Welcome back to another entry of Gaming on the Fringe. I’m doing another in the “currently somewhat scientifically plausible FTL device” series by going after something nearly all gamers are familiar with. With that, I’m saying one thing outright now to stop the meme brigade:
The Cake Is A Lie. We get it. We’ve all heard it. There’s more to the game than four freaking words. Just like “DO A BARREL ROLL” of a few years prior, it was a joke that ran its course very very quickly. End of rant. As with all Gaming on the Fringe entries I’m not looking at the plot of the game but rather the technology they use in game. I will be spoiling the end of Portal 2 so let’s get our old friend SPOILER ALERT to make an appearance. Alright, let’s take a look at the Portal gun.
The game wouldn’t be Portal without the ability to make portals and it does so with the obviously named Portal Gun. This device, once at full strength, allows the user to make two connecting portals. While they are differentiated by color you can enter either one to exit out of the opposite one. The training sections make sure you know that all momentum and inertia are unaffected by going through a portal, and in fact a good amount of the game’s puzzles rely on this feature. There is no limit to the amount of times portals can be used or how many times you can fire them at another surface, but you must have two portals out in order to travel. You can even set up a portal on the floor and ceiling to have an infinite falling loop, though in game this is just a way to kill time. Unlike many portals in fiction you can bounce up against the side of the portal with no ill effects, like being cut in half. I’m not sure how that actually works, but it does save a whole lot of frustration during the game.
This isn’t to say that the portal gun has no limitations. Portals can only be made on surfaces prepared with a suitable covering. The game mentions most of the walls that you can shoot portals onto have been painted with a paint containing moon dust, but it never states that portals can only be made on substances with moon dust or that there might be other suitable landing zones. If you fire a portal at a surface that doesn’t have the appropriate coating it just splashes off. Yes, splashes, as it most resembles a bit of Kool-Aid bouncing off the wall. You also cannot fire a portal through another portal as this would cut off the paired portals anyway. The portals fire out of the gun rather fast, apparently speeding up the farther they travel, though travel between portals is instantaneous.
That last point is where we get to Portal 2’s final boss battle and one of the finest examples of scientific accuracy in gaming. As mentioned earlier, moon dust allows portals to be made. During the final battle against Wheatley you fire a portal at the moon. The portal actually takes time to get there, allowing for the distance and the lightspeed limit. Once the portal opening reaches the moon, the portal devices prove to be a faster than light mode of teleportation as it instantly transports anything to the moon. Interestingly, the game notes the moon is a near vacuum and as such the portals act as a vacuum sucking up Wheatley. Too many examples of portals/wormholes in media seem to forget that places like the moon or space are vacuums, but Portal 2 gets this absolutely right.
Portal may be one of the most famous uses of the eponymous portals in games, but could such a thing exist in real life? It’s time to go through the wormhole. A small caveat: I’m not a physicist, just a layman with a strong interest so I’m going to be avoiding some of the higher end discussions here. I’d recommend the wikipedia page for a better overview.
A wormhole is a theoretical construct where a hole in spacetime is connected to another hole in spacetime through the higher dimensions. While some scientists still refer to these higher dimensions as hyperspace, many refer to this as “the bulk” to avoid comparisons to the hyperspace of classic science fiction. Now, when I say “higher dimensions” I don’t mean things like alternate universes/dimensions – don’t worry, that’s another article – I mean spatial dimensions beyond the standard height, width and depth. Our universe is mostly fourth dimensional, as time is the extra dimension, but most higher physics accept there can be up to seven more dimensions. I could honestly do most of an article just discussing higher dimensions, but we’ll leave the discussion at the fact that there are higher spatial dimensions.
Wormholes were actually originally envisioned by Albert Einstein himself as a thought experiment. The experiment was based upon recent investigations into the possibility of black holes that general relativity allowed. He and his student Nathan Rosen demonstrated that following the lines of a black hole it might be possible to connect two separate areas of spacetime, linking vast distances via a very short hole. The actual term “wormhole” was coined by John Archibald Wheeler in 1957. He used the now famous analogy of a worm in an apple. A worm crawling on apple may take a long time to crawl around the outside of the apple, but if he simply eats through it he can arrive on the other side much faster. This is exactly what a wormhole would do with large sections of interstellar space. A wormhole is similarly two sections of spacetime, called the “mouths” of the wormhole, connected through the bulk by the “throat” of the wormhole. Since the wormhole is created by things like black holes or singularities, the edge of a wormhole would have severe gravity which could destroy a ship that didn’t enter the wormhole correctly. Interestingly, unlike Portal a real wormhole would be a sphere instead of a 2-D circle so you could theoretically enter from any direction depending on the tidal forces.
