Hyperspace travel in SG is incorrect

[K^2]

That's closer to how wormholes work, except, the two original points don't need to be on any specific surface. Even if they are separated by some large distance on a STRAIGHT line, there can be a shorter path by going around. Of course, that would also be a straight line. That's relativity for you.

Hyperspace is like going onto a different circle all together, and on that circle, things happen to be closer together.

[Lord Excalibar]

Originally Posted by wowser147

When a rocket or somekind of spaceship travels at extreme velocities, time almost cease to apply on the ship and the passengers within. If a ship travelled around our solarsystem for about 2minutes, 20 years have gone by on Earth. So how is it that the characters in SG travel around in ships at extreme velocities but still share time with everyone else on Earth? At one point, SG-1 travelled at 800 times the speed of light in a Ha'tak modified by the Replicators ... One of the greatest mysteries, or can this be explained?

dont get upset einbstien the real world doesnt apply in movies

[thecomposer02]

A ship in hyperspace is not actually traveling faster then the speed of light, its traveling at pretty much normal speed like they would with sub light maybe faster cause the hyperspace pull them forward more, but instead of making the ship travel really really fast hyperspace is creating a shortcut for the ship to travel in, its getting to a location faster then light but it is not traveling that fast it is just taking a shortcut much like a wormhole does but different. Wormholes are way faster and demilitarize you, hyperspace is more of a dimension where you can interacted and do stuff while in it and its slower more stable also. Thats also why in hyperspace you can go through planets and other things because you are no longer in our dimension your in a subspace if thats what you want to call it.
There is probably different kinds of hyperspace dimensions giving to the reason why the different races, such as the wraith, Asgard,and Ancients have such different hyper drive capabilities. Thats why no matter how much power you give an Asgard hyper drive it can not go faster and it would also explain why that one weapon in Atlantis that destroyed wraith ship when entering hyperspace only affect wraith hyper drives. This also deal with how the replicates made that one Goa'uld ship like 20x times faster because they probably rebuilt the hyper drive to enter a different kind of hyperspace.

[Quadhelix]

Originally Posted by K^2

Mass conservation only works under condition that speed of light is a constant.

Okay. I guess I was begging the question.

Originally Posted by thecomposer02

A ship in hyperspace is not actually traveling faster then the speed of light

Well, if Daniel's explanation video is anything to go by, there might not even be a "speed of light" in hyperspace. Interestingly, this would make photons massive particles in hyperspace, which means (IIRC) that they would decay after a certain amount of time, which would put a range limit on photon-based subspace communication.

Originally Posted by thecomposer02

Thats why no matter how much power you give an Asgard hyper drive it can not go faster

I'm going to make an analogy here: let's consider hyperdrives to be similar to car engines. Now, a car engine uses fuel to push the car forward. The faster it uses that fuel, the faster it can move the car. However, there comes a point were the engine cannot use the fuel any faster. This has nothing the do with the road that the car is on, nor does it have anything to do with the amount of fuel available or the rate at which the fuel pump can provide that fuel.

Now let us apply that analogy to the Asgard hyperdrives: the more power you put in, the better the drive performs, but it eventually you get to the point where the drive cannot handle any more power. It has nothing to do with hyperspace but everything to do with the drive.



Also, for the record, we haven't established that the Asgard hyperdrives have a maximum speed, only that there is a minimum amount of time that it takes them to travel a certain distance (i.e., 4 days from Earth to Atlantis). However, this does not necessarily mean that the ships have a maximum speed: it could very well mean a maximum acceleration.

Originally Posted by thecomposer02

it would also explain why that one weapon in Atlantis that destroyed wraith ship when entering hyperspace only affect wraith hyper drives.

If you were right about this, then any Wraith hyperdrive with a different speed than the "standard" would be unaffected by the weapon.

Originally Posted by thecomposer02

This also deal with how the replicates made that one Goa'uld ship like 20x times faster because they probably rebuilt the hyper drive to enter a different kind of hyperspace.

Except that the ship was picking up speed while in hyperspace. Therefore, not only would the Replicators have had to keep the hyperdrive running while rebuilding it, but also transfer directly from the one "kind" of hyperspace to the other without leaving.

[K^2]

Well, if Daniel's explanation video is anything to go by, there might not even be a "speed of light" in hyperspace. Interestingly, this would make photons massive particles in hyperspace, which means (IIRC) that they would decay after a certain amount of time, which would put a range limit on photon-based subspace communication.

I think the fact that no matter as we know it can exist in such space would prevent anyone from sending/receiving any signals in the first place.

[Quadhelix]

Originally Posted by K^2

I think the fact that no matter as we know it can exist in such space would prevent anyone from sending/receiving any signals in the first place.

...oops.

...what about matter as we don't know it?




