During my re-watching of some of the early SG-1 seasons, I came across a classic episode, "The Fifth Race". During this episode, using purely Terran technology, O'Neil constructs what is discovered to be a 'Power Booster Device'. While O'Neil DID have the entire repository of Ancient knowledge at his disposal, his materials (excepting the staff weapon power source) were entirely Terran.

This device, draining the entire power source for a Staff Weapon, was able to open a wormhole to an Asgard planet by supplementing the existing power source for the Earth gate.

They learned how to recharge it in a later episode, "Point of View", but left the device in an alternate reality.

Obviously, this device wouldn't solve all their problems - it's a one-shot device which requires some amount of rework before it can be used a second time, and it's doubtful it would work on non-Earth gates (without the power generators it's designed to hook into).

But why didn't they build a few more of these - they can be made from spare parts, powered by the plentiful staff weapons, and would have provided the Tau'Ri with a method of calling the Asgard in case of a serious emergency (prior to them gaining a reliable method of doing so). It also could have potentially served to open the wormhole to Atlantis...so why did they drain the Earth ZPM instead of building and using one of these?

In-universe answers preferred, the storytelling reasons are fairly obvious.

4 Answers 4


Just because it's made from Terran parts, must it be able to be duplicated by a non-Ancient? We know unstable Stargates can be built from purely Terran parts, for example. If I handed Archimedes a 386 CPU and blueprints for it, how long would it take before he understood even the basic principles of electricity?

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    True, but would you still say that if you'd just seen him re-solder a northbridge chip? They watched him assemble it and have shown limited ability to modify and repair it.
    – Jeff
    Commented Apr 18, 2011 at 21:06
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    @Jeff Given that it took 2 Carters to even get it to accept a fresh power source, it seems like there's definitely something incredibly advanced in its construction.
    – user1027
    Commented Apr 18, 2011 at 21:30
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    I tend to agree that there's something advanced in the construction, but they had two years to study it. They had all that time where they could look at every connection and evaluate every bit of the hardware. And they DID manage to learn how to recharge it...
    – Jeff
    Commented Apr 19, 2011 at 14:45
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    Also bear in mind, that we have regular ancients, and also ascended ancients - they themselves had a massive age of technology, it's like a regular human from today, bringing the concept of horsebased warfare to cave men. We'd be seen as awesome yet a bunch of drunk jaffa with a ship could take over the planet today ... man i love this site! Commented Apr 22, 2011 at 9:52

I'll address the second part of your question first.

Why didn't they build more of O'Neill's booster device?

Basically they did. Carter's work on what became the Mk1 naquada generator was the direct result of attempting to duplicate the power booster. It wasn't a perfectly straight line and it depended on learning some things from the race that used brain nanites to spread knowledge (which Carter also needed to figure out how to reuse O'Niell's original.)

It's also worth noting the booster was only meant to run a few minutes at a time while the Mk1 runs weeks or months at a time powering much of Atlantis later on. The Mk2 was just a Mk1 rigged to run at 500% output for much shorter times. So in fact they even improved on the original first by making the more stable and reliable Mk1 and then with the Mk2 that did the same thing with 5 times the output.

I suspect but cannot cite any evidence that either the Mk1 or Mk2 must match the output of the booster device since they were both based on and inspired by it. It only seems natural use it to base the operational specs for the requirement.

Now for why they still needed ZPMs...

The show rarely gives us detailed figures but we know from SGA, from the Carter-McKay gate bridge that the normal range of a Milky Way or Pegasus gate is 90,000 light years. That's because the 34 gates of the bridge are spread out at 33 points (with one of both kind of gates at Midway station) across the 3,000,000 ly span.

We also know that the power requirements of establishing a wormhole rise "exponentially" with distance. Technically by the definition of "exponential" all that means is that the distance/power relationship isn't linear, like 2x distance takes 2x power. That's why an exponent is needed. This could actually be less than one, meaning power requirements increase more slowly than distance (which would run counter to most people's misconception of the term) but in this case the show makes it clear that power required increases sharply as distance grows but without ever precisely quantifying it.

