Favorite type of FTL?

[Illuminatus Primus]

NO. Just acknowledging that if a interstellar drive is possible, none of us will have a clue NOW what it is, and will probably just make shit UP.

Total nonsense. We can accurately predict what kind, if any, might be possible, by analyzing which ones rely on the smallest number of 'breakthroughs' that upend our understanding of the universe. For example, to enable Saxton-interpretation Hyperspace, we need only find negative energy, and prove that casuality doesn't give a damn if some frames of reference see things out of order(Because as I understand it, there's no preferred frame of reference.), and as long as one.. Say, the time-traveller.. Sees it in the right order, it works out.

That's one impossible uprooted, and one unknown supplied. Compared to 'The Warp' from 40k, that's a shitload more likely.

Stark is right, you're trying too hard to have it your way despite being dead wrong.

Saxton-interpretation SW hyperspace - which, thanks to AOTC ICS, is also canon SW hyperspace, does not require negative energy density. It requires complex mass-energy (ballast) and some magic gizmo - SW hyperdrive - that can transit the real mass of the ship to a complex value (instantly making the ship go from a bradyonic to tachyonic reference frame relative to the rest of the galaxy; it goes from STL to FTL without accelerating intermediately), using the hypermatter ballast to "fix" the total mass of the ship and prevent CoM violations. But yeah, it requires that some reference frames will permit tachyonic FTL transmission of information without any apparent causality violations to observers.

[SirNitram]

Saxton-interpretation SW hyperspace - which, thanks to AOTC ICS, is also canon SW hyperspace, does not require negative energy density. It requires complex mass-energy (ballast) and some magic gizmo - SW hyperdrive - that can transit the real mass of the ship to a complex value (instantly making the ship go from a bradyonic to tachyonic reference frame relative to the rest of the galaxy; it goes from STL to FTL without accelerating intermediately), using the hypermatter ballast to "fix" the total mass of the ship and prevent CoM violations. But yeah, it requires that some reference frames will permit tachyonic FTL transmission of information without any apparent causality violations to observers.

I swear, my memory falls apart more every day... I'm not that old, I shouldn't be going senile...

[Illuminatus Primus]

Basically if there are reference frames where FTL is possible without causality violations, then they are ipso facto objectively preferred reference frames. The central basic axiom behind Relativity is no objectively preferred reference frames exist - all are equivalent and the only constant is the speed of light.

So really, there is no way to get around FTL problems unless one violates one of the two essential ideas of Relativity: there are no preferred reference frames (this is the preferred solution of SF), or the speed of light is not constant (a minority but not unteniable postulate in theoretical - and I stress purely theoretical, here - physics). Personally, I think the "hardest" (very relatively speaking) sci-fi solution to FTL is to handwave of magic teleporation drive like Red's Maeda-drive that let's massive vessels move a fixed time at c and have a universe where there are very special conditions where c can greatly exceed its "ground" value with some way of controlling or laying down paths where c is very high.

There's some resistance to just breaking the light-speed barrier like this, and manipulating the speed of light as opposed to using "tricks" and attempting superficially to maintain coherence to Relativity, but really having special reference frames is no better, and speaking of scientific likelihood its much more likely there are special conditions surrounding a variable speed of light. I think most laymen just here "nothing can go faster than the speed of light, Einstein said so" and don't any deeper, but who knows.

Red, if you ever write up a follow-up story, I'd have your posthumans figure out how to lay superphysical "faster than (normal) c" "tracks" where the Maeda drive to propel them much faster than light normally goes.

[Nyrath]

So really, there is no way to get around FTL problems unless one violates one of the two essential ideas of Relativity: there are no preferred reference frames (this is the preferred solution of SF), or the speed of light is not constant (a minority but not unteniable postulate in theoretical - and I stress purely theoretical, here - physics).

I had read that there is a third option. Some say that one can have Relativity, Causality, and FTL travel if one postulates some sort of law that makes it impossible to utilize a closed-timelike curve (i.e., a time machine) to create a causality paradox. Some species of Novikov self-consistency principle

http://www.physicsguy.com/ftl/html/FTL_ ... provisions

Hinton lists four possibilities, but the last one doesn't count, since it boils down to the dreaded preferred reference frame.

[Illuminatus Primus]

So really, there is no way to get around FTL problems unless one violates one of the two essential ideas of Relativity: there are no preferred reference frames (this is the preferred solution of SF), or the speed of light is not constant (a minority but not unteniable postulate in theoretical - and I stress purely theoretical, here - physics).

I had read that there is a third option. Some say that one can have Relativity, Causality, and FTL travel if one postulates some sort of law that makes it impossible to utilize a closed-timelike curve (i.e., a time machine) to create a causality paradox. Some species of Novikov self-consistency principle

http://www.physicsguy.com/ftl/html/FTL_ ... provisions

Hinton lists four possibilities, but the last one doesn't count, since it boils down to the dreaded preferred reference frame.

Self-fullfilling time-travel prevents useful FTL information transmission. So while technically true its not really on the table for what authors want to use it for.

[Catman]

Time Machines and causality problems just to cross stars quickly?

Weird.

[Nyrath]

Time Machines and causality problems just to cross stars quickly?

Weird.

Yes. The basic problem is that the distance between stars is incredibly freaking huge

[RedImperator]

Time Machines and causality problems just to cross stars quickly?

Weird.

The lightspeed barrier isn't just some arbitrary number: it's almost like it's weaved deep into the structure of the universe, and it's a constant in a great deal of other physical laws. The laws of physics depend on c being an absolute speed limit, and you can't really find a way around it without badly breaking something else. Even "realistic" FTL like the Alcubierre warp drive requires heaps and piles of things which cannot be proven to exist to work.

[Lord Zentei]

I may have mentioned it before, but IMHO extention of the human lifespan would be a far more plausible alternative to the distance problem: no fundamental physics need be broken and if you need 100 years to cross the gulf between the stars, that won't be as much of an issue if your life expectancy is 10000 years or so.

And it would be more utilitarian for those who don't choose to travel as well...

[Lord of the Abyss]

I may have mentioned it before, but IMHO extention of the human lifespan would be a far more plausible alternative to the distance problem: no fundamental physics need be broken and if you need 100 years to cross the gulf between the stars, that won't be as much of an issue if your life expectancy is 10000 years or so.

And it would be more utilitarian for those who don't choose to travel as well...

Did you ever read Charles Sheffield's Between the Strokes of Night ? They have a treatment that both extends subjective lifespan and drastically slows down a persons metabolism, actions and time perception. They accelerate at a fraction of a gravity, which the slowed people perceive as a full gravity, and they travel between stars subjectively faster than light because they live so slow. A good book, I thought.

[Nyrath]

I may have mentioned it before, but IMHO extention of the human lifespan would be a far more plausible alternative to the distance problem: no fundamental physics need be broken and if you need 100 years to cross the gulf between the stars, that won't be as much of an issue if your life expectancy is 10000 years or so.

I've noted a few alternate methods of dealing with the lifespan problem here:
http://www.projectrho.com/rocket/rocket ... l#lifespan

[Agemegos]

nBSG jump drives are fun, but I like the fixed jump-point system, since that nicely creates terrain in space.

Me too. These start-anyway go-anywhere drives play merry Hell with concepts like 'distance', 'remoteness', 'proximity', 'adjacency', 'line of communication', 'border', and 'defence', while reinforcing such concepts as 'trade', 'concentration of force', and 'first strike'.

Give me a setting in which the map still matters.

[Agemegos]

It is most emphatically not. A LaGrange point is a point within a gravity well.

It's even worse than that. A Lagrange point is a trajectory.