By Seth Mayo, Curator of Astronomy
2019 will usher in a new celebration of science fiction in the MOAS Planetarium. We are excited to bring a series of influential sci-fi motion pictures to our dome, taking advantage of the unique and intimate layout of the Planetarium facility. The Planetarium will not only allow us to project and display the movies in a novel way, we will also take an opportunity to use our digital universe to hold a Q&A about the realities and the more fictional portrayals of the science behind the movies, and to provide a general discussion of the big ideas found in the stories.
Although Hollywood has produced some amazing movies with heavy science themes, there are many common misconception and assumptions, about physics and astronomy most specifically, that have wound up making the cut on the big screen. Here are some common space movie tropes and the scientific reality behind them.
Sound and Fire in Space
The issue of sound and fire in space is a good one to tackle first since it is a favorite effect in big production sci-fi space movies.
Apparently, in galaxies far, far away, like in the ever-iconic Star Wars universe, massive ka-booms and fiery explosions are as ubiquitous as lightsabers and the "force." this is understandable since loud and flashy things that explode make for exciting movie-going experiences.
In reality, the vacuum of space is essentially that, a vacuum - mostly devoid of particles of stuff. For sound energy to travel to one's ear, the molecules found in air, or a liquid, or a solid (travels easiest through this) will bounce off one another as a pressure wave moves through them, transporting the sound that eventually may vibrate organs in the receiving ear.
This space-vacuum is also a problem for fire and sparks as well since you need some type of oxidant to burn. This can be demonstrated if you put a glass cup over a lit candle. The small flame burns out the remaining oxygen in the air which develops a slight vacuum, and the flame extinguishes quickly. Imagine this on a larger scale in space, however, the vacuum is always there.
Explosions can happen in space, throwing out material in all directions including light, but the big ka-boom and torrential fires that follow would be non-existent. To be fair, movies like Interstellar, The Martian, and even some scenes in the new Star Wars films have approached this topic with accuracy, going for the quiet, fireless explosions, that can still provide the same dramatic effect as their louder counterparts.
If you have heard that lines "warp speed" from Captain Kirk in the original movie series, Star Trek, or "engage," from Captian Picard in Star Trek: The Next Generation, or even "punch it," by the infamous Han Solo in Star Wars, then you most likely know what "warp" is in the sci-fi universe of space travel.
For these fictional characters to traverse the extraordinary distances found in space, they need ways over overcoming the cosmic speed limit: the speed of light. And as you probably already known, light is pretty fast. The speed of light is about 300,000,000 meters per second, or 670,000,000 miles per hour. That is fast enough to travel from the Sun to Earth in about 8.3 minutes, and closer to home, a beam of light could travel around Earth 7.5 times every second.
That sounds fast - and it is - but when you want to travel through interstellar space, even the speed of light becomes inadequate. If you could travel at light speed (a huge problem anyways since your mass would become infinite), the nearest star system, Alpha-Centauri, at 4.3 light-years away, would take just that - about 4.3 years. As of now, the fastest spacecraft ever sent into space - the recent Parker Solar Probe - at about 432,000 miles per hour (0.06% the speed of light) at its fastest, would take about 6,700 years to get to Alpha-Centauri going in a straight-line distance.
That is a problem in the movies, where the stories need to take the characters from place to place far from each other without worrying about the time it would take to get there.
Enter warp travel: the fictional method of getting around in science fiction without worrying about light speed.
Star Trek has provided a pretty interesting explanation for warp speed travel. In the Trekkie universe, the giant starships can bend space around them - whereby the space is moving faster-than-light, but not the ship within the space itself. In some form, this is theoretically possible since the universe technically is expanding faster than light, but light within the universe is still constrained to the mundane 670 million mph limit. The bend space around a spacecraft, this would take an unfathomable, pretty much unattainable amount of energy. That is why they use fictional materials, called dilithium crystals, in their warp drives to power such an endeavor.
Another method of moving past light speed in the movies is by entering a wormhole. The idea is that you warp space and time so much, that you essentially fold it on itself, allowing the space traveler to create shortcuts through the universe and drastically shortening the travel time between two points.
Again, this is theoretically possible, and in physics, this phenomenon has a more technical name: Einstein-Rosen bridge.