In any case, what about the possibility that hyperspace is a short-cut, but that the longer you are in hyperspace, the "deeper" you get. In other words, when you start the journey, a light-year in hyperspace equals a light-year out, but the longer you fly, the shorter a distance you have to travel in hyperspace to travel a light-year in realspace.

[K^2]

Originally Posted by Quadhelix

...oops.

...what about matter as we don't know it?

Sure, some form of condensed matter is possible, even likely under sufficient concentrations of energy density, but problem is, if that was nature of hyperspace, no living thing would be able to cross in and out even under tiniest variations in light speed.

Originally Posted by Quadhelix

In any case, what about the possibility that hyperspace is a short-cut, but that the longer you are in hyperspace, the "deeper" you get. In other words, when you start the journey, a light-year in hyperspace equals a light-year out, but the longer you fly, the shorter a distance you have to travel in hyperspace to travel a light-year in realspace.

I don't think it's how long you stay, but basically, yes.

Say, I was God Almighty, and I was designing the world with Sci-Fi in mind, intending the sentient creatures of the world to one day overcome the issues with light barrier. I would design the world to rest on something like a surface of a hypersphere or flat hypertorus. (I have some reasons to suspect that true universe is closer to former, but it doesn't matter.)

The square of the distance between any two points on the hypersphere is given by:

ds²=dr²+r²*dTheta²+r²*sin²Theta*dPhi²+r²*sin²Theta*sin²Phi*dChi² where Theta, Phi, and Chi are the three hyperspherical polar angles.

Similarly, on flat hypertorus, the square of the distance is given by:

ds²=dr²+r²*(dx²+dy²+dz²) where x, y, and z are normal 3-space coordinates.

Note that either one of these will appear, locally, to be normal flat 3-space if you fix r to be some constant R. In the hyperspherical case, R needs to be sufficiently large to prevent inherent spherical curvature from being obvious.

Now, let me focus on toroidal case, because it is a bit easier algebraically. Say you want to travel along x axis from some x? to some x?. In normal space, you have to travel distance R*(x?-x?). But lets say you have ability to travel along r as well. Now you can go down to some r=R'<<R and travel distance R'*(x?-x?) which may be significantly shorter.

Final part. Why matter sticks at r=R? And why do different hyperdrives allow different distances to be covered in different amount of time? Gravity! Basically, we haven't talked about time yet, and it's important. In flat case, the hypertoroidal space needs to include one more element.

ds²=-dt²+dr²+r²*(dx²+dy²+dz²)

Now, at some r=R, the local space time is very similar to Minkowski Metric (-dt²+dx²+dy²+dz²) with control parameter R. And in order to add a bit of a pseudo-gravitational force to push things away from r=0, we add a bit of a curvature. For example, we may take Schwarzschild metric, representing gravity of spherically symmetric bodies, apply it to just the t and r coordinates, and invert the sign of curvature to force gravity out instead of in. We'd get something like this:

ds²=-(1+R0/r)*dt²+1/(1+R0/r)*dr²+r²(dx²+dy²+dz²)

Here, R0 is a tunning parameter similar to Schwarzschild Radius. I won't bore you with calculus involved, but this gives you a force proportional to 1/r² away from r=0 for r>>R0 and an infinite force near R0. It also makes almost no difference on physics in the X-Y-Z 3-space at constant r. If the space-time now happens to have a hard boundary at r=R, things would exist pretty much exclusively on that boundary, and it would take some trickery to drop down to r<R, with it becoming increasingly more difficult to stay low as you decrease r. But if you can go down to r<<R, you can travel between two points much, much faster, while still enjoying essentially the same type of physics as you have in normal space.

Edit: This board appears to be non-Unicode so it killed all my Greek letters and subscripts. :'( I'll replace these with text.

[Quadhelix]

Originally Posted by K^2

Now, let me focus on toroidal case, because it is a bit easier algebraically. Say you want to travel along x axis from some x? to some x?. In normal space, you have to travel distance R*(x?-x?). But lets say you have ability to travel along r as well. Now you can go down to some r=R'<<R and travel distance R'*(x?-x?) which may be significantly shorter.

I'm quoting this to give an idea of what I'm trying to say: what if the ship, instead of going to R' and traveling with v=R'*(d[Theta]/dt) instead starts out at r=R and then travels with v^2=(dr/dt)^2+r*(d[Theta]/dt)^2? In this way, it starts out slow and then "accelerates" as it continues to travel.

You of course, already explained why the ship would "pop back" to r=R when the drive was deactivated.

[K^2]

But why?

[Dodgified]

Originally Posted by Quadhelix

Also, for the record, we haven't established that the Asgard hyperdrives have a maximum speed, only that there is a minimum amount of time that it takes them to travel a certain distance (i.e., 4 days from Earth to Atlantis). However, this does not necessarily mean that the ships have a maximum speed: it could very well mean a maximum acceleration.

