Another Gate Physics Question

The Borgified Corpse · Dec 11, 2009

I'm interested. I was waiting for you to post it or figure out how you were going to format it.

Silvercrest · Dec 11, 2009

Well... I was prepared to just post a few pages of the .pdf at a time. But if I understand the "insert image" button, it appears I have to host it on my own web site before I can do that. I don't have a web site, and I don't know how to make one. Is there any other way to attach images?

Or I can simply cut and paste the text, a few pages at a time... ?

Silvercrest · Dec 14, 2009

Okay, in the absence of anything better, it's cut-and-paste time.

This is about the first quarter of my document (through the chapter entitled "funnel"). Hopefully it doesn't read too funky. I had to remove a lot of the formatting, and the spacing is a little messed up. The Borgified Corpse (and anyone else), let me know what you think and whether I should post another installment. Or the whole thing.

This document was taken from my watching of the first eight seasons of SG-1 and a small amount of data from the other shows. (The last two seasons of SG-1 feature almost no lore on the Stargate proper, so I didn't study them.) I also cribbed material from the wiki page and several other web sites. None of the other sites were quite complete or satisfactory in their explanations, so I rewrote a lot of it to make it consistent. The only part I'm dissatisfied with is the discussion of neutrinos in the first section, which still seems to have some logical inconsistencies.

I also tried to straighten out some inconsistencies within the show. In places where my writing contradicts the show (such as how many times a receiving gate spins), it's because the show contradicts itself and I had to pick the most logical answer.

Finally, please bear in mind that I wrote this as a reference source for a d20 gaming system. You'll have to ignore a lot of references to saving throws or DC checks. There are also a few passages, such the reference to climbing an event horizon, that I extrapolated from existing Stargate lore, with adventurers in mind.

Let me know if you have questions. I can explain most of what I wrote, even if you disagree with the explanation.

THE DEFINITIVE STARGATE

INTRODUCTION
DIALING A STARGATE
DHD
FUNNEL
EVENT HORIZON
ENTERING A STARGATE
TRANSIT
EMERGING FROM A STARGATE
DURATION OF A WORMHOLE
DISRUPTING A WORMHOLE
BLOCKING A STARGATE
MULTIPLE GATES ON ONE PLANET
SPECIAL DIALING PROCEDURES
DIALING WITHOUT A DHD
STELLAR DRIFT CORRECTIONS WITHOUT A DHD
ENERGIZING A STARGATE
WARNINGS ON ENERGIZING A STARGATE
TRANSPORTATION RINGS

INTRODUCTION

The Stargates were developed millions of years ago by the race known as the Ancients. Although the technology to build new Stargates has been lost, most of the original Stargates are still functional. Since the disappearance of the Ancients, the parasitic Goa’uld (and many other races) have continued to use the durable Stargates they left behind.
A Stargate is an advanced piece of technological hardware, linking planets together across space. It operates by generating an artificial stable wormhole which emerges at a second Stargate, bypassing the limits of normal space travel. A network of Stargates was created to allow instant travel across the stars, without clumsy spacecraft or long flights. The network allows travelers to reach any intended destination by merely walking.

The Stargates themselves are created from refined naquadah ore, which resembles quartz. Naquadah is a stable mineral with a half-life of 150 years, which is believed to be element number 234 on the periodic table. It is capable of many applications and uses, including the creation of weapons of mass destruction and the generation of seemingly limitless amounts of clean energy. In its refined state, a Stargate’s naquadah only reacts with neutrinos — (electrically neutral particles) — converting and storing energy as a large superconductor. Neutrinos are not affected by the electromagnetic forces that act on electrons and are thus able to pass over great distances and through solid matter without noticeable effect. Streams of neutrinos are stored within a crystal lattice structure of naquadah, built into each Stargate. The lattices act as great capacitors, allowing the Stargate to store immense quantities of energy.

A Stargate is a perfectly circular device, approximately 25 feet in diameter and weighing 32 tons (64,000 pounds). These devices are incredibly enduring and can survive many thousands of years without corrosion or wearing. They will also often withstand even severe impacts, although if the Stargate is still active, the wormhole may be deactivated. Stargates have been known to survive the destruction of planets or comparable massive explosions.
The diameter of a stargate is not arbitrary. There is a specific correlation between the energy required to create a stable wormhole and the size of the gate, with the energy exponentially proportional to the size. The Ancients apparently built their Stargates to a standard size which balanced functionality and expediency. The gates are large enough to transport any object of reasonable size, but are small enough to be powered efficiently. (The few known custom-built Stargates have typically been smaller than average, presumably due to power limitations.)

A Stargate contains two rings and nine “chevrons” placed equidistant along the outer circumference. The second ring — the inner ring — is placed inside the larger outer ring, and moves independently of its larger “housing”. The inner ring is divided into 39 segments, each of which is engraved with a symbol, or glyph.
All Stargates are identical in appearance, with the exception of the 39th glyph on the inner ring. Each glyph takes the form of a constellation as recognized from Earth, and are generally named after those constellations (with the exception of one glyph which is different and unique to every Stargate). The singular 39th glyph is programmed to represent the point in space where the Stargate is located. The other glyphs represent points in space at the perimeter of the galaxy. (In actuality, the glyphs have nothing to do with constellations beyond a passing resemblance. Since the Stargates predate human civilization on Earth, it is likely the glyphs were not actually named or patterned after constellations. It is more likely that the constellations on Earth were named by primitive cultures after the glyphs, once similar star patterns were identified.)

The Stargate “dials” a destination by spinning the inner ring. The chevrons are used to encode particular glyphs on the inner ring as it rotates. When encoded in a particular order, these glyphs form a set of coordinates, or an “address”.
Once an address is dialed, the Stargate generates a wormhole between itself and a complementary Stargate at the destination, by being supplied with a threshold amount of raw energy. Objects in transit between gates are broken down into their individual elemental components, and then travel through a wormhole before being reconstructed on the other side.

DIALING A STARGATE
A Stargate is dialed in a manner comparable to a rotary telephone, by locking the chevrons one at a time onto a series of glyphs, as the inner ring rotates. Once locked, they encode those glyphs into memory. Each chevron indicates that it is locked by glowing bright orange.
Normally an address is composed of seven glyphs. These glyphs must be encoded into the Stargate in a particular order. Each of the regular glyphs represents a point in space. They are arranged in lines along the galactic rim.
Each pair of glyphs map an imaginary line. Three lines are drawn, on three axes — east/west, north/south, and up/down (with respect to the ecliptic). Three pairs of glyphs form an address.
The seventh glyph must be the one unique to that Stargate. It provides a “point of origin”, an orientation point indicating the location of the dialing Stargate. (If a Stargate is transported elsewhere, its “point of origin” glyph must be reprogrammed to identify its new location in space. This requires a Stargate skill check with a DC of 22. Until this is done, all dialing performed with that Stargate will fail.)
The combination of the address and the point of origin allows a line to be drawn between the two points. The line can be drawn on a physical map, showing the path between entry and destination. If the spatial address is valid and there is a functioning Stargate on the other end, the dialing Stargate uses its stored energy to open a stable wormhole along that line, allowing travel to that world.

The first six chevrons can be locked in any order. The Stargate is programmed to recognize that the first two glyphs to be dialed form a line from galactic east to galactic west, so it has no regard for which chevrons are used to encode the glyphs. When dialing begins, it will automatically rotate the inner ring the appropriate direction for that glyph to reach the nearest chevron, and lock the chevron onto that glyph. The next five glyphs are handled in similar fashion, being locked by whichever chevrons they rotate to first. (This means that the first six chevrons tend to lock in random order.)
In the standard upright mounting of a Stargate, the seventh chevron is located at the top. This chevron must always be dialed last. It is programmed to accept only one glyph, which is the Stargate’s point of origin symbol. (Locking this chevron onto another glyph manually, or doing so out of order, results in an invalid dialing sequence and no wormhole.)
When an incoming wormhole opens a Stargate, the inner ring of the incoming gate spins just one time, to lock the seventh chevron. Once this occurs, the event horizon appears. (See EVENT HORIZON, below.)

Dialing with a DHD (see below) normally requires a full-round action, with an additional half action required for the wormhole to actually form. A successful Concentration check (DC 10) can reduce the dialing time to half a round, thus requiring a total of one round to both dial the gate and form the wormhole.

The eighth and ninth chevrons are not used in normal Stargate dialing. (See SPECIAL DIALING.) In normal Stargate upright mounting, these two chevrons are often embedded in the platform which is used for walking into the gate. They may not be visible. In the special cases where these two chevrons are used, they are dialed after the first six chevrons, but before the point of origin.