As a movie already mentioned with its scientific accuracy, Interstellar seems to get this mostly right. The characters in this Christopher Nolan film use an Einstein-Rosen bridge, or wormhole, that mysteriously shows up near Saturn to travel to another star system with potentially habitable planets. This scene was shot with a very accurate computational model to depict what it would be like to enter a wormhole. Some of the models were even published in a real scientific journal for their accuracy. It also helps that Interstellar had a world-renowned physicist, Kip Thorne, as a science advisor.
Just like a warp drive in Star Trek, a wormhole would need a gargantuan amount of energy. So much energy in fact that it would possibly need some exotic form of it called negative energy (not enough room on this page or possibly the whole magazine to explain this).
So, in summary, faster-than-light speed travel is theoretically possible if you drastically alter the fabric of space-time, but pretty much unattainable at this point because of the mind-boggling energy requirements.
Our real-life universe is mostly out of reach at the moment.
Pretty much every movie about space must grapple with gravity, or lack thereof, in some form or another. Most people have seen a video or two of an astronaut floating around the Space Shuttle, a scientist gliding through the International Space Station, or an Apollo astronaut bouncing merrily on the surface of the moon.
Many films just avoid the issue of a lack of gravity altogether and just have all their ships somehow create it automatically in some fashion (looking at you Star Wars). In others, the pilot of the ship may flip some random switch connected to a special device that just turns on gravity suddenly. And some films seem to try to create realistic means of gravity by spinning some type of cylindrically shaped compartment.
This is a tough one for movies since having to film realistic weightless environments is very challenging and expensive to pull off well. The 2013 movie, Gravity, starring Sandra Bullock and George Clooney, does a pretty spectacular job of simulating this weightlessness. They probably should have if the word gravity is in the actual name of the movie (Sandra Bullock's non-floating hair was a little issue).
All mass in the universe has gravity. Even our bodies have a little big, but it is infinitesimally minute and not noticeable on most measurable scales. Clump enough matter together into moons, planets, stars, or galaxies, and you have enough to exert a noticeable amount. Starships, even the absolute largest in sci-fi (unless planet-sized), do not have enough mass to exert an appreciable amount of gravity.
So far, we do not have any special machine that can miraculously create gravity fields. Maybe someday when the discovery of the highly theoretical gravitation takes place in physics might we be able to do this, but that is pretty far-fetched.
As mentioned before, some movies and even sci-fi television shows have figured this out by using a centrifuge, or a large rotating device. Think of one of those slightly untrustworthy tilt-a-whirls at your favorite carnival or fair, and you can get an idea of how a spinning device can produce an outward motion, utilizing centrifugal forces.
The iconic 1960s movie by Sanley Kubrick and Arthur C. Clarke, 2001: A Space Odyssey was one of the first major films to portray a means of artificial gravity in a fairly accurate way. As one of the most famous scenes in cinema, not just a space sci-fi, commander Frank Poole as played by Gary Lockwood, is seen quietly jogging around upright in a circular rotating module. An amazing blend of movie cinematography and science coming to life, the scene shows the possibility of using the outward rotating motion of the craft to create the conditions similar to Earth's gravity.
The major hitch with the design of this module in 2001 is its size, even though it seems to be rather large. Most likely, the character Poole would be toppling over as he ran due to the Coriolis effect - a force felt perpendicular to the rotating direction. His top half would always want to fall forward due to this effect and he would most likely be stumbling over himself the entire time. To develop enough artificial gravity, the spacecraft in the movie must spin pretty fast due to its relatively small size, amplifying the Coriolis problem.
Earth has a Coriolis effect as well, but due to the sheer size of Earth relative to a person and its spin rate, this force is barely noticed. Although, this effect can be seen in winds and clouds, attributing to the differing rotations of storms between the northern and southern hemispheres (sorry, this does not apply to toilet water spin direction).
In order to minimize the Coriolis effect in spacecraft, you would have to enlarge them to extraordinary size and diameter, allowing a slower rotation to get the same simulated gravitational tug needed. This means a negligible Coriolis effect. This also means that depending on the design of the spacecraft, you may have to build a structure many miles long and with ultra-sturdy materials that may or may not exist in real life. From an engineering standpoint, this becomes increasingly difficult and unrealistic, but not totally out of the realm of possibility in the far distant future.
