|
Post by Kage2020 on Jul 13, 2004 0:26:46 GMT -5
Ok remembering please my grasp of physics is at best tenuous can you explain this, and dose it have any thing to do with unified feild theorys, strings or zero point energy Why reactionless thrusters work? Who knows. Impose whatever theory you want.
|
|
|
Post by Sojourner on Jul 29, 2004 1:56:28 GMT -5
I'm still not quite getting this 'reactionless thruster' business. Are we saying that they 'magically' push the vessel forward without throwing anything out of the back?
Well, as for my take on this idea, not only is it practically impossible, it doesn't even make any sense...
Though I suppose if you consider massless particles such as photons which have an infinitesimally small but discrete amount of momentum, throwing enough photons out of some sort of nozzle might work, and as they are energy you have as many of them as you can generate energy to produce them.
|
|
|
Post by CELS on Jul 29, 2004 2:23:11 GMT -5
It makes about as much sense as the propulsion system used by the Jokaero; changing the shape of the ship to change its position in the grand order of the universe, which causes the ship to drift in the direction of their choice.......
|
|
|
Post by Kage2020 on Jul 29, 2004 2:30:00 GMT -5
I'm still not quite getting this 'reactionless thruster' business. Are we saying that they 'magically' push the vessel forward without throwing anything out of the back? Yes, a staple of soft sci-fi. Without reaction matter, therefore reaction less. Well, as for my take on this idea, not only is it practically impossible, it doesn't even make any sense... It is one of those things that people say "wave your hands around and come up with whatever explanation suits you, but understand that they violate what we currently understand of physics". So of course it doesn't make any sense... This is, quite literally, not rocket science! The aim is to find a reasonable and consistent way of represent the various drive systems of the various races for incorporation into the RPG and the 'fluff'... so that we know or can roughly model what things will do, how they will do them (ish), etc. It has no real impact on the wargame since the abstractions and rules therein will be used... you don't need to know how the eldar sublight drive system works, only that it does and it has a reduced efficiency in one randomly determined direction. It does have an impact on RPG - which few seem directly interested in - but also more considerably the 'fluff'... That is what the Factory is here for... a means of getting the two poles (RP'ers and wargamers) to interact, communicate and discuss.
|
|
|
Post by Dazo on Jul 29, 2004 2:47:57 GMT -5
Quote:Why reactionless thrusters work? Who knows. Impose whatever theory you want
Inertialess drive might be better, i have a theory about this. Normal starship engines have to propel a mass by first overcoming its inertia or lack there of, this requires a large degree of energy to get started and a continued output to keep it going and increase its speed but that is limited because as you know the faster somthing goes the more mass it generates. This then requires greater energy output to maintain. You then have the problem of manouvering at high speeds you cant, the energy required to overcome its inertia would be prohibitive and so could only be achieved slowly. If a ship has no mass it will have no inertia therefore acceleration would be instantaeous up to almost light speed, and it would be able to alter its tragectory instantly as well, as it has no actual momentum in any given direction am i making sense. so would that make thrusters reactionless
|
|
|
Post by Kage2020 on Jul 29, 2004 2:59:43 GMT -5
That's basically the same idea, though I really don't like the Necron drive system... In terms of representation, the above suggestion of eldar drive system creates something that is consistent with the wargame (while offering a different explanation which, while equally hand-waving, actually works). It seems to conform broadly to most peoples' interpretation that the Necrons are in advance of eldar (hence not only the use of a lesser thruster type, but actually reducing the efficiency in a gravitational field)... Of course, it makes no never mind to the rules of BFG. It does to the 'fluff' and how it might be interpreted and, as such, I like to discuss these things. Just as I like to discuss the nature of the Imperium sublight drive system... 'Twould be nice if everyone worked together!
|
|
|
Post by ErnestBorgnine on Jul 29, 2004 9:40:10 GMT -5
In a reactionless drive, you turn it on and your ship starts to move, without losing mass in the form of propellant being exhausted, or from something striking the ship to drive it forward. Most sci-fi reactionless drives have been handwaved to be based on some kind of magnetic or gravitic field propulsion system. If you can generate gravitons artificially, it might be possible (in handwaving theory) to arrange it so that your ship always “falls” forward at great accelerations into an artificially developed gravity well, which you continue to project just ahead of you. The key problem in my mind with using reactionless drives in 40K is that such a ship can keep going as long as it has power to run the drive (though in practice, the food/water/air requirements of the crew are also an issue). How long it can thrust for depends on how much power the engines need and how much power the ship can generate without stopping for more whatever (deuterium/dilithium/handwavium). If you can run the engines off relatively small amounts of power, fission and fusion plants result in a ship that can accelerate for months at a time. However, the description in the BFG manual of gravitically driven weapon systems (don’t have it with me at the moment) suggests that a gravitic based reactionless drive may be within Imperial tech limits, though it may be pushing their abilities.
