: in his view the particle always has a well-defined position, and measurement just reveals it. The apparent randomness comes from ignorance of the exact initial position. This restores a form of classical determinism: there is no inherent chance in nature, only complex hidden dynamics. (Of course, in practice one cannot know the hidden variables, so predictions remain statistical as in ordinary quantum mechanics.)

Despite its mathematical consistency, Bohm’s pilot-wave theory was met with strong resistance in the 1950s. Leading physicists of the day criticized it. Niels Bohr dismissed it as philosophically misguided, and Wolfgang Pauli noted that Louis de Broglie had proposed a similar idea in the 1920s but had abandoned it after objections. Oppenheimer wrote it off as a “juvenile deviation,” and even Einstein, while intrigued, remarked it had “no hope.” In short, most of Bohm’s peers were not convinced. They objected that restoring determinism was unnecessary if it was as good as impossible to test experimentally. Bohm’s insistence on a real “pilot wave” and potental underlying quantum phenomena seemed to them metaphysical. By the end of the 1950s, the physics community largely ignored it. However, Bohm continued refining his theory (often with collaborators like Jean-Pierre Vigier and later Basil Hiley). In 1993, after his death, Bohm and Hiley published The Undivided Universe, a comprehensive exposition of the hidden-variable approach with modern developments. Today Bohmian mechanics is recognized in quantum foundations as a legitimate interpretation – taught in some courses and the subject of ongoing research – even if it remains outside the mainstream approach to quantum physics.

Other Contributions (Aharonov–Bohm Effect, Brain Theory, etc.)

Besides his main work on hidden variables, Bohm made a number of other important contributions to physics. In 1959, together with physicist Yakir Aharonov, he discovered what is now called the Aharonov–Bohm (A–B) effect. They showed that in quantum mechanics a charged particle can be affected by an electromagnetic potential even when passing through a region of zero magnetic and electric fields. In practice, electron interference fringes can shift in the presence of a magnetic flux confined to an inaccessible region (like inside a solenoid). This demonstrated that the potentials themselves have physical significance in quantum theory – a nonlocal effect since the electrons never touch the actual field. The A–B effect was experimentally confirmed in the 1960s and is now a textbook result in quantum physics. It underscores the same lesson Bohm had found in his interpretation: the quantum world allows connections that have no classical analogue. The A–B effect has even been cited as a reason Bohm’s work was deserving of a Nobel Prize in physics.

Bohm also ventured into areas outside conventional quantum theory. In the 1960s he collaborated with neuroscientist Karl Pribram to develop a holonomic model of brain function. They proposed that memory and perception could be understood in terms of wave interference in the brain’s neural networks, somewhat analogous to holography. Though not empirically proven, this “holonomic brain theory” applied Bohm’s ideas of waves and fields to consciousness. (Pribram continued working on these ideas later.)

In condensed matter physics, there is even a phenomenon called Bohm diffusion: anomalously slow plasma diffusion in a magnetic field, which Bohm himself studied. His name also appears in elementary discussions of motion under electromagnetic potentials due to the A–B effect. However, these technical contributions are generally of niche interest compared to his interpretive ideas.

Wholeness, Dialogue, and the Implicate Order

In addition to his technical work in physics, Bohm spent decades developing a sweeping philosophical vision of reality. He grew increasingly dissatisfied with the way science and culture divided the world into separate, isolated parts. Inspired by dialogue with Eastern philosophers (especially Jiddu Krishnamurti) and by Marxist thought on unity, Bohm proposed that the deepest level of reality is an undivided whole. He expressed this in his 1980 book Wholeness and the Implicate Order. The central idea was that what we see – particles, fields, bodies, even thoughts – emerges from and is connected by a deeper background reality he called the implicate order (literally “enfolded order”). The world of distinct objects and events is the explicate order (“unfolded” reality) that unfolds out of and enfolds back into the deeper implicate order.

Bohm often used analogies to explain this. For example, a hologram is an image where each small piece contains information about the whole picture. If you cut a hologram in half, each half still shows the entire original image (though fainter). In Bohm’s view, this is like the implicate order: every part of reality contains an “impression” of the whole, even if we only see a local fragment. He also talked about fractals and self-similar patterns as illustrations of a generative order, though his notion of implicate order was more general than any mathematical fractal. The key was that the universe is constantly “unfolding” and “enfolding” itself: physical processes and even moments of thought arise from (are implicate in) an underlying dynamic and then return to it.