Exceptions:
· If the address is not valid, or if the Stargate on the receiving end is not present or not functional, no wormhole is formed.
· A Stargate cannot dial an address that is already in use (i.e., it cannot dial a gate to which a functional wormhole is already active). Attempting to dial a functional gate gets the equivalent of a “busy signal”, and simply results in no wormhole. Similarly, a currently engaged gate cannot initiate a dialing sequence. Thus, one could dial another Stargate and intentionally keep it open in order to prevent the recipient from dialing out to any other address. This tactic is commonly employed on worlds which are about to be invaded, as it prevents any victims from fleeing.
· It is possible to dial out while someone else is attempting to dial in, as long as a wormhole has not yet been established. It is simply a matter of who dials faster. Once the wormhole opens, it may not be clear which dialing sequence succeeded, to those standing near the contested gate. However, the DHD (see below) will give indications if it is in control of the wormhole.
· A Stargate cannot dial its own address. It cannot dial another gate that is located within the same star system, as both gates would effectively possess the same address. (When this is attempted, both gates spin and their chevrons light simultaneously, but neither will engage the seventh chevron.)
· A Stargate can be mobilized if required (used on a space vessel, for example). However, it is not possible to dial to the gate’s original address if it is very far from its home system, as the physical coordinates will no longer be valid. (It may be possible to dial in to the gate if its new coordinates can be identified.) It is also not possible to dial to the gate if it is moving at speeds faster than light, even within its system. If it is very far from its home system, the point of origin will no longer be valid. For this reason, it will not be possible to dial out from that gate under any conditions, until either the DHD or the gate’s Point of Origin glyph are reprogrammed or updated.
· In all cases, when a Stargate is unable to form a wormhole, it retains whatever charge it previously contained. A failed dialing sequence does not discharge the Stargate’s energy reserves.
· A Stargate with no power source and no charge will be inert. The inner ring will lock in place and cannot be rotated. (The inner ring also locks in place while a Stargate is in use, as a safety measure.)
· Note that Stargates can dial each other even though their temporal reference frames are not the same. (In actuality, this is probably true for most of the Stargates in the galaxy, due to relativistic effects.) Stargates can also connect even if they are out of phase with each other.

DHD
Most Stargates are also found in the presence of a “Dial Home Device”, or DHD. Also composed of naquadah and control crystals, the DHD is the “brain” that makes a Stargate function. It gives commands to the Stargate and completes the dialing procedure. A DHD also contains a small naquadah power source that is capable of energizing a Stargate’s internal lattice and opening a wormhole. (See DIALING WITHOUT A DHD for how to deal with a DHD with a failed power source.)
A DHD is depicted as a pedestal-shaped device with a round inclined control panel on top, consisting of two concentric circles of "keys", and a translucent red hemispherical crystal in the center. The keys are engraved with the 38 symbols on the rim of the Stargate; there are 19 in each circle. By pressing these keys in the correct order, a traveler builds an address. (See DIALING A STARGATE.). Each glyph, and the perimeter of the key, lights up when pressed. The central crystal (commonly known as the “Big Red Button”) is programmed to encode the Point of Origin symbol, which is not otherwise represented on the DHD. Pressing the crystal is all that is needed to activate the Stargate once a destination has been dialed.
A DHD uses a wireless interface with its Stargate, communicating via neutrino flow. For this reason, a DHD can control a Stargate even if the two are not within direct line of sight, or even through solid matter. It can control the gate from an undefined distance away, although the limit on this distance is believed to be within a mile or so.
Any DHD can work with any Stargate. However, an imported DHD must be programmed to recognize the new Stargate (and new Point of Origin) before it can dial or exchange data.

The DHD and Stargate exchange in excess of 400 types of feedback signals. Among other things, these signals control safe reintegration of a traveler, prevent power overloads, and interface with the Stargate network to correct for stellar drift. This feedback also analyzes wormhole routes to avoid hazards. Although it is not harmful to a traveler to pass through a celestial body en route, it may affect the body itself. (See DIALING WITHOUT A DHD.) In addition, gravity and other phenomena may affect the path of the wormhole. (See DISRUPTING A WORMHOLE.) For these reasons, a DHD will curve or reroute the wormhole as necessary. In extreme conditions, the DHD has protocols which will keep a wormhole from opening at all. This means it is possible to dial a correct address and still not get a lock "until the stars are right."

A DHD’s programming typically holds the last 50 addresses that were dialed. It is difficult to retrieve any given address, but a random number of them can be retrieved with a Stargate check (DC 14). If that same check (or a subsequent check) exceeds 20, all of the addresses can be retrieved. If it exceeds 30, the order of dialing can be determined.

FUNNEL
When a Stargate establishes a wormhole, it creates a funnel-shaped “splash” of highly energized plasma, resembling water or quicksilver, which lasts roughly two seconds and projects perpendicularly to the gate for a distance of 20 feet.
The funnel, often referred to as the “kawoosh”, is emitted from both the sending and the receiving gates. This funnel is an unstable energy vortex which will automatically disintegrate any matter caught in its path. A character in the path of the funnel can get out of the way with a successful Reflex save (DC 15).

Although visually the funnel appears to be a distorted event horizon (see below), in actuality it is materializing from the event horizon, just as a regular object would. The funnel is made up of ice crystals, dust particles, nebular gas, and any other material in the wormhole’s path that might adversely affect a traveler. The material is converted to plasma and reintegrated on each end of the wormhole in a “spray”. This expulsion leaves a clear travel path through the wormhole.

No form of matter can resist the funnel without being destroyed; therefore, it cannot be blocked with a simple barricade. However, it can be prevented from reintegrating, in the same way as any other object. (See BLOCKING A STARGATE.) If prevented from reintegrating, the funnel does no damage. (The debris is still cleared from the wormhole, but is emitted as a slow, imperceptible stream of particles, rather than a sudden burst.)

It is possible to tune a Stargate to a fine enough degree to prevent the appearance of the funnel on a given occasion. This requires a Stargate skill check, with a DC of 18. It is also possible to fine-tune a Stargate to such a degree that the funnel no longer appears. The DC for this check is considerably higher (35). It is likely that when the Stargates were originally in use by the Ancients, this tight level of tolerance was the norm. In the ages that have passed since that time, practically all of the gates have fallen out of tolerance.

David cgc · Dec 14, 2009

Interesting. There are a couple of things that don't jibe with my own interpretations, though. First of all, where's this stuff about the kawoosh not appearing coming from? The only time I can remember that is "48 Hours," and that was the establishment of an event horizon without a wormhole. And the kawoosh always appeared when we saw a stargate operated by an Ancient, like in "Before I Sleep." The Ausuran and Ori gates also had kawooshes, and they'd be just as good with the technology as the Ancients (slightly better, definitely, in the Ausuran's case).

It seems strange to say that the glyphs for an address can be entered in an arbitrary order. Yes, I realize that sometimes the dialing scenes didn't match the addresses, but that's because of stock footage and the fact that after the first season, they decided the glyph being dialed slotted in under the top chevron instead of one corresponding to the one being encoded at that moment.

For incoming wormholes, my interpretation had been that if a gate was "cold," and hadn't been used recently, it dialed its own address (like in "Children of the Gods" or "Icon"). If it was "warm," and had been used within a few hours or days, the ring would spin while the chevrons all locked sequentially (like most of the time we see it). If it were "hot," and had either just been used moments ago, or was in the process of being dialed when the incoming signal arrived, all seven chevrons would light up at once and the wormhole would open immediately, no spinning required (as in "Watergate" and "Endgame").

Also, you haven't gotten to this point yet, but from "Air," we now know that when a Stargate dials an eight- or nine-symbol address, the extra bottom chevron(s) doesn't align at the end of the sequence, but in it's place proceeding around the gate clockwise. Which means they should've realized something was up in "The Fifth Race" once chevron 4 encoded under the ramp instead of on it's usual lower-left chevron, but, well, screw it.

Silvercrest · Dec 14, 2009

Lya, in "Enigma", and future Cassandra, in "1969", both opened wormholes with no kawoosh. Lya apparently didn't even use any hardware, but just did it psionically. That implies that high enough control can keep the kawoosh from occurring, so I extrapolated that it may originally been the normal state of operation for a gate. (The kawoosh is a pretty dangerous thing, and it seems reasonable that the gates weren't originally intended to do it!) I didn't consider the Ausurans and the Ori, as I didn't take notes on those parts of the series, but you could argue that being who they are, they don't care enough about safety to bother fine-tuning their gates. As for the Ancient... was that when Weir went to the past, when the technology should have been at its peak? Okay, I give.

Just to be clear: I'm not saying that the glyphs can be encoded in an arbitrary order, but that the chevrons don't have to lock in a particular order. A glyph (entered in the right order) can be encoded into whatever chevron it spins to first. That still sounds weird, but that's how the chevrons were portrayed on the show. Or rather, sometimes they lit up in clockwise order, and sometimes they lit up in random order. Sometimes they were staggered from the left side to the right. I watched episode after episode to try observing a pattern, and never found one.

Your idea for chevrons on an incoming gate is pretty good, and I may have to incorporate it. With your permission, of course.

I hadn't seen "Air" yet when I wrote that, but I envisioned that the eighth and ninth chevron would be dialed third or second to last. That's discussed under "Special Dialing" when I get to it.

