Welcome back to Gaming on the Fringe. I had a lot of fun describing the faster-than-light (FTL) mechanism in Mass Effect in the inaugural article in this series, so I thought I’d take a look at other FTL drives. While I called this article “Warp Drives,” I’m not limiting myself to drives with that name. I’m strictly looking at engines that allow superluminal travel in real space so we’re leaving behind hyperspace of any kind and wormholes. Don’t worry, wormholes are another article.
Fiction doesn’t have to be bound by the laws of real world physics, although science fiction does tend to stick somewhat closely to the rules. The bad thing is that real world physics say that FTL travel is impossible, and space is measured in light-YEARS. A light-year is exactly what it sounds like, how far light travels in one Earth year or about 6 trillion miles. Unfortunately, the nearest star to our own sun, Sol, is Alpha Centauri which is about 4.5 light years away. Einstein ruined the fun of FTL by using his theory of relativity to show that as an object with mass approaches light speed it gains “relativistic mass.” Unfortunately, to attain light speed a massed object would gain infinite mass and therefore require infinite energy to get there. That obviously is not going to happen so as far as we know FTL is impossible, though a few theories to get around it have been introduced. We’ll look at the most well known and discussed FTL drive in actual physics later on, but let’s talk sci-fi. Science fiction authors are not exactly bound by physics so they can get around the speed limit in many clever ways. Luckily, games offer a myriad of choices to flip off the light speed barrier and start traveling to any star system you want. Let’s get to it.
I’m eschewing taking the obvious route of picking a Star Trek game because of reasons I’ll discuss later and the fact that I don’t like Star Trek. Instead of picking a setting in the far future where mankind is united under a single banner that uses post-scarcity technology to become post capitalist, why not a setting in the far future that’s weapons grade capitalist? EVE Online can and has filled dozens of articles on its gigantic in game economy, but here I’m focusing on the tech. While most science fiction settings have just one method of FTL, or even just one per species/faction, EVE Online features three. I’ll ignore both stargates and wormholes for a future topic but stick with the aforementioned warp drive. EVE Online’s warp drive is used strictly for travel within a given star system as it requires some type of gravity well – from a planet, star or artificially generated at an orbital station – as opposed to the vast majority of FTL options elsewhere. This is actually a great option to have as EVE Online tries to be somewhat realistic with system layouts. Thus, each system is many light hours in diameter so a form of FTL you can use in-system makes things much easier. The game usually states the speed of warp drive as 1AU/second with an AU or “astronomical unit” being the average distance from Earth to Sol which is about 8 light minutes. So warp drive in EVE Online offers you a very respectable 480c for scooting around star systems. While more limited than most warp drives, it at least offers a technical reason for its shortcomings.
Rebel Galaxy is a fantastic indie game that’s available for purchase on PS4 that lets you play as a future trader, flying your ship to different locales to trade wares. It’s as close to a video game for the Firefly universe as you can find, currently. You inherit a small trading vessel from your late aunt and spend your time completing missions while shuttling various trade wares between space stations and planets in a single star system – at least to begin with. Like EVE Online, the developers of Rebel Galaxy were educated enough about the size of most star systems to know that even without going interstellar, a FTL drive would be very handy in getting where you need to go in-system quickly enough. Interestingly, in RG the warp drive doesn’t actually have a speed per se. To activate warp drive you must be traveling fairly quickly using your sublight drives and then activate warp drive. Under warp you are given a “multiplier” that does what it says on the tin and multiplies your current sublight speed by a large margin to help make the further stations and planets quickly reachable. This idea of a FTL drive being simply a multiplier of your sublight speed is a very interesting concept that gets almost no traction in sci-fi, but it’s an idea we’ll come back to later on.
