II: The Science of Interstellar
by
Howard Adelman
As far as I can recall, there is no mention in Kip Thorne’s book, The Science of Interstellar, of the science of ions of interstellar origin as documented by the Solar Wind Ion Composition Spectrometer on the spacecraft Ulysses. One wonders why since the connection with the thrust of the movie as a modern day Odyssey is so obvious. Further, the Ulysses spacecraft was designed to study interstellar space, specifically, the poles of the sun and the interstellar space above and below the two poles. Further, the spacecraft, Ulysses, with its two stage rocket and its smaller thrust engine, could easily have been the model for the space craft that rendezvoused with the spaceship, Endurance.
Instead, the shuttle used in Interstellar to reach the Endurance appeared to rely on chemical rockets rather than alternative forms of thrust that would be needed to propel a spaceship into outer space, possibly a laser-powered ion propulsion system or, at least, a nuclear powered spacecraft or even fusion propelled spacecraft. Alternatives could have relied on beamed lasers mounted on asteroids and laser reflectors, or a plethora of small spinning microsails. However, Interstellar is not about traveling between suns or from our solar system to the nearest one, Alpha Centauri, a triple system closer than any other star. It is about traveling to another galaxy altogether through a wormhole.
The reason is that even by using these alternative forms of energy propulsion to travel between solar systems, it would still take far too long even if such systems could be perfected in the next two centuries. The probable speed would be from 1/13th the speed of light to 1/5th the speed of light. Even if the latter were achieved, it would still take forty years to reach Alpha Centauri, and that solar system does not seem to have any planets that could support life. Working in any of these directions would take far too long if Earth were dying as a habitable planet and, in any case, even when such systems were developed, would take decades, even a century, to get to and back from that other solar system to report on whether there was a habitable planet.
However, if one envisioned traveling to a planet within this solar system to move proximate to a wormhole, if one were to be located there, this offers an option far more feasible and closer to technology currently available and under development. What appears as a disconnect between the old fashioned mode of thrust portrayed in the film and more credible alternative systems for interstellar travel, is, in fact, more credible than the far-out thought experiments for interstellar travel. Further, a movie viewer would not have recognized these innovative propulsion systems as characteristic of interstellar travel. Ironically, travel to another galaxy seems to be more scientifically plausible than interstellar travel. I presume that is why Chris Nolan opted for the portrayal of old-fashioned chemically-propelled thrust rockets which accord more with viewer expectations as well as with scientific evidence. The problem is the verisimilitude of traveling to a wormhole, going through it and still being able to explore another solar system in a different galaxy to find livable planets.
Is this important to the movie? It is the scientific crux on which the plausibility of the whole film depends. If verisimilitude and plausibility are goals, then far out solutions, such as traveling the immensely greater distances between galaxies rather than the relatively short distances between nearby solar systems, is the better option. The stated aim of the movie is to be as true to scientific actuality or possibility as movie makers can manage. Where there are deviances, as when Amie Brand in her argument with Cooper over which planet they should travel to next, offers a bunch of mumbo-jumbo, the viewer who has some familiarity with the science does not know whether she is making a scientific mistake (unlikely, since she is so advanced as a scientist) or whether she is just being emotional at the time because she wants to find her lover, or, most plausibly, she is just bullshitting Cooper who is an astronaut and pilot and not an astrophysicist. Thorne, the famous astrophysicist who first co-conceived the movie and served as a consultant and executive producer for the film, claimed that the science in the film was either established fact, an educated guess or speculation, but in either of the latter options, never impossible.
But that is not how one experiences the opening pre-story of the film that Jonathan Nolan developed in his script of a world in which blight has attacked one crop after another so that corn remains the only cereal crop left and we soon learn that it too will soon be ravaged by blight. The population on earth has been devastated. Human civilization has gone in reverse mode and almost everyone is a farmer or services agriculture. America is the 1930’s dust bowl ten times over with the landscape ravaged by huge dust storms. This is the dystopia with which the film begins, not the current wave of environmental disasters caused by humans, but one wrought by nature itself.
Kip Thorne wrote that, while such a scenario was highly unlikely, it was not impossible. At least that is what he and fellow scientists at Caltech with whom he consulted concluded – including an expert on plants in general, a top cell biologist, a microbe expert and a fourth Nobel-Prize-winning biologist. However, what is highly unlikely is not verisimilitude or even plausibility. And to entice us if the movie is to be an exercise in science fiction and not science fantasy, “highly unlikely” is an unacceptable criterion. So the movie starts on a wrong note and then leads us into the world of astrophysics. Instead of establishing a really possible if not probable foundation, we are led into a strange world that, for most movie goers, seems far closer to fantasy than it should or could have been.
