NGC_4414_(NASA-med)Science fiction has never been my favorite genre. Not that I didn’t get a kick out of reading or watching fanciful space travel stuff and freaking out over invading aliens when I was a kid, but my main rap against it was that it didn’t try hard enough to be real. By definition, all fiction is unreal, but for me a novel or movie works best when it comes close enough to recognizable real life to allow for the willing suspension of disbelief. I’m not denying that the Star Wars and Star Trek movies are fun to watch and sometimes even insightful about the human condition. But if space travel is ever to be real, we must seriously question if and how these things can be done. We can’t build spaceships on current models that can accelerate to “warp light speed.” Never will we venture way out yonder to find human-like creatures populating galaxy after galaxy, speaking perfect English. When it comes to the “war” part of Star Wars, we will probably never develop an arsenal fearsome enough to make whole worlds explode at the push of a button. Special effects don’t add up to reality.

Lately, however, the genre has been expanding with the growing popularity of what we might call scientific science fiction. Movies like Interstellar (2014) and The Martian (2015) push the edges of what is theoretically possible in space travel. The ordinary mind boggles at the concepts of theoretical physics and engineering feats that must be mastered to make these space forays possible. By “ordinary mind” I mean one like my own, lacking in scientific skills but greatly respectful of science. Yet our long-term survival as a species may depend on coming to grips with it all.

Carl Sagan’s 1985 novel, Contact, posited the idea of wormholes as a means of feasible space travel. A wormhole, if real, might enable us to defy the limitations imposed on us by relativity and gravity. These blips in time and space might allow for deep-space travel that could be completed within reasonable timeframes. One of Sagan’s scientific pursuits throughout his career was the search for extraterrestrial intelligence (SETI). The scientist-heroine of his story, Eleanor Arroway, receives the signal from space that Sagan dreamed of finding himself. It’s a repeating message composed of prime numbers, presumed to be the universal language of mathematics. The message, once fully decoded, reveals a blueprint for building a spaceship that can make use of a wormhole. Plenty of Earthlings are skeptical of the discovery. Who’s to say these aliens aren’t evil and diabolical, intent on luring us to our doom? Sagan’s theory was that a highly technical society capable of sending such a message must have passed some threshold of survival. The aliens had evidently developed nuclear and every other form of energy without destroying themselves in the process. That could only mean that they had learned, somehow, to live peaceably among themselves. They sensed that we were on the precipice, flirting with self-destruction, so they reached out.

Interstellar borrows the wormhole concept. According to side notes in the Kindle version of the movie, these ideas were developed by theoretical physicist Kip Thorne. “Based on warped space-time,” Dr. Thorne says, “the most exotic events in the universe suddenly becoming accessible to humans.” By contrast, The Martian seems tantalizingly close to present-day reality. We have already sent numerous unmanned probes to the red planet, and manned missions are on the drawing board. A proposed one-way trip is drawing plenty of applicants, despite the prospect of never returning home. NASA has a working prototype of the Mars Launcher Habitat used in the movie. The buried Pathfinder lander that figures in the story is an actual spacecraft built by NASA in the 1990s. One of the launches shown in the movie is actual footage of the Mars Science Laboratory launch.

The Martian isn’t about a one-way trip. On the contrary, its travelers hope to return to Earth to be welcomed back and lauded by their fellow citizens. The astronauts aboard the Hermes spacecraft mourn a crew member, Mark Watney, whom they had to leave behind after a catastrophic explosion apparently killed him. When they are informed that against all odds, he survived the incident, they return to rescue him, adding over 500 days to their mission.

The Martian is about adventure and exploration, however perilous. Interstellar, by contrast, is about desperation. The opening scenes show Earth in peril, with the crops dying, the air polluted, and water in short supply. It’s all too easy to believe this is an accurate snapshot of earth in coming decades. The need to escape this hellhole is urgent. Schools in these end days are training more farmers than engineers, but agriculture is still failing. They’re also teaching hopelessness, denying kids not only a future but rewriting history to deny that men ever walked on the moon.

A young girl, Murphy, feels haunted by a ghost in her bedroom. Her father, Cooper, an engineer who is also a pilot, shares her feeling that this apparition, whatever it is, has the answers. By taking a scientific rather than a mystical view of it, they discover a message leading to a facility where NASA scientists are working on the problem of human survival. There are all sorts of theories, problems, and equations that must be worked out. Gravity anomalies have been detected for the past 50 years, they say, but can an anomaly actually defy gravity? A possible wormhole has been detected near Saturn, a disturbance in space-time that might allow escape to another galaxy. Whoever is sending these messages must live in five dimensions, with a different conception of time than humans have. Can those of us limited to three dimensions ever understand them? Will humans ever be able to see into a black hole and uncover its mysteries? A space station has been built, based partly on the current International Space Station, but dependent on gravitational anomalies and a “mishmash of technologies.” A stash of fertilized eggs on board represents the only glimmer of hope.

Both movies have a lot to say about human emotions, which both help and hinder the fight for survival. “We must begin to think as a species, not as individuals,” declares the physicist who sends Cooper on his outer space mission, lying to him in the process. He believes he’s sending Cooper to colonize another planet, never to return. He can’t allow his true opinion of the mission to be known, because Cooper’s instincts as a parent would never allow him to undertake it if he believed it meant leaving his children and all the children of earth behind to starve. During the mission, one of Cooper’s colleagues risks everything by advocating colonization of a planet that is obviously an inferior choice. She’s in search of the man who explored it previously, who might still be alive, although it seems unlikely. Maybe, she declares, her love for him is a powerful force beyond human understanding, one she shouldn’t be expected to resist.

The Martian is more optimistic about present-day humanity than Interstellar. When Mark Watney is rescued and brought back to Earth, he lectures astronauts in training about the perilous life they have chosen. The fear and possibility of death will be close and constant, since outer space is cold and stark and does not cooperate with humanity. Only if they solve all the problems that come their way will they get to go home. That’s how Watney finally gets home—by solving one practical problem after another, against terrible odds, aided by a sense of humor. He knows his food rations won’t last long enough, so he must grow his own potatoes. “Luckily, I’m a botanist.” When this crop is destroyed in an unexpected mishap, he needs to create a source of water to prepare more soil. He knows water can be created by lighting up hydrogen, a prohibitively dangerous process but the only one available. So is digging up a radioactive energy source that was buried on a previous mission and remains deadly. At every step, he says he must “science the shit out of this.” A hundred different hazards could kill him, including the boring disco music collection that the commander of the mission left behind.

When the problems seem insurmountable, and death seems all but certain, Mark passes on a message to his parents: if he perishes, he did it for something big and beautiful. He didn’t do it because it was a choice between exploring new worlds and dying out as a species, as in Interstellar. He did it for curiosity, a love of learning, and the spirit of exploration, human traits that are probably just as essential to survival as food, water, and oxygen.