Werner Heisenberg occupies an ambivalent role in the history of physics. Working in Munich, Göttingen, Copenhagen and Leipzig in the 1920s and 30s, he was an intuitive genius who made crucial contributions to the development of quantum physics. In 1932 these earned him the Nobel Prize for Physics.

However during the Second World War, he was also drawn into the German war effort, leading development of their potential nuclear capabilities. This rather overshadowed his work in later life. Despite this, Heisenberg is best remembered for the uncertainty principle that takes his name and the fundamental impact it had on the way we understand reality.

Perhaps understandably, for such an influential figure, references to Heisenberg are frequent in science fiction.

 Heisenberg’s Uncertainty Principle

The uncertainty principle formulated by Heisenberg in 1927 can be expressed very simply: the more precisely we know the location of a quantum object, the less well we can know how rapidly it’s travelling and in which direction. The reverse is also true. In other words, if we make measurements and can say, with confidence, that an atom is precisely there, it’s probably moving so fast and in such a random direction that it’ll be lost again before we finish the sentence. Likewise if we can measure its speed and direction accurately, we might know where it’s going but not where it started from when the measurement was taken, so again cannot predict its future movement.

What is key to quantum physics is that this principle applies no matter how good our measurements and techniques become in the future - this uncertainty about position and momentum (or equivalently about energy and time) really is built into reality at a fundamental level. This is very different from the large-scale world we’re more familiar with in which observations can give precise measurements of many things simultaneously. In more technical terms, the macroscopic world is deterministic (the fate of objects can be determined), while the quantum world is probabilistic (the likelihood of different fates can be estimated but, until another measurement is made, which occurs remains uncertain).

Together with the other famous quantum thought experiment, Schrodinger’s Cat, the uncertainty principle articulates an aspect of a wider paradigm in quantum physics: that it is impossible to observe a system without changing the system under observation. In this context, it’s impossible to measure a position or velocity without observing it - for example by bouncing photons off it. Each of those photons itself imparts a tiny force, and so their impact changes the observed position or velocity of the test particle leading to the increased uncertainty. The more precise the measurement desired, the more photons need to be used, and the less accurate the result in the other quantity. The translation of this from the atomic scales to macroscopic consequences is challenging, but this has not prevented a number of science fiction authors from exploring the possible consequences.

Heisenberg Compensators

Perhaps one of the best known science fictions to address Heisenberg’s uncertainty principle - and one to do so most directly - is the Star Trek universe. Originally intended as a simple way to avoid long and tedious shuttlecraft sequences, the matter transporters of this universe are described as dissociating the molecules of the traveller at the point of departure, recording and transmitting a “pattern”, and using this pattern to reconstruct the traveller at the other end of the journey. As many people have pointed out over the years, this is philosophically difficult (requiring us to address the existence and encodability of the soul, and whether the original is killed during every transport), as well as a technical challenge.

Setting aside the tricky question of how matter is reconstructed at the destination of one-directional transports, or where the matter in question comes from, the idea of creating a storable pattern (or perhaps wavefunction) that accurately describes the location and state of every particle in a human (or Vulcan or Other) body is in fundamental violation of the uncertainty principle. If every atom in a reconstructed body is placed precisely next to its neighbours on a quantum scale (as would be required for life), the uncertainty on momentum would require that the body would fly apart in a nuclear explosion a fraction of time later.

As a result, all Star Trek canon material since Star Trek: The Next Generation (TV, 1987-1994) has described “Heisenberg compensators” as an essential component of transporter devices. These have the effect of circumventing the uncertainty principle within the transportation field, although their mechanism is firmly in Clarke’s Law [1] territory. Indeed, this issue gave rise to a famous quotation:

Asked “How do Heisenberg compensators work?” by Time Magazine in 1994, ST:TNG technical advisor Michael Okuda simply replied “they work very well, thank you.”

The Eyes of Heisenberg 

The concept of uncertainty on a molecular scale formed a key element of Frank Herbert’s 1966 novel The Eyes of Heisenberg (originally serialised in Galaxy magazine the same year). The story focuses on a future society in which humanity has divided into a rigid hierarchy between long-lived, near-perfect but sterile Optimen and oppressed, carefully managed but occasionally fertile Folk. The Optimen control the rare permissions for reproduction and order “cutting” - that is genetic editing - of every viable embryo. Occasionally this leads to the production of another Optiman (or woman). More often the goal is maintaining the low average potential of the Folk population. The story focuses on the aftermath when a cutting operation, together with a fluke event, accidentally produces a genius-level, optimal and fertile (hence potentially true-breeding) embryo. Two of the genetic surgeons explicitly discuss this event in the context of the uncertainty principle:

“You’d like to lay it to uncertainty, to Heisenberg,” Potter said. “The principle of uncertainty. Some result of our own meddling. Everything an accident in the capricious universe.”