Why is the opening dystopia implausible even though not entirely impossible? Well it is not presented as an all-out dystopia, uncomfortable perhaps, but baseball continues. Education deformed by dogma prevails, but there is still education. But it is a form of education in a country that has lost its way, a society in defensive mode, a society that has lost sight of aspiration in favour of mere survival. The last is the least plausible. Having studied and written about genocide – in Rwanda and the Holocaust – in societies far worse than the extreme dust bowl of the opening scenes, even these societies, where genocide is widespread, evince more hope. Further, the calamity is set in America, the land of hopes and dreams, where a Jewish son of immigrants from Eastern Europe could write America’s most famous and best-loved song about imagining somewhere over the rainbow way up high, a place where skies remain blue, where the clouds are far behind and dreams that you dream of really do come true.
Certainly pathogens can mutate, certainly monocrop agriculture is more fragile and more prone to attack at the same time as scientifically produced seeds have developed inner systems for protecting against pests and lethal microbes. The mutant microbe IS part of our everyday fears. The melting ice cap could release an ancient pathogen that could overcome all current defence mechanisms. These, and many other scientific scenarios, are possible, if highly improbable. What is not probable or even plausible is the passive surrender to a virulent natural disaster. Nothing we know about America, as self-destructive as it has become, prepares us for such a presumption. The problem is not in the natural science but in the political science, the sociology and the psychology. And the movie offers no preparation or plausible account for that shift.
Nothing wrong with that if the movie is a true dystopia. But the movie leads us into recovering our scientific dreams that have continued to take place in secret. Cooper, through the “magic” of the moved books and the magnetic arrangements of the sand from the dust storm, is offered the message of where, surprisingly within a relatively short driving distance, a secret NASA operation continues to build manned spacecraft for flights to outer space. A scenario of blight feeding on the enormous supply of nitrogen in our air and wiping out all crops, a blight in which microbes are both 100% lethal AND transferable to all vegetation, is not plausible given what we know of biological science. Such a scenario is theoretically possible, but Kip Thorne agrees is highly unlikely. So why start with such an opening if the movie intends to restore our faith in science?
I protest too much. After all, this is science fiction. But Interstellar is supposed to be science fiction that is as close to fact or at least to possible fact as possible in exploring the cosmos. It is not science fiction that strays off into the fantasies of a disaster movie. Instead of setting the audience up for truly believing in the possibility of the exploration of outer space taking place via travel through a wormhole, the opening pre-story undermines that goal. This is quite aside from the contradictory messages received from that fifth dimension that tells Cooper he should stay but, at the same time, gives him the clues that will enable him to resume his career as an astronaut.
Professor Elliot Myerowitz offered some plausible scenarios for a nature-caused die off – enormous algae blooms as a result of ultraviolet light getting to earth through the ozone hole; a recurrence of the cyanobacteria that produces oxygen rather than carbon dioxide and once managed to kill almost everything on earth. He also offered the suggestion of a microbe that attacks the chloroplasts in plants that, on the one hand, produce the carbohydrates a plant needs to grow and, on the other hand, releases via photosynthesis the oxygen from carbon dioxide which humans need to breathe. So a scenario of excess production of CO2 is much more plausible than nitrogen (already 80%) increasing at the expense of oxygen. Further, it is a scenario that is part of our daily fears, for CO2 need only increase to 2% in our atmosphere to radically change how we can live.
But this is science fiction. Who cares whether the science is credible! When it comes to science, moviegoers are credulous. But credibility, plausibility and verisimilitude are not only important to Kip Thorne who conceived the movie, but to the absorption of the audience in the dramatic action. I have no idea why a more realistic political and biological foundation was not provided for the film. What we observe is very entrancing, but it does not lead us to expect a realistic – or as realistic as possible – excursion into outer space. For science fantasy is an escape genre. Science fiction, on the other hand, prepares us for enlarging our aspirations, the central message of the film. A world where aspiration and vegetative life have been exhausted may serve as a great counter to a restored faith in science, but if it leads us to believe that science is sheer fantasy, then that purpose has been undermined. And my very small survey of viewers of the film is that they saw the movie as science fantasy which they equated with science fiction. In other words, instead of strengthening the human belief in science, the movie undermines it. And there are so many more plausible scenarios that could have pressured humans to seek a new home on another planet.
