Part I:
“Ursula K. Le Guin and the Ansible” by Theo Downes-Le Guin

My mother coined the term “ansible” in her debut novel Rocannon's World (1965). The ansible is a sort of interstellar SMS, a communications device limited to short, instantaneous text exchanged across very long distances. The novel's titular character, stranded on a planet to which he was assigned as an ethnologist, describes a technology no longer available to him: “You remember the ansible, the big machine I showed you in the ship, which can speak instantly to other worlds, with no loss of years…” The ansible went on to play an important role in Ursula's Hainish novels and stories, which center on interstellar human colonies (including our own) established by a technologically sophisticated species called the Hain. The Hainish works include some of her best-known writing, such as The Left Hand of Darkness (1969) and the story “Vaster than Empires and More Slow” (1971).

After Rocannon's World, Ursula returned to the ansible in City of Illusions (1967), in which faster-than-light (FTL) travel for autonomous, non-crewed spacecraft also appears. ( In these and later books, life forms can only travel nearly as fast as light (NAFAL): “Lightspeed, with its foreshortening of time for the voyager, was the limit of human voyaging, then and now.”) Over a decade, she articulated the capabilities and limitations of the ansible across numerous novels and stories: any two ansibles may communicate, but only one can be in motion—either the sending or receiving ansible must have fixed coordinates, and one must be on a large-mass body. The Left Hand of Darkness elaborates on ansible science as Genly Ai, a Terran envoy to the planet Gethen, attempts to convey to a bored and suspicious king how the tech works:

“It doesn't involve radio waves, or any form of energy. The principle it works on, the constant of simultaneity, is analogous in some ways to gravity…What it does, sir, is produce a message at any two points simultaneously. Anywhere. One point has to be fixed, on a planet of a certain mass, but the other end is portable…A NAFAL ship takes 67 years to go between Gethen and Hain, but if I write a message on that keyboard it will be received on Hain at the same moment as I write it. ”

While Ursula never contradicted her early definitions of the ansible, she tinkered over time. In the story “Vaster than Empires and More Slow” she imposed a final limitation: “Cosmic mass interference” makes instantaneous communication reliable only within a range of 120 lightyears. Ursula didn't fetishize high technology, so none of her descriptions go into detail about the ansible's industrial design, other than to indicate that it uses a keyboard and a display. The device size seems to vary, possibly getting smaller after Rocannon's World as the tech proliferates across the Hainish worlds.

Ursula didn't care to create a clear, linear chronology of the Hainish civilizations' development, so whatever we can infer about the ansible's development timeline is rough, and doesn't match the order of publication of the books and stories. The Dispossessed (1974) was published nine years after the ansible's first mention in Rocannon's World, but it is only in the former that we learn a bit about the science behind the ansible. The physicist Shevek fears that a theory he has developed might be used by others to develop FTL space travel or weaponry. But, knowing his theory better than those who seek to co-opt it, he realizes that instantaneous communication will be easier to achieve:

“What they want,” he said, “is the instantaneous transferral of matter across space. Transilience. Space travel, you see, without traversal of space or lapse of time. They may arrive at it yet; not from my equations, I think. But they can make the ansible, with my equations, if they want it.”

For the writer, the ansible was above all an extremely useful literary device. To tell stories that involve relationships between species existing light years apart, writers must either resort to “rubber science” solutions that permit rapid FTL travel for life forms, or provide for some form of instantaneous communication. Much of science fiction, including Ursula's, hews to our current understanding that life forms might travel long distances via some kind of hibernation technology, but cannot travel faster than light. With this constraint, an inability to communicate with “home” or with other beings beyond the reach of voice or radio would severely limit imaginative possibilities and pose narrative challenges. How do you advance a story at a pleasing pace for the reader when an interstellar communication arrives millennia after it is sent, perhaps after both sender and receiver have died?

In the Hainish stories, for example, Ursula's League of Worlds and Ekumen imagine societies that exchange knowledge and goods in a more or less timely fashion. These exchanges are possible only if far-apart societies have a way to share information instantaneously, establishing a need, opportunity, or conflict that eventually leads to physical connections. As well, the ansible posits a certain level of sophistication in a society—a theory of physics and high technology—that can be used narratively to differentiate people and societies, to create perceived threat for differently tech-enabled peoples (as in The Left Hand of Darkness), or to create a source of aspiration for a less tech-enabled civilization that wishes to seek community with more “advanced” civilizations.

Ursula used the arrival or destruction of ansible technology, to a planet or society, to great effect. Rocannon's loss of access to an ansible effectively cuts him off from his home and his original purpose, leading the character down a radically different narrative path. In The Word for World is Forest (1972), Ursula explores how the introduction of an ansible might affect and change behaviors on remote planets or colonies, both for “locals” and visitors. Early in the novel, anthropologist Raj Lyubov observes how the introduction of the ansible affected the behavior of the Terran powers that have dispatched him to “New Tahiti” (as the colonists name it):

“Reports home meant something, now that this ansible, this machina ex machina, functioned to prevent all the comfortable old colonial autonomy, and make you answerable within your own lifetime for what you did. There was no more fifty-four-year margin for error. Policy was no longer static. A decision by the League of Worlds might now lead overnight to the colony's being limited to one Land, or forbidden to cut trees, or encouraged to kill natives—no telling.”

Other narrative possibilities opened up as Ursula explored how communication sent and received need not be communication answered. In The Telling (2000), a monotheistic Terran ruling party chooses to cut off ansible contact with authorities on Hain, in order to assert independence and exercise power in secret.