We were told that dialing the Asgard home world Othalla took ten times the power of a normal dialing, which the booster supplied. We also know that (at least later on) the show used real life galaxies and distances to them, such as with Pegasus. Though we are never told which irl Galaxy is Ida, we can reason that it's almost certainly either the Large or Small Magelleanic Could. I know some references place Ida 4,000,000 ly away but the show also clearly states it takes a ZPM to dial the 3M ly to Pegasus... So Ida can't be even farther away.

In fact if we assume that the "exponential" in power required "exponentially increases" is equal to distance cubed then a 10x power increase from the booster would increase range of the SGCs gate from 90,000 ly to just under 200,000 ly, enough to reach the Large Magelleanic Cloud. If instead power equals distance squared then a 10 fold boost gets you 280,000 ly. That's enough to reach the Small Magelleanic Cloud. No other (major) Galaxy is within 2.5M ly of us except Andromeda but again, that's barely closer than Pegasus.

Sorry for the long winded runup but the payoff is we can now estimate how much more power it takes to dial Pegasus compared to destinations within the MWG or the Asgard home world. Pegasus is 33 times further away than a gates "normal" range so given a distance squared relationship power draw would increase over 1000 fold. But if it's a cube rule then power drain is 40,000 times as much.

For comparison that means, if we assume a Mk2 matches the boosters output, Atlantis would need at least 1000 and as many as 40,000 Mk2 reactors to dial Earth. As of "The Siege" in SGA there were two working Mk2 that we know of. I think it's entirely possible that in the past decade or so they could've built enough and improved the design where they might not need a ZPM to dial to/from Pegasus or even power Ancient weapons, shields and drives. It's going to take up a lot of space though and certainly wouldn't run as long as ZPMs. Those are as powerful as an exploding star ya know.

But when SG was still on the air there just wasn't anything but ZPM they could possibly use to power distant gate trips or the Atlantis shields and hyperdrive.


I don't think that it drains a ZPM much to open a wormhole to another galaxy really, it's more of a sharp charge to begin with. Think of starting a car.

The one time devices, while very interesting, might be limited on the storage time, might involve complex geometry. They could have any number of restrictions that we just don't know about, preventing their use. It was very rare for humans to want to leave the galaxy until much later on in the series, maybe the technology just didn't work that well, so...

  • Carter says she fixes the device using the field stabilization (calibrated to the naquada decray rate) which she figured out how to do during her creation of the naquada generator. So her work on this device might lead to improvements on naquada generators but it wasn't the progenitor of this technology.
    – user11676
    Commented Mar 23, 2023 at 5:06

A ZPM is not only required to dial another galaxy but also to maintain a stable wormhole. Once the worm hole is established the ZPM is used to keep it active. It's not at all like jump starting a car, it's more like starting a car that doesn't have an alternator: once you remove the battery the car stalls. The same is true with a Stargate dialing another galaxy - remove the ZPM and the gate shuts down.

What you have to keep in mind is that the gate uses an large amount of power just to dial within a galaxy, so to dial from our galaxy to Atlantis in the Pegasus galaxy the gate needs the boost to establish a stable worm hole and then keep it open. When you're using an already nearly dead ZPM to start with you run the risk of killing it. When the earth gate uses a ZPM it doesn't have a DHD to maintain and control the flow of energy which can drain the ZPM. Atlantis has a DHD with a special control crystal and city power control systems that control the flow of power from the ZPM to the gate preventing the ZPM from being depleted.

  • Hi and welcome to Sci-Fi Stack Exchange! Thanks for your apparent desire to participate in our site. I'm going to edit your answer for clarity and grammar, but it would be nice if you could add some references. I also recommend removing your personal e-mail address - that's just asking for it to be picked up by spambots.
    – Jeff
    Commented May 30, 2014 at 13:10
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    There we go, I think that's a bit better. I do wonder, however, about your assertion about the Atlantis DHD's 'special crystal'. As I recall, that was more of a special security thing that permitted the Atlantis gate to dial Earth, not something that was designed to keep the ZPM from losing energy. There's no indication that Atlantis uses less power to dial an intergalactic address than any other gate does.
    – Jeff
    Commented May 30, 2014 at 13:16

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