Hard Light Productions Forums
General FreeSpace => FreeSpace Discussion => Topic started by: Grey Wolf on August 31, 2003, 09:02:01 pm
-
I was wondering: How exactly do the the engines on the fighters and capships work? Is it a reaction drive, an ion drive, a fusion torch, what? (Note: I'm talking about normal space, not subspace)
-
well they must bend the ships inerta to keep it aligned with it's forward vector somehow, based on the games weird ass physics
-
*Guesses some sort of Fusion
*Has nothing to back that up, other than it just sounds right.
-
maybe its the burning of fart? :shaking:
makes you wonder what that 'nebula' beyond gamma draconis was...
-
Fusion reactors, subspace coils, ion boosters, plasma cores, nuclear fission, kinetic drives.
-
As the gas mining ships in the game suggest, it would have to be some sort of fusion engine. Probably as simple as running a stream of hydrogen through the center 'spoke' of a fusion reactor (does anyone remember the proper name for the machinery in the center of a toroid fusion reactor?) and spitting it out the back superheated and at high velocity.
-
Thought I remebered a reference to a ship's "fusion drives" but I could be wrong.
Uses fusion reactions to generate thrust? Small intertial balancers or something inside the ships keep the ship on it's forward vector.
'course then there's the Colossus...I don't know how to explain the baseball bat thingy it does...
-
Originally posted by Solatar
'course then there's the Colossus...I don't know how to explain the baseball bat thingy it does...
Blame it on Command. That seems to be the trend with the Colossus...
-
Fusion drives.
But knock the Colosuss considering that it can take down a Ravana by itself while taking no more than 8% damage.
-
I already explained this back on the VBB - FS ships use Walkers reactors, which basically consist of a magnetic bottle thingy in which the elementary particles 'cheese' and 'onion' are mutually anihilated to produce tremendous ammounts of energy and flavour.
Even an0n laughed the first time around.
-
They run off Fusion, I'm sure of it. The tech room entry for one the the gas miners mentionssomething about how they're designed to collect and process deuterium to power the fleets fusion drives or somesuch.
-
What i wonder is how they need so much damn crew.
10,000 crew for one orion?!?!
I dont even know how they fit that many people in there...
Maybe They put them inbetween bulkheads for extra armour?
-
well, It's easy. Take the Bismark ( largest Nazi cruiser ):
it had a lenght of 251 meters ( so roughly the lengh of the Titanic ), a weight of 50 400 tons ( twice the Titanic ).
all that is ridiculously small compared to your average Orion.
the Crew on the Bismark? 2065 men ( they all died save for 3, btw ).
-
Originally posted by diamondgeezer
I already explained this back on the VBB - FS ships use Walkers reactors, which basically consist of a magnetic bottle thingy in which the elementary particles 'cheese' and 'onion' are mutually anihilated to produce tremendous ammounts of energy and flavour.
Har har. That is funny. :nervous:
Do they sell Walkers in the US? If not, I doubt many people get it.
But I subscribe to the MacGyver Theory, that everything runs off a variation of simple Duct-Tape/Rubber-Band dynamics.
-
Originally posted by Krackers87
What i wonder is how they need so much damn crew.
10,000 crew for one orion?!?!
I dont even know how they fit that many people in there...
Maybe They put them inbetween bulkheads for extra armour?
Actually 10,000 is a pretty low number when you look at it. A Nimitz class carrier today is 332 meters long, supports 85 aircraft and has a crew of 5680 when you include the air wing. Also, if the Nimitz had to carry ship-to-ship weaponry in the way an Orion does, it's crew compliment would be even higher. The 2km+ Orion must be using fairly sophisticated automation, or some very efficient systems to keep the crew level down.
-
Not that it's hard to put 10,000 in 2km's length of anything...
-
Well, they reckon the population of the world could be stuffed on to the Isle of Wight...
-
Would they all be alive though, or would you have to mush them into a fine pulp first?