As proven by general relativity, nothing with mass can exceed or even attain the speed of light – 186,000 miles per second – but you can get around this with a wormhole. By using gravity to rip a hole in spacetime you could connect two locations in spacetime that are otherwise seperated by lightyears. This could allow effective superluminal (faster than light) travel yet the spaceship travelling the wormhole never goes faster than light locally. Let’s say that a wormhole connects two places that are 5 light years apart in regular space, but the wormhole throat (the actual part you travel) is only a light minute. If you traveled both methods at .5c (c being the scientific shorthand for the speed of light) it would take ten years in regular space but the same distance through the wormhole would only take you two minutes. In neither case did your starship go faster than c but can have what’s called “effective superluminal travel” by using the wormhole shortcut.
The problem is that most wormholes form and immediately dissolve so quickly you would have to have superluminal travel through the wormhole to use them. This theory got changed in 1981 when legendary astronomer Carl Sagan asked his friend physicist Kip Thorne, who had been exploring wormhole physics for years, to figure out a way to use them for FTL travel without violating physics. He came up with a set of equations that described what has became known as a “traversable wormhole” because you could actually traverse it. However, it would require negative energy/matter as in the previous entry of the Alcubierre Drive. The negative matter would keep the throat of the wormhole from collapsing, as well as hold back the very strong gravitational effects of the sides of the wormhole mouth. Interestingly, if you have even more negative energy, perhaps generated by Mach Effect, you could create what’s actually referred to as an “absurdedly benign traversable wormhole”. This would use the negative energy to compress the tidal forces enough to make them very easily used. Two problems still exist: whether negative energy can be created in sufficient quantities and how in the hell to make a wormhole in the first place. This is obviously not something we’re going to throw together in a garage over the weekend to show those stiff NASA bastards.
What’s very interesting with a wormhole is that it could theoretically be used for time travel as well. Spacetime is a thing for a good reason, and a pair of wormholes could conceivably connect past and future times. The main caveat is that no pair could ever go back further than their creation, and anything that would violate causality was proven by physicist Matt Visser to collapse. There’s even an interesting application of time dilation of high speed travel that would use wormholes to time travel. Considering in most interpretations of wormholes in science and science fiction you have to deliver one mouth of the wormhole to the destination at slower than light speeds, you could conceivably make a wormhole mouth and fire it at a nearby star. If the mouth traveled at a high fraction of c, what’s called “relativistic speed,” it would experience time that is much shorter than the outside world. While it may take 60 years for light to reach this destination maybe our wormhole travels at .9c and so makes it there in 66 years. However, because of time dilation the wormhole experiences a much shorter trip so the other mouth, still at Earth, sees it find its destination in about 26 years. That said, if someone on Earth goes through the wormhole when it reaches its destination they will find themselves 40 years in the future but can go back and forth through the wormhole. Comparing it to Portal, it’s hard to really tell if the they factored in time dilation as the moon is just over one light second away. A second or so of difference won’t really be noticeable.
The travel through a wormhole, avoiding the tidal forces near the edges, would involve flying your ship towards a large sphere which would start warping the view of stars around you thanks to the gravity causing gravitational lensing. As you are going through the wormhole proper, this view would be more distorted as the light from both mouths is trapped in the gravity tides. You would eventually come back out the other side to see the stars in that area slowly unwarping themselves. It would be one hell of a trip, to say the very least. It’s also somewhat close to what Portal describes as you could see the opposite end through the wormhole. Portal doesn’t get all parts of wormhole theory correct, but the fact that a game that isn’t too worried about science actually get so much right is rather impressive.
The problems with wormhole construction – negative matter/energy and a lack of a definitive way to make a wormhole in the first place – makes this a device for a much more advanced civilization. Carl Sagan believed that such a civilization could maintain a network of wormholes to have an interstellar polity, and so far science hasn’t really ruled these out. Unlike with the time travel problems associated with the Alcubierre Drive, there’s not a concern of a closed timelike curves in wormholes so they’re more likely to be usable. We still of course have to deal with creating a large amount of negative energy, but there’s nothing that says it’s impossible. One can only hope that Science Marches On. However, if you want a movie that is very meticulous about how it approaches wormholes check out Interstellar. It’s amazingly close thanks to one of the head writers and executive producers being none other than Kip Thorne, who developed traversable wormhole theory in the first place. His book “The Science of Interstellar” is also highly recommended, and was the catalyst for writing this article.
Thanks for reading this entry in Gaming on Fringe. As always, I’ve hoped you’ve enjoyed this and maybe learned something new. If you have any comments, feel free to comment below or find me on twitter @ithinkibrokeit. If there’s a physics topic you’d like to see me cover in GoTF please let me know. Thanks for reading.