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Introduction: The Cold Equations

David Hartwell holds up Tom Godwin's "The Cold Equations" as an iconic representation of the "hard" science fiction genre. This story is built around the following core statement:

A physical law decreed: h amount of fuel will power an EDS with a mass of m safely to its destination; and a second physical law had decreed: h amount of fuel will not power an EDS with a mass of m plus x safely to its destination. (p. 210)

The action of the story revolves around the decision of Barton, the pilot of an emergency dispatch shuttle (EDS), when he discovers a stowaway on his ship. Barton's shuttle has been dispatched to deliver critical medicine to Team Two, one of the outposts on the planet Woden. EDS ships are sent out with an exact amount of fuel; there is just enough to safely carry the shuttle, its cargo, and its pilot to the destination. When Marilyn (the stowaway) is discovered, Barton faces a problem: the laws of his job state that any stowaway is to be immediately jettisoned, or else the ship will not have the proper fuel to reach its landing. There are to be no exceptions, but Barton is moved to compassion by Marilyn's innocence and by the fact that she is female.

Marilyn hides herself on the EDS pod in order to visit her brother, a member of Team One on the other side of Woden. She comes onto Barton's ship not knowing the consequences of her trespass. Barton tries unsuccessfully to find a solution that allows Marilyn to live. He contacts his mothership, the Stardust, but the officers there are uncompromising, saying they are powerless to help. Barton explains the situation fully to Marilyn, and he stalls on jettisoning her as long as he can. Marilyn calls her brother Gerry on the planet Woden during their approach, and her brother begs Barton to do something to save his sister, but he eventually realizes that nothing can be done.

After the conversation ends, Marilyn gives herself up to be jettisoned. Barton does not have to force her; she accepts her fate. She is jettisoned, and the shuttle is able to continue safely. According to Barton, a "cold equation" has been balanced. Marilyn dies not in punishment for a heinous crime, but for her ignorance of the physical "laws" of space travel. Barton constantly asserts that nothing could have been done to save her.


This is a highly provocative story, and it has been touted as "the touchstone of hard-core science fiction" by James Gunn, editor of The Road to Science Fiction, Vol. 3, a collection that features the story (p. 198). Hartwell asserts that a reader must accept "The Cold Equations" if he is to read any story of hard science fiction, because the story is a metaphor for reading hard SF in general (p. 199). In hard SF, the story must be a cold extrapolation of precise scientific laws, and any departure from this formula is the basis for a reclassification as a "softer" form of fantastic fiction.

These are "The Cold Equations" which fuel Godwin's story. The story is not just an acknowledgement of the cold brutality of the laws of the universe; it is a celebration of these laws. In celebrating the laws of space through his narrator Barton, Godwin fails to sufficiently explore the possibilities for Marilyn's salvation. This failure undermines the characterization of Barton as empathetic and compassionate; his decision is not justified given both his feeble attempts to find a compassionate alternative and his reasoning behind condemning her to death. Barton does not attempt to devise additional ways to save his stowaway; instead, he is limited by his trained devotion to the "laws" of space, and his training unreasonably overcomes his compassion. Godwin establishes binary oppositions that reinforce Barton's belief in his own helplessness. The oversimplified conflict between "compassion" (on one hand) and "adherence to the laws of the frontier" (on the other) is never transcended in the pilot's actions. His paradigm renders him sexist, and he condemns Marilyn to death.

Binary Oppositions

Barton's reasoning and motivation reveal a system of binary oppositions lined up to support his unwavering devotion to the laws of the frontier. Two elements are always directly opposed, and these sets are lined up to make a coherent belief structure that indicates Barton's paradigmatic system of thinking. Cold/warm, space/Earth, hard/soft, and male/female are the four component binaries of the schema that blinds him to any real hope of saving Marilyn.

The opposition of cold and warmth is the first to come up, initially introduced with the title, and then repeated twice in the story. The coldness refers both to sentiment and temperature, and it is expressed in each of these ways. When the man from Team Two on Woden asks if there is anything else he can do, Barton says "No, no you can't"; Marilyn then asks if it's cold in the shuttle (pp. 215-6). The despair and unfeeling forces of nature dictating her situation are represented in the story through a mentioning of the decrease in temperature in the shuttle, which the pilot confirms. The shuttle is not a warm place, one of compassion, but a cold place, controlled by the laws of space. The environment of the ship confirms the unfeeling atmosphere of space.