While I briefly discussed the FTL mechanism of Mass Effect in the inaugural entry in this series, I want to spend a bit more time on how it works in-universe. The titular Mass Effect can be used to adjust the mass of a given unit of space-time up or down, depending on what kind of charge you apply to the element zero core. By suitably decreasing the mass of the space-time around your starship, you can not just have “effective” FTL speeds but objective FTL. In a lot of FTL methods both in fiction and theory the local movement never exceeds the speed of light, but with a Mass Effect core your ship does go faster than light, it’s just had the relativistic mass removed. In a very clever nod to actual physics it’s mentioned in background lore that half of a trip the ship will accelerate in FTL as normal, while in the second half it will flip end for end to decelerate to a normal speed at the destination. A lot of sci-fi media just has the ship drop out of FTL with no need for braking, but this method is how actual rockets work. Very nice. It’s taken a step further with the Tantalus drive of the SSV Normandy. It uses the mass effect technology to create a gravity well ahead of the ship that the ship “falls” into, thereby giving it FTL and a reactionless drive. It’s actually very interesting that the fictional FTL system of Mass Effect, especially the Tantalus core, echoes the real world theory of the Alcubierre Drive.
For most of the twentieth century after Einstein’s world changing theory of relativity, it was assumed that faster than light travel was completely impossible. With the lone exception of wormholes – which is another article in this series – the old space opera dream of traveling quickly from star system to star system seemed dead. All that would change thanks to a single science fiction fan on vacation. Miguel Alcubierre was relaxing on vacation when he caught a rerun of the original Star Trek. Over the years many Trek fans had wondered how the Enterprise’s warp drive might actually be constructed in real life, and Alcubierre pondered that as he watched. The difference is that he was a recent PhD graduate who specialized in solutions to Einstein’s Theory of General Relativity. He decided to sit down and use his physics knowledge to extrapolate how a faster than light warp drive would work without violating physics. While others had tried before and failed, Alcubierre took a different approach – he started with a section of space-time that was already moving FTL and worked the math backwards from there.
His drive is deceptively simple, yet far beyond current technology. The basic Alcubierre drive – also called an Alcubierre metric – would warp space-time by contracting space in front of the starship while expanding it behind. This would create a “warp bubble” – that’s actually the phrase Dr. Alcubierre himself used, I told you he was a sci-fi fan – that could exceed the speed of light. The joke a lot of writers use is that since nothing can exceed the speed of light, Alcubierre figured out a way to ride that bubble of nothing to go FTL. Since space-time has no mass, it can exceed lightspeed, and by most cosmological theories of the early universe it has and still does. What’s very cool about the use of this drive as a FTL device is that the ship inside the warp bubble feels no acceleration forces. In fact, inside the warp bubble a ship is in “free fall” like the gravity in Earth orbit. While at the edge of the bubble gravity would rip most things to shreds, a simple calculation of the volume of the ship and the size of the bubble could counteract this. While the contraction in front could be done with use of gravity, the expansion of space-time behind leads us to a bit of a problem.
The original paper where Alcubierre described this theortical warp drive used exotic matter to create the expansion of space-time, and he estimated the amount of said exotic matter to be more than the mass of the universe. Later variations on the idea lowered the mass down to that of Jupiter, and with the work of NASA’s Sonny White, down to just a few hundred kilograms. The problem is that we still don’t know how to create exotic matter or if it even exists.
Exotic matter is called that because it’s very different than everyday matter. It’s often called “negative matter” though that does not mean it’s antimatter, which we can make. Negative matter has negative mass and energy which gives it some weird properties so as going faster the less energy is applied to it and being antigravity. While I discussed using Mach Effect to generate it previously, the only other way we know of that generates negative energy is the Casimir Effect. Check that Wikipedia link for details as it’s a bit more in depth than we can go into here. What’s very cool about negative matter is that we could actually use it to propel a ship slower than light without use of any reaction mass. Finding negative matter would be a huge scientific breakthrough, but at least nothing in physics really says it is impossible. That’s a start. To be fair, if conformal gravity holds true, then it’s been shown that an Alcubierre drive wouldn’t need negative matter. But that’s just an aside currently.
