Incoming wormhole anomaly

[Abiron]

I think we first need to put together the sequence of events for a "proper" wormhole connection and then see what works and what might be in error from a show perspective. (I know, it's all fiction anyway, but what the heck...)

I think it goes something like this:

1. Traveller begins dialing an address in the DHD.
2. DHD sends the address to the Gate, which warms up its hardware and gets ready to do its thing.
3. As each symbol is transmitted, the Gate begins to form the target address.
4. When the Big Red Button is pressed, the Gate transmits via subspace to the target Gate and either gets an acknowledgement that it's a valid address that can accept an incoming wormhole, or it gets one of a number of "busy" or "error" signals. This has to happen in milliseconds, because if the target address is valid the wormhole forms very quickly after the BRB is pressed.
5. Assuming that the target Gate ack'd that it's available, the sending Gate forms its end of the wormhole and prepares to receive the traveller in its buffer. At this point, the other end of the wormhole has no exit, and the traveller entering the event horizon would simply be stored awaiting transmission.
6. At the same time, the target Gate's chevrons light up in sequence as it powers its buffer and receiving hardware.
7. If nothing prevents the target gate from doing so, it "receives" the incoming wormhole and matter transmission begins. This could take anywhere from seconds to minutes; from the traveller's perspective, it's all the same.
8. If, on the other hand, someting does prevent the target gate from forming its end - such as an outgoing wormhole forming first - the original wormhole has nowhere to go, and shuts off. If this were the case, one could assume that the traveller would exit the Gate he had just entered, as that Gate would reintegrate him, having nowhere to send him.

Unfortunately, this sequence of events is contradicted many times onscreen. In-show, it seems like a receiving Gate starts to activate as soon as the traveller begins dialing at his end...even though the traveller has not entered enough symbols to target it. The simple way to fix this would be if the sending gate did not form a wormhole until the receiving gate is "dialed in," but we don't see our travellers standing around waiting for that to happen. The wormhole always appears right after they push the BRB.

So the real question - even disregarding whether or not my sequence above is valid at all - is if it's worth trying to explain, when what it really amounts to is a storytelling tool that varies depending on the needs of the narrative.

[Splitsecond]

In the show they have stated it takes 3 seconds from EH to EH.

[Flibby]

I was thinking that they just sort of eventually came to a decision on exactly how they want it to work, instead of changing it based on each story.

[Quadhelix]

Unfortunately, this sequence of events is contradicted many times onscreen. In-show, it seems like a receiving Gate starts to activate as soon as the traveller begins dialing at his end...even though the traveller has not entered enough symbols to target it. The simple way to fix this would be if the sending gate did not form a wormhole until the receiving gate is "dialed in," but we don't see our travellers standing around waiting for that to happen. The wormhole always appears right after they push the BRB.

Well, like I mentioned earlier, the concept of "now" gets rather complicated when dealing with distant objects. If you have a star ten light-years from you, then you would say that what is happening there "now" is the events there that you will see in ten years, because that is how long the light takes to reach you. However, it is very easy in Special Relativity to construct a frame of reference in which those events are in the past or in the future.

Thus, when two Stargates make a connection, there is the issue of "when" both ends of the connection are. Let us assume, for a moment, that the two ends of the wormhole open simultaneously. The question then becomes, "Simultaneously for whom? For observers on on of the planets? For passengers on a rocket ship traveling a 70% of the speed of light from the origin planet to the destination planet? For passengers on a ship going the same speed but in the other direction?" Each one of these would have a different physical frame of reference, and none of them would agree on whether the two Stargates activated simultaneously.

The end result of of this that it is possible for a Stargate to emit a signal when it finishes dialing and, in the frame of reference where the two ends of the Wormhole open simultaneously, have that signal arrive before that Stargate even started dialing.