If it's acceleration, then asgard ships could go faster than ours because they have bigger/more engines than our ships so can accelerate to the higher speeds faster then our ships?
Ours will eventually get there with enough power, but they can get there faster because of greater acceleration.

oh and i wish i understood half the maths and science talk in this thread.

[Quadhelix]

Originally Posted by K^2

But why?

If a hyperdrive gives you constant "acceleration" (with no maximum speed) instead of constant velocity, then "Air" makes sense again: it would take a BC-304 roughly an hour to travel 21 light-years, as opposed to the nine seconds that it would take with a constant speed.

This would imply that ships in hyperspace start out with negligible speed and have a (somewhat) constant acceleration. The "speed" of a hyperdrive is R*(d[Theta]/dt) and so, if r*(d[Theta]/dt) is constant (conservation of angular momentum), then the ship's "acceleration" would be dr/dt. The ship would start out at r=R and would "accelerate" pretty much the entire way to its destination, then drop out of hyperspace upon arrival, "popping back" to r=R almost immediately.

[K^2]

Then why should it take time to go to lower r, but possible to pop back instantly? What you are saying might make sense with the show, but not the spherical/toroidal model of hyperspace. If acceleration really is a part of it, then my model is inadequate to describe it.

[Quadhelix]

Originally Posted by K^2

Then why should it take time to go to lower r, but possible to pop back instantly?

I was thinking that it would "pop back" due to the outward force that keeps most material on the surface - ships actually don't exit hyperspace instantly: there is the time during which the hyperspace window forms (which could result from "turbulence" cause by the ship "surfacing").

Actually, this posses problems for my own model, because of the 1/r^2 nature of the repulsion force (i.e., the "faster" the ship is going, the harder it has to work to go faster). I suppose that one aspect of a hyperdrive might be the ability to nullify the effects of that force upon the ship, but then that raises conservation of energy concerns (or not, seeing as how ships always return to normal space almost instantly when their hyperdrives fail).

Originally Posted by K^2

What you are saying might make sense with the show, but not the spherical/toroidal model of hyperspace. If acceleration really is a part of it, then my model is inadequate to describe it.

Maybe, maybe not.

Like I noted above, as long as the ships could move relatively freely between different values of r, there is nothing to keep the ship from accelerating mid-flight.

[K^2]

Yeah, but with the 1/r² repulsion, if you have enough "thrust" to go down to some R', your thrust/weight is going to be huge most of the way down, so your acceleration going down to R' is going to be even higher than when you 'pop' back up.

Edit: This forum needs a community game project. I looked at some of the 3D models of the ships that are being made, and damn. I can write up the code for flight physics and hyperspace navigation. If some people would come up with a good concept...

[_Famrir_]

its television half of that stuff doesnt make sense

[Quadhelix]

Originally Posted by K^2

Yeah, but with the 1/r² repulsion, if you have enough "thrust" to go down to some R', your thrust/weight is going to be huge most of the way down, so your acceleration going down to R' is going to be even higher than when you 'pop' back up.

Well, that's why I raised the possibility that the hyperdrive somehow nullifies that force. In this way, the ship could move through various levels of r without any change in the amount of thrust needed to accelerate, but would find itself with "negative" kinetic energy once the hyperdrive disengaged and thus be forced back to real space rather quickly. I have no idea how plausible any of this is, of course, but it's food for thought.

One thought that I had is that the "force-nullification" ability is unique to "intergalactic" hyperdrives: normal hyperdrives can push themselves to some R' and no further, accelerating to maximum speed quickly but not capable of going any faster, while intergalactic hyperdrives have worse acceleration (most of the power goes into force nullification) but can accelerate pretty much indefinitely.

[K^2]

Hmm... Maybe. But then with intergalactic drive, it would take much longer to exit hyperspace. You'd also be far more likely to overshoot destination, but navigation being difficult for long jumps seems to be consistent with this and other shows.

Edit: By the way, this would make intergalactic drive function very similarly to inertial dampeners. In both cases, it takes distortion of space-time to work.

[henty]

Originally Posted by wowser147

When a rocket or somekind of spaceship travels at extreme velocities, time almost cease to apply on the ship and the passengers within. If a ship travelled around our solarsystem for about 2minutes, 20 years have gone by on Earth. So how is it that the characters in SG travel around in ships at extreme velocities but still share time with everyone else on Earth? At one point, SG-1 travelled at 800 times the speed of light in a Ha'tak modified by the Replicators ... One of the greatest mysteries, or can this be explained?

as explained : hyperspace travel = not travel in our space
but that brings another question
Destiny doesnt have hyperspace engine, it only have that FTL - and it is actually happening in our space, but no time dilatation occurs.
if it did, then it would be strange when using those comunication stones.
only strange behavior of stones happens when going from or to FTL and that is all. during normal travel or FTL travel they can control each other without problems which implyes they are experiencing same time speed as Earth..

[K^2]

You aren't going to get significant time dilation in FTL.