If the footage shows the bottom chevrons lighting up at a different point in the sequence... well, screw it, as you say. There's no way to make every single item 100% consistent.

cylkoth · Dec 15, 2009

Thor also initiated a kawoosh-less activation in the 3rd season(?) episode where he took Carter to help him fight the bugs using their O'Neill warship.
Sorry, I'm very poor in the episode title department for the early seasons.

David cgc · Dec 15, 2009

Silvercrest said:
Lya, in "Enigma", and future Cassandra, in "1969", both opened wormholes with no kawoosh. Lya apparently didn't even use any hardware, but just did it psionically. That implies that high enough control can keep the kawoosh from occurring, so I extrapolated that it may originally been the normal state of operation for a gate. (The kawoosh is a pretty dangerous thing, and it seems reasonable that the gates weren't originally intended to do it!)

Right, the hand-thingy! Forgot about that one. Though, each time it was used, it was probably just reversing the last connection the gate had made (definitely, in the case of Lya and Thor), so it could be a very special case where the kawoosh can be avoided if and only if you're trying to reopen a connection that was just open. Normally, you'd still get a kawoosh if you redialed an address that had just dialed in, because the gate would be carving a fresh wormhole with an arbitrary path, but the hand device puts in just enough energy to recreate the one that was just there, so that exact path has already been cleared of debris.

Just to be clear: I'm not saying that the glyphs can be encoded in an arbitrary order, but that the chevrons don't have to lock in a particular order. A glyph (entered in the right order) can be encoded into whatever chevron it spins to first. That still sounds weird, but that's how the chevrons were portrayed on the show. Or rather, sometimes they lit up in clockwise order, and sometimes they lit up in random order. Sometimes they were staggered from the left side to the right. I watched episode after episode to try observing a pattern, and never found one.

I'd chalk those up to goofs and ambiguous editing. All the way back to the movie, they seemed to dial going clockwise. All three dialing computers support that, too, though I can only find a screencap of the Season 8 revision at the moment.

Your idea for chevrons on an incoming gate is pretty good, and I may have to incorporate it. With your permission, of course.

Sure. We're all just shooting the breeze, anyway.

I hadn't seen "Air" yet when I wrote that, but I envisioned that the eighth and ninth chevron would be dialed third or second to last. That's discussed under "Special Dialing" when I get to it.

If the footage shows the bottom chevrons lighting up at a different point in the sequence... well, screw it, as you say. There's no way to make every single item 100% consistent.

That's exactly what I thought, too. I feel like this is still a little confusing to describe, but I don't feel uploading a picture to illustrate, so let's try it this way.

My impression had been an eight chevron address would be dialed

Code:

Or, the same as a regular address, with one of the bottom-two chevrons slipping in right before the origin symbol. In "Air," however, it went

Code:

Silvercrest · Dec 16, 2009

I very much like the idea of a cleared wormhole path, but I don't think it's consistent with all cases where the kawoosh was missing.

Anyway, here's the next installment.

EVENT HORIZON
An event horizon manifests at both the sending and receiving Stargates. It is a two-dimensional plane of highly coherent energy, appearing within the Stargate’s inner ring, which forms a tangible surface. As such, the event horizon appears as a silvery rippling pool of water (although usually it sits vertically). It seems to be brightly backlit, although there is no visible light source. (The event horizon has no back side. From behind, it is quite insubstantial. See ENTERING A STARGATE.) The surface of the Stargate produces “ripples” similar to those in water when an object comes in contact with it.

The event horizon is not part of the wormhole. It is an interface between normal space and the subspace in which the wormhole forms. Without it, a traveler would enter the wormhole in material form and be torn apart. With it, the Stargate can decompile the traveler, store the traveler’s pattern, and send it through the wormhole as a controlled matter-stream, which can be recompiled and reintegrated on the other side. (It is called the “event horizon” because, as with a black hole, it forms an “information barrier” beyond which matter, energy or information become undetectable. Although these phenomena are retrievable once they emerge from the destination, they are untrackable and unretrievable while in transit.)

The Stargate has immense memory storage, comparable to a computer buffer. It is used to temporarily store patterns before either transmitting the matter-stream (for a sending Stargate), or before reconverting them (for a receiving Stargate). The Stargate reviews the pattern in order to make sure the information is complete before either transmission or reintegration. The pattern is erased if a wormhole is created either to or from the Stargate. This is a safety measure to prevent the mixing of two patterns.
Both gates store the record in their data buffers and retain it for some time. A successful Stargate check will identify the approximate time of the last traveler or travelers.

A pattern which has been sent through a wormhole is flagged as such by the originating gate. A pattern which has been reintegrated from an event horizon is also flagged as such. A Stargate cannot be ordered to reintegrate a pattern which carries one of these flags. (Essentially, it treats the pattern as a reference copy, rather than the original.) This is a safety measure to protect against a traveler being accidentally duplicated.

An event horizon can be formed independently of a wormhole. When this action is performed, the event horizon materializes without the usual “funnel” effect.
An event horizon which is disconnected from a wormhole will still automatically dematerialize any object that enters, although it will not send a matter-stream anywhere. It will store the object’s information in the buffer for an indeterminate amount of time. (The pattern will still be automatically erased if another gate creates a wormhole to the gate in question.)

This technique is occasionally used to experiment with storing and retrieving patterns. It is used to retrieve objects that were dematerialized by inadvertently entering a destination gate (see ENTERING A STARGATE). It can also be used in the rare case that an object failed to come through a destination gate due to a transmission error (see EMERGING FROM A STARGATE). The event horizon will not reintegrate the pattern until the Stargate is given a specific command to do so.

The reintegration command requires a separate Stargate check, with a DC of 35. When using a DHD, it is easier to reintegrate a pattern, but still requires a Stargate check with a DC of 25. This is a hazardous procedure in either case. When using a DHD for this purpose, the master control crystal must be removed from the DHD, which carries a significant risk of damage to the DHD due to uncontrolled power flow. Using an external interface is just as risky, but it is easier to restrict the scope of the damage. (See WARNINGS ON ENERGIZING A STARGATE.)

A Stargate is not allowed to indiscriminately admit matter which comes in contact with the event horizon. For example, a higher level of air pressure at the sending gate than at the destination gate would cause an unstoppable torrent of wind from one Stargate to the other. The Stargate must exert a high level of control over the event horizon, by monitoring feedback from both ends of the wormhole. It uses this information to decide whether to allow passage to anything which comes in contact with the event horizon.

The gate analyzes density, molecular structure, pressure differential across the event horizon, and pressure differential between Stargates, to decide if something is trying to pass through. An item of different composition and greater density than the surrounding medium, actively pushing on the event horizon (i.e., most travelers), will be allowed through.

By contrast, a common substance pressing on the event horizon at a uniform average pressure, such as atmosphere, will not be allowed through. Slight differences in pressure from the same material, such as modest air currents, will also not be allowed through. However, any substance pressing on a portion of the event horizon that is a significantly different level of pressure will be allowed through. Therefore, a high-pressure stream of air fired at the event horizon will be allowed through, even though it is composed of the same material as the surrounding atmosphere. Similarly, a Stargate submerged in water will not let the water pass through indiscriminately, but a high-pressure stream of water under the same conditions will pass through. Naturally, a Stargate in air will allow a stream of liquid to pass through.

Under conditions of more or less equal pressure: If a substance that is only slightly greater density than the ambient material comes up against the Stargate, it will only be allowed through the event horizon if it is of significantly different molecular composition. Substances of lesser density than the surrounding material will not be allowed through at all. This prevents freak meteorological or other phenomena from traveling through the wormhole.

Similarly, if a substance of different molecular composition tries to pass through, it will only succeed if it has somewhat greater density. This prevents poison gases, for example, from traveling through the wormhole accidentally.
Most of the criteria listed above can be circumvented or defeated by making a Stargate check.

Note that the event horizon is capable of detecting and accepting matter that exists in other phases of reality. When an out-of-phase object enters the event horizon, the surface does not ripple as it does with a normal object. It is not easy to tell that an out-of-phase object has used a Stargate at all. However, as noted above, both the sending and receiving gates will store the pattern in their data buffers as normal. As noted earlier, it is possible to identify the approximate time of the last traveler.

Gravity is nullified for any object in immediate contact with an event horizon. A person who inserts his arm will feel the arm become weightless. An object inserted in the event horizon without being pushed all the way in will hang there in space. (Usually it will gradually slip through due to changes in air pressure and its own inertia.) If a person’s foot was inserted into the event horizon and he put his entire weight on it, the imbalance and lack of leverage would generally cause him to topple forward into the event horizon, or backward out of it.

However, a skilled climber who takes these things into account can insert his hands and feet and use a combination of weightlessness, momentum and leverage to climb the event horizon. This must be done quickly, and the surface must be treated as if it is an extremely treacherous wall.