[...]

Svengaard glared at Potter. The man was mocking him. He spoke stiffly: “Heisenberg did point out that we have our limits.”

“You’re right,” Potter said. “There’s a caprice in our universe. He taught us that. There’s always something we can’t interpret or understand… or measure."

While the leading Optimen are determined the new embryo should be destroyed to maintain the status quo, and a (rather bizarre) cyborg faction are determined to use it against them, the Folk parents simply wish for their unborn child to be protected.

Quite honestly, the first half of the story, which focuses on the gene editing sequence, is stronger than the second, in which the consequences of what happened ripple outwards. Throughout though, the story is focused on the impact of possible change on society and individuals. The story ends just a few days after the embryo’s conception - long before it matures - with its mere existence producing a vast impact on the society into which it will be born. The nature of quantum uncertainty as a source of randomness on a macro scale is explored both through anomalies in the carefully genetically-edited population and in its impact on the rigidity of the society.

Another example of DNA manipulation invoking the uncertainty principle is Heisenberg is Dead by Richard Ashby (short story, Vertigo, Feb 1974). This concerns a scientist who makes a breakthrough in direct gene editing, only to find no one can reproduce his results. Indeed, the success of his technique proves to be a result of his own centuries of breeding as an African witch doctor, rather than a product of his very real scientific credentials. The relevance of the uncertainty principle to the actual application is a little oblique here and refers to the reproducibility of experimental results, since quantum physics suggests that the act of measurement changes the result and so it cannot be reliably reproduced. Technically this is a statement of the observer effect rather than Heisenberg’s uncertainty principle in itself (which is somewhat misquoted by the author), but draws from the same probabilistic and wave-function based paradigm of quantum physics. 

Heisenberg Visions

The pivotal role of Heisenberg’s uncertainty principle in quantum physics leads to its appearance in a number of other science fiction narratives. Jack of Eagles by James Blish (novel, 1952) follows the experiences of a normal man who gradually learns to control unexpected psi powers. The equations of quantum physics prove to be key to this process, giving him a way to visualise the manipulation of his abilities, and perhaps even hinting at their underlying nature. The mathematical formalism of Heisenberg’s uncertainty principle, in the form that a combination of coordinate and momentum must exceed a multiple of Planck’s constant, h, is pondered at length, and (stepping beyond the physics) the main character hypothesises that a vast number of parallel worlds might be separated by slightly different values of that constant. Evidently, the connection with psi powers is pure science fiction (verging on fantasy [2]), and the physics principles quoted are simplified for the readers, but it’s interesting to see Blish go as far as presenting the Heisenberg’s uncertainty equation in algebraic form in his novel.

By contrast, the problem in M K Joseph’s novel The Hole in the Zero (1967) is external. Here, the universe is encroached upon by another realm, in which physical laws break down and alternate probabilities are played out (either physically or psychologically). When a wealthy crime-baron entrepreneur, his daughter and lead henchman decide to go on a sight-seeing excursion into this realm, taking a border warden with them, all four become trapped and their personal realities become mingled and confused when their so-called Heisenberg shields fail. Their combined wills shape scenarios ranging from mediaeval to mythic and futuristic. The shields are not described in detail but are clearly limited and power-hungry - indeed the warden character expresses amazement that such shields can be fitted to a larger-than-usual private vessel. Here the Heisenberg shields are occupying much the same conceptual space as Star Trek’s Heisenberg compensators - they are attempting to suppress the uncertainty and randomness that comes with the quantum mechanical understanding of the nature of the Universe.

Heisenbergs Everywhere

Isaac Asimov, in his humorous short story Thiotimoline and the Space Age (Astounding SF, Oct 1960) [3], also invoked the name of Heisenberg without direct reference to the uncertainty principle. Here he imagines a device which triggers a reaction before the event that causes it - a real problem in an indeterminate universe. Ever more complex experiments to try to demonstrate a “Heisenberg failure” - a signal of reaction seen when the eventual cause is prevented from occurring - leads to increasingly unlikely and disastrous incidents disrupting the experiment. These ensure the trigger is given (whether or not the experimenters intend it), preventing the paradox.

