Playability of STL Only Interstellar travel in GURPS?

[Ze'Manel Cunha]

Originally Posted by sir_pudding

Why not? Software based PCs could easily travel this way.

Yeah, um, I thought we were staying on the semi-realistic side of things, no?

Originally Posted by scialytic

Actually you could. According to a paper published by Michael Morris, Kip Thorne, and Uri Yertsever (MTY) at the California Institute of Technology in 1987 and summarized here

All of that works great, except for the "99.995% of the speed of light" bit, the mass/energy needed to do that is just too far fetched to be on the semi-realistic side of things.


BTW, the Peacekeeper books, the Major Ariane Kedros Novels by Laura E. Reeve are actually very much a take on the wormhole seeding theme, I actually recommend the series despite the author being ex-AF and the space ranks being AF instead of proper Navy ranks.

[malloyd]

Originally Posted by scialytic

Actually you could. According to a paper published by Michael Morris, Kip Thorne, and Uri Yertsever (MTY) at the California Institute of Technology in 1987 and summarized here

It should be noted that these schemes are easily shown to produce causality violations. For example the ship at Vega could load a second wormhole and return to Terra with a second link. According to this logic, it is then possible to step to from Terra to Vega 6 months after the ship first left Terra, fire a missle back along it's course and destroy it before it arrives at Vega the first time.

[scialytic]

Originally Posted by Ze'Manel Cunha

All of that works great, except for the "99.995% of the speed of light" bit, the mass/energy needed to do that is just too far fetched to be on the semi-realistic side of things.

Well the 99.995% light speed isn't necessary it's only an example. But remember that it also states the ship can be refueled via the mouth meaning it does not have to carry all it's reaction mass with it therefore allowing it to accelerate indefinitely as long as it has a steady supply of reaction mass coming in.

[scialytic]

Originally Posted by malloyd

It should be noted that these schemes are easily shown to produce causality violations. For example the ship at Vega could load a second wormhole and return to Terra with a second link. According to this logic, it is then possible to step to from Terra to Vega 6 months after the ship first left Terra, fire a missle back along it's course and destroy it before it arrives at Vega the first time.

True, but since we are already dealing with FTL then we either have to toss causality or relativity out the window you can't have all three.

[Ze'Manel Cunha]

Originally Posted by malloyd

It should be noted that these schemes are easily shown to produce causality violations. For example the ship at Vega could load a second wormhole and return to Terra with a second link. According to this logic, it is then possible to step to from Terra to Vega 6 months after the ship first left Terra, fire a missle back along it's course and destroy it before it arrives at Vega the first time.

Originally Posted by scialytic

True, but since we are already dealing with FTL then we either have to toss causality or relativity out the window you can't have all three.

There's no violation of anything with this type of scheme, if you step from Terra to Vega 6 months after the ship first left Terra, then you arrive at Vega 6 months later, if you then send a missile back to Terra through the same worm-hole it arrives on Terra 6 months + whatever time it took you to send the missile back from when the ship left.

The only relativistic effects are that the crew on the ship only aged 1 day and 20 hours, (at the 100 factor from 99.995% of C), while the people on Terra aged 6 months.

[malloyd]

Originally Posted by Ze'Manel Cunha

There's no violation of anything with this type of scheme, if you step from Terra to Vega 6 months after the ship first left Terra, then you arrive at Vega 6 months later, if you then send a missile back to Terra through the same worm-hole it arrives on Terra 6 months + whatever time it took you to send the missile back from when the ship left.

No, you fire it back along the ship's *normal* space track. Since it can't travel FTL with respect to Vega, and 6 months after it left Terra from the standpoint of Vega it had not arrived there yet, when you get there via the second wormhole, the first one doesn't exist yet. Yes it makes no sense. That's the point. FTL travel in a relativistic universe is equivalent to time travel, and inherently causes paradoxes like this.

[scialytic]

Originally Posted by malloyd

No, you fire it back along the ship's *normal* space track. Since it can't travel FTL with respect to Vega, and 6 months after it left Terra from the standpoint of Vega it had not arrived there yet, when you get there via the second wormhole, the first one doesn't exist yet. Yes it makes no sense. That's the point. FTL travel in a relativistic universe is equivalent to time travel, and inherently causes paradoxes like this.

Well you could say the setting could incorporate some kind of censorship principle that doesn't allow for wormholes to become time machines thus maintaining causality.

The fact is that if you want FTL you are going to have to handwave away the messy stuff and, at least in my experience, the players really don't care that your FTL isn't hard science because it can't be. They want a ship they want to fly around and they want to do stuff. Just state what your FTL system can do and maintain internal consistently in your setting don't get hung up on the technobabble and trying to explain how it does it because if causality and relativity are correct then your FTL can't really exist anyways.

[sir_pudding]

Originally Posted by Ze'Manel Cunha

Yeah, um, I thought we were staying on the semi-realistic side of things, no?

Artificial Intelligence isn't realistic?

[malloyd]

Originally Posted by scialytic

The fact is that if you want FTL you are going to have to handwave away the messy stuff and, at least in my experience, the players really don't care that your FTL isn't hard science because it can't be. They want a ship they want to fly around and they want to do stuff. Just state what your FTL system can do and maintain internal consistently in your setting don't get hung up on the technobabble and trying to explain how it does it because if causality and relativity are correct then your FTL can't really exist anyways.

The classic dodge with a wormhole system is to have somebody else build it a long time ago. If enough time passes for photons to be exchanged between the most extremely separated elements of it before anything can traverse it, you can synch all the clocks beforehand, and simply declare Opening Day the origin point of Network Standard Time. Everybody disagrees on how much time passed between the start of construction and Opening Day, but they can't use the system to travel back before it in any frame, so the causality problems can be ignored. Though note that all the wormholes do need to be at rest with respect to each other, or your'll eventually build up time discrepancies between the exits, so they're pretty shortly going to be out in interstellar space somewhere as the relative proper motions of the stars moves them around.

[Fred Brackin]

Originally Posted by sir_pudding

Artificial Intelligence isn't realistic?

On the one hand it doesn't appear to violate any conservation laws. So it isn't superscience.

On the other hand, I haven't seen much sign of it's development in the real world. If I look at the capabilities pf systems that interact with the real world (and tier complexity in Gurps terms) and compare that to animal models it does not match up with the IQ formulas in UT. It doesn't even come close.

We've got C2 or 3 systems partially matching IQ1 insects and C4-5 systems matching (again only partially) IQ 2 lizards.

If I had to take a guess the "realistic" formula for computer IQ is no better than IQ=Complexity/2.

Even at 2 or 3 C levels per TL we're a long way from AI PCs.