Moving more slowly actually increases the risk of falling. The DC increases for every additional round the climber spends with no other support. If the climber falls, 90% of the time he will fall away from the event horizon (and typically sustain d6 hit points upon impact with the surface below.) The other 10% of the time, he will fall into it, at which point the reader should refer to the rules under ENTERING A STARGATE.

A Stargate in proximity to a source of intense gravitation (such as a black hole) will transfer the effects through the wormhole, regardless of whether the gravity appears on the sending or receiving gate. This will cause a visible swirling effect on the surface of the event horizon. It is unknown if the swirling event horizon is some sort of physical effect, or a simple visual distortion of the event horizon’s energy. (The swirling is unaffected by Coriolis forces or atmospheric effects.)

Under these conditions, the time dilation effects caused by the intense gravity will also propagate through the wormhole and affect conditions on the other side. Other side effects of gravitation, such as tidal forces, will also propagate through. However, for unknown reasons, the time dilation affects the other side of the wormhole far in advance of the other effects, despite the fact that they have a common source. It has been theorized that the time dilation is focused ahead of the other effects due to the energies of the event horizon acting as a temporal lens.

ENTERING A STARGATE
Upon entering the event horizon of a Stargate, a traveler is dematerialized, beginning with whichever body part was inserted first. Transportation through the wormhole does not occur until the entire object is dematerialized and stored in the Stargate’s buffer. Once the traveler has entered an originating gate, his entire pattern is converted to a matter-stream and the pattern is sent on to the destination. (Conversion is instantaneous. It is not possible to turn around or back out of the Stargate once this has occurred.) If the traveler changes his mind before completely entering and backs out of the gate, his body will rematerialize in proper order as he does so.

On average, only one person (or several walking abreast) may enter the Stargate per round.

Multiple travelers attached together (using a rope, holding hands, etc.) are treated as a single traveler by the Stargate’s mechanisms. None of this “large traveler” will be sent through the wormhole until the Stargate registers that the complete object has cleared the event horizon. The Stargate will remain open as long as necessary to accomplish entry, up to its operating maximum of 38 minutes (see DURATION OF A WORMHOLE).

This means that it may be possible to pull a traveler back out of a Stargate after entry, if something or someone had a grip on him before he entered. It is not possible to grab or snare someone once they have completely entered the event horizon and dematerialized.

If the Stargate runs out of power, reaches its 38-minute limit, or is manually shut off on the originating end while an object is only partly entered, the object will be severed at the location of the event horizon. The portion of the object which did not enter the Stargate will appear to have been sliced completely through, as if by a razor-sharp blade. (For a person, this often means instant death from shock or blood loss. It may be possible to save the person’s life, depending on how much of him remains.)

A character in this situation must make a Reflex saving throw. (The player must declare whether the character will leap into the event horizon, or out of it.)

The portion of the traveler which was dematerialized is often lost and will not appear at the receiving Stargate. (Safety protocols within the Stargate and DHD try to prevent the transfer of part of an object). However, if the receiving Stargate’s reintegration mechanism judges that the dematerialized pattern somehow constitutes a whole object (or the important parts, anyway), it will rematerialize the object regardless. (See EMERGING FROM A STARGATE.)

Normally, something must be sent through a Stargate in order to keep it open. This can be as little as a nominal-strength radio signal. Otherwise, the Stargate will close d12 rounds after the last object or signal was sent through. A sending gate can be specifically commanded to remain open, even with nothing entering, for up to its 38-minute maximum. It is not possible to issue this command to a receiving Stargate. The receiving Stargate will close at the same time as the sending gate. (Of course, both gates can be held open for up to 38 minutes simply by inserting an object partway into the event horizon of either gate, and leaving it there.)

Note that inserting part of an object, such as a hand, into the event horizon of either gate will keep it from shutting down for as long as the object is present. This will “hold the gate open”, in case incoming travelers have not yet had a chance to enter. The Stargate can be held open for up to its 38-minute operating limit (see DURATION OF A WORMHOLE). After this time, it will shut down automatically. It is best if the traveler removes his hand before this occurs.

As noted earlier in this section, the originating gate can be commanded to shut down by the DHD or other interface. If this happens, both Stargates will shut off regardless of whether the time limit has been reached, or whether anything is still inserted in the event horizon. See the appropriate passage in this section for how to treat the results.

The Stargate has a defined front and back. The back side, which has no glyphs, is inoperative. The funnel does not appear there when the wormhole opens. The event horizon, being a two-dimensional phenomenon, is undefined from the back. Anyone looking at the back of the Stargate when the event horizon is present will see a silvery sheen which is quite transparent. It is possible to step through the back of the event horizon and appear in front of the Stargate without being dematerialized. (To any observers, it will appear as if the person has just traveled through the wormhole and emerged from the Stargate.) This is true regardless of whether it is the sending gate or the destination gate.

Wormhole travel is one-way (see TRANSIT). For this reason, a traveler must not enter the event horizon on the destination side. The destination gate will perform exactly as a sending gate would, down to dematerializing the traveler and storing it. However, the Stargate cannot send a pattern the “wrong way” through the wormhole. Furthermore, a DHD has no automatic function for retrieving a traveler who enters a destination gate. The traveler’s pattern has a very good chance of being permanently lost. It is possible to inject a reintegration command into the Stargate, to force the event horizon to recompile the traveler’s pattern, but this is difficult and can be hazardous. (See EVENT HORIZON.)

TRANSIT
The most important and unique rule surrounding wormholes is that travel can only occur in one direction. A traveler cannot enter one Stargate and emerge from another, then turn around and travel back to the first Stargate through the original wormhole. It is necessary to allow the first wormhole to shut down, then establish a new one that goes back to the first Stargate.

This is true because the aperture of the wormhole is extremely small, probably microscopic. The matter-stream which conveys the traveler can only transport a small amount of the pattern at a time. There is also a continuous flow of energy from the originating Stargate to the receiving gate, to provide power to the latter. A matter-stream sent the wrong direction would be forced to “buck the flow”. There is a very high probability that it would be disrupted. Some or all of the traveler’s pattern would be lost. For this reason, a Stargate will not even attempt to send a pattern into an incoming wormhole. This feature is hardwired into every Stargate and there is no known way to defeat it.

Conversely, most forms of energy can travel bidirectionally through a wormhole. Energy is not decompiled by the event horizon, but passes directly into the wormhole. It is not affected by the natural flow of the wormhole. Therefore, most known types of energy can travel through a wormhole in either direction. These types include radio, video and data signals, microwaves, gamma rays, lasers, electromagnetic pulses (EMP), other forms of electromagnetic radiation, and gravitational fields.
Sonic effects or similar mechanical vibrations cannot travel either direction through a wormhole, as their operating medium is not present. Electrical, plasma and similar particle effects cannot travel backwards through a wormhole, as they are subject to the same limits as any other stream of particles. However, they can travel forward, and have the added advantage of not requiring reintegration on the other side.

The transit time through a wormhole is not constant, but depends upon distance. The relationship is not linear. Observed transit times are never less than one round for distances up to 30,000 light-years. It seems to last for a variable number of additional rounds at greater distances, probably due to variations in the wormhole paths.)

Traveling through a wormhole is not something that can be sensed, as the traveler’s sensory apparatus is dematerialized along with everything else. However, many travelers report a feeling of being stretched to infinity during transition. This is likely a result of sensory stimulation during dematerialization and/or reintegration, rather than a sense of the transition itself.

EMERGING FROM A STARGATE
As a traveler emerges from the event horizon, the Stargate’s reintegration mechanism activates, rematerializing the traveler in the same order in which he was dematerialized. (If the traveler put his left foot into the Stargate during departure, his left foot is the first thing to emerge, and so on.)

Under normal conditions, the momentum of the traveler is preserved, and he will emerge at the same speed he entered. Certain conditions, usually irregularities in dialing, will cause the traveler to be ejected from the destination gate at high speed. (This and other side effects are described under DIALING WITHOUT A DHD.)

Feedback signals between the two Stargates and their respective DHDs are used to ensure that the complete traveler is reintegrated; thus, in normal operation, a Stargate will not spit out just half of a traveler even if something went wrong on the sending end (see ENTERING A STARGATE).

The originating gate sends an “all-clear” signal to specify that the pattern was decompiled and sent correctly. If that gate loses power or is otherwise cut off prematurely, the signal may not be sent. The receiving Stargate’s DHD will attempt to compensate for this problem. It will try to determine whether the received pattern constitutes a complete object. If the conclusion is yes, it will reintegrate the pattern. (It is possible for the traveler to be incomplete. The DHD has no way to determine if any missing parts were important.)

If more than 10% of the pattern is missing, the DHD will not reintegrate it. If no DHD is present on the receiving Stargate and no confirmation signal was received, the Stargate will not reintegrate the pattern regardless of how much, or how little, is missing. In such a case, it is possible to create a temporary event horizon and force the reintegration. (See EVENT HORIZON.)

Any missing percentage of the pattern constitutes a portion of the matter-stream that never reached the destination Stargate. When the wormhole disengages, this portion returns to real space as disassociated particles. There is no way to recompile or reconstitute it.