The Necrons, on the other hand, have an inertialess drive (though motive power could still be provided by a reactionless drive). Since F=ma, if you can reduce m to a very small number through some unimaginably high tech means, you can get a very large a for a very small F.
Depending on the properties of the intertialess drive, this also means that conservation of energy is right out the window – if you keep the velocity when you turn off the drive, you effectively gain a huge KE without having done the work to get that mass to that velocity.
What interests me is that if you applied this tech to subatomic particles, you could accelerate them with almost trivial magnetic or gravitic fields... sounds a lot like Gauss weaponry, doesn't it? Maybe each gauss weapon contains a miniaturized inertialess field that can make a few micrograms of matter inertialess long enough for a grav coil to accelerate it to relativistic velocities. How you use that beam to "suck" the victim back, who knows?
Obviously, there must be limits on how much inertia the Necrons can dispose of or some other technical limitation or else they would be completely unstoppable naval power that could crush any other fleet at a whim. It seems clear given the specific mention of this Necron tech that the other races do NOT have an inertialess drive system.
I'd prefer not to have either drive system as they have too many consequences if extrapolated to other technologies that SHOULD work on the same principles.
|
|
|
Post by Dazo on Jul 29, 2004 11:06:42 GMT -5
OH MY GOD thats the exact same system i came up with for a sub light engine awesomem, great minds truly do think alike. Incidently this is the kind of propulsion system i envision the eldar using, you would definatly get your drop of in performance the closer you got to a planet of large gravity field as it would interfere with the field the ship is producing, hows that work for you Kage
|
|
|
Post by Kage2020 on Jul 29, 2004 11:51:05 GMT -5
That's actually fascinating and would be consistent with the structure that I'm working with. Yup. Once again the proposition is consistent. <grin> You would prefer solar sails that require even more hand-waving than a reactionless drive. I'm all years for a better suggestion...
|
|
|
Post by Dazo on Aug 3, 2004 1:33:52 GMT -5
I found this little snippet about reactionless thrusters I won't pretend to understand it. If you do a google search for star drives you should find the rest. Edit heres somthing else thats sort of the same as the above apparently Edit Edit oh and hears somthing else about gravity drive i think
|
|
|
Post by Sojourner on Aug 3, 2004 2:31:39 GMT -5
The gravity drive thing is the most absurd concept I've ever heard...very GW, well done dazo.
|
|
|
Post by Dazo on Aug 3, 2004 2:37:09 GMT -5
Don't mention it...eh heyy wait a minute....lol So hard feelings that i nicked your world then
|
|
|
Post by ErnestBorgnine on Aug 3, 2004 10:28:16 GMT -5
So to recap, we not only have to find a material with negative mass, we have to find a support material capable of dealing with compression forces on the grip structure and shear forces on the arms equivalent to enough negative mass to cause an entire 3.5km Imperial Cruiser to fly off at several g's acceleration, and at the other end of the strut an equal mass exerting tensile forces on the strut and grip assembly. Since we're presumably using a mass along the lines of a neutron star fragment on the positive side to get that kind of mass, this poses an interesting engineering challenge. :-)
Personally, I'd rather just imagine a drive with an (anti) graviton emitter of some kind rather than imagining really exotic matter with really exotic containment requirements.
Edit: However, it did occur to me that this would explain the comparative expense/rarity of antigrav tech and the lack of tractor and repulsor beams.
Of course, it also occurs to me that if the anti-gravity is a natural property of the substance, you wouldn't be able to turn it off and I'm fairly certain that Imperial ships can, in fact, stop accelerating.
|
|
|
Post by Sojourner on Aug 4, 2004 12:09:38 GMT -5
Gravity damping, possibly? Some sort of dense material that can be moved to soak up gravitons?
a la 'Gravity plates' in Red Dwarf...
|
|
|
Post by ErnestBorgnine on Aug 11, 2004 12:47:02 GMT -5
As I mentioned on another thread, could the visible structures/fluff description and artwork of engines and huge plasma trails be a coolant system rather than a propulsion system? It would remove one of the largest objections to a reactionless drive - it breaks the imagery because all of the sudden you don't need hot plasma spewing out the back of the ship.
|
|