This vision of wholeness extended beyond physics. Bohm believed that human consciousness and society follow similar patterns. He argued that thought itself tends to fragment reality by dividing things artificially, and this “fragmentation” causes confusion and conflict. To address problems of communication and understanding, he proposed a method of group conversation, now known as Bohm Dialogue. In a Bohm Dialogue, participants speak and listen without agendas or debate, allowing meaning to emerge from the flow of communication. Bohm saw this as a practical application of his ideas: just as physics needs to recognize underlying continuity, people need open dialogue to rediscover the wholeness of ideas and relationships. Dialogues of Bohm with Krishnamurti and with psychologists were recorded (e.g. The Ending of Time, 1985) and have been influential for researchers of communication and group dynamics.

In science, Bohm’s implicate order implied that everything – including mind, matter and society – is grounded in the same fundamental process. He wrote that “reality is an unbroken wholeness in flowing movement,” and he called this flow the holomovement. In his later writings he even suggested that physical laws themselves might not be fixed forever but could evolve from this underlying order. His holistic philosophy was often described as metaphysical or visionary by outsiders, but for Bohm it was a logical extension of the quantum findings. Since quantum theory had shown particles to be innately connected (nonlocal entanglement), Bohm reasoned that the universe cannot be fundamentally composed of isolated bits. All apparent separations (in space, time, or conceptual categories) are secondary. At the deepest level, the world is enfolded into an indivisible whole.

Influence

David Bohm’s ideas have had a varied and growing influence in the decades since he introduced them. In physics, his hidden-variable interpretation forced theorists to take the conceptual foundations of quantum mechanics seriously. His work directly inspired John Bell, who in the 1960s proved that any theory reproducing quantum predictions must violate locality. Experimental tests of this finally came in the 1970s and 1980s (Aspect, Clauser, Zeilinger, and others), which confirmed quantum entanglement and the violation of Bell’s inequalities. In a real sense, Bell’s famous theorem and the ensuing experiments can be seen as extensions of Bohm’s challenge. Nobel Prizes awarded in 2022 to Aspect, Clauser and Zeilinger for entanglement trace their roots back to the questions Bohm raised.

More recently, there has been a revival of interest in Bohm’s approach within the quantum foundations community. Special journal issues and conferences (for example, “Emergent Quantum Mechanics” workshops) explore the de Broglie–Bohm theory and related ideas. Researchers have also noted parallels between Bohm’s pilot waves and new experiments in fluid dynamics: for instance, oil droplets bouncing on a vibrating surface can mimic “pilot-wave” behavior, providing a classical analogy to Bohm’s particles guided by waves. While not literally Bohm’s theory, these experiments demonstrate that particle-like trajectories guided by wave-fields are not just abstract math. In the field of quantum chemistry and atomic physics, practical numerical uses of Bohmian trajectories have been explored, providing insights into tunneling and reaction dynamics.

Outside physics, Bohm’s influence has been wide. His ideas have been taken up by philosophers of science interested in holistic and process-oriented metaphysics. He is often cited in discussions of consciousness and the mind-body problem, where his view that cognition might be tied to underlying fields resonates with some modern theories (such as quantum mind or informational field models). Bohm’s dialogue concept has been influential in fields like leadership, education, and organizational development: corporate and community groups around the world practice “Bohmian dialogue” to improve communication and creativity. In the intersection of science and spirituality, Bohm became a bridge figure: the Dalai Lama famously cited Bohm as his “science guru,” and dialogues between Bohm and spiritual teachers remain popular on the subjects of meaning and awareness.

Bohm’s legacy also includes literature and media. Several biographies and books (for example, David Peat’s Infinite Potential and Olival Freire Jr.’s A Life Dedicated to Understanding the Quantum World) have chronicled his life and thought. A documentary film (Infinite Potential, 2020) introduced his work to a new generation. The David Bohm Society and related organizations preserve his writings and foster events on his ideas. In academic physics, the Stanford Encyclopedia of Philosophy and other references now routinely mention Bohmian mechanics as a serious interpretation. Thus, while he never achieved mainstream fame like Einstein or Bohr, Bohm is remembered as a pioneer who expanded the conceptual horizons of 20th-century science.

Critiques and Controversies

Bohm’s theories have drawn criticism from various quarters. Physicists have pointed out that his approach is empirically indistinguishable from standard quantum mechanics, offering no new experimental predictions. To some, reintroducing deterministic trajectories and a quantum potential looks like adding unobservable machinery with no payoff. Moreover, the explicit nonlocality of Bohm’s theory is seen as a major drawback: it appears to conflict with the spirit of Einstein’s relativity. No one has yet formulated a fully satisfactory relativistic quantum field theory in Bohm’s framework that covers the range of the Standard Model and respects Lorentz invariance. Critics therefore argue that Bohmian mechanics, while consistent, has limited practical use in modern particle physics. (Supporters note that the same problem plagues all realistic nonlocal theories, and work toward de Broglie–Bohm quantum field theory is ongoing.)