The Borgified Corpse · Dec 17, 2009

Interesting stuff. It seems that your rules fit in with my thin teather theory, reconciling why Earnest Littlefield could rematerialize with his airhose dragging behind him, yet the half-stuck Puddle Jumper in "38 Minutes" was SOL. (It's oddly appropriate that, in "38 Minutes," it was Paul McGillion who asked why the front half of the Jumper wouldn't rematerialize.)

Here's a question: You say that while the Stargates are 25 ft. wide, the wormhole itself is much smaller, probably microscopic. So, would it be possible to build a larger gate, like a SuperGate, that utilized a standard sized wormhole? I would theorize under these rules that it would be possible but that it would increase the transit time to a rediculous level. It would be like trying to download the Lord of the Rings movies on a dial-up modem.

The 1-way-only travel through wormholes never made sense to me before I read this. Now, I think I get it. Your explanation also probably explains how Vala Mal Doran's data-matter stream could travel backwards through the SuperGate back to the Ori Galaxy in "Beachhead."

The rules about air pressure & other matter pressures on the departing end mostly make sense. However, what about a Stargate that was only half submerged in water? When the Stargate sank into the lava in "Inferno," would any of the lava have traveled back to Atlantis had Dr. McKay not ordered them to raise the shield.

Which reminds me of a question I had about "The Shrine." In that episode, Col. Sheppard's team spends the night trapped on top of a Stargate because the valley it was in had flooded. They ended up waiting for several hours for the water to subside. Why didn't Atlantis send a Jumper through to rescue them right then & there? Plus, once they had a Jumper with its own DHD, why wait until the water subsides to dial out? If they were afraid the water would flood Atlantis, why not dial to a space Gate, take the Jumper through, then dial Atlantis from there?

Where do you get that naquadah is suspected of being atomic element #234? And aren't elements that heavy extremely radioactive and totally incapable of existing in nature?

cylkoth said:
Thor also initiated a kawoosh-less activation in the 3rd season(?) episode where he took Carter to help him fight the bugs using their O'Neill warship.
Sorry, I'm very poor in the episode title department for the early seasons.

You're thinking of "Small Victories," the 4th season premiere and the 2nd episode to ever feature the Replicators.

Silvercrest · Dec 17, 2009

The Borgified Corpse said:
Interesting stuff. It seems that your rules fit in with my thin teather theory, reconciling why Earnest Littlefield could rematerialize with his airhose dragging behind him, yet the half-stuck Puddle Jumper in "38 Minutes" was SOL.

Actually, if I understand you correctly, I'm not certain those theories are compatible. But yes, my theory was intended to cover both Ernest and the stuck Puddle Jumper, as well as the Jaffa who had his staff weapon cut off.

My treatment of Ernest's situation is that the Earth gate kept him decompiled in the event horizon, and remained open while they kept feeding in his air hose. During this time, he didn't go anywhere or emerge on Heliopolis. After a fairly short time, the Earth gate ran out of power and disengaged, severing the air hose. My rules under "EMERGING FROM A STARGATE" were intended to cover that situation. They declare that the receiving gate will attempt to compensate for errors and will make a decision to reintegrate if less than 10% of the pattern is missing (and hope that none of the missing parts were important). That was what I figured happened to Ernest.

But I see a logical flaw there. If Ernest was waiting in the buffer and didn't travel through the wormhole right up to the point of cutoff, how could the receiving gate have anything to work with? It's not the same as Teal'c in "48 Hours", since he was a whole object who was already in transit at the time of cutoff.

Well, we could amend that rule to say that a gate that is cut off (for any reason) while an object is still partway through will initiate an emergency transmission through the wormhole with the last of its power. It will send whatever part of the pattern it has, and let the receiving gate deal with the consequences. I believe that preserves consistency. Ernest, being more than 90% of an object, would emerge with a broken air hose. So would that Jaffa who got the end of his staff weapon cut off. The front half of the puddle jumper, being about 50% of an object would not, and Dr. McKay and any other gate experts aboard (I forget) would know that.

And BTW, the top of Kawalsky's head, being about 1% of an object, would not be rematerialized by the receiving gate either.

Here's a question: You say that while the Stargates are 25 ft. wide, the wormhole itself is much smaller, probably microscopic. So, would it be possible to build a larger gate, like a SuperGate, that utilized a standard sized wormhole? I would theorize under these rules that it would be possible but that it would increase the transit time to a rediculous level. It would be like trying to download the Lord of the Rings movies on a dial-up modem.

Just to be clear, I culled a lot of my information from the Stargate Wikipedia entry, from Arduinna's site www.stargatehandbook.org, and from a couple of documents on fan sites. One of those documents refers to the address davenorry.co.uk, and the other one refers to SourceGate.org -- but I am not sure that's where the documents originated. I'm also not sure which factoids came from which place. None of those sites really had complete information, so I cut, copied, chopped, diced, sauteed, and rearranged the information until I got something that was more or less consistent. (The SourceGate one in particular had some good ideas, but was really terribly written.)

The point here is that I didn't come up with the concept of the wormhole being microscopic. It came from one of those sites, and I've rearranged my sources so much that I'm not even sure which one. I went with the idea of a microscopic wormhole because it made a lot of sense. But I can't analyze it any further than that.

The rules about air pressure & other matter pressures on the departing end mostly make sense. However, what about a Stargate that was only half submerged in water? When the Stargate sank into the lava in "Inferno," would any of the lava have traveled back to Atlantis had Dr. McKay not ordered them to raise the shield.

Well... I think that would be covered by the rule that "an item of different composition and greater density than the surrounding medium, actively pushing on the event horizon will be allowed through" (2nd paragraph under the rules for discrimination). But that's fudging it a bit, since in the case of a differential between atmosphere and denser material, I don't know how the gate could tell the difference between simple high pressure and someone actively pushing on the event horizon.

Of course... if the gate can identify a pressure differential from one part of the event horizon to another, it should be able to recognize when matter is trying to enter at the perimeter. Even if there's something pushing on the event horizon with higher pressure and density than ambient atmosphere, the gate should be smart enough to realize that any object or substance widespread enough to press on the perimeter and the center at the same time is either not a traveler, or it's one so large that it won't be able to enter normally. So, neither water nor lava will enter a half-submerged gate.

You know, I'm starting to think that the Stargates are smarter than the Ancients who built them.

Which reminds me of a question I had about "The Shrine." In that episode, Col. Sheppard's team spends the night trapped on top of a Stargate because the valley it was in had flooded. They ended up waiting for several hours for the water to subside. Why didn't Atlantis send a Jumper through to rescue them right then & there? Plus, once they had a Jumper with its own DHD, why wait until the water subsides to dial out? If they were afraid the water would flood Atlantis, why not dial to a space Gate, take the Jumper through, then dial Atlantis from there?

You got me there. I chalk it up to Sheppard being an idiot.

Where do you get that naquadah is suspected of being atomic element #234? And aren't elements that heavy extremely radioactive and totally incapable of existing in nature?

Well, that's another bit of lore that I picked up from one of the other sites, and I kept it because it made the whole thing sound exotic. I have heard speculation that "superheavy" elements beyond 120 or 130 or so on the periodic table could be stable, not radioactive. So I could defend it on that basis.

Besides, the show already contradicts itself as far as naquadah is concerned. In "A Hundred Days", they say naquadah has a half-life of 150 years... which in and of itself already means the gate should be radioactive! And yet elsewhere I believe they say naquadah is a stable element. I put in both of those statements side by side as a deliberate oxymoron.

cylkoth said:
cylkoth said:

Thor also initiated a kawoosh-less activation in the 3rd season(?) episode where he took Carter to help him fight the bugs using their O'Neill warship.
Sorry, I'm very poor in the episode title department for the early seasons.

Click to expand...

You're thinking of "Small Victories," the 4th season premiere and the 2nd episode to ever feature the Replicators.

Oh, and thanks for that factoid, cylkoth. The more instances I have of kawoosh-less activation, the more ammunition I have for my theory. :cool:

Silvercrest · Dec 17, 2009

Oh, and I'm still waiting to see if anyone comments on my concept of being able to climb an event horizon. I'm sure a lot of people will consider it just plain weird. :cool:

That particular idea is one I came up with myself. I extrapolated it from the visual evidence that gravity is negated for objects in direct contact with the event horizon. (Apophis' body, etc.) :vulcan:

The Borgified Corpse · Dec 18, 2009

Yeah, that's weird but kinda interesting. I suppose it might work. I'd like to see someone try it.

I like your theory about what the kawoosh is (an expulsion of particulate matter from the wormhole's path). Is there any episode where Carter or anyone else explains it?

Silvercrest said:
You got me there. I chalk it up to Sheppard being an idiot.

True enough. But even if Sheppard didn't think of it, you'd think that super-complaining super-genius Dr. McKay would have.