[Steelbox]

From my undertanding there is a time when nothing can transpass the wormhole, the time that takes to the unstable vortex to stabilize. Now radio signals re energy not matter correct? So they don't need to be dematerialized (or de molecularized) so can go immediately the the wormhole whit saves them time. The time the caller gate need to stabilize the vortex is the time need to the other gate(called) to stabilize the subspace connection(wormhole) with the other gate. The time for the traveler to walk from the DHD to the gate is similar to the time needed by the other gate to stabilize his vortex. As soon as the traveler enter the gate and is closed, the data it transmitted to the called on that receives it in the buffer and reconstruct the object.
The main problem is that the lights go on one after the other. They should go on the the same time all at once.

[Splitsecond]

Well, like I mentioned earlier, the concept of "now" gets rather complicated when dealing with distant objects. If you have a star ten light-years from you, then you would say that what is happening there "now" is the events there that you will see in ten years, because that is how long the light takes to reach you. However, it is very easy in Special Relativity to construct a frame of reference in which those events are in the past or in the future.

Thus, when two Stargates make a connection, there is the issue of "when" both ends of the connection are. Let us assume, for a moment, that the two ends of the wormhole open simultaneously. The question then becomes, "Simultaneously for whom? For observers on on of the planets? For passengers on a rocket ship traveling a 70% of the speed of light from the origin planet to the destination planet? For passengers on a ship going the same speed but in the other direction?" Each one of these would have a different physical frame of reference, and none of them would agree on whether the two Stargates activated simultaneously.

The end result of of this that it is possible for a Stargate to emit a signal when it finishes dialing and, in the frame of reference where the two ends of the Wormhole open simultaneously, have that signal arrive before that Stargate even started dialing.

Special Relativity does not allow causality to change. An event that causes another event must always happen before the event it causes.

[Quadhelix]

Special Relativity does not allow causality to change. An event that causes another event must always happen before the event it causes.

Special Relativity also disallows faster-than-light travel, for exactly that reason. If you can travel faster than light, as a Stargate allows you to do, then you can violate causality.

[Splitsecond]

Special Relativity also disallows faster-than-light travel, for exactly that reason. If you can travel faster than light, as a Stargate allows you to do, then you can violate causality.

You never actually travel faster than light in a wormhole. You just have a shorter route. Almost no form of FTL travel in sci-fi actually has the person move faster than light through space.

[Quadhelix]

You never actually travel faster than light in a wormhole. You just have a shorter route. Almost no form of FTL travel in sci-fi actually has the person move faster than light through space.

Which is irrelevant: the mere ability to get between two points faster than a beam of light is the same thing as time travel.


Proof: an object disappears from x=0 at t=0. It reappears at x=500c*s at t=100s. We have no idea how it got from one position to another; it could have fallen through a wormhole, taken a trip through "subspace," etc.

The point is that it is rather trivial to construct a frame in which the travel was instantaneous. t'=0, thus (vx)/(c^2)=t=100s. This corresponds to a ship passing through the origin at t=0 while traveling in the positive-x direction at 0.2c.

However, if the ship is traveling any faster than 0.2c, then the object will appear, to observers on the ship, to have arrived before it left. Since all reference frames are equally valid, the observers on the ship have a legitimate claim that the object has fallen back in time. Furthermore, if the object could go back in time in the ship's reference frame, it could go back in time in any other reference frame.

[Splitsecond]

The light from the ship after the jump cannot reach the ship before it jumped. The travel time is also not instantaneous in subspace or a wormhole.

[Quadhelix]

The light from the ship after the jump cannot reach the ship before it jumped.

You misread my argument: the ship did not jump, "an object" jumped. The ship and the object are two different things. I never specified what it was because the identity of the object is not relevant to my argument.

The travel time is also not instantaneous in subspace or a wormhole.

The travel time experienced by the object is irrelevant: it could be instantaneous or several trillion years, as far as my argument is concerned.

The only issue is that the object got from point A to point B faster than a beam of light. It is therefore trivial to construct a frame of reference in which the object arrived at point B before it left point A.

[Splitsecond]

You misread my argument: the ship did not jump, "an object" jumped. The ship and the object are two different things. I never specified what it was because the identity of the object is not relevant to my argument.

The travel time experienced by the object is irrelevant: it could be instantaneous or several trillion years, as far as my argument is concerned.

The only issue is that the object got from point A to point B faster than a beam of light. It is therefore trivial to construct a frame of reference in which the object arrived at point B before it left point A.