Although Ursula is sometimes credited as the inventor of the idea of instantaneous FTL communication in fiction, she was not the first to imagine it. In Jack Williamson's 1944 novel The Humanoids, “rhodomagnetic waves” are a source of energy based on a triad of rhodium, palladium, and silver, which are used by an intergalactic human diaspora to make weapons and to facilitate telepathic communications. Frank Herbert, in the 1969 novel Whipping Star, takes an organic approach, in which a symbiotic species called Taprisiots can telepathically project at intergalactic distances from a “user” to which they attach. The Dirac Communicator, in James Blish's 1954 story “The Beep,” allows instantaneous and FTL communication by sending a signal into a timeless, deterministic null-dimension where every message from past, present, and future exists simultaneously. (I don't know which, if any, of these Ursula read, but I see a faint echo of The Dirac Communicator in the fact that the ansible is a device, not a form of telepathy, and produces a message at two points simultaneously.) Proving the durable usefulness of the literary device, later generations of writers have continued to employ the ansible, adjusting its capabilities or the name to their needs. In Orson Scott Card's Ender's Game (1985), for example, the ansible is a crucial technology in the climax of the novel, a battle between the insect-like “buggers” and humans in space.

I'm struck by how the etymology of the word “ansible” is often what people ask about first. A note in Ursula's archive (brought to my attention by scholar Michael Everson) indicates that the original placeholder name for the ansible was “whatsit.” In a 2001 Usenet post, Dave Goldman wrote that Ursula told him that ansible is a contraction and modification based on “answerable.” I don't know how she went from “whatsit” to ansible, though Goldman's version seems quite credible. The fact that ansible is an anagram of “lesbian” was a source of amusement for Ursula, but I'm as certain as I can be that this was not in her mind when she invented the word (contrary to some people's assertions). This wasn't her style of neologism, and has no relevance to the novel in which the ansible first appears. In the final analysis, however, I'm not sure what we call it matters too much: like so many of my mother's ideas, the ansible has proven to be versatile, profound, and often—in its flexible elusiveness—quite funny.

Part II:
“Modern Physics and the Ansible” by Claire Isabel Webb

Faster-than-light (FTL) communication breaks the laws of physics as we know them. Albert Einstein's 1905 paper that famously introduced the concept of special relativity demonstrated that any object or information that were to exceed c, the speed of light, would violate causality — the concept that time is linear, and that events unfold according to those that precede them. In FTL, though, past, present, and future would blur together, creating paradoxes in spacetime. If you sent a telegram faster than c you would have received the message before you even sent it. Faster-than-light technologies would produce other cosmic conundrums, for instance, the ability to travel back in time to kill an ancestor before they had children — children who would have led to your very existence. (If you were never born, who would go back in time?)

In science fiction, a technology called an ansible allows for FTL. It is a key literary device that renowned writer Ursula K. Le Guin uses to explore how characters would exchange messages at very large distances. In our familiar physics, photons, quanta of light, hurtle through a vacuum at nearly 300 million meters per second, but the light from our Sun still takes eight minutes to reach Earth because of its speed limit. But in Le Guin's work, the ansible allows for nearly instantaneous communication. Her characters can send each other messages between planets, to spaceships, and indeed, anywhere in the universe.

The ansible could operate by fudging a fundamental aspect of the quantum world as we know it today: entanglement. When Le Guin began writing fiction in the late 1960s, entanglement was relatively new. In the 1930s, Einstein and father of quantum, German physicist Niels Bohr, bitterly debated its existence. What Einstein disparaged as “spooky action at a distance” described the perplexing fact that the characteristics of one particle, say, its spin (up or down), instantly corresponded to that of another — breaking the laws of light he had laid out two decades earlier. At the Institute for Advanced Studies in Princeton, along with his colleagues Nathan Rosen and Boris Podolsky, Einstein argued in a 1935 paper that quantum entanglement was impossible based on the conservation of energy and momentum of all matter. Bohr undermined a key assumption in a riposte he published just months later.

Fundamental to the field of quantum mechanics Bohr had helped define is that the very measurement of a particle defines its characteristic such as spin (and its companion's spin). Until one makes the measurement, it is both spin up and spin down, a state called “superpositioning.” Superpositioning only exists before the act of measurement, and the measurement itself collapses the simultaneous doubleness of spin up or spin down. Erwin Schrödinger's cat in the box (a “burlesque” analogy, as the physicist put it) is both alive and dead — until you open the lid.

Entanglement seems baffling, but over and over again, it explains how the quantum world of particles operates. Over the decades, physicists have shown that there are no “local hidden variables” that would only make it appear as though particles are entangled. They are not secretly connected in the classical sense, like two ends of a jump rope, and the experiments aren't flawed. There are no underlying but unperceived mechanisms.

A recent experiment, “Cosmic Bell” affirms this at awesome distances. Researchers observed two galaxies at opposite ends of the universe. Because of the speed of light, galaxies that are billions of light years away from Earth are also billions of years old. Quasars are galaxies of that early universe; they are very far away, and therefore very old. What the scientists found is that the light from quasar 1 and quasar 2 behave the same way. They are entangled. This demonstrates that quantum entanglement of light is a property that existed at the beginning of the Big Bang.

In Le Guin's fiction, the ansible leverages this property we know exists. But it violates the laws of physics because in her universe, the ansible is engineered to modify information at a quantum level. Superpositioning exists in harmony with the observation. Encoding a message in one ansible would instantaneously communicate that message to the ansible's companion anywhere in the universe.