Spoilers for the Battlestar Galactica series finale

In the climactic moments of “Daybreak,” the Colony is struck by a volley of nuclear warheads—fired (depending on how you choose to interpret it) either by our heroine Maggie “Racetrack” Edmondson in her dying moments, or at least, by divine intervention, from her plane. In its death-throes, the Colony slides toward the black hole it orbits, dragging with it the Galactica and what’s left of her crew. At this moment, the significance of “The Music” (i.e. the Final Five theme and Hera’s notes) is revealed: Ordered to jump the ship to literally anywhere else, Kara “Starbuck” Thrace intuits numerical values from the notes, punches them into the FTL control console, and turns the key.

For just a moment, above the report “Jump Complete” displayed in large, friendly letters, we glimpse what Kara typed:

1123,6536,5321

“Where,” Laura asks, “have you taken us, Kara?” Home, it turns out.

“Daybreak” ties together many threads of story and mythos, but it leaves us with some technical questions. This post considers one of them: What did Kara tell the FTL system to do?

I.

Some context. Colonial faster-than-light technology involves an instantaneous, space-folding jump rather than rapid travel in what Larry Niven’s books call “Einstein space” à la Trek. The mechanics and limitations of this technology are unspecified. The practical limit on its use is the compounding uncertainty about one’s destination as jump-range increases: The speed of light is finite, so any observed information about a destination 1 light-year distant is, by definition, a year old. Safe operation of jump-drives therefore require sensory equipment to observe the vicinity of your destination and computers to calculate the motion of every object that may cross through your arrival-point. The farther you jump, the greater potential for error, and the less certain you can be about your destination.

During production of season 4.5, producers asked composer Bear McCreary to figure a theory that could explain Kara’s intuition, linking his Final Five theme to something the FTL system can accept as input. In a blog post that has won wide but uncritical fan acceptance, McCreary explains where he came out on the question. First, he consulted science advisor Kevin Grazier, who said:

“When we specify coordinates in astronomy, it’s usually done with two angles – one that ranges 0 to 360 degrees, the other +90 to -90 degrees. Necessary also is the distance … we’ve already established that one unit of measure used by Galactica is the SU, … similar to the Astronomical Unit used in our Solar System … So as I see it, we will need from the music: XXX carom YYY dist ZZZZZZ.”

Then, after discarding more complex approaches to generating numbers, McCreary

decided to assign each note in the C# scale a number, excluding the chromatic notes between them. This is a diatonic approach instead of a chromatic one … [with] several advantages. It produces only single digit numbers. It is also the most intuitive solution … [because] In basic ear training exercises they make you sing melodies with words or numbers corresponding to the notes … So, someone like Kara who was taught by a professional musician as a youth could be familiar with thinking of the tonic as ‘1’, the second scale degree as ‘2’ and so forth. It’s believable that Kara might be humming the tune to herself as the numbers come to her mind. With this philosophy in mind, I took a second look at the Final Five Theme. The melody is either 11 or 13 notes (depending on if you count the little triplet ornament figure that does not consistently appear with the theme). The easiest way to arrive at 12 notes was to discount the triplet figure and then repeat the first note, which is technically the way the phrase is looped in my arrangement of “Watchtower” anyway. Assigning numbers based on the diatonic scale system I described earlier yielded … [a vector]: 112 carom 365 dist 365321.

For the record, I wrote everything published heretofore with the Grazier-McCreary solution assumed. It never became relevant to consider in depth. But further reflection has changed my mind: While the producer’s intent is clear, intent isn’t canon, and that can’t be how the FTL targeting system works.

In Grazier-McCreary, Hera’s notes become Kara’s vector: 112365365321 becomes 112 carom 365, range 365,321. The smaller objection to this solution is that it doesn’t match what’s shown on screen. The number-grouping displayed on the FTL console is 1123,6536,5321 not 112,365,365321. It would be very strange—nay, weird—to write military software displaying a vector that way. That contradiction bugged me while I was writing; not enough to get stuck on a detail that wasn’t relevant to my project, and it’s not conclusive, but it’s worth noting in this context.

The bigger objection is units—365,321 whats? Grazier & McCreary say that the range input is in SU, the Colonial equivalent of AU. That can’t be right.

For one thing, if the FTL targeting computer takes SU as its range, then, with no room for decimal places in evidence, 000,001 SU would be the minimum range cognizable by the computer. That feels far too imprecise. If the targeting computer uses SU, it is incapable of the precision that we have seen in the show: Jumping into orbit, jumping into an atmosphere, jumping in close formation, jumping within a boat-length of the Colony. SU is just too coarse a unit.

And even if the minimum jump distance were precisely 1 SU, i.e. 150 million kilometers, that’s far larger than the minimum-distance jump we’ve seen Galactica perform. For example, in “Exodus,” Galactica jumps from ~4900 meters (sic.) over New Caprica to orbit, a jump of no more than ~40,000 kilometers. So the input can’t be in SU.

