[Spaceships] Your preferences regarding plausible/playable Reactionless Drives

[vicky_molokh]

Originally Posted by teviet

In other words, the speed of light? :)

Somehow I expected the two units to give a very small speed, but now I realize it's small/small==big.

I wonder if there even exists a reasonable technobabble that will allow me to say something along the lines of:

A minimum possible fraction of time passes, in which the objects should've moved less than half of the minnimum possible distance, but the universe rounds down, so they remain where they were.

[lexington]

Originally Posted by teviet

I didn't read the whole atomic rocket site; what problem, if any, do they have with non-reactionless "reactionless" drives? My preferred handwavium is a mechanism that converts baryons into leptons, specifically neutrinos, and preferentially emitted in one direction with the recoil passing to the mechanism. Technically this is three handwaves, but it gives you a "reactionless" total conversion drive (i.e. no noticeable exhaust) that is inefficient as a power plant.

That does seem imply pretty efficient power plants. You just chain the ship to an enormous turbine. Planets, but maybe not most ships, with access to it end up with a huge source of energy.

[teviet]

Originally Posted by lexington

That does seem imply pretty efficient power plants. You just chain the ship to an enormous turbine. Planets, but maybe not most ships, with access to it end up with a huge source of energy.

Yes but what I meant was that the internal reaction itself could not readily be turned into a power plant or a bomb.

No matter what the underlying mechanism, a thruster is obviously going to be able to use fuel energy to power a generator, at up to 100% efficiency for a conversion drive, at greater than 100% efficiency (i.e. free energy) for GURPS-style reactionless thrusters.

TeV

[Sunrunners_Fire]

Originally Posted by vicky_molokh

Somehow I expected the two units to give a very small speed, but now I realize it's small/small==big.

I wonder if there even exists a reasonable technobabble that will allow me to say something along the lines of:

A minimum possible fraction of time passes, in which the objects should've moved less than half of the minnimum possible distance, but the universe rounds down, so they remain where they were.

The problem is that moving (start and stop) for a duration less than the planck scale period of time means that existence/the-universe can't resolve the movement and so you either appear to have teleported (start/stop points with no movement across the space in between) or you never moved (and then one wonders where the energy involved in your movement went ...). Or you break space/time, resulting in existence being violently smeared across the breadth of non-existence and no survivors down to the planck scale on up to the most macro of the macro-scale. :)

I think.

[panton41]

I'll sometimes require a single "Fuel Tank" space to be taken for Fusion, Super Fusion and Antimatter reactors and any reactionless drives, but ignore fuel consumption unless dramatically important as a nod toward the various science fiction franchises that do the same. (Star Trek was the original inspiration.) Basically the "Fuel Tank" is miscellaneous power-related consumables which is assumed to be refilled either in normal operations (like by the "Buzzard ramscoops" on Star Trek), as a part of routine docking fees at a port or both.

It's my way of saying, "They're not REALLY reactionless, they're just super efficient."

[David Johnston2]

I have suggested that "reactionless" drives were somehow using "dark matter" as ambient reaction mass.

[Trachmyr]

The only Reactionless drive I have ever used in a campaign was the "EM Drive", simply stating that it works the way 'Shawyer' (sp?) says it does. I gave it decent but lower-side thrust (0.033) and made it a High Energy System, but it was the best drive for interstellar voyages. It made travel between nearby systems possible & thus colonization, plus exploration vessels were practical (but VERY cut-off). Added in Q-Comms, and it made for a decent "episodic exploration" campaign, with years of nanostasis passing between games (11 years I think it was for a Earth-Alpha Centauri journey using 4 drives).

But I choose drive specs that I wanted for the campaign style, then I looked online for whatever wild theory I could use for Handwaiving.

[teviet]

Originally Posted by Trachmyr

The only Reactionless drive I have ever used in a campaign was the "EM Drive", simply stating that it works the way 'Shawyer' (sp?) says it does.

Heh. It's perfect as a scenario hook for a campaign, but the anonymous engineer on Wikipedia said it best: "it's a load of bloody rubbish." Though an open magnetron would work, at vastly reduced thrust (the usual 3 micronewtons per kW of any photon drive).

TeV

[Pomphis]

Besides, why does the drive have to be understood completely in-game ? Maybe it was discovered by accident and is being build without the theory being fully understood.

[vicky_molokh]

Originally Posted by Sunrunners_Fire

The problem is that moving (start and stop) for a duration less than the planck scale period of time means that existence/the-universe can't resolve the movement and so you either appear to have teleported (start/stop points with no movement across the space in between) or you never moved (and then one wonders where the energy involved in your movement went ...). Or you break space/time, resulting in existence being violently smeared across the breadth of non-existence and no survivors down to the planck scale on up to the most macro of the macro-scale. :)

I think.

No, the time of each 'step' of movement of the sphere around the ship (excluding ship) should be more than one plank. It's the distance that should fall through the rounding error. One could as well demand some other, bigger unit of time in which the distance travelled by the sphere should be below one plack. You just end with a 'reaction' drive with no contact between the ship and the reaction mass, much like the EM tether.

There isn't such a thing as a quantum of speed, is there?