Science in Society Archive

Life & the Universe After the Copenhagen Interpretation

The ultimate reality beyond the Copenhagen interpretation of quantum mechanics is also beyond ordinary physics. Dr. Mae-Wan Ho

The quest for the ultimate reality of nature

Atoms and elementary particles are the ‘stuff’ of nature, as far as western science is concerned. Thousands of years have been dedicated to the scientific quest of discovering the most fundamental particles of matter and to explaining nature in terms of those particles.

In a way, the quest came to an end when Max Planck identified the smallest quantum of action in the constant named after him [1], and quantum mechanics was born. 

The ‘Copenhagen interpretation’ was the first general attempt to understand quantum mechanics in terms of atoms and elementary particles [2, 3]. It was the work of Danish physicist Niels Bohr together with Werner Heisenberg and Max Born from Germany and others who made important contributions. However, Bohr and Heisenberg never agreed on how the mathematical formalism of quantum mechanics should be interpreted, and there is no definitive statement of the Copenhagen interpretation.

The Copenhagen interpretation and the measurement problem

Nevertheless, the Copenhagen interpretation is widely regarded as consisting of the following elements.

  1. A system is completely described by a wave function that represents an observer’s knowledge of the system.
  2. The description of nature in quantum mechanics is essentially probabilistic as opposed to deterministic in classical physics.
  3. Heisenberg’s uncertainty principle ensures that it is impossible to know the values of all the properties of the system at the same time; and those properties that are not known with precision must be described by probabilities.
  4. Matter exhibits a wave-particle duality; an experiment can show up the particle-like or the wave-like behaviour of matter, but not both at the same time.
  5. Measuring devices are essentially classical devices, and measure classical properties such as position and momentum.
  6. The Correspondence Principle says that quantum mechanical description of large systems should closely approximate the classical description.

Most notably, the Copenhagen interpretation denies that the mathematical formalism of quantum mechanics has anything to say about what nature is really like, in particular, as regards the central problem of measurement. The wave function of a physical system evolves, according to the Schrödinger equation, into a linear superposition (combination) of different quantum states encompassing all possibilities. But actual measurement always finds the physical system in a definite state; and this is referred to as “the collapse of the wave function.” The paradox is usually presented as the parable of Schrödinger’s cat [4] (see Quantum World Coming series, Science in Society 22), imprisoned in a box with a capsule of deadly cyanide gas that would be released the moment a radioactive nuclide decays. The cat is therefore in a superposition of being alive, being dead, and being both alive and dead at the same time until the box is opened, i.e., a measurement is performed; at which instant, the cat is either dead, or alive.

There is thus a complete discontinuity between the evolution of the wave function and the measurement, what happens in the measurement that converts the probabilities to an actual, sharply defined outcome is not explained by the theory. The Copenhagen interpretation says we must not even ask that question, which is meaningless. As Aage Petersen said in paraphrasing Niels Bohr [3]: “There is no quantum world. There is only an abstract physical description. It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.” And what we can say is not how nature really is.

The central problem of measurement has provoked many alternative interpretations of quantum mechanics, some of which takes us to the realm of ultimate reality, well beyond what ordinary physics can say.

Mohrhoff’s ultimate reality is eternal and unchanging and without properties

Ulrich Mohrhoff at Sri Aurobindo International Centre of Education, Pondicherry, India, has presented one interpretation of quantum mechanics that is rather appealing [4] (Beyond the Central Dogma of Physics, this series). He departs from the Copenhagen interpretation in so far as he rejects the ‘evolutionary paradigm’ of the wave function, and the ‘collapse’ of the wave function on measurement. He goes beyond the Copenhagen interpretation as well as classical physics in rejecting the usual description of reality in terms of atoms, particles or ‘things’ underlying “manifest” phenomena.

Mohrhoff goes beyond science into the realm of Indian Vedantic philosophy when he takes nature as One Being without properties, manifesting as “multiplicities” that enter into spatial relations with itself, thereby “giving rise to [the semblance of] both matter and space”. Or, as he qualifies in a later communication [5]: “The multiplicity qua nothing but multiplicity is an illusion. The multiplicity as a result of the One’s entering into relations with itself, presenting itself to itself under a multitude of aspects, is not.” Of course, it is not possible to test such an assertion, and it does remain in the realm of belief, or cosmogony.

