The holy grail of any science fiction story, and truly any hope of extended manned spaceflight is -without a doubt- the ability to go faster than light. An FTL engine is a piece of technology that has been depicted countless times in literature, movies, television, and the sugarplum dreams of children for nerds. Whether you want to call it a hyperdrive, a warp drive, jump drive, mass drive, improbable drive, or whatever we have seen it over and over again and for good reason.
The Milky Way Galaxy is about 100,000 light years across, and it is more than 4 light years to our closest stellar neighbor, Alpha Centauri. We can never travel at the speed of light because that would be impossible, thanks to Einstein’s Theory of Relativity, and not just because of all the weird time dilatation stuff. Traveling the speed of light would require infinite energy to accomplish, and infinite is kind of a hard number to come up with in practical terms, even with today’s cheaper gas prices. Yet, even if we were to figure out how to travel that fast it would still mean that it would take 4 years to reach Alpha Centauri, and that just won’t do when you are trying to keep a dramatic pace in your science fiction Disney-owned blockbuster. That is why the entertainment industry has given us to following:
It Ain’t Like Dusting Crops, Boy
Hyperdrive is the engine of the Star Wars universe. It allow ships like the Millennium Falcon and others to enter what is called “hyperspace,” Though Star Wars is not the only science fiction property to theorize such a dimension, they are the best known for it. According to Star Wars canon -at least we think it’s still canon but who can tell anymore- hyperspace is “a dimension of space-time that could only be reached by traveling at lightspeed or faster.” In essence it’s like a higher dimension or a pocket dimension that exists next to the Star Wars universe. Somebody took the time to do the math, but what is the most interesting aspect of this superluminal space is that it is still affected by the gravity of the normal dimension. Thus, hyperspace calculations are incredibly difficult because objects with enough mass can pull ships out of hyperspace, sometimes fatally. There are only certain routes that people use to navigate the galaxy, much like highways and back roads through hyperspace that avoid most major gravity wells. This also is used to explain Han Solo’s boast, “It’s the ship that made the Kessel Run in less than twelve parsecs.” The mining world of Kessel is situated next to the Maw, a cluster of black-holes, so getting to it is more about daring the shortest and most suicidal route rather than the fastest time -yes, by the way, we’re those kind of geeks.
We have talked about the science of Star Wars before, but it is worth covering this part more in depth. To begin, the rapid acceleration that we see in the movies would leave Han and Chewie as a fine paste on the back of their seats. Human beings -and possibly Wookiees- can withstand about a max of 5 g’s for about 2 minutes. Accelerating to lightspeed, even at 9 g’s would take about 19 days, though our favorite smuggling duo would be dead long before they reached it. We know the crew experiences at least some of the force of movement, because in The Empire Strikes Back R2-Ds falls backward when they jump to hyperspace. So we can only assume that the Falcon has some amazing inertial dampeners.
As for the dimension of hyperspace itself, it is a very cool storytelling element, but for the most part it is fictitious. The closest we have come to even discussing it on Earth is in terms of the Heim Theory which tried to purport a unifying theory between quantum physics and general relativity. It allows for the existence of such higher dimensions that could theoretically be accessed and used like hyperspace. Burkhard Heim even speculated that a rotating magnetic field could reduce the influence of gravity on a spacecraft enough for it to take off, and -for a while- these theories actually made him something of a celebrity in the 1950’s. Unfortunately, they also never quite passed peer review and Heim is no longer studied as part of mainstream scientific research.
The jump drive is another fantastical engine that is best portrayed in Battlestar Galactica where ships are instantaneously transported from one point in space to another, light years away, but is also appears in other science fiction media. Unfortunately, shows like Battlestar Galactica seemed to be too preoccupied with high impact drama and suggestive PG-13 sex scenes to really go into the mechanics of how their FTL drives worked. So we are left with only speculation.
It is possible that a jump drive would be related to a phenomenon known as quantum tunneling. In its purest form, tunneling is the process by which a particle passes through a barrier that it would not normally have passed through. It has a very low probability of happening at all, which increases as the target barrier’s thickness decreases. Also, as rare as this phenomenon is, it happens quite frequently inside the core of our own sun, mostly because the unfathomable number of particles in the sun means that statistically even low probable actions still take place on a regular occurrence. Scientists like Günter Nimtz, claim that when a particle tunnels through an object it does so instantly making its movement faster than light, though that has been heavily debated. Still, if that were to be true, this could be the basis for what you would call a jump drive.
