FTL Flavors: Summary

This is the sixth and final installment of my series on the different flavors of FTL. We’ve warped through hyperspace and jumped through wormholes… or something like that. To clear it up, here’s a summary table showing how these various flavors stack up on the criteria I used:

FTL-Flavors-summary

Clearly, that’s a simplification of several simplifications, but in reducing the various drive features to simple yes/no pairs, it highlights a couple of things. First, not all of the options are represented. What if you took something like warp drive and changed the FTL-FTL box to no? What would that look like if FTL ships could no longer interact? Is it that they cannot see each other? Or maybe they only see each other long after they’ve passed? Maybe they have FTL drives but not FTL sensors?

For another example, what if we put a “yes” in the FTL-Navigation box for wormholes? Maybe instead of simple point-to-point tubes, we’re actually cruising through a complex network of junctions and connectors. Maybe our expected Sol-to-Rigel trip is merely the result of taking all the default options at every junction? What if we could alter course at key junction points and end up somewhere entirely different? What if that kind of exploration can only be done by trial and fatal error?

The second thing I notice with such a table reduction is that there are very different ways to expand these choices into the story mechanics of the drive system. Consider that wormholes and jump drives have almost identical table entries, i.e. Rarely or No across most of the table. Yet these two FTL systems have very different feels to their stories.

Similarly, even staying within a single system can give you FTL drives that end up looking quite different in the actual stories. Consider warp drive. We’re all familiar with how it works in Star Trek. We tear across the universe, warping space and manipulating subspace fields and so on. In my space opera universe of the Hudson Confederacy, ships are using tachyon drives, essentially throwing up ephemeral sails to catch the tachyon wind and yank them up to FTL speeds. The mechanism looks completely different, yet functionally, my tachyon sails are just another warp drive. But my navigators don’t worry about subspace interference. Instead, they worry about shifting winds and tachyon storms.

Furthermore, it’s also an over-simplification to think that a story must use only one flavor of FTL. Many combine them. For example, the Honor Harrington series by David Weber uses a mix of hyperspace and wormholes. That is, while most travel occurs via hyperspace, one planetary system hosts the intersection point of several long-distance wormholes, giving them a huge strategic advantage both for shipping and war. Similarly, some of the later Star Trek series (TNG, DS9, and Voyager) added rare wormholes on top of their trusty warp drive fleet.

So, did I skip a flavor? Probably. There’s a lot of SF out there. Some of those FTL systems may indeed be fundamentally different, but I suspect that a lot of them will boil down to being one of these four with different names and different hand-waving for the so-called science.

But the most important thing for all of them is to get your characters from here to there before they grow old and die. And once there, they can try to write a letter home, which brings up the matter of FTL communication, but that’s a subject for some future series of articles. With luck, I’ll get to that before we reach Sirius.

The whole series: Intro, Warp Drive, Hyperspace, Wormholes, Jumping, Summary

FTL Flavors: Hyperspace

hyperspaceThis is the third in my series on different flavors of Faster Than Light (FTL) travel, and today I’m taking a look at hyperspace. The general idea here is that there is a separate space, parallel to our own, that allows for shorter travel between two points. It’s no longer four light years to Proxima. Instead, you transition over to hyperspace, travel a hundred thousand kilometers, and drop back into normal space at Proxima.

Generally, hyperspace is considered to be as Euclidean as normal space (which is not always truly Euclidean) and is scaled linearly with normal space. That’s the $5 way of saying that if you go twice as far in hypespace, you’ll go twice as far in normal space and in the direction you would have expected.

gateThe only tricky thing about hyperspace is getting between normal space and hyperspace. In some stories, your ship can contain the necessary equipment to open a transition point. In other tales, it requires a gate in normal space to open that transition point. But once you’re over in hyperspace, it’s just a matter of throttling up or sailing away.

Let’s see how the details break out.

FTL-to-FTL interactions: This varies. In some stories, hyperspace is a chaotic or void space that is completely incomprehensible, so you cannot interact with other ships even if they were supposed to be flying formation with you. In other tales, hyperspace is pretty much just like normal space but with better graphics. In those cases, you can fly around, talk to other ships, and even shoot at them. Of course, there’s room to play around between those two extremes such as limiting communication range due to “hyperspace flux” or the likes.

FTL-to-sublight interactions: Usually there are no interactions here. You are in a truly separate space. At best there is a level of communication, but that is typically done via fixed points like gates. However, I have seen a couple of odd exceptions to this rule, typically where something unusual in normal space (such as a supernova or black hole) will cause a disturbance in hyperspace.

Relativistic effects: Generally there are none. The ships aren’t typically travelling very fast in hyperspace. It’s just that the distance there is shorter. Either that, or there is simply no special relativity in hyperspace. However, I have seen an odd time variation in some of C.J. Cherryh’s stories where mental processes continue on at a normal pace while other biological processes slow down. This allows frequent travelers to have a mental age of 40 while still appearing to be only 30.

In-FTL Navigation: This can vary, but there is almost always some. At the very least, ships travelling through hyperspace have the option of dropping back to normal space early, short of their destination. Course changes might require such a transition back to normal space, but there is that option. However, in most cases, hyperspace seems to allow as much navigational flexibility as the warp drive, complete with screeching turns and barrel rolls. Still, one limitation on this is the fixed points of gates. If you can only transition via the gates, then all the zigs and zags of your pilot won’t change the fact that you really only have a handful of destinations.

Speed Differential: Again, there typically is speed differential in hyperspace, typically achieved simply by travelling faster or slower within hyperspace. Sometimes, though, I have seen it done with multiple parallel spaces with different speed limits with them, e.g. hyperspace-A allows an effective 10-to-1 speed boost, while hyperspace-B gives 1000-to-1. However, I have seen a few cases (notably most of Jack McDevitt’s Omega Cloud series) where all ships travel through hyperspace at the same rate, since that is believed to be a fundamental property of hyperspace.

Malfunctions: These can suck. The most common malfunction is with your ability to transition to and from hyperspace. If you end up stuck in normal space, you’re just like the folks with the busted warp-drive, sticking your thumbs out in hopes of rescue. Except, of course, if you’re out in the middle of interstellar space, there won’t be any warp-drive ships careening past to see you. Instead, they’ll all be passing by unseen in hyperspace. Even worse is when you get stuck in hyperspace. Unless you can get to a gate to transition back, you’re left to the mercy of whatever monsters the author has left lurking in the dark corners of this alternate reality. Most often, those ships will simply disappear like the sailing ships of old, leaving only grieving widows and frustrated insurance adjusters.

Special traits: This is a nice dodge around relativity’s limits that doesn’t require much hand-waving with dubious physics. About the only big decision to make is whether or not ships can generate their own transition points or if some or all of them require a system of gates.

Tune in next week for a look at wormholes.

The whole series: Intro, Warp Drive, Hyperspace, Wormholes, Jumping, Summary