But obviously if SU is too large and coarse a unit, the input can’t be in a unit so small and precise as meters, either. So—what?

II.

Let us observe that if one aspect of Grazier & McCreary is unsound, others may be, too. Fan Thomas Roewer has suggested that we discard the vector framework entirely and consider the possibility that the FTL computer takes only range as input. We don’t need bearing, Roewer argues, because the system could take those from the orientation of the ship: From the axis made between the FTL spin-sync generator and some counterpart unit that, in the Galactica and most other Colonial ships, is located in the bow.

That solutionis surprising, but, intriguingly, nothing on screen contradicts it. Several things are at least consistent with it; a few could be read to affirm it, if implicitly. In several episodes, not least “Daybreak” itself, we see Colonial vessels engage in positioning-maneuvers before making jumps. We also see the apparent conservation of rotation and direction through jumps, not to mention conservation of relative positioning and attitude of the ragtag fleet. It could also explain why jumps produce first a visual flash from the presumed location of the spin-sync generator and a second flash that travels down the long-axis of the jumping ship.

At very least, then, canon doesn’t exclude the Roewer solution. And there’s a very good argument in favor of it: Roewer liberates Kara’s numbers from the need to provide a bearing. If all twelve numbers are available to describe range, we can solve the “stellar units are too big but meters are too little” riddle.

Assuming that the input takes a single variable, range, we’re back to the “what units” problem with a different number: 112,365,365,321. Still, we can now discard SU as a contender. For one thing, any problem of the coarseness of SU as a unit of input is vastly multiplied. But there’s another and stronger reason why it isn’t SU.

Bracket the question of the theoretical range of the FTL system itself. Assume that the engines are effectively limitless—or at very least, they can perform any jump within a margin of safety beyond the maximum input range of the FTL targeting computer. (Why would anyone design a control system that lets a helmsman ask the engines to perform beyond their ability?) If the FTL input is range in SU, the Galactica’s last jump was 112,365,365,321 SU or 1,776,778 light-years. And the maximum range that can be entered into the system is 999,999,999,999 SU, or 15,812,507 light-years.

That’s an absurd result, and so an implausible one. It isn’t just that the telescopy and computing-power required to perform the necessary observations and calculations at even the lower end of that range is implausible, although that’s certainly a problem. The fatal flaw is: Why would Colonial civilization—limited, so far as anything even vaguely canon-adjacent tells us, to a single system less than a light-year across (Cyrannus rounds to .1616LY at total Opposition)—write software that accepts so vast a range as an input? That doesn’t pass the laugh-test.

So if SU isn’t a viable unit, what about something smaller? 999,999,999,999 kilometers is .1057 light-years. Better yet, 999,999,999,999 miles is a very Trek-friendly .1701 light-years. We don’t know what units the Colonies use in this ballpark, but any unit in the general scale of miles/kilometers would allow for jumps as precise as those into and out of the atmosphere of New Caprica, and as far as from one end of Cyrannus. That’s a reasonable distance that fits within the parameters and scale of the presented world.

* * *

Two objections should be met. First: The QMX map says that Kobol is 2,000 light-years from the Colonies, and a maximum jump-radius of .17 light-years is too small to make it there in the number of jumps shown in season one. Still, that objection isn’t fatal. The 2,000 LY number isn’t canon, and there’s no particular reason to believe that the Colonials share our lack of a standard unit larger than 1km but far smaller than 1AU. As “33” opens, the fleet is on the run from the Cylons and has completed jump 237; we see jump 238. At a range of .1701 LY, if they are running in a straight line, they’ve made it 40.48 LY from Ragnar. Kobol could be closer than QMX says, and the colonial unit of input could, without any violence to the foregoing analysis, be significantly larger than a kilometer. If the Colonials have a unit of measurement answering to 5000 meters, the same logic applies.

Second: It’s stated more than once that it’s supposed to be impossible to track a ship through a jump, and if Roewer’s right, insofar as a ship’s orientation can be seen before a jump, wouldn’t you just need to look along that axis to track a ship? Not necessarily. For every additional light-second of range, the uncertainty field increases in area, spreading conically, with different possible solutions based not only on distance but small variations in observed orientation. You would need to know orientation with great precision past a few light-minutes.

All told, the evidence is not conclusive, and significant deference is owed to production statements like the Grazier & McCreary solution.And Roewer’s theory isn’t without difficulties and contrary evidence; one could point, for example, to “Crossroads,” in which Racetrack does not appear to perform an orientation before the emergency jump back to the fleet. Nevertheless, Grazier & McCreary leaves a significant problem for interpreting Kara’s numbers, and adopting Roewer’s theory opens the way to solving those numbers: An FTL control system that takes bearing from orientation and accepts input in some unit approximating miles (or within a few orders of magnitude thereof) provides a possible solution for how the FTL system operates.