-
my question is: how many do they shove into the escape pods?
and where do they store their oxygen, and how do they store it so that they dont explode to hell when their oxygen supply gets shot, or do they recycle their air (pretty efficent setup if they do)
-
Modern Nuclear subs recycle their air, that's how they manage to stay underwater for so long, FS2 ships probably use an advanced version of the same technology. As for 10,000 people, the Orion serves no single purpose, it is Carrier, Heavy Cruiser and Troop Ship all rolled into one, so I wouldn't be surprised to find about 60% of that crew is pilots and GTVA Troops. Not to mention the Emergency docking bay, so that guy from command can always be in the area, no matter which part of the Galaxy you are in ;)
I also recall Cmdr Snipes saying something about fitting bombs to the fighters Fusion Reactors :)
Flipside :)
-
Already had a big discussion ages back... Have a search.
If i remember rightly, the set of serious answers was....
A magnetic fusion bottle uses hydrogen compression to genertae ionic plasma that is vented out the back of the ship as thrust and heat.
But, to allow the fighters and GTVA capships to perform massive changes in vector, the fusion "thrust" is actually channeled through a device called an (well various really but mine was) Kinetic sink. The sink is a subspace field generated by the SS coils (also used topower the ship into SS) which takes the kinetic force generated by the fusion drive and channels it in various directions depending on the direction it needs to go.
However the fusion drive can also be forced into overdrive releasing it an extra amount of kietic energy to provide a momentary burst of speed. This generates heat which is why afterburners cause a brighter glow. The reason it takes time to recharge is that this stresses the field of the SS coils and requires a set time (depending on the level of power used) to reinforce the SS field of the sink.
this is all techno blub, but it explains why a huge GTVA crusier can suddenly swing around like a fighter and why a fighter can suddenly stop and swing round without inertia problems.
Remember, in collisions your fighter can be pushed into an inertial slide which takes a few seconds to get out of. Almost as if the kinetic sink is trying to compensate.
I think I named my idea "Inertia Drive". Corny I Know but accurate.
PS- this is also why fighters and capships do not reduce their crew to chunky salsa when entering SS. They can channel the kinetic force of the acceleration into the SS field of the node through the inertia drive.
Hope that helps.
(sits back and waits for all the physics experts to go NO!!!!)
-
A very simple answer to a question without a real one.
On Fighters:
Throttle off=short blue thing.
Throttle up=longer blue thing.
Press tab=long orange thing, go faster.
On Capships: They work very slowly.
-
Aww, that's no fun. It's always good mental exercise to ponder these questions... even when the answer is "glowing thing(s) of varying length"
-
I like the idea except for the subspace coil part.
Subspace wouldn't solve your inertia problems.
I think we can agree on the part that FS crafts run on nuclear engines. These can be either fission (late 21th century experimental crafts) or fusion(FS standard).
However, it's not the atomic pile itself that's flame is vented - that wouldn't be too cost efficent by the way.
Instead a propellant is passed through a reaction chamber where the immense heat from the nuclear reaction forces the matter to expand, and in turn propulse the craft.
The high degree engines of warships use so called plasma engines, where the heat is sufficent to turn matter into plasme, these crafts have to use magnetic coils to steer their flames.
This is the reason why you can knock out a warships engines without killing it - its actually the coils that you've destroyed.
The warships have a huge set of inertial channels in their core block - this enables them to went the plasma in any direction necessary, and thereby kill the ships inertia within a matter of seconds.
Fighters on the other hand can't use this mehtod, primarly 'cause they can't use plasma engines either. In fact they can't even hold an ordinary fusion plant. Instead the usual hydrogen based reaction they utilise a lot more expensive He3+ and deutherium reaction that creates no neutron stream, so a lot less shielding is needed.
The reason why this more efficent reactor is not used on warships is that the fuel would be astronomically expensive - it already is for fighters.
Remember! It's not the same fuel that the craft expells, it the fuel that the reactor runs on, so a lot less is needed.
Afterburners are a secondary magnetic chamber tapped onto the reactor - inside plama is created, that when expelled gives an extra burst of power. Time is needed to create sufficent extra plama for a burst.
[EDIT]
Oh, I almost forgot.