Here's something I've wondered about: In the Milky Way Galaxy, the inside of the wormholes are blue. In the Pegasus Galaxy, they're green. This seems like an arbitrary difference but I can accept it because the 2 galaxies use 2 different models of Stargates. However, there's also a different color made when ships go into & out of hyperspace. On SG-1, it's a dark blue/purple hyperspace window. On Atlantis, it's a pale green hyperspace window. I can't chalk it up to differences in equipment either because we see Daedalus-class ships on both series.

Silvercrest · Dec 18, 2009

The Borgified Corpse said:
Yeah, that's weird but kinda interesting. I suppose it might work. I'd like to see someone try it.

I like your theory about what the kawoosh is (an expulsion of particulate matter from the wormhole's path). Is there any episode where Carter or anyone else explains it?

No, I extrapolated that from the following items:
1) The kawoosh is specifically stated to be materializing from the event horizon, and is not part of it.
2) It can be blocked like any other material object. These two things tell us it's some kind of plasma, or anyway some highly energized form of matter. Where does it come from? Pretty much has to be from the wormhole itself. This is consistent with "48 Hours", in which we have an event horizon with no wormhole, and no kawoosh.
3) We know that the wormhole interacts with normal space enough that it tries to avoid passing through celestial bodies. If it does pass through them, particles can be exchanged ("Red Sky"). This tells us that the wormhole can probably pick up matter from normal space. It would certainly be likely to do this when it's first being established.

So, it appears that you've got an initially formed wormhole that is full of crud. Even if the wormhole didn't pass through any celestial bodies, it's almost certainly going to pick up dust particles and gas molecules here and there. The gate apparently feels the need to get rid of these things. It happens automatically whenever the wormhole is opened.

Why is it so necessary to expel it in so dramatic a fashion? Why is it necessary to expel it at all? Well, on Deep Space Nine, that wormhole was specifically shown to have objects occupying it. Those objects presented a navigation hazard to travelers. I theorized that could be true here too. Imagine a matter-stream hitting a particle of dust at high speed. Couldn't that mess up the recompiling process? Either part of your pattern wouldn't arrive normally, or you'd bring the particle with you and reintegrate with it inside your body. :wtf:

The gate has a lot of safety protocols that are designed to protect travelers. This is another one.

I like to think of it as though the "worm" was vomiting out all the...

well, never mind. :eek:

Here's something I've wondered about: In the Milky Way Galaxy, the inside of the wormholes are blue. In the Pegasus Galaxy, they're green. This seems like an arbitrary difference but I can accept it because the 2 galaxies use 2 different models of Stargates. However, there's also a different color made when ships go into & out of hyperspace. On SG-1, it's a dark blue/purple hyperspace window. On Atlantis, it's a pale green hyperspace window. I can't chalk it up to differences in equipment either because we see Daedalus-class ships on both series.

Frankly, I've always felt that they've never put enough thought into the FTL technology portrayed on these shows. There were all the discrepancies in early seasons about how the ships could only go so fast, and yet Apophis has a ha'tak that can reach Earth in a few hours, and Teal'c and Carter are surprised by this, and yet no one ever analyzes how and when the Goa'uld could get such a huge quantum leap in their technology. Particularly since it didn't seem to impact their civilization at all.

Personally, I think the Goa'uld ships could always go that fast. Teal'c just didn't want to admit that he didn't know how fast the speed of light was, so he just made up a number. :rolleyes:

He's a warrior, after all, unfamiliar with Goa'uld magic....

And then there's "Unending", where the Ori ships could follow SG-1 all the way to the Ida Galaxy and back. How did they do that? They don't have intergalactic drives-- that's why they need the supergate! :confused:

And why is it they refer to "subspace" for Stargate operation, but "hyperspace" for ship operation? Are they really two different things? :vulcan:

David cgc · Dec 18, 2009

I'm sure the Ori did have intergalactic drives. Their home galaxy was just so far away that it wasn't practical to fly the whole way out.

The Borgified Corpse said:
Here's something I've wondered about: In the Milky Way Galaxy, the inside of the wormholes are blue. In the Pegasus Galaxy, they're green. This seems like an arbitrary difference but I can accept it because the 2 galaxies use 2 different models of Stargates. However, there's also a different color made when ships go into & out of hyperspace. On SG-1, it's a dark blue/purple hyperspace window. On Atlantis, it's a pale green hyperspace window. I can't chalk it up to differences in equipment either because we see Daedalus-class ships on both series.

It's more a difference in effects companies. I never did a point-by-point comparison, but one company has a sort of loose, gassy, dark hyperspace window that reminds me of light refracting through a puddle of motor oil on the street, one has the blue vaporous cone, and one has the bright green one with the tendrils of energy. At first, I tried to explain it away with it being different tech (Wraith had the oily one, Goa'uld had the blue one, and Asgard had the green one), but it quickly became apparent they were being used interchangeably across both shows. I think they've more-or-less standardized on the green one, now.

Silvercrest · Dec 21, 2009

No more thoughts on the half-life of naquadah or whether a gate should be radioactive? Okay, next installment then.

DURATION OF A WORMHOLE
An operator on the originating Stargate can manually send a shutoff command at any time, via the DHD or other interface. A manual shutoff disengages the wormhole immediately without regard for objects or travelers which are still entering. (See ENTERING A STARGATE for notes on how objects are affected while entering the event horizon. See EMERGING FROM A STARGATE for whether anything will come out the other side.)

Otherwise, the Stargate will maintain the wormhole continuously as long as objects or signals continue to be sent through it. (It will close the wormhole and shut off if there is no activity for d12 rounds.) The maximum time that a Stargate can normally maintain a wormhole is 38 minutes. It is possible to exceed this amount of time; however, longer-lived wormholes tend to become unstable. This presents a significant risk that the traveler’s pattern could be lost. For this reason, both DHD and Stargate are programmed with a 38-minute maximum. Under normal conditions, a wormhole will not last longer than this amount of time.

It is possible to override the 38-minute limit from the originating end with a Stargate check (DC 25). The Stargate will draw additional power, an amount which increases geometrically with every additional minute beyond 38 minutes. Any traveler who passes through the wormhole during this additional time must make a Fortitude saving throw. The DC is 10, plus 1 for every additional minute the Stargate remains open. Failing this saving throw means that something bad happens to the traveler, the exact nature of which is up to the referee. (It can be anything from frost forming on the traveler’s skin to the traveler’s pattern being permanently lost.)

Note that it is possible for a wormhole to last longer than 38 minutes, if the wormhole is being powered by a source on the receiving end. (See the last paragraph under ENERGIZING A STARGATE.) In such a case, the wormhole is no longer under the control of the originating gate. This means that neither the manual shutoff command, nor the 38-minute programming, will be in effect.

This is the only time that a destination Stargate can affect the wormhole at all. A destination gate can never send a shutoff command, or influence the wormhole in any other way. (See DISRUPTING A WORMHOLE for the other means of disengaging a Stargate from the receiving end.)

DISRUPTING A WORMHOLE
Although a Stargate exerts precise control over the wormholes it generates, certain high-energy phenomena can cause a wormhole to do unusual things.

Hiccuping a wormhole:
As stated under DURATION OF A WORMHOLE, the destination Stargate is never in command of a wormhole. It cannot issue shutoff commands or anything else. However, there is one way to disengage a wormhole from the receiving end. If the destination Stargate is struck by a truly staggering amount of energy, the resulting “hiccup” can keep the originating gate from registering it as a viable destination. In such a case, the originating gate will shut down the wormhole.

This is not an easy condition to achieve. The amount of energy required to do this is on the order of a nuclear weapon, or an earthquake. It is also usually a temporary condition. The discharge will not generally cause permanent harm to the receiving gate (although there is a minor chance of damage). Under most conditions, the destination gate can be dialed again once the conditions have cleared.

Jumping a wormhole:
If an originating Stargate becomes overloaded by energy while active, and is unable to dissipate the excess energy, a wormhole can ‘jump’ to another destination Stargate. This appears to be an emergency safety measure built into the Stargates. This action disperses the energy between all three gates and prevents damage to the first two.
The third Stargate can be anywhere in the proximity of the wormhole’s path, by quite a few light-years. However, the wormhole is statistically more likely to jump to the Stargate that is next closest to the destination, as that is the path of least resistance.

Due to the instabilities caused by this “jump”, the originating Stargate is not always able to maintain a functional wormhole afterward. Thus, it will tend to shut down as soon as the “jump” is completed.

If objects are in transit during the “jump”, they may be sent to the second destination gate. The instability often results in side effects upon rematerialization. (See DIALING WITHOUT A DHD for examples of mistranslation side effects.) However, it rarely results in permanent harm.
It is possible to “jump” a wormhole on command. A high energy discharge will accomplish this if directed at the Stargate. It requires approximately the energy of a medium-sized bomb, or a lightning bolt. (A Goa’uld staff weapon, for example, is not enough.) A smaller continuous charging source, such as a generator, can work, but only if it is able to deliver enough energy during the duration of the wormhole. Along with the energy source, jumping a wormhole requires a Stargate check with a DC of 20.

