In Stargate, we learn that seven symbols are needed for a stargate to activate and open a wormhole. The first six create a three dimensional axis that points to the destination at the center of the axis. The seventh symbol is for the origin point. That is why every address they use to get from Earth somewhere ends the same.

But in one episodes where O'Neil travels to the Asgard galaxy and in Atlantis they use an eighth symbol. In Universe they use a ninth symbol to get to Destiny. What do these symbols do to the logic of the address?

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    Were I to guess, the question was likely down voted because the purpose of the extra symbol(s) is explained in the shows, as well as fairly easily found via Google.
    – Xantec
    Jul 6, 2013 at 0:55
  • @Xantec 8th symbol was ad-hoc explained (that is, nowhere near the same detail as 1-6 and 7), but I don't remember if 9th was explicitly explained inside the show itself. There are only 2 known 9-chevron addresses, after all.
    – Izkata
    Jul 6, 2013 at 1:47
  • @Xantec I know what it is used for, however, it is the logic that I cannot make sense of.
    – user15742
    Jul 7, 2013 at 16:35
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    @Izkata: Those two being destiny and earth from destiny? I originally could only think of one but realised that the second is presumably implied if not explicitly stated?
    – Chris
    Jul 9, 2013 at 16:34
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    @fredsbend It was a "one-way ticket" solely because they didn't have enough power to dial Earth. During their attempt to dial Earth while inside a star, Telford successfully gated from Destiny to Earth.
    – Izkata
    Aug 5, 2014 at 3:39

7 Answers 7


For the eight chevron, it's used as an additional calculation for extra-galactic travel (outside of our own galaxy), which serves as distance from here to there. For Atlantis, you'd most certainly need it as it is sitting in its own galaxy and separate from our own.

The ninth chevron is less conventional and is mainly used for Destiny as it points to a specific gate instead of a location. Because Destiny does not inhabit a fixed point in space like every other gate we've come across, it can't be dialed without this chevron due to the nature of where Destiny may be at any given time.

Both require a lot of energy to work and create a functioning wormhole for travel, much more than your average Stargate is meant to handle. However the last chevron, no matter how long the address, will be the point-of-origin and is thus not always the seventh chevron. If you were dialing to Atlantis, you'd still need an extra chevron for the extra-galactic address but the last (now eighth) would be the origin gate. The Atlantis chevron is inserted someplace between the address and origin chevrons. Same for the ninth.

For more information, I found the Stargate Wiki to be a great resource as well as where I remembered most of my Stargate-verse. It's been a while since I've been to visit this universe.

EDIT: More information with thanks to Arammil

The Stargate address can be seen as mathematical equation with the solution being the destination Stargate. Thus, if letters A-F were the first sixth chevrons, with the letter P being the point-of-origin (usually Earth), would make an address/equation look like this:

A+B+C+D+E+F+P = Destination

If you added an eighth chevron, to get to Atlantis, you'd add that extra co-ordinate (which we'll name G) for the extra-galactic travel needed. Our address/equation would look like this:

A+B+C+D+E+F+G+P = Destination

You can see that our P value (point-of-origin) has stayed in the same relative, but not absolute, spot as the first: the last value added to create our destination value.

And, finally, for the ninth chevron, our address/equation would be like so, assuming H for the rough equivalent of Destiny:

A+B+C+D+E+F+G+H+P = Destination

Again, P stays in its relative position to the others and remains as the last variable to be added to our destination address. Of course, how the actual "math" of gate travel is not known, and to my knowledge was never adequately explained in the show, so this is the best I could come up with. I'm sure that if they did, it would be a much more complex equation.

  • Thank you for the brief descriptions. I was looking for more of an explanation of the logic. Using an eighth symbol must change the meaning of the other seven, but how?
    – user15742
    Jul 7, 2013 at 16:50
  • @fredsbend I'm not entirely sure what you mean by logic but I'll try and take a guess. The first conventional six are the destination address. The last chevron, no matter how long the address, will be the point of origin and is thus not always the seventh chevron. If you were dialing to Atlantis, you'd still need an extra chevron for the extra-galactic address but the last (now eighth) would be the origin gate. The Atlantis chevron is inserted someplace between the address and origin chevrons. Same for the ninth. Was this the particular you were looking for? If so, I'll add it into my answer. Jul 7, 2013 at 17:40
  • It might be easier to think of the stargate system as a computer network and each of the symbols as mathematical instructions. You have a 6 string code (say.. something like binary) with a seventh digit that completes the equation. Additional variables alter the calculation in such a way as to alter the corresponding physical target. I.E. A+B+C+D+E+F=G is not the same as A+B+C+D+E+F*(Q+R)=G
    – Arammil
    Jul 9, 2013 at 8:08
  • also redknight, you're free to steal that and use it if you wants.
    – Arammil
    Jul 9, 2013 at 8:09
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    Also, the gate addresses technically ARE mathematical equations where glyph represents a point in three dimensional space. Then a center point is calculated from the position of each point. This comes directly from Stargate the movie. This would indicate that additional glyphs only modify the initial equation. An 8th symbol obviously adds a distance modifier (as stated by Daniel Jackson) and a 9th glyph would indicate velocity.
    – Arammil
    Jul 10, 2013 at 10:13

What do these symbols do to the logic of the address?