Fighters too have an anti inertia system.
It is another layer arround the reactor, the so called metalic liquid coolant.
The waste heat from the reactor is vented into this layer, where it melts a special alloy. The alloy has a relativly low melt temperature, however it is similar to today's semiconductors.
Any acces heat charges this layer.
When the craft changes heading this liquid metal passes through a collection of screens and shutters. The interesting part is that these are actually coils.
The charged particles create electricity in the coils, that's passed into the reaction chamber. Therefore the extra interia can be transformed into extra burst!
[/EDIT]
For atmosperic crafts ion drives are used. These crafts actually run on chemical engines.
Their specialty is that they strip the atoms from their upper layer of electrons and thereby create charged particles that can be accelerated to a lot greater speeds that conventional rocket fuel.
-
Referencing post near top of thread:
Machinery in a toriodal reactor? Are you referring to magnetohydrodynamic power generation, where the plasma stream in the torus is used as the coil of a transformer? I can't recall Fusion reactors having any 'machinery', on the basis that the temperatures involved make stationary parts bloody hard to maintain, let alone moving parts.
As for how FS2 ships are propelled, it's probably a varient of the nuclear drive that uses less fuel than modern ones. A standard chemical rocket engine to reach Earth orbit is 70% fuel. A nuclear engine to do the same thing would only be 30% fuel, and provide twice the thrust. Nuke drives are quite efficient, but generate such a massive amount of radiation that there's no way anyone would be allowed to operate one inside a planet's atmosphere.
It's possible that they use some sort of antigravity drive to allow the ships to turn like they do, since antigravity would probably mean anti-inertia too.
They damn well should have antigravity in FreeSpace, since the ships in Descent were based on antigravitic propulsion.
-
Originally posted by Descenterace
Referencing post near top of thread:
Machinery in a toriodal reactor? Are you referring to magnetohydrodynamic power generation, where the plasma stream in the torus is used as the coil of a transformer? I can't recall Fusion reactors having any 'machinery', on the basis that the temperatures involved make stationary parts bloody hard to maintain, let alone moving parts.
Perhaps my phrasing was poor. I was refering to the machinery the runs through the volume the torus surrounds, not withing the torus proper. Using heat bled from the reactor, a stream of hydrogen atoms could be superheated and accelerated to useful velocity to use as propulsion, provided the reactor could be made small and efficient.
-
Originally posted by Flaser
I like the idea except for the subspace coil part.
Subspace wouldn't solve your inertia problems.
I think we can agree on the part that FS crafts run on nuclear engines. These can be either fission (late 21th century experimental crafts) or fusion(FS standard).
However, it's not the atomic pile itself that's flame is vented - that wouldn't be too cost efficent by the way.
Instead a propellant is passed through a reaction chamber where the immense heat from the nuclear reaction forces the matter to expand, and in turn propulse the craft.
The high degree engines of warships use so called plasma engines, where the heat is sufficent to turn matter into plasme, these crafts have to use magnetic coils to steer their flames.
This is the reason why you can knock out a warships engines without killing it - its actually the coils that you've destroyed.
The warships have a huge set of inertial channels in their core block - this enables them to went the plasma in any direction necessary, and thereby kill the ships inertia within a matter of seconds.
hang on, that would mean you`d need venting areas on the Capship doesn`t it? GTVA ships don`t have any.
Whats wrong with using the plasma generated by a fusion reactor? If the ship has one designed rouchly on the Tomahawk design, which smashes Hydrogen to make pasma then it would be easy for the ship to siphon someof that plasma off to use as a thrust. I would have thought it would be quite efficent. (or at least efficent enough for a Fighter that can refuel quite easily at capships ect. They really do not need to be that economic.
Originally posted by Flaser
Fighters on the other hand can't use this mehtod, primarly 'cause they can't use plasma engines either. In fact they can't even hold an ordinary fusion plant. Instead the usual hydrogen based reaction they utilise a lot more expensive He3+ and deutherium reaction that creates no neutron stream, so a lot less shielding is needed.
The reason why this more efficent reactor is not used on warships is that the fuel would be astronomically expensive - it already is for fighters.