A DHD cannot be commanded to jump a wormhole by itself, due to its safety protocols. However, it can be forced to do so. In this case, the Stargate check DC is 30.

It is very difficult to direct the results of the jump to a specific destination. If this is desired, the user must first map out the desired destination Stargate, and then make a second Stargate check. The DC of this check will be high, but will also depend on how far “off-track” the jump will be.
It is not possible to jump a wormhole from the destination end.

Time Travel:
Although they are essentially an interdimensional conduit and operate in subspace, wormholes interact on a limited basis with normal space and are to a limited degree, ‘line of sight’. A wormhole can be manipulated by intense solar, gravitational, and space-time effects such as sunspots, solar flares, and singularities, if it passes close to a star or another body. The wormhole could be distorted by the intense forces, reverse course, and return a traveler to his point of departure. Due to the nature of the space-time continuum, this could take the traveler to another point in time.

Gate-based time travel usually sends a traveler back to the gate he started from, traveling in time but not in space. However, in theory it is possible to travel in both dimensions at the same time, emerging from a different Stargate AND at a different point in time. (It is known that if the gate is in different locations in the two time frames, the traveler has a chance of coming out in either location.)

Note: As the timing of the outgoing wormhole must be precisely timed with the manipulating forces, and both the originating and destination Stargates must be in a specific line for the wormhole to pass close to these forces, it is almost impossible to use the Stargate as a reliable method of time travel. There is no check DC for time travel.

BLOCKING A STARGATE
If a barrier is placed in front of the Stargate (or if travel is otherwise somehow impeded), the traveler will tend to rebound back into the event horizon and will dematerialize again. This usually results in the traveler’s being permanently lost. (See the section on entering a destination Stargate under ENTERING A STARGATE.)

Although simply placing a barrier in front of the destination Stargate is an effective block to travel, it will almost always be destroyed when the funnel forms. Even if the barrier is put into place after the funnel vanishes, it will not necessarily stop weapons fire if the projectiles have enough distance to reintegrate. Thus, the barrier may eventually be destroyed.

However, when the barrier is within three microns of the event horizon, most matter is unable to reintegrate at all. This is a far more effective method of blocking Stargate travel. (It will also block the funnel effect from materializing in front of the Stargate whenever a wormhole appears.)
Rather than machining a precise, smooth shield to fit 3 microns from the event horizon, often it is more expedient to simply push a rough shield directly up against the Stargate while it is active. The portion of the shield that enters the event horizon will dematerialize. The portion which remains will be shaped to the precise size and distance to block the Stargate if it is turned on again.
The advantage with permitting a wormhole to open (but blocking reintegration) is that radio signals and other communications can still be sent via the Stargate. This permits negotiations with unfriendly parties, or the exchange of information with unknown parties, without permitting them to come through.

Note that if the majority of the Stargate’s inner circumference is occupied by solid matter, an event horizon cannot be formed. This is an effective method for cutting off a world from gate travel.

The most common way to achieve this is to bury the Stargate. Other methods may involve a “coverstone” or similar casing which seals off the glyphs, chevrons and ring, to prevent anyone accessing them, and which also extends within the gate’s circumference (to keep it from opening). (Some cultures may choose to bury the Stargate after installing the coverstone, for good measure.) Alternately, a simple plug may be inserted into the gate, sealing it off from use, but removable so that the gate can be used on its owners’ terms.

If less than half the inner circumference is occupied by solid matter, an event horizon will form, cutting the obstacle in half. (The front half will also tend to be disintegrated by the funnel that accompanies the event horizon.)

If force field technology is available, it can be used to block the Stargate. In this case, if the force field is durable enough to resist weapons fire, it may not be strictly necessary to place it within 3 microns of the event horizon.

MULTIPLE GATES ON ONE PLANET
If two or more Stargates are on a planet and only one has a DHD, that gate becomes the default gate. Incoming wormholes will automatically be routed to it.

The Stargate that was used more recently becomes the default gate if any of the following conditions apply:
1) both Stargates have DHDs,
2) both Stargates are in regular use (even if one does not have a DHD), or
3) only one gate has been used recently, even if it does not have a DHD. A Stargate that has some energy reserves will take priority over a gate that does not, even if neither has been used in a long time.

If there are two DHDs, or none, and neither Stargate has been used for a long time, priority may be assigned randomly. A user should be able to assign priority by providing energy reserves to a gate, even if there is not enough energy to open it. The standard rules for charging a Stargate apply in this case.

Note: It is accepted as fact that a gate actually on the planet always takes priority over an orbital Stargate, regardless of frequency of use or any other factors. Because orbital Stargates are rare or nonexistent in the Milky Way, this theory has not been completely tested.

SPECIAL DIALING PROCEDURES

Wormhole forwarding:
It is possible to program a particular Stargate so that, upon receiving an incoming wormhole, it automatically dials a different address. This will automatically forward the wormhole to another Stargate. It will not be possible to travel to this Stargate as long as the alteration is in effect (although it is still possible to dial out). The DC for this check is 20.

Note: Altering two Stargates so that they dial each other continuously will keep both gates from working normally. In addition to not being able to dial in to either gate, it will not be possible to dial out from either gate. This constitutes an uncontrolled feedback loop, which has a slight chance of damaging one or both gates. Note that any character caught in such a loop is effectively in stasis for as long as it continues. This application could be used to hold a dangerous prisoner, or preserve someone’s life.

Multiple wormholes:
With special software, it is possible to command a Stargate to dial multiple addresses at the same time. This is typically used to disseminate information. The initiating Stargate does not literally dial the entire network at once, as no DHD carries the power to generate that many wormholes. However, it is known that at least half a dozen gates can be dialed simultaneously, and probably more. This application can then use the “call-forwarding” feature so that any Stargate dialed will automatically dial more Stargates to pass on the same information. The entire galactic Stargate network can be reached this way. (Essentially, this sort of software constitutes a virus, and can do great harm if misused.) The DC for this application varies widely, depending on what is being attempted.

Travel through the initiating gate is not recommended while this is going on. It is unclear what would happen to the traveler’s pattern if he attempted to travel to half a dozen destinations at the same time. It is possible he would travel to a random destination, but there is a greater likelihood that the pattern would simply be lost.

Additional Chevrons:
Normally, Stargates operate in a local network. These networks can spread across an entire galaxy; however, other networks exist in other galaxies. It is possible to dial to other galaxies, but a substantial power source is required to lock onto an extra-galactic Stargate. To dial another galaxy, a Stargate needs 10 times as much power as it does normally.

In addition to the high-energy requirements, a distance co-ordinate is required. Specifically, eight glyphs require locking by eight chevrons, instead of seven. The eighth chevron is either an additional distance factor for calculating co-ordinates, or else it is a specific galactic code. There are Stargates known to exist in the galaxies Ida and Pegasus, and the galaxy of the Ori, in addition to the Milky Way. Other galaxies are known to have been seeded, but they have not been mapped.

The purpose of the ninth chevron is still not entirely clear. It is known that the ninth chevron is used for reaching the Stargate aboard the Ancient starship Destiny. However, since the Destiny is in motion and thus is not always located at the same address, it is uncertain whether this means the ninth chevron is dedicated specifically to that ship and enables a Stargate to find it, or whether it has a more generic purpose. It has been suggested that the ninth chevron is intended to connect planet-based Stargates with moving Stargates, the ninth chevron enabling a velocity or correction factor to be introduced into coordinate calculations.

David cgc · Dec 21, 2009

I have some thoughts on the priority, and the distance sections.

After "Before I Sleep," when Janus mentioned that he specifically set the Atlantis dialing computer to reject any connection that didn't come to Earth, I decided this is probably what happened to the Antarctic DHD. After the Ancients returned to Earth from Atlantis, they deactivated or locked out the Antarctic DHD the same way Janus rigged the Atlantis gate. That's why Ra, presumably, couldn't make a connection to Earth when he found it and assumed he'd have to bring another stargate to the planet, and why the Antarctic gate never took precedence while it was connected to the Antarctic DHD, neither while it was in Antarctica, nor when the rogue NID team was using it. They had to overcharge the off-world gate every time to return to their stargate and not the SGC, even while it was connected to a DHD, while the Russians were able to take priority over the SGC at any time just by plugging in the DHD to their stargate. Similarly, the russian teams didn't need to overcharge to return home, they simply waited for prearranged times when the russian DHD would be plugged in.

So I would theorize that it's possible for someone with enough know-how to set a DHD to automatically reject all incoming wormholes, with an optional white-list of addresses that it will accept connections from.

As for 8 and 9 chevron addresses, I don't think it's a hard-and-fast rule how much more power an 8 symbol address requires. O'Neill and, later, the two Carters were both able to dial the Ida Galaxy with a tricked-out naquadah reactor, while dialing the Pegasus Galaxy required a ZPM, and dialing Destiny required an entire planet's worth of explodium.