Barton contrasts the frontier, "where the lives of men could be fragile and fleeting," with Earth, the world of "soft winds and warm suns." Thus, since men are of the frontier, women are of Earth (p. 211). Our main characters are Marilyn, a female from Earth, familiar with its ways, and Barton, a male who knows and lives by the ways of the space frontier. Earth is the place of softness and warmth versus the hard cold of space, and thus the cold of "the cold equations," where reason triumphs over sentiment. Nature does not have feelings, and laws of nature do not have feelings; they are just variables and equations to be balanced. A mathematic equation doesn't care about the feelings of a number when it is canceled out in an equation. Barton says "men" here rather than "man," which is closer to gender-neutral in usage. This is part of a gendering of space in the story.

Godwin's space is a male place, a "boys only" club, and it is because Marilyn is out of her world and does not know the way of the frontier that she must die. Barton is conflicted by sentiment, which has no place on the frontier. His schema creates a misogynistic paradigm that leads him to justify her murder. With men on the side of space in the binary system, women are neither presumed nor allowed to know the ways of the frontier. Their place is in the safety of Earth, not the expanse of space, and by transgressing into male space in the frontier Marilyn violates its laws and is doomed to a cold death.

Barton feels he is merely following the way of the frontier; he is being pragmatic in his devotion in order to protect himself and the men of Team One who need the medicine that causes the entire incident. The way of the frontier includes a utilitarian reasoning that dictates the needs of the many outweigh the needs of the few. Barton values his life and the lives of the men on Team One more than Marilyn's, weighing one life against seven. As a result of adhering to these beliefs, he has cut himself off from the other side of the binaries; he is not able or willing to act more effectively on his compassion for the innocent Marilyn. He has sacrificed his capability to be compassionate and warm, as well as the ability to relate to people from Earth, so that he can survive on the frontier. Marilyn is a doomed victim because she doesn't know the laws of space; she is out of her place and is therefore punished for transgressing into male space—not just on the EDS, but on the frontier itself.

Gendered Space and Dogmatic Faith

This schema genders the frontier as male, as I have said, which seems very odd from the standpoint of human perpetuation. Settlers were both male and female by necessity in order to continue their population. However, women do not belong in Godwin's space frontier. Space remains a "No Girls Allowed" boys' adventure clubhouse. Marilyn dies because she doesn't play by the boys' rules.

Barton is not without compassion in the story; he finds himself torn between his sympathy for Marilyn and his experience on the frontier. Before he knows anything about Marilyn, he is able to resign himself to a cold-blooded murder of the mystery stowaway. However, when he sees Marilyn, when he hears her nonconfrontational words ("Now what?"), he is shocked (p. 202). The importance of Marilyn's gender in Barton's consideration is also notable. He thinks how easy it would have been to kill the unwanted passenger "had the stowaway been a man" (p. 202). Barton acquiesces to her request to call her brother, and he does everything he can to delay the inevitable, but he does very little to actually avoid or solve the situation. His compassion makes him want to do something for her, but his experience of the frontier and his training makes him believe that nothing can actually be done.

The statement that he "can't" do anything becomes a mantra for Barton, and it is one shared by the crewmen of the Stardust. He reassures himself that nothing can be done, saying it again and again to make it true and to exonerate himself of any guilt. In fact, the repetition of the Barton mantra leads into a prayer-like meditation upon the laws of nature which comes off as a celebration: "all things move in obedience" to nature's laws, and the frontier-men therefore give up trying to innovate new solutions (p. 213). Instead, they surrender to their perception of these laws, living by them and acknowledging their power at a level that borders on religious devotion. This is Barton's paradigm, which his compassion struggles against. In the end, he cannot escape his training; he cannot resist what he has become in learning the laws of the frontier, and he ultimately decides to uphold his beliefs and send Marilyn out the airlock.