So fighters use a more advanced and smaller (and expensive) plant. Ok that`s fine.
I disagee with the idea that the fuel they use is more expensive. Deuterium would be easy for a technologically advanced group to synthesise using solar energy and the right tech. You`re basing that assumption on todaies tech level I think.
Look at petrol. Back in the really early days of motoring it was really expensive, now as everyone uses it they`ve discovered cheaper and bulk capable ways of making it.
Capships only use basic hydrogen for fuel as they can possibly filter it out of space itself using the famous "bussard ramscoop" idea. It`d help keep their fuel enconomy high.
Originally posted by Flaser
Afterburners are a secondary magnetic chamber tapped onto the reactor - inside plama is created, that when expelled gives an extra burst of power. Time is needed to create sufficent extra plama for a burst.
Fine, not a problem. Can also be used to generate enough extra kinetic thrust for the sink to give a burst of speed.
Originally posted by Flaser
Fighters too have an anti inertia system.
It is another layer arround the reactor, the so called metalic liquid coolant.
The waste heat from the reactor is vented into this layer, where it melts a special alloy. The alloy has a relativly low melt temperature, however it is similar to today's semiconductors.
Any acces heat charges this layer.
When the craft changes heading this liquid metal passes through a collection of screens and shutters. The interesting part is that these are actually coils.
The charged particles create electricity in the coils, that's passed into the reaction chamber. Therefore the extra interia can be transformed into extra burst!
I can`t see that working I`m afraid. I just can`t see how that stops the entire fighter moving. Wouldn`t that require the system to cover the whole fighter? And what about the pilot? You can`t cover him in metal, so when he does the first manouver he ends up plastered against the cockpit as a fine layer of ooze?
plus the system would be mass intensive for a fighter and impossible for a capship. Consider the huge network... one hit on the hull plating by a photon cannon and kiss all inertial compensation (and your crew) goodbye.
With a subpace field generating a null point bubble field of counter gravity around the ship the extra or excess inertia can be dumped, preventing "chunky salsa" syndrome for both pilot and ship.
If the inertia needs to be directed in another direction to allow manouvers the field can be manipulated to allow the kinetic thrust of the plasma stream to be directed elsewhere.
-
Originally posted by hobnob1978
hang on, that would mean you`d need venting areas on the Capship doesn`t it? GTVA ships don`t have any.
Whats wrong with using the plasma generated by a fusion reactor? If the ship has one designed rouchly on the Tomahawk design, which smashes Hydrogen to make pasma then it would be easy for the ship to siphon someof that plasma off to use as a thrust. I would have thought it would be quite efficent. (or at least efficent enough for a Fighter that can refuel quite easily at capships ect. They really do not need to be that economic.
So fighters use a more advanced and smaller (and expensive) plant. Ok that`s fine.
I disagee with the idea that the fuel they use is more expensive. Deuterium would be easy for a technologically advanced group to synthesise using solar energy and the right tech. You`re basing that assumption on todaies tech level I think.
Look at petrol. Back in the really early days of motoring it was really expensive, now as everyone uses it they`ve discovered cheaper and bulk capable ways of making it.
Capships only use basic hydrogen for fuel as they can possibly filter it out of space itself using the famous "bussard ramscoop" idea. It`d help keep their fuel enconomy high.
Wouldn't the rather prominent engine exhausts on every Shivan and GTVA count as a 'venting area'? As potent as directly venting fusion plasma would be, plasma intense enough to sponsor fusion represents an enormous investment in energy, and must be maintained at an extremely high temperature if it is to radiate more energy than it consumes (in both ignition and containment). Venting this plasma directly would take too much energy out of the system, changing an energy producing system into an energy draining load requiring outside power.
I think when he refers to Deuterium-Helium3 fusion being expensive, it's not the deuterium causing the expense. Helium-3 is an extraordinarily rare isotope of Helium, found in only minute quantities on Earth. Of course, it would come down in expense in much the same way you mentioned, but it would still be significantly more expensive than simple Hydrogen-Hydrogen or Deuterium-Hydrogen fusion.