Well as far as the ship is concerned there are simply two identical objects. Causality is not broken because the ship registers the two ships as separate objects and does not see the disappearance of one as the cause of the appearance of the other some time ago, so there is no time travel. This comes down to the 'does the lightning cause the thunder or did the thunder cause the lightning but go slower' problem.

You should specify in your last point that it's a beam of light traveling the normal route because a real wormhole will let light through.

[Quadhelix]

Well as far as the ship is concerned there are simply two identical objects. Causality is not broken because the ship registers the two ships as separate objects and does not see the disappearance of one as the cause of the appearance of the other some time ago, so there is no time travel. This comes down to the 'does the lightning cause the thunder or did the thunder cause the lightning but go slower' problem.

Not really: let us say that the object is a "warp drive probe." It then uses its drive to travel 500 light-seconds in 100s, in the frame of reference of the launch site (say, the Earth). According to the crew of the USS Einstein, which was chasing after the probe at 0.3c, the probe arrives 52 seconds before it left. Not a problem, you say, because there is no effect preceding the cause, etc., and you are right.

Then the probe turns around.

Let us say that the "warp drive" malfunctioned so that the probe, instead of coming out of warp stationary relative to the Earth (as it started out), comes out of warp traveling away from the Earth at 0.5c. In negligible time (delta-t<<1), the probe launches a "black box" back toward the Earth; the black box is equipped with its own warp drive which it uses to get back to Earth. The probe, on the other hand, obeys Newton's first law of motion.

In the probe's frame of reference, let us say that it takes the black box about 58 seconds to get back to Earth. This is a problem, because in the Earth's frame of reference, the black box got back to Earth 200 seconds before it was launched...which is about a hundred seconds before the probe itself was launched.

You should specify in your last point that it's a beam of light traveling the normal route because a real wormhole will let light through.

Much obliged, thank you.

[Splitsecond]

Not really: let us say that the object is a "warp drive probe." It then uses its drive to travel 500 light-seconds in 100s, in the frame of reference of the launch site (say, the Earth). According to the crew of the USS Einstein, which was chasing after the probe at 0.3c, the probe arrives 52 seconds before it left. Not a problem, you say, because there is no effect preceding the cause, etc., and you are right.

Then the probe turns around.

Let us say that the "warp drive" malfunctioned so that the probe, instead of coming out of warp stationary relative to the Earth (as it started out), comes out of warp traveling away from the Earth at 0.5c. In negligible time (delta-t<<1), the probe launches a "black box" back toward the Earth; the black box is equipped with its own warp drive which it uses to get back to Earth. The probe, on the other hand, obeys Newton's first law of motion.

In the probe's frame of reference, let us say that it takes the black box about 58 seconds to get back to Earth. This is a problem, because in the Earth's frame of reference, the black box got back to Earth 200 seconds before it was launched...which is about a hundred seconds before the probe itself was launched.

No it won't. I think you've unnecessarily included the distance traveled by the black box in real space in your calculation. The spacial speed of the black box is always <<c so relativity doesn't need to be used. The black box was launched from the probe at 100s Earth time and took a positive amount of Earth time to travel back. At 500s Earth time the launch of the black box is finally detected.

[Quadhelix]

No it won't. I think you've unnecessarily included the distance traveled by the black box in real space in your calculation. The spacial speed of the black box is always <<c so relativity doesn't need to be used. The black box was launched from the probe at 100s Earth time and took a positive amount of Earth time to travel back. At 500s Earth time the launch of the black box is finally detected.

Incorrect: the black box is equipped with its own "warp drive" to allow it to return to Earth at FTL speeds. There is nothing to prevent this from being the case. It takes, for example, 58 seconds (using its "warp drive") to get back to Earth in the probe's frame, and since the probe is traveling away from Earth at 0.5c (e.g., because the reactor exploded, but the probe is really well built), the black box's travel time in the Earth's frame is -200 seconds, meaning it reaches the Earth about a hundred seconds before the probe left.

Unless, of course, you're saying that there is some reason that things can go "back in time" in the USS Einstein's frame of reference but not in the Earth's.