Let’s ignore that large issue for a moment. Assume that we can warp space-time in such a way to produce an Alcubierre drive. Could we actually use that to travel FTL? While originally the paper was just a semi-serious thought experiment, a lot of actual theory has been applied to the idea and a lot of them have been negative. Some researchers have put forth papers stating that at FTL speed the warp bubble would be full of Hawking radiation. Another theory has stated that you would only be able to use the Alcubierre drive at FTL speeds in columns of space set up for this already. Yet another theory has stated that any FTL travel with the drive would be a blind jump. Others have raised issues on starting/stopping the drive as well as questioning what would happen to the various high-energy particles and micrometeoroids that would appear in the way of any ship travelling at FTL speeds. There have of course been response papers that offer answers, but one I want to point out is by Dr. Jose Natario who reconfigured the shape of the warp bubble. He put the expanded space-time in front, which would move away anything in the way.
Interestingly, using the drive for a slower than light journey would eliminate the radiation as well as the lack of control. So if we figured out the drive in the next few years, and it wasn’t FTL, it’d still be a revolution in space travel. Our current fastest object is 0.03%c, where c is the speed of light. An Alcubierre drive would have little trouble approaching c so it’d be an increase of almost 9000%. Insert the “IT’S OVER 9000!!!” joke here.
However, other research has went into more interesting directions. Dr. Chris Van den Broeck offered a new take on the Alcubierre metric that was quite different from the original design, while also reducing the negative energy requirement. He discovered that you could increase the size of the inside of the warp bubble while reducing the size of the bubble itself. His version of the metric would have the ship inside of a volume that, due to space-time curving, can be larger than the surface volume of the same space in a flat space-time. Essentially, there’d be a pocket of regular space curled off from the rest of space-time with a small opening connecting them. The standard Alcubierre metric would be used then to accelerate this tiny opening to FTL speeds. The inside bubble could be expanded by the sheer act of slowing down at the end of a journey. However, since the ship is closed off of the rest of the universe it’d still be a blind jump, but that’s still a good start. Going further on the limiting of negative energy, Dr. Sonny White of NASA showed that by making the warp bubble shape from a sphere to a toroid – think a donut – you could lower the energy requirements and oscillating the warp metric lowers it even more. He’s actually working on microscopic space-time warp experiments currently.
Alright, now for that important question: how fast can it go? Dr. Alcubierre doesn’t really mention an upper limit in his original paper, but later estimates put the speed at anywhere from 10c to 100c. Very, very fast but it would still take almost 4 days to go one light-year. However, in his very interesting paper “Warp Field Mechanics 101” Dr. White talks less about outright speed as much as he does speed multipliers. Much like how warp drive functions in Rebel Galaxy, the Alcubierre drive might work as a multiplier of realspace speed. A craft going .25c in realspace could activate their Alcubierre drive and multiply their speed by hundreds or thousands. Very cool to read, but we won’t know hard data on a Alcubierre drive speeds until more research is done.
In a great bit of turnabout, especially for a lifelong sci-fi fan, the canon Star Trek warp drive is now a derivative of the Alcubierre drive. Dr. Alcubierre no longer works on the theory of his warp drive, though he can be seen on science shows here and there discussing it. He currently is working on other solutions to general relativity. He’s also on Twitter. Give the man a follow. I also highly recommend the Wikipedia article on the Alcubierre Drive as it goes far more into the theory, problems, and research related to this idea. While this technology is still a long way ahead, it’s very interesting to see that we can still invent ways to circumvent the speed of light barrier without violating known physics. I’m optimistic that we can one day use this as an FTL drive and I look forward to future breakthroughs. This may be the only physics-approved way to travel FTL in realspace, but it’s not the only way we’ve come up with that can allow for FTL. However, that’s the next article in this series and for that one I hope you’ve been thinking with portals. I hope you’ve enjoyed this article, thanks for reading and please feel free to contact me on Twitter or comment if you’d like to discuss anything in this piece.