-
Originally posted by Atlur
Wouldn't the rather prominent engine exhausts on every Shivan and GTVA count as a 'venting area'? As potent as directly venting fusion plasma would be, plasma intense enough to sponsor fusion represents an enormous investment in energy, and must be maintained at an extremely high temperature if it is to radiate more energy than it consumes (in both ignition and containment). Venting this plasma directly would take too much energy out of the system, changing an energy producing system into an energy draining load requiring outside power.
No because they point in one direction. His post seem sto suggest that the engines have magnetic driver coils that vent the plasma in specific directions.... the question of what to do with the plasma once you`ve sent it along the tube needs addressing. this means vent ports. Plus how do you stop a cap ship from moving forward suddenly? GTVA ships have no vent ports on the front or side to vent the plasma stream?
Using hydrogen (or helium isotopes and deuterium) in a reactor designed as an engine would be fine. If Hydrogen was fed into a toriod electromagnet and compressed by it sufficently,then the resulting hydrogen plasma could e vented while extra hydrogen is used to make more. Fighters could carry Hydrogen in liquid form in sufficent quantities to be a usable force for two hours or so before refulling.
A secondary reactor is used to power shields, guns and also to generate a plasma "burst" for afterburners.
Originally posted by Atlur
I think when he refers to Deuterium-Helium3 fusion being expensive, it's not the deuterium causing the expense. Helium-3 is an extraordinarily rare isotope of Helium, found in only minute quantities on Earth. Of course, it would come down in expense in much the same way you mentioned, but it would still be significantly more expensive than simple Hydrogen-Hydrogen or Deuterium-Hydrogen fusion.
We don`t know that as we have no idea how expensive it is for the GTVA to take gaseous helium from space and convert it into isotopes. These guys have harnessed subspace... Soemthing we have little idea how to do.
-
No because they point in one direction. His post seem sto suggest that the engines have magnetic driver coils that vent the plasma in specific directions.... the question of what to do with the plasma once you`ve sent it along the tube needs addressing. this means vent ports. Plus how do you stop a cap ship from moving forward suddenly? GTVA ships have no vent ports on the front or side to vent the plasma stream?
I assume the plasma stream may be manipulated much the same way as the vectoring of thrust in a jet engine, a series of magnets near the maw of the exhaust stream articulated in such a way as to produce deflection on the stream of electrically neutral plasma as it exits the vessel, and thus generate movement in X, Y and Z axis. This wouldn't mean a nice lateral shift of course, it would involve movement much like an aircraft. This fits the game nicely, with one exception, there would be some engine wash at strange vectors to the ship's rear as it changes direct, but it's close enough for my taste. As for the sudden stopping, I assume the network of thruster ports along the hull would be too insignificant a detail to render or portray in a texture.
Using hydrogen (or helium isotopes and deuterium) in a reactor designed as an engine would be fine. If Hydrogen was fed into a toriod electromagnet and compressed by it sufficently,then the resulting hydrogen plasma could e vented while extra hydrogen is used to make more. Fighters could carry Hydrogen in liquid form in sufficent quantities to be a usable force for two hours or so before refulling.
A secondary reactor is used to power shields, guns and also to generate a plasma "burst" for afterburners.
Such an arrangement of would require extensive outside power, as the hydrogen added to the system would need to be raised in temperature by a large degree in order to maintain a fusion reaction. Your reactor/engine would require another closed cycle fusion reaction to maintain its power demands. Using heat from a fusion reaction to generate hydrogen plasma (of a relatively low, below fusion intensity) from liquid hydrogen in an engine is efficient form of thrust, but directly venting fusion plasma isn't.
We don`t know that as we have no idea how expensive it is for the GTVA to take gaseous helium from space and convert it into isotopes. These guys have harnessed subspace... Soemthing we have little idea how to do.
I never got the impression that the GTVA was advanced enough to directly edit atoms precisely en masse, but who can say? *Shrugs*
-
Atlur has it quite right.