If many movies of the sci-fi genre are dealing with grand space battles, evil alien overlords, or long scientific voyages through the universe, there are an equal number of space disaster films involving Earth as well.
This can be seen with the barrage of planet-destroying asteroid films that have propped up over the years - Armageddon, Deep Impact, and Meteor, to name a few. With many of these big-budget, mega CGI infused movies, they seem to deal with asteroids that come out of nowhere that are about to unleash impending doom on planet Earth. Unless some heroic last-minute mission can save the day.
Now it is true that Earth is constantly bombarded by space rocks. Each day, many tons of tiny meteors are entering Earth's atmosphere. If you go a little bigger into the hundreds to low thousands of feet in diameter-sized asteroids with the potential to destroy a small area or even city, than on average, Earth gets hit every thousand to tens of thousands of years or so with that class of space rock. For the global devastating type asteroids or comets, a half a mile and larger in size - they bombard Earth every hundred of thousands to millions of years on average.
For reference, the asteroid that brought an end to the dinosaurs about 66 million years ago forming the Chicxulub crater beneath the Yucatan Peninsula in Mexico was anywhere from 6 to 9 miles in diameter.
Through natural historical record, the planet-destroying type of asteroid on a collision course with Earth does not come around all too often. And if one did, it is most certain that we would have more than just weeks or months to detect a potential threat and determine a way to protect ourselves.
Fortunately, NASA has created the Planetary Defense Coordination Office (PDCO) that helps coordinate and track the potentially hazardous objects that are considered near Earth.
There is about a handful of planet-destroying class of asteroids nearby that could pose a threat some point in the future that are being tracked. As of now, none are of too much concern, although just the slightest nudge could set any number of them on a trajectory that could spell trouble for our fragile planet.
If this were the case, and certainly not out of the realm of possibility, then most likely we would have years, and probably decades to prepare. This probably would not mean we would be sending a ragtag team of oil drillers to fly to an asteroid and implant a nuclear explosive device (Armageddon), or a team of trained astronauts on a secret mission to a dangerous comet for explosive delivery as well (Deep Impact).
The reality for impact defense would be a bit less dramatic, and most likely uncrewed. One method would be to send a spacecraft to impact the hazardous asteroid, hopefully pushing it into a very slightly new orbit. This would not have to be a huge push since small adjustments early on would mean big differences later when the object is closer to Earth.
One very innovative approach would be to send a hefty spacecraft to the object in question and carefully position it extremely close to the space rock. Taking advantage of the tiniest amount of gravity that the spacecraft exerts on the asteroid, the spacecraft could thrust itself ever so gently in a certain direction that would slowly drift the object away from its destructive orbital path over a couple of years.
This way we don't have to sacrifice Bruce Willis (apologies for the 20-year-old Armageddon spoiler) to save planet Earth.
Sci-Fi Movies in the Planetarium
These are just some of the science-related issues you find in space movies through Hollywood history. Even when ideas seem far-fetched and totally unrealistic, the explanation that can take place can serve as an interesting way of discussing how our universe works.
We hope to create these types of enthralling discussion in the Planetarium this year with the first two movies on our sci-fi film schedule.
The first will be the showing of 2001: A Space Odyssey on January 25, 2019. Presented in rectangular 16:9 aspect ratio in stunning 4K on the dome, we are starting this exciting new program off with one of the most highly regarded space movies of all time, even 50 years after its original release date. Following the showing of the movie in the unique dome setting, we plan on holding a Q&A about the science and topics of the movie, utilizing our sophisticated universe software. An encore will take place on January 26, 2019.
Our second showing will be a much newer film, firmly placed in the annals of sci-fi movie greatness, is that of Interstellar on March 1, 2019. As one of the few remaining movies filmed partly on IMAX 70mm, this beautifully shot space adventure will also be played in rectangular 16:9 aspect ratio in 4K across the Planetarium dome. After the conclusion of Interstellar, we will also have time for discussion on the scientific subjects found throughout the story. An encore will also follow on March 2, 2019 (check the calendar for more details on these events).