Mohrhoff rejects evolution in the usual sense of the word. To him, the One (ultimate) Being is “ineffable” and “infinite”, if not eternal and unchanging. It “plays Houdini” with itself for the ‘fun’ and ‘excitement’ of it, manifesting as “the Adventure of Evolution” [5].

In my opinion, the Mohrhoff interpretation is not entirely self-consistent. A major difficulty is in seeing how the One Being without properties can conform to the mathematical formalism of quantum mechanics, which is quite specific as well as paradoxical. This tells me that there is nothing arbitrary about nature, i.e., it would argue against a nature without properties, or, for that matter, a capricious God or Deity that merely “plays Houdini”.

Mohrhoff has later clarified [5] he does not believe “there is anything arbitrary about the physical laws.”  Nature as world does have properties, he says, but as “force responsible for the existence of properties does not itself have properties.”

He then takes me to task for proposing that the universe is quantum coherent [5] (see below). But ultimately, we are in total agreement when he says, “I believe that none of the interpretative frameworks of our present consciousness has an exclusive claim to truth.”

For me, the overriding importance is how contemporary western science has recovered the unity of nature that has been taken for granted by indigenous knowledge systems worldwide. And that is more than sufficient basis for a new world order and transformation towards a better, more enlightened and equitable world.

The ultimate reality of a participatory creative universe

My own starting point is also as a critic of the Copenhagen school of quantum mechanics, and not as one who wants to defend or popularise it, as a casual reading of Mohrhoff’s critique of my statements taken out of context might be misled into thinking.

I too have argued against the collapse of the wave function [6, 7] ( Quantum Coherence and Conscious Experience, ISIS scientific publication; The Rainbow and the Worm - The Physics of Organisms 2nd Edition ), but from a different scientific perspective. I go beyond conventional quantum mechanics in proposing, on the basis of empirical evidence as well as theoretical considerations, that the organism tends towards a “superposition of coherent space-time modes (i.e., activities)”; and that the universe itself may also be quantum coherent, like a superorganism, consisting of organisms that are mutually entangled in such a way that each organism participates in every other [8] ( Quantum Jazz, the Tao of Physics, this series). In this, I follow in the footsteps of Alfred North Whitehead, who had argued persuasively that quantum theory requires a thoroughly organic interpretation [9]. He saw the entire universe as being composed of organisms ranging from elementary particles to galaxies, although he had not considered quantum coherence, a universal wholeness, which I believe necessary to complete his picture.

Indeed, there is now experimental evidence that the wave function does not collapse, and entangled states may survive ‘measurements’ or interactions with macroscopic devices and scientists other than myself are suggesting that the universe itself may be quantum coherent. So the Copenhagen interpretation may be wrong, or at best incomplete; and one can reject it and still be agnostic about the nature of ultimate reality.

But I too, go beyond ordinary physics to the meaning of life and the universe. I reject the notion that science, as knowledge of nature, is divorced from life and the meaning of life. I see the universe developing and evolving, with every organism participating, constantly creating and recreating itself anew. It is a truly creative universe in that the future is not preordained, but spontaneously and freely made by every single being, from elementary particles to galaxies, from microbes to the giant redwood trees, all mutually entangled in a universal wave function that never collapses, but like a constantly changing cosmic consciousness, maintains and informs the universal whole.

Article first published 30/04/07


References

  1. Planck M. Nobel Lecture, 2 June 1920, Nobelprize.org, http://nobelprize.org/nobel_prizes/physics/laureates/1918/planck-lecture.html
  2. Copenhagen Interpretation of Quantum Mechanics, 3 May 2002, Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/qm-copenhagen/
  3. Copenhagen interpretation. Wikipedia, http://en.wikipedia.org/wiki/Copenhagen_interpretation
  4. Mohrhoff U. Beyond the Central Dogma of physics. Science in Society 34 (in press).
  5. Mohrhoff U. Comment to Mae-Wan Ho, 6 April 2007.
  6. Ho MW. Quantum coherence and conscious experience. Kybernetes 1997, 26, 265-76.
  7. Ho MW. The Rainbow and the Worm, The Physics of Organisms, 1st ed, 1993; 2nd ed., World Scientific, Singapore, 1998, reprinted 1999, 2002, 2003, 2005, 2006.
  8. Ho MW. Quantum jazz, the tao of biology. Science in Society 34 (in press).
  9. Whitehead AN. Science and the Modern World, Penguin Books, Harmondsworth, 1925.

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