Faster than light travel or "jumping"

[Galethorn]

I'm definately a fan of the onboard jump drive concept...the following features are things I'd consider icing on the 'interstellar travel cake'

* Only big ships (battleships, carriers, civilian freighters and transports, and some smaller specialized ships) can carry one

* It takes a while to recharge the capacitors (or whatever) between jumps

* The further something is away, the more difficult it is to plot (so, the farther away you are, the farther from gravity wells you should plot your destination)

* The bigger the ship, the more difficult the calculations (so it takes a long time/a huge navigation crew/computer to plot a jump for a big ship)

If you write the 'science' of it off as 'quantum teleportation', then it's even semi-believable (and to justify only larger ships being able to jump...well, only big ships can have fusion/matter-antimatter/zero-point/whatever reactors, of course).

And now for a short dissertation on travelling at (or faster than) light.

Now, travelling faster than light in realspace (or whatever you want to call 'normal space')...that's just impossible. Even if you had truly infinite power to keep speeding up, and could negate the effects of the g-force of acceleration, and didn't mind the relativistic effects on time...you'd run into one fundimental problem as you approached the speed of light...

Mass (which, at its heart, isn't "how much" of something you have, but actually the resistance to change in velocity of an object) increases exponentially (or some other mathmatical word ending in 'ially' that means "increasing returns") as you approach the speed of light, and the reason it would take infinite power to accelerate to the speed of light is because the mass of the object would increase infinitely.

And, we run into a couple of problems on the way to infinite mass.

1. Any object that isn't currently fusing (i.e. an active sun) over 1.4 times the mass of our sun collapses in on itself, causing its electrons and protons to 'blow each other up,' resulting in just neutrons crammed together in such a way that they're incredibly dense.

So, say you could deal with being a neutron for a little while (!), and kept speeding up...well...

2. Any object that isn't currently fusing (i.e. an active sun) over 3 times the mass of our sun collapses in on itself, and turns into a black hole. Yeah, a black hole.


So, the moral of this story is that if you got your FTL drive fired up, you'd turn into a black hole travelling at close to the speed of light. A great idea for a weapon, but not a very fun way to travel.

Ok, I'm done.

 

[SWBaxter]

For those of you that said that you like the jumping method of traviling, is it instantanious or do you spend time in "hyperspace"?

I generally have it take time, since that allows for adventures to occur (Murder on the Orient Express has inspired many sci-fi adventures, I'm sure) and also builds some automatic downtime into an adventuring life.

Is there anybody that publishes rules for having space battles in hyperspace?(or at faster than light traveling if I ever choose to go that route)

I haven't read the rules, but I'd imagine Babylon 5 covers space combat in hyperspace if it covers it at all - it happened a few times in the B5 TV series so it should be in the game. So far as FTL combat goes, I think 2300 AD might have covered it since their pseudovelocities can go above c. But most systems seem to enforce a pretty strong divide between FTL and sublight travel, and only allow combat at the latter.

 

[Jack Daniel]

Here's what I use in my sci-fi games:

The most primitive (and slowest) form of FTL travel is a warpdrive. Warpdrive is simply a specialized application of artificial gravity technology, because once you can create your own gravity fields, you can manipulate the curvature of spacetime enough to create a bubble of warped space (or "subspace") around a ship and move the bubble forward like a wave. This drags the ship along with it, but since the ship itself is all but stationary within its own reference frame (it's spacetime that's moving, not the ship), there is no inertia, no time-dilation, and no light-barrier. The only limit on how fast the ship can actually go relative to the rest of the universe is how powerful the engines are. Warp speed is measured in "warp factors" (W), which relate directly to the number of lightspeeds (X) by a factor of W^(10/3) = X. Warp 5, for example, is about 213 times the speed of light, or fast enough to reach Alpha Centauri in a couple of days. Ships with warpdrives in my campaign tend to be fairly advanced, with warp 9 being a slow cruise and warp 14 or 15 being the top speed of a high-end military cruiser (none of this Star Trek: Next Generation "warp 10 is infinite speed" crap).

Less common than the warpdrive is the hyperdrive, which is only possessed by the very technologically advanced. A hyperdrive, rather than bending spacetime into a subspace bubble, uses quantum tunneling to essentially teleport all of the ship's particles forward along a tunnel of "hyper-warped subspace", or "hyperspace". A ship traveling at hyper speed is zipping along at warp 85, or nearly 2.7 million times the speed of light, which is fast enough to cross the galaxy in a matter of days. (Meanwhile, communications signals sent through subspace can only travel at warp 40 or so, which means that a ship with a hyperdrive can outpace most transmissions!) Faster hyper speeds are measured in factors refered to as "marks past hyper speed", which follow the same forumla as warp factors, but where hyper speed mark 1 (2.699 million C) is the multiplier. So mark 5 past hyper speed is 5^(10/3)*2,699,803 C, or 0.57 billion times the speed of light, fast enough to make a short trip to the Andromeda galaxy in a matter of days.