I suggest you take a look at this page:
http://pwg.gsfc.nasa.gov/stargaze/Sintro.htm
It deals with a lot of issues.
The plasma I'm speaking of, does not come from the reactor - if it were so, you wouldn't see anything coming out of the exhaust.
It is a low degree plasma, where all kinds of agregates are found.
You know, plasma does exist in our daily life - have you ever looked at a flame? It is plasma.
The engine I'm speaking of is a nuclear engine, but don't confuse it with a fusion engine.
It merly uses the heat from a nuclear rection to heat a prolusion mass - that matter could be anything!!!
That's a lot less expensive than using hydrogene - or fusion close hydrogene namely.
Atlur is right about the magnetic coil thing - the reason why plasma is used, is that it can be contained with a magnetic field, so you don't need a super heat resistant fan to steer the hot gas - this is also the method behind ion engines.
It has no moving parts, so it can be a lot faster.
This also conforms with Bobbau's new trusters.
As for the your engine problem with capships:
The vents and tunnels I'm speaking of are internal!
So you have a system where the matter of nuclear reaction is transformed into kinetic enegy.
The tunnels are used to capture this momentum and give it to the frame and the hull.
A fighter can't use a system this big, so it uses a more complex system.
It's not the liquid that stops the fighter, it is its own engine.
However, the process is made easier by the liquid core.
It IS a burden in terms of mass - because it has to be heavy.
The reason is, that it holds most of the crafts momentum, when the liquid is set loose (in the core exclusivly!) it takes away the crafts inertia.
By converting that force into electricity - that's why the layer has to be charged - you strip the fighter of its own momentum.
Imagine fishbowl on wheels, filled with water by 1/2.
Now, when you try to stop the bowl, the water will still go in the original direction the bowl used to go.
You would validly think, that it's easier to stop an empty bottle, so far the liquied core seems useless.
However if the liquied was a completly charged collection of positive particles, the story would be different.
If passed through a magnetic field, the particles loose their speed, but in turn generate electricity. That's how your hard drive works actually.
The reason why liquid is used, that it can easly conform to any direction necessary, while building a concrete system that would do so (like the magnetic disk od your HD) would never be as efficient.
BTW it is indeed the He3+ part that makes this reactor a lot more expensive.
That way you don't need small thrusters Atlur, and you don't need any moving parts except for the core itself.
-
Hmmm... I'm still not entirely clear on the dynamics of that anti-inertia system. Are there any papers regarding it you could point me to?
-
Unfortuantely I can't because I've thought it up myself.
However I think I've made a physically probable system, since I don't remember to have corrupted any major laws.
I'll try to devise some sort of chart, and write a couple of formulas to show its physics.
-
Here is it:
(http://users.freestart.hu/szandtner/inertial.jpg)
-
Originally posted by Flaser
Atlur has it quite right.
Imagine fishbowl on wheels, filled with water by 1/2.
Now, when you try to stop the bowl, the water will still go in the original direction the bowl used to go.
You would validly think, that it's easier to stop an empty bottle, so far the liquied core seems useless.
However if the liquied was a completly charged collection of positive particles, the story would be different.
If passed through a magnetic field, the particles loose their speed, but in turn generate electricity. That's how your hard drive works actually.
The reason why liquid is used, that it can easly conform to any direction necessary, while building a concrete system that would do so (like the magnetic disk od your HD) would never be as efficient.
<"scritch scritch" scratches head.">
So let me see....
As the vessel moves in one direction and generates inertia the liquid remains steady.
upon changing direction the liquid "slops" in the inertial direction the craft was initially moving as the craft turns...
Due to it`s unique nature, the liquid alloy as it moves along the channels in the core absorbs the kinetic "inertia" of the ships origional direction and converts it into current as it returns to a stable gradient.
Upon completing the turn, the lqiud returns to a stable gradient. This allows the ship to cancel it`s inertia while the "fusion drive" is free to put new kinetic energy into a new direction free from having to compensate for the origional courses inertia....