What is more, many in the physics community found Bohm’s style and broader philosophy puzzling. By the 1960s and 70s, Bohm was not working on concrete lab predictions but on far-reaching ideas about thought and society. Some scientists viewed this as a leap into mysticism or New Age thinking. His emphasis on dialogue and Eastern philosophy struck many as unorthodox for a theoretical physicist. On the other hand, Bohm himself argued that these interests were necessary extensions of his scientific insights. Historically, his erstwhile colleagues (like Pauli and Bohr) simply thought his hidden-variable approach was a regressive step – returning to the notion of definite reality that they believed quantum theory had correctly sacrificed.

Nevertheless, Bohm’s supporters stress that his critiques of the Copenhagen orthodoxy were never answered in a satisfying way. He remained confident that the standard interpretation leaves important questions (e.g. the precise role of the observer, the meaning of the wave function) unresolved. By raising those issues, he inspired others to explore alternatives. In the end, Bohm’s picture stands as a reminder that quantum theory’s puzzles are conceptual as well as mathematical.

Legacy

Today, David Bohm is regarded as one of the most original thinkers of twentieth-century physics and philosophy. His ideas serve as a touchstone for anyone questioning the foundations of quantum mechanics or seeking a more coherent understanding of reality. Although he is not part of the scientific mainstream, his legacy lives on in the fact that a whole branch of physics literature (often dubbed “Bohmian mechanics” or “de Broglie–Bohm theory”) continues to be written and studied. Many textbooks on quantum foundations now mention Bohm’s interpretation, and new generations of physicists learn of it as a possible way to view quantum phenomena. The experiments that test quantum nonlocality are in part a realization of questions Bohm posed.

Outside science, Bohm’s influence persists in interdisciplinary fields. Ideas of wholeness and dialogue inspired by his work have impacted psychology, sociology and systems theory. Educators and consultants still teach Bohmian dialogue as a method for group communication. His notion that mind, society and matter share deep order resonates in some schools of consciousness research and in holistic philosophies. Even if some dismiss Bohm as too speculative, others see him as a “grand synthesizer” whose vision anticipated later trends toward unification in science and spirituality.

In recognition of Bohm’s contributions, the year 2017 marked his centenary. Scholarship continues to examine his life and thought. Numerous papers and books have been written on Bohm’s physics and on his dialogues with Krishnamurti. The popular press and media occasionally revisit his story. Overall, Bohm’s legacy is that of a relentless questioner: he refused to take any part of reality on faith, always probing deeper for unity beneath fragmentation. His work reminds us that the “unfinished” business he left – reconciling quantum laws with relativity, mind with matter, dividing lines in culture – is still with us to explore.

Selected Works

Quantum Theory (1951) – A textbook introducing quantum mechanics with philosophical commentary.
Causality and Chance in Modern Physics (1957) – A discussion of determinism, statistics, and the human outlook in science.
Wholeness and the Implicate Order (1980) – Bohm’s seminal work on the notion of an underlying unified reality.
The Ending of Time (1985, with J. Krishnamurti) – Transcripts of dialogues exploring mind and consciousness.
Science, Order and Creativity (1987, with F. David Peat) – Essays on science, society and new ways of thinking.
The Undivided Universe (1993, with B. J. Hiley) – A comprehensive exposition of Bohm’s quantum interpretation (published posthumously).
On Dialogue (1996) – A collection of talks outlining Bohmian dialogue methodology (edited Lee Nichol).

Timeline

1917 – Born in Wilkes-Barre, Pennsylvania (Dec. 20).
1939 – B.S. in engineering physics, Pennsylvania State College.
1943 – Ph.D. in physics, University of California, Berkeley. Works at Manhattan Project (Berkeley).
1946–51 – Assistant Professor of Physics at Princeton University.
1949–50 – Invoked Fifth Amendment before HUAC; loses Princeton position and U.S. citizenship.
1951 – Moves to Brazil as Professor at University of São Paulo.
1952 – Publishes two foundational papers on hidden-variables (pilot-wave) interpretation.
1957–61 – Research Fellowships in Israel (Technion) and UK (University of Bristol).
1961 – Appointed Professor of Theoretical Physics at Birkbeck College, London.
1976 – Publishes Fragmentation and Wholeness (prelude to Implicate Order).
1980 – Publishes Wholeness and the Implicate Order.
1985–86 – Publishes The Ending of Time and The Future of Humanity (dialogues with Krishnamurti).
1987 – Publishes Science, Order and Creativity (with Peat).
1990 – Elected Fellow of the Royal Society.
1992 – Dies in London (Oct. 27).