Barton, upon discovering Marilyn and her innocence of all crimes except the simple action of breaking the "laws of space," only does one thing to try to save her, which he admits beforehand is futile (p. 204). He defers to the men on his ship, not yet accepting the responsibility of consigning her to death, looking to the Stardust to provide him with a solution. The crew of the Stardust fail to give him what he wants (which is an easy out); they don't care about Marilyn's situation enough to even suggest alternatives. Barton, having exhausted that option, gives up on saving Marilyn. There is not any mention of considering other options, something that would convey Barton's compassion, moving him to wrack his brain attempting to come up with a solution. When Gerry, Marilyn's brother, questions her fate, the pilot lists off the possibilities that he could think of for her salvation, all having failed. Barton doesn't consider jettisoning any other kinds of materials, ripping out extraneous/secondary computer parts to balance out the added weight of the girl, replotting his course to make his fuel last using some kind of trick of using a moon's gravity as a slingshot, or any other number of clever saves that Barton could have tried which would have been attempted in other subgenres of SF.

The story is not about those options or the effort it might take to explore them. It is "hard" SF, powered by inviolable rules. Barton's effort to save Marilyn is not even mentioned after contacting the Stardust. He doesn't ask the teams on Woden for assistance in locating a safe crash point so as to allow both of the people aboard the EDS to survive, and he most certainly doesn't even consider sacrificing himself to save Marilyn, becoming a martyr. Barton is just a guy on the job, going through his routine, only deviating from the book when forced to by his bouts of compassion, and even when he does so, it is not enough to save Marilyn. He is held captive in his own way of thinking, and he condemns Marilyn to death because of the combination of space frontier "law" and EDS regulations. Barton questions the man-made law, looking for an alternative from the Stardust, but he never doubts the inevitability dictated by the natural laws.


In "The Cold Equations," Barton is a character who is moved to compassion over Marilyn's plight, but he does not sufficiently act on his compassion in any creative or constructive manner in any attempt to save her. She has transgressed into male, cold, hard, logical space, a place where she cannot and does not survive. She is punished as part of Barton's devotion to the laws of space, which serve as something between a tyrannical set of laws and a nature-worshiping frontier cult where physics creates the laws of human society. His decision is justified within his own paradigm, filled with binary oppositions designed to designate space as a man's world, but his paradigm willingly excludes compassion and the human ways of Earth for "the cold equations" of space. To believe that his decision is justified, we have to believe that his paradigm is correct, that "the cold equations" are in fact laws to be lived by, and in so doing, become misogynists who believe space is a place for boys' adventure, not for mutual exploration or the perpetuation of our species.

In his essay "Hard Science Fiction," Hartwell describes hard SF as being about "the beauty of truth" (p. 30). The key moment of hard SF is the "eureka" moment (p. 31). The "eureka" moment in "The Cold Equations" is not one that leads to a character's salvation from danger, as in other stories, where a last-second revelation saves the character from death. The "eureka" moment is Marilyn's final acceptance of her inevitable death. Marilyn accepts the rules of the frontier and her own death, "rightful" according to the rules of space. According to Hartwell, hard SF is about accepting the laws of nature. Barton already knows the inevitable, has already come to accept the fact that Marilyn cannot understand until the end.

There is much more at stake in "The Cold Equations" than just the life of a character in a story. Depending on how a reader reacts to the story, its cold brutal logic, extolling knowledge and reason over sentiment, the reader may be forever soured on science fiction, as the price paid for knowledge it brings is accepting the inhumane mindset that is sometimes needed in its stories. "The Cold Equations" is such an extreme story (Marilyn's only choice in her death is whether she goes willingly, Barton can do nothing to save her) that it approaches the level of an oversimplified "parable" (Gunn 198), illustrating a hard SF story in line with John Campbell's rules for the genre. Whether you agree with the story and accept its cold logic or recoil from its extreme nature, "The Cold Equations" is a critical work of hard SF which must be considered if one is to understand or speak of the genre.


Godwin, Tom. "The Cold Equations" in James Gunn, ed. The Road to Science Fiction, vol. 3. Clarkstown, CA.: White Wolf, 1979. (pp. 198-220)

[Editor's note: This has since been reprinted; the link above goes to that reprint.]

Hartwell, David G. "Hard Science Fiction" in David Hartwell and Kathryn Cramer, eds. The Ascent of Wonder: The Evolution of Hard SF. New York: Tor, 1994. (pp. 30-40)

Michael Underwood is a Student at Indiana University majoring in East Asian Studies and Creative Mythology. He is a geek of great distinction, and spends more time thinking about stories than perhaps is wise. He continues to do so, regardless. You can email him at
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