Is that right? (This stuff is really complex and I hated physics at school)
I can understand your idea now of a capship drive with the magnetic tubes directing plasma to create kinetic energy into the hull.... However wouldn`t it be easier for the GTVa having harnessed SS and logically gravity (if we assume that a SS drive forms a wormhole to the subspace dimension which would require gravity manipulation yes?) A cap ship drive would need to be nothing more than a gravity force acting on the sides of the ship to move it.... Plus the same drive could generate anti gravity to cancel inertia....
I would have thought for the GTVa that this would be smaller, more efficent and more effective as a drive.
As they have both the ability to form a nano wormhole into the SS dimension and also seem to generate gravity on their ships I presume they use a "gravity drive" then instead of a fusion based "thrust".... The glow we see is the reactor excess from the system that powers the drive.
-
That's the way it works hobnob1978, it indeed only helps to eliminate original inertia.
However, I guess the GTVA hasn't harnessed artficial gravity so far.
If they had gravity drives they wouldn't need any thrusters or whatsoever.
Using subspace on the other hand - how would that help?
A subspace drive merly resonates the target at the precise multidimensional frequencies, that the infinitly small loops of the universe have.
This stuff is actually based on the latest loop theory - an offspring of quantum physics, an attemt to unite it with the relativistic physsics.
You could make a particle jump through a tunnel or into subspace, but that has nothing to do with inertia, so I must assume, that the GTVA can't use the subspace drive for these purposes.
Here's an actual article
String Theory Acquires Rival In Loop Quantum Gravity
Loop quantum gravity (LQG), rival of string theory in the quest to unite quantum mechanics with general relativity, does not suffer from certain mathematical "infinities," a new study shows.
(Those infinities correspond to ephemeral but numerous alternatives in the way that interactions take place in spacetime.)
This clears up some doubts as to the theory's usefulness. What is LQG, and why has it been so difficult to quantize gravity? To address this question, return to classical (pre-1900) physics, a regime in which space was fixed.
Then the relativity and quantum revolutions changed everything utterly. With the advent of general relativity, space was combined with time in an integrated, but deformable, spacetime. Meanwhile, in quantum mechanics, spacetime remains fixed but matter becomes fuzzy; the whereabouts of particles can only be expressed in terms of probability clouds.
In a theory that would combine quantum and gravity features, spacetime would then have to be both deformable and fuzzy, and this has been difficult to do.
In string theory, the merger is accomplished by imagining that matter ultimately consists of tiny strings.
In loop theory, the merger is attempted by imagining that space itself consists of moveable tiny loops. Carlo Rovelli (Center for Theoretical Physics, Marseilles, also University of Pittsburgh) argues that loop theory does not have to import the extra commodities (additional dimensions and particles) needed by string theory.
Rovelli argues to loop theory offers, in principle, more testable predictions, such as the idea of quantized surface areas (that is, regions of space would come in discrete chunks and there would be a minimum possible size scale) and the notion that quantized spacetime might manifest itself as a minute difference in the speed of light for different colors.
The new version of loop gravity studied by Rovelli and his colleagues pictures spacetime as being foamy: points in space sometimes grow into bubbles. The bubbles are not "in" space; they constitute space itself.
The infinities pondered in the present paper represent not difficulties posed by the reality of particles within particles (a necessary complexity dealt with in Richard Feynman's quantum electrodynamics theory) but rather, analogously, to those potentially corresponding to interactions occurring on spacetime loops within loops. (Crane et al., Physical Review Letters, 29 October 2001; text at this URL.)
(Editor's Note: This story, with minor editing, is based on PHYSICS NEWS UPDATE, the American Institute of Physics Bulletin of Physics News, Number 562, October 23, 2001, by Phillip F. Schewe, Ben Stein, and James Riordon.)
31-Oct-2001
-
Did someone suggest vectored thrusters? In space?
Let's assume that you pitch upwards by diverting a stream of plasma from your engines upwards. This force only acts at the rear of the vessel, so the engines go down and the nose goes up.
Wrong.
The ship will indeed pivot around its centre of mass, but will also move downwards due to conservation of momentum. To only pivot around a point, an equal and opposite impulse would be required at the front of the ship (forces paired in this manner are known as 'couples').