Unfortunately, quantum tunneling has several major set backs. First of all, it has only ever been observed at the particle level, and would be incredibly hard to scale up to more complex forms of matter like you, or Starbuck, or Edward James Olmos. Even if we could scale it, quantum tunneling happens an improbably low amount of the time. An FTL drive that only allows you to jump 1 out of every 1,000 times is not going to be great when you’re fleeing from cylons. Even then, it is only possible over short distances, and we’re not talking four or five light years. We’re talking about minuscule distances, centimeters and multiple planck lengths. Lastly, scientists cannot even seem to agree if the particle even is traveling faster than light, as it would be inconsistent with Einstein’s Special Relativity. So we’re thinking a jump drive is probably fracked.
Wormholes could offer a better solution. They have been portrayed in various science fiction properties, most notably in the Stargate franchise and the Mass Effect series. The best part about wormholes is that they are scientifically plausible. It has become almost cliche at this point to make the old analogy of space-time being like a piece of paper. You may not be able to go faster than light from the top of the page to the bottom of it, but if you fold the paper over and create a bridge through it than you could travel there almost instantly and still stay on Einstein’s good side. -We are also aware that we called the example cliche and then proceeded to use it as our example, but if it works it works- General relativity even predicted their existence, though we have yet to observe one.
Size is the first issue. If naturally occuring wormholes exist, they happen on a microscopic scale. Another issue is stability. As of right now we have very few ideas on how we could open a wormhole and even less on how to keep it open. It would require some sort of exotic negative mass or negative energy to do so. Both of which are theoretically sound, but we have yet to reliably observe them, let alone harness them for our purposes. Another tiny problem is the fact that, even if we could create or find one big enough, and even if we could keep it open and stable, we have no guarantee that inserting a foreign object or a human body would not cause it to immediately destabilize and collapse. Then even if does remain stable the affects of gravity inside the wormhole would unevenly affect anyone entering it, turning them into spaghetti, which would be very bad for MacGyver or whoever else was inside at the time.
We come now to the warp drive. It is one of the most talked about and plausible science fiction faster than light engines ever dreamed up, though we at the NYRD personally believe that is because most NASA scientists are also Trekkies. Star Trek has laid out the details of the warp drive pretty extensively. So we know it is powered by a mater/anti-matter reaction which is mediated through a non-reactive substance held in check by an electromagnetic field. This creates warp plasma which is channeled through warp coils that ultimately distort space around the ship. Now most of that is sci-fi technobable, but it has a foot in actual theoretical science, we mean at least as much as any show about Tribbles and green women can.
The Alcubierre Drive is a theoretical warp drive worked out by Mexican physicist Miguel Alcubierre, and essentially it works just like a Star Trek warp drive -again because Alcubierre is a Trekkie. According to Einstein, nothing can go faster than light, except -and its a big exception– space itself. At the moment of the Big Bang the fabric of space expanded faster than the speed of light, and space is still expanding to this day. The Alcubierre drive would essentially warp the space itself around a starship, causing the space in front to contract and the space behind the ship to expand. All the while, the USS Patrick Stewart is contained safely in a bubble of normal space time. Thus, a ship can achieve speeds faster than than light and the crew inside the ship would not even feel the inertia of acceleration.
Unfortunately, Alcubierre himself stated that this would take an amount of energy on par with the mass of the observable universe, though some scientists at the Johnson Space Center, believe they have gotten that down to about the mass of Voyager 1, which is better but still not ideal. Even more problematic, maintaining the stability of the warp bubble around the ship would again require negative or exotic matter, same as it would for the wormhole solution. However, and despite all its flaws, this theory is the current front-runner for the most plausible superluminal engine we have yet to come up with.
So, sorry Star Wars fans. You may have cool things like lightsabers, the Force, and a deep seated hatred of Jar Jar Binks, but Star Trek has the most plausible fictional way of traveling across the galaxy. Still, it is worth mentioning that Star Wars has always been more about myth and fantasy than science, and that is okay. The Jedi are samurai, Han Solo is a cowboy, and originally no one ever put much thought into how things work, just that they looked cool while doing it, but even impossible science fantasy is as a vital part of the human imagination and science. Ultimately, if you remove either science or imagination from the human experience, the remaining one would not be as strong as they it is today. The fantastical worlds of writers and artists inspire scientists and vice versa. Unfortunately, in the realm of interstellar flight our collective imagination is still outpacing our scientific achievement, at least until that day we all get a visit from a British man in a police box.