How the eighth and ninth chevrons do their work is technobabble. What they do exactly as shown in the series. They extend the address space in a way that's addressable via the same user interface as a normal dial.

An explicit analogy is drawn with phones for the eighth chevron. Let's say I want to call +1-123-555-1212. If I'm already inside area code 123 in the United States, I can just dial 555-1212, and that gets routed in a particular way at my local exchange. If I'm in the US but my local exchange isn't 123, I have to dial 123-555-1212. If I'm outside the US, I have to dial +1-123-555-1212. In all cases, the "fully qualified" phone number is +1-123-555-1212, but I don't always have to type in all of it.

In the case of the eighth chevron, it's explicitly noted that this routes the wormhole into the Stargate network in another galaxy - exactly like an area or country exchange code.

The ninth chevron triggers link-layer addressing (the language used in the show is "dialing specific Stargates"). It bypasses the (normal, more useful) location-based network addressing in favor of hardware-based addressing. This is harder to find an analogy for because everyone has dialed another area code, but most people have never heard of network layers. A simple (but poor) comparison would be typing an IP address vs. a domain name. A more complicated (but better) one would be InARP lookups.

  • The area codes is a very good analogy. +1
    – user15742
    Jul 10, 2013 at 22:58
  • @fredsbend i believe it was the exact analogy used in the show. Link: stargate-sg1-solutions.com/wiki/index.php/… Look for: "dialing a different area code"
    – DickieBoy
    Sep 1, 2015 at 16:21

The eighth chevron is used for intergalactic travel (travel to other galaxies);to do this you would require a zpm (zero point module) or an alternate power source. The ninth chevron is used for travelling to a place which doesn't have an exact point in space; for example destiny is ship which doesn't have an exact point in space (it is always moving). Both the Eighth and Ninth chevron address's require a huge amount of power like a zpm or another power source.


To me, the reasons for the 8th and 9th chevrons are kind of like dialing a landline phone number... in example, here is a random UK landline phone number; 581 6552.. If I'm in this area, i don't require an area code. So think of our galaxy and every gate address in it in the same way... 7 chevrons; 6 to map the 3 dimensional space, and a point of origin. I wouldn't need an eighth chevron as it is taken for granted i am dialing the galaxy i am occupying. Now, imagine I want to call that number while I'm NOT in the local area...now i need an area code.. so the number becomes (0191) 581 6552... the eighth chevron can be considered an area code, specifying which galaxy you are dialing... now, if i need to make an international call, i need a country code.. so now the number becomes +44 191 581 6552.. Since Destiny is a vast area of space away (and is mobile with no fixed location) the ninth chevron is needed to pinpoint a specific gate, since it is unknown which galaxy it is in at any one time.. though in my mind, since there is no way of knowing which galaxy the ship is in, I'd argue that there isn't one additional chevron, but two - a standard SEVEN chevron address, with TWO additional chevrons to dial a specific gate (since it would make no sense to have an 'area code'in this case) That is my personal take on it :)


The eight and ninth chevron calculates a scalar, a single value that multiplies the coordinates on the vector now if the six point coordinates were say -72 x 866 y and -826 z then calculate a scalar to be about 3,000 that's 3,000(-72) x 3,000(866) y and 3,000(-826) z = -216,000 x 2,600,100 y and -2,480,400 z which comes close to 3.6 million light years out

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    Welcome to SFFSE! Do you have any evidence to support your initial premise that the eight and ninth chevron calculates a scalar? Thanks! Jan 3, 2016 at 7:54
  • From reading math, vectors in 3d space and my best theory on this. Look up scalar multiplication on wikipedia, you will see that one short vector will stretch to a greater distance with scalar multiplication. Also this scalar multiplier needs to be positive or the course vector would flip in the opposite direction 180 degrees out of alignment with using a negative factor. Apr 18, 2016 at 6:02
  • Also if you have any theories on how the position x, y, z to the first six points is determined to a completely dialed address please share. I have some idea that position adjustment based on what the positions are and the order and some vector manipulation to intersect them is involved. Perhaps vector rotation and distance measure as well. How this is achieved I would like to find out, perhaps further reading into this Apr 18, 2016 at 6:09

It's explained in show that the 8 symbol address are exactly like local area codes for national telephone exchanges (as described above). The traditional 6 symbols that triagulate the destination point are translated into the new reference frame (that of the other galaxy) and hence define a point in that reference frame (the origin point remains constant).

The 9 symbol sequence is not an address in the traditional sense. It does not point to a location. It's described in the show as a hardcoded sequence (kind of like a password). But it's not some arbitrary password, it's definition is algorithmic and changes depending on your origin point - where you dial from - hence the discussion between Eli and Rush in the first SGU episode before they leave for Destiny ('what if we're not meant to be here?!')

  • Welcome to the site. Please have a look at the tour to get a better idea of how things work around here. This question already has an accepted answer; you don't seem to provide any new information or new interpretations.
    – T.J.L.
    Apr 20, 2016 at 13:20

The eighth chevron dials a different galaxy and the ninth brings them to an ancient ship that is many millions of galaxies away from the Milky Way. This happened in Stargate Universe.

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    what episode(s) of stargate universe explained this?
    – phantom42
    Sep 1, 2015 at 5:35