Vectored thrust on aircraft works because air resistance provides the other force in the couple. The resistance is small compared to the thrust, but acts along the whole length of the aircraft. Most planes have their CoM near the rear, so the air resistance provides a greater moment of impulse near the nose than at the rear. The airflow over the wings also plays a part in completing the couple.
For a FreeSpace ship to effectively use vectored thrust, it would require retro rockets all over it just like a modern spacecraft does.
The physics in FreeSpace is screwed up. It was made that way for simplicity, and to avoid confusing people who don't realise that the physics we observe within our atmosphere is affected by air resistance. Therefore, FreeSpace physics only makes any kind of sense if you fill space with a fairly dense gas.
So don't try applying 'plausible' propulsion theories to FreeSpace ships. They won't tally up without being far more complex than realistically possible. Use something blatantly ridiculous to explain why a Destroyer comes to a halt when its engines are shot out, eg. Heisenberg Compensators... or Phase Variance Drive... because then you don't need to explain the 'physics'.
And finally: Atlur, I understood exactly what you meant by 'inside the torus', but I can't think of any reason for having moving parts anywhere near a Fusion torus except for fuel insertion. The whole point of Fusion is that it's mostly solid-state. Magnetohydrodynamics replaces the old coolant-and-turbine system, the reaction is self-controlled, and containment is achieved with a big electromagnet.
Cold Fusion is a common source of confusion. Fusion reactions require temperatures of 10 million degrees C, but the word 'temperature' always seems to confuse. Temperature is simply atomic energy, and hence a vaccuum is not at absolute zero because it has no particles in it to which the term 'temperature' can be applied. The plasma in a Fusion torus is extremely low-density. The ions in it are at very high energies, but the total energy is low. If you put your hand in it (disregarding radiation damage), then the plasma would come down to body temperature without raising the temperature of your hand noticably. 'Hot' nuclear reactions, such as the bog-standard Fission we're all used to, generate massive amounts of heat energy which is transferred to some sort of coolant which drives turbines. This means lots of shielding, and lots of wasted energy.
Cold Fusion bypasses this entirely. Creating a Fusion torus that can heat up water is extremely difficult, because of the aforementioned low energy density and the low efficiency of the energy transfer. Using magnetohydrodynamic power generation, only a low-output 'cold' reaction is necessary (relatively easy to start and maintain) but the efficiency is high. It is likely that many torii would be used in stacks, producing little power individually but a great deal overall.
-
It`s fun trying to work out a plausible way for the ships in FS2 to move the way they do, descentreace. :) using something like a Hiesenberg compensator is cheating without an explanation as to how it works.
We know it`s F**** up but trying to figure out plausible ways of doing them is good clean brainstorming. who knows maye far off in the future one of these suggestions will become reality (gets out my Crystal ball of the future...)
Hey flaser, if the GTVA don`t have artificial gravity why do their crews walk on the deck plate in the movies? Their ships don`t have any rotating areas to generate gravity....
So if the GTVA haven`t been able to harness AG how do they make it?
I was thinking that as a SS drive "warps" the ship making it vibrate in multiple dimensions to open a SS gateway, the same drive could be used to generate channels for gravity...
Don`t intrasystem jumps work in High gravity areas such as a star? If thats the case then the SS drive could harness a fraction of that gravity from the sun or equivilent body to use as a drive through SS "pipes"?
I dunno, [V] reluctance to include inertia has left those of us trying to make sense of it for fun a tricky bastard to solve.
They have to have gravity as they are sitting, and Admiral whatshisname is walking around, in FS1`s Taranis briefing on the Galatae.
If they do have gravity then a gravity based drive IS possible yes?
-
Descenterace, I apreciate your comment and I have to agree with the contant.
My whole reason for coming up with this anti inertia system was to make some reason to why do FS crafts fly - or float:ick - as they do.
The vectoring indeed can only be used to turn the craft in one direction. However, once turned, and stabilized (I mean it's no longer spinning - this can be achieved, by vectoring the thrust in the opposite direction) the thrust of the craft will push it