When we get to the science of leaving earth and reaching another galaxy, the scenarios, however unfamiliar, are scientifically much more plausible. Tau Ceti, the nearest sun with a possible planetary system with a possible earth-like planet is 11.9 light years away. (Proxima Centauri, the nearest sun, is only 4.24 light years away, but it does not have planets conducive to supporting life.) So if spaceships could travel at the speed of light, that planet could be reached in just under a dozen years. But space travel at the speed of light is just implausible in science. So the problem is not just the distance of alternative solar systems, but the difficulty in getting there within a reasonable time. Voyageur 1 has been traveling for 37 years and is only 18 light hours – not 18 light years – from Earth. As Thorne has written, this is like traveling to downtown Manhattan from midtown when your destination is Perth, Australia.
Hence wormholes. Traveling to the moon, the only space body to which humans have traveled, is fact. Traveling to Mars is within range of achievement. Traveling to Saturn, though much more difficult, is feasible. An advanced version of Voyager I, using gravitational slingshots as Voyager I did around Saturn and Jupiter to give the spaceship a boost, make such travel possible. If we can get to Saturn, and if there is a wormhole near Saturn, travel to another galaxy becomes plausible. Not yet feasible, but scientifically plausible.
The movie set in what is no longer Oklahoma or the Kansas of the Wizard of Oz, which blames nature rather than humans for the extinction of life on earth – in contrast with Elizabeth Kolbert’s The Sixth Extinction – has universal appeal because the message is acceptable to both tree huggers as well as the anti-environmentalists who believe that environmental science is a religious cult. But if the effort was intended to seduce the anti-environmentalists into at least accepting the validity and superiority of science as an awesome enterprise through the beauty and fascination of the power of science as well as a love of nature’s magnificence, the film lacks coherence, which is as important to the credibility of science as Thorne’s preoccupation with a correspondence theory of truth.
Matthew McConaughey as Cooper in the dystopian pre-story poetically laments that, “We used to look up at the sky and wonder at our place in the stars. Now we just look down and worry about our place in the dirt.” Unfortunately, the opening pre-story does not help restore that faith in science. Aim higher, break barriers to ignorance, reach for the stars, explore, pioneer and persevere. Most of all, as Dr. Brand intones repeatedly like a sledgehammer that sucks the music out of Dylan Thomas’ great poem, “Do not go gentle into that good night.” For although wise men know that death – personal or of the Earth itself – is inevitable, humans cannot and should not lie down before the awesome inevitability.
Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.
Though wise men at their end know dark is right,
Because their words had forked no lightning they
Do not go gentle into that good night.
Good men, the last wave by, crying how bright
Their frail deeds might have danced in a green bay,
Rage, rage against the dying of the light.
Wild men who caught and sang the sun in flight,
And learn, too late, they grieved it on its way,
Do not go gentle into that good night.
Grave men, near death, who see with blinding sight
Blind eyes could blaze like meteors and be gay,
Rage, rage against the dying of the light.
And you, my father, there on that sad height,
Curse, bless, me now with your fierce tears, I pray.
Do not go gentle into that good night.
Rage, rage against the dying of the light.
That is why this movie is deeply religious, not in terms of organized religion, but in terms of its spiritual message. Jesus did not go raging into that good night. He accepted his crucifixion with equanimity. But he refused to passively accept the death of others whom he raised from the dead, such as the young girl who supposedly died in Luke 8:49. Jesus insisted that she was only sleeping. While everyone around was wailing and weeping, Jesus woke her up. So Jesus spoke with a forked tongue, a tongue which offered two opposite lessons at the same time – total acceptance of his own demise while quietly raising others from the dead.
Dr. Brand, who we learn in the movie has spoken with a forked tongue in a very different sense, as both a liar and a man who believes that radical alternative choices have to be made when two roads diverge in a wood. He is given those precious lines of Dylan Thomas’ villanelle as his motto to pass onto future generations. But the Welsh poet’s message to his own father is a rant against acceptance of death by the other, whereas Thomas was a fatalist alcoholic when it came to his own death. So which are we to believe, the forked tongue of Dr. Brand in which science has to operate via the use of Plato’s noble lie or Cooper’s raging efforts to live up to the vow he made his young daughter?
Cooper could have recited lines from another famous poet, an American one, to counter that of Dr. Brand, the last verse of Robert Frost’s “Stopping by Woods on a Snowy Evening”.
The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep.
Next Blog:
Wormholes and Intergalactic Travel
Speed, Distance, Navigation, Communication, Long Duration, Propulsion and Time Dilation