Heisenberg also appears in science fiction as a starship name - recognising his role as one of the leading quantum physicists of the twentieth century. Examples of vessels or characters named after Heisenberg can be found in the Star Trek universe (although in the non-canonical world of novels and games). The name also appears in science fiction critic and essayist Norman Spinrad’s 1979 novel A World Between, where it is used by the "Transcendental Sciences Institute" for one of their Arkologies - an artificial planetoid used to spread the Institute’s philosophy between planets [5]. The novel describes the arrival of the “Pink and Blue War” between male-dominated Transcendental Scientists and entirely female Femocrats (who keep genetically degenerate males only for breeding) on the peaceful world of Pacifica. In this context, the name Heisenberg is one of a number of scientists (others arkologies mentioned include Einstein and Planck) used to emphasise the traditionally male-dominance of the physical sciences, although by the end of the novel, it is clear that the Pacifican middle path has clear advantages, including in the sciences themselves.

Inevitably a final strand of Heisenberg stories in science fiction results from his wartime role in the German nuclear effort. As I’ve already discussed in previous blogs, alternate histories of wartime scientific innovation are relatively common in science fiction, with many of them focussing on a key scientific breakthrough: the production of an atomic bomb by the Manhattan Project. Since Heisenberg was the director of the equivalent German effort (and has sometimes been credited with its slow progress - either through incompetence or deliberate action), he often features in stories where this effort was delayed or otherwise unfolded differently.

He appears, for example, in Gregory Benford’s The Berlin Project (novel, 2017, in which atomic weapons are developed more quickly and are used against Germany in 1944) and in Alan Steele’s VS Day (in which the focus is instead on rocketry rather than nuclear weapons). In the same vein, the 2015 Amazon Prime television adaptation of Philip K Dick’s alternate novel The Man in the High Castle (novel, 1962) describes the atomic weapons with which Nazi Germany won the war as Heisenbergs (although this name was not used in the novel). More detailed analysis of Heisenberg appears in the short story Absolute Uncertainty by Lucy Sussex (appearing in Fantasy and Science Fiction magazine in April 2001). This narrative imagines a future “Biocultural Studies 101” university course, in which the students use a detailed simulation of Werner Heisenberg to explore “moral ambiguities and the limits of biography”. The students draw on key events in Heisenberg’s life, simulating possible or known encounters in order to try and understand Heisenberg’s moral position. The story ends with the culpability of Heisenberg for his wartime efforts on behalf of the Nazi party still judged uncertain.

By contrast, Something Real by Rick Wilber (short story, Asimov’s, April 2012) imagines an alternative history in which history appears to have diverged from ours in 1938 and Heisenberg ultimately decides on a different target for his super-bomb. As well as exploring moral ambiguity, the story plays on the multiverse theory of quantum mechanics and its relation to the uncertainty principle. Like several of the other explorations of this period mentioned above (including Absolute Uncertainty) the focal point of the story is Heisenberg’s December 1944 visit to deliver a lecture on S-Matrix theory at ETH Zurich in our own timeline, and his encounter there with American baseball player-come-spy Moe Berg.

Berg had been sent to assess the progress towards a German atom bomb and assassinate Heisenberg if that was deemed necessary. While in our history Berg decided against assassination, the key moment of decision provides fertile ground for parallel world speculation. This is also the case in Kristine Kathryn Rusch’s short story Uncertainty (Asimov’s, March 2013 [4]). Where Wilber had written about a female agent present at the Zurich lecture, jumping between parallel realities and trying to influence them, Rusch also imagined a female agent present at the lecture, but sent from the future. Here ill-advised time-travelling historians have accidentally destroyed their own timeline, and the agent, together with others, must work to restore the “river of time” to the path it originally followed. The Second World War, and particularly the role of Heisenberg and other quantum physicists, is key to the direction of that river and its modification.

Shadows of Heisenberg 

Science fiction has always celebrated the names of great scientists and seized upon their discoveries for inspiration. Heisenberg, together with the other early quantum physicists, redefined our picture of the nature of the Universe. His uncertainty principle provided a clear and comprehensible statement of this nature, as well as articulating a mathematical truth that underlies phenomena from the quantum scale to the explosion of stars as Type Ia supernovae. It was inevitable that he should appear in science fiction - as an individual, as a discoverer and as an object lesson in the misuse of scientific knowledge.

However it should be noted that in a number of cases the uncertainty principle is misstated, or confused with other aspects of quantum physics. Heisenberg’s name is also invoked in scenarios which have little connection with his work. It is easy for such misinformation to spread, and corrupt public understanding of the truth. It is perhaps fortunate that by far the best known application of Heisenberg’s shadow in science fiction - the Heisenberg compensators that enable every Star Trek transporter - is one of the most accurate.

Heisenberg’s legacy will always be a complex one. He is just one example of a scientist whose name lives on in both his discoveries and in popular culture. With the Star Trek universe producing ever new spin-offs and histories, no doubt Heisenberg’s name will remain unforgotten.