Also, rather than suggesting the 9th chevron is a velocity correction (because the Destiny does maneuver), I'd say that it's a "serial number" that causes the stargate to attempt to make a connection to a specific gate regardless of its physical location, rather than making a connection to whatever stargate is in the region of space defined by the address.

The Borgified Corpse · Dec 21, 2009

Silvercrest said:
And then there's "Unending", where the Ori ships could follow SG-1 all the way to the Ida Galaxy and back. How did they do that? They don't have intergalactic drives-- that's why they need the supergate!

I'm with David cgc. The Ori have intergalactic drives that allow them to travel between relatively nearby galaxies. The Ori Galaxy is simply so rediculously far away from the Milky Way that Supergates are the only way to travel between them in any reasonable amount of time.

But I sometimes think that the show forgot that the Asgard were from another galaxy. After all, it was the Asgard that were first menaced by the Replicators. Yet, "Menace" seemed to imply that the original creator of the Replicators was from the Milky Way Galaxy. So how did the Replicators get into the Ida Galaxy?

And why is it they refer to "subspace" for Stargate operation, but "hyperspace" for ship operation? Are they really two different things?

Perhaps they are. After all, we seem to have established that the Stargate wormholes interact with matter in real space. That's why the kawoosh forms. On the other hand, when a ship is in hyperspace, it seems to pass through matter completely unaffected. On a couple of occasions, our heroes saved the day at the last minute by opening a large hyperspace window that allowed an object to harmlessly pass through a planet rather than crash into it at a suicidal speed. This was how SG-1 prevented Anubis' asteroid from hitting Earth in "Fail Safe" and how Col. Sheppard saved the Daedalus in "The Lost Tribe."

Silvercrest · Dec 22, 2009

David cgc said:
I have some thoughts on the priority, and the distance sections.

After "Before I Sleep," when Janus mentioned that he specifically set the Atlantis dialing computer to reject any connection that didn't come to Earth, I decided this is probably what happened to the Antarctic DHD. After the Ancients returned to Earth from Atlantis, they deactivated or locked out the Antarctic DHD the same way Janus rigged the Atlantis gate. That's why Ra, presumably, couldn't make a connection to Earth when he found it and assumed he'd have to bring another stargate to the planet, and why the Antarctic gate never took precedence while it was connected to the Antarctic DHD, neither while it was in Antarctica, nor when the rogue NID team was using it. They had to overcharge the off-world gate every time to return to their stargate and not the SGC, even while it was connected to a DHD, while the Russians were able to take priority over the SGC at any time just by plugging in the DHD to their stargate. Similarly, the russian teams didn't need to overcharge to return home, they simply waited for prearranged times when the russian DHD would be plugged in.

So I would theorize that it's possible for someone with enough know-how to set a DHD to automatically reject all incoming wormholes, with an optional white-list of addresses that it will accept connections from.

I agree with that conclusion, although I'm not sure I agree with your examples. I never really considered how the rogue NID team was able to return to Earth, but jumping the wormhole every single time strikes me as a pretty risky way to do it. Besides, the only way that would work was if they opened a wormhole to the SGC first and then jumped it. Seems like Hammond would start getting a little suspicious about all these incoming temporary wormholes with no messages and no traffic. :shifty:

And there's no guarantee that the jump would take them to the second Earth gate. Statistically likely, yes. But sooner or later, they'd accidentally jump somewhere else.

As for Ra: Apparently someone was able to dial the Antarctica gate at some point, since that Jaffa was buried there. And Ra should have been able to detect the presence of the Stargate due to naquadah sensing, like Hathor did. He may have known the Antarctic gate was there and may have been able to dial it, but felt it was simpler to bring in another gate than to excavate that one. That must be relatively common practice; otherwise, why was Apophis transporting a gate to Earth when he invaded?

On the other hand... during the 5000 years that the Giza gate was buried, anyone dialing Earth should have been routed to the Antarctic gate instead. It's hard to believe that just one lone Jaffa was the only person to dial Earth in 5000 years. On that basis, it is easier to believe that the Antarctic gate was locked out, and that poor Jaffa was the victim of an accident.

In any event, even if the Antarctic gate was locked out, I don't think it contradicts anything in my document about gate priority. What you wrote about the Russian team is exactly what I had in mind.

As for 8 and 9 chevron addresses, I don't think it's a hard-and-fast rule how much more power an 8 symbol address requires. O'Neill and, later, the two Carters were both able to dial the Ida Galaxy with a tricked-out naquadah reactor, while dialing the Pegasus Galaxy required a ZPM, and dialing Destiny required an entire planet's worth of explodium.

I'm pretty sure I got the 10x figure from an episode. And it doesn't sound unreasonable, as a rough figure. A ZPM can put out that much power on a regular basis. A tricked-out naquadah reactor can do it one time, but it burns itself out in the process and probably barely achieves the threshold anyway.

As for a nine-symbol address... I didn't even think about how much power that would require. Orders of magnitude greater. Bring on the explodium, baby! Or a black-hole-powered supergate! :techman:

Also, rather than suggesting the 9th chevron is a velocity correction (because the Destiny does maneuver), I'd say that it's a "serial number" that causes the stargate to attempt to make a connection to a specific gate regardless of its physical location, rather than making a connection to whatever stargate is in the region of space defined by the address.

That's basically the same as my first explanation, or pretty close. My second explanation is quoted from somewhere else and I'm still trying to wrap my head around it.

The Borgified Corpse said:
Silvercrest said:

And then there's "Unending", where the Ori ships could follow SG-1 all the way to the Ida Galaxy and back. How did they do that? They don't have intergalactic drives-- that's why they need the supergate!

Click to expand...

I'm with David cgc. The Ori have intergalactic drives that allow them to travel between relatively nearby galaxies. The Ori Galaxy is simply so rediculously far away from the Milky Way that Supergates are the only way to travel between them in any reasonable amount of time.

But I sometimes think that the show forgot that the Asgard were from another galaxy. After all, it was the Asgard that were first menaced by the Replicators. Yet, "Menace" seemed to imply that the original creator of the Replicators was from the Milky Way Galaxy. So how did the Replicators get into the Ida Galaxy?

<McKay> Don't even get me started on that movie! <McKay>

And why is it they refer to "subspace" for Stargate operation, but "hyperspace" for ship operation? Are they really two different things?

Click to expand...

Perhaps they are. After all, we seem to have established that the Stargate wormholes interact with matter in real space. That's why the kawoosh forms. On the other hand, when a ship is in hyperspace, it seems to pass through matter completely unaffected. On a couple of occasions, our heroes saved the day at the last minute by opening a large hyperspace window that allowed an object to harmlessly pass through a planet rather than crash into it at a suicidal speed. This was how SG-1 prevented Anubis' asteroid from hitting Earth in "Fail Safe" and how Col. Sheppard saved the Daedalus in "The Lost Tribe."

Very good points! And you're using my own logic against me. Okay, I'll buy that they are separate things. But that still suggests that they didn't really put a lot of thought into the concept of hyperspace.

David cgc · Dec 23, 2009

Silvercrest said:
I agree with that conclusion, although I'm not sure I agree with your examples. I never really considered how the rogue NID team was able to return to Earth, but jumping the wormhole every single time strikes me as a pretty risky way to do it. Besides, the only way that would work was if they opened a wormhole to the SGC first and then jumped it. Seems like Hammond would start getting a little suspicious about all these incoming temporary wormholes with no messages and no traffic.

And there's no guarantee that the jump would take them to the second Earth gate. Statistically likely, yes. But sooner or later, they'd accidentally jump somewhere else.

I just checked a transcript of "Touchstone." I assumed that when Jack and Daniel overcharged the offworld gate to get a MALP to the stolen gate, they were doing the same thing the NID guys had been doing, but there wasn't anything in the episode that said one way or another.

On the other hand... during the 5000 years that the Giza gate was buried, anyone dialing Earth should have been routed to the Antarctic gate instead. It's hard to believe that just one lone Jaffa was the only person to dial Earth in 5000 years. On that basis, it is easier to believe that the Antarctic gate was locked out, and that poor Jaffa was the victim of an accident.

That what I figured. Either it was just after the Giza gate was buried, and Apophis assumed it was some trick of Ra's and tried to force a connection, or it was during the heady days of the first couple episodes of SG-1 when he was doing his "throw a bunch of crap at the iris" strategy. Either way, at one point her accidentally jumped it and a Serpent Guard went through.

Silvercrest · Dec 23, 2009

I only remembered he was a Jaffa-- I overlooked that he was a Serpent Guard. It seems logical that it would have happened during those first couple episodes, when Apophis really started taking an interest in the Earth. Except I think the Jaffa was buried a little too deeply for the few months that passed until "Solitudes."

Ah, well-- it could have been after Ra was evicted, or some other dialing accident in the last few centuries or millennia. A wormhole that got bumped to Antarctica that wasn't supposed to go to Earth at all. "Contrary to popular human belief, the Earth is not the center of the galaxy." I heard that somewhere.

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