Finally, the jumpdrive, which is the rarest FTL technology of all, because it creates a stable wormhole between two distant locations, allowing for near-instantaneous travel to any point in the space-time continuum. But wormhole navigation is very dangerous, because you have to account for time as well as space. As if it weren't easy enough to get lost in space, there's always chance you'll take a wrong turn and end up 1 or 10 or 10,000 years lost in time. If you've gone forward, no problems, but backward... that, in the immortal words of Cmdr. John Crichton, "screws the pooch". Alternate timelines, unrealized realities, grandfather paradoxes galore... jumpdrives are the perfect tool for the cruel DM who wants to mess with his PCs!

 

[D-rock]

The one thing with that is did anyone in Battletech ever NOT use a pirate point?

Yes, I know. I always did like the setting better than the authors who wrote about it.

I would make them a lot more dangerous.

 

[D-rock]

Now, travelling faster than light in realspace (or whatever you want to call 'normal space')...that's just impossible. Even if you had truly infinite power to keep speeding up, and could negate the effects of the g-force of acceleration, and didn't mind the relativistic effects on time...you'd run into one fundimental problem as you approached the speed of light...

Well thats assuming that what we know now about physics is as far as it goes. Who is to say that what we know now isn't but one aspect of a larger picture that will let us someday be able to go faster than light.

2. Any object that isn't currently fusing (i.e. an active sun) over 3 times the mass of our sun collapses in on itself, and turns into a black hole. Yeah, a black hole.

I will admit I have no Idea what I am talking about, but I though the mass required to form a black hole had to be much greater than that.

So, the moral of this story is that if you got your FTL drive fired up, you'd turn into a black hole travelling at close to the speed of light. A great idea for a weapon, but not a very fun way to travel.

Ok, I'm done.

Well maybe you could turn yourself into some form of massless particle before you accelerate, or minipulate gravitons around you.(although they haven't proven they even exist yet) Although the turning into a singularity might make for a good adventure idea.

 

[D-rock]

This drags the ship along with it, but since the ship itself is all but stationary within its own reference frame (it's spacetime that's moving, not the ship), there is no inertia, no time-dilation, and no light-barrier.

So that is not the way Star-Trek does it, because I though they needed inertal dampers so there not crushed aginst the wall when they go to warp. Or are they just very inconsistent in the show.

Note: I am not a hardcore trek fan so don't tear me apart(always have horrors about the trek head swat teams busting in my room if I get something wrong)

 

[Cheiromancer]

I think the best alternative is to use gates, which have mass, and which allow ships to jump from one gate to the next. A gate which "absorbs" a ship gains mass equal to the ship's mass, while a gate which "emits" a ship loses an equal quantity of mass.

These arrangements are favored by "hard" (more physically realistic)varieties of science fiction since they do not involve violations of the law of conservation of angular momentum, something that gateless jumping would involve. They also do not involve local violations of the law of conservation of mass/energy.

 

[D-rock]

A ship traveling at hyper speed is zipping along at warp 85, or nearly 2.7 million times the speed of light, which is fast enough to cross the galaxy in a matter of days. (Meanwhile, communications signals sent through subspace can only travel at warp 40 or so, which means that a ship with a hyperdrive can outpace most transmissions!)

Is hyperspace one way, or can the signal travel both ways? For example if a ship is in front of you and sends a signal back does that mean that that the signal travels at warp 125

If you've gone forward, no problems, but backward... that, in the immortal words of Cmdr. John Crichton, "screws the pooch". Alternate timelines, unrealized realities, grandfather paradoxes galore... jumpdrives are the perfect tool for the cruel DM who wants to mess with his PCs!

Ahhh.....Temporal paradoxes, the authors best friend sense time-traveling stories began.

 

[Captain Tagon]

Yes, I know. I always did like the setting better than the authors who wrote about it.

I would make them a lot more dangerous.

Very true. Not that I dislike the books. But I reread the Warrior trilogy and now I'm going through the Blood of Kerensky trilogy again and every time anyone jumps anywhere it is with a pirate point. Crazy stuff.

 

[D-rock]

There is something else that I have always though about. Is speed is just relative to what you are basing it aginst? For example if nothing else exist except for me and somebody else and I am moving at say 10 meters/second and the other person is moving at 9 meters/second, then in essence I am only really moving at 1 meter a second right? That would seem to create a problem, because there are distant objects like galaxies that are moving faster than the speed of light away from us. We cant see them anymore, because the light that they emit can't catch up to us. Wouldn't that mean that everything is moving faster than the speed of light from something, and thus would put us at infinite mass already.

(I told you I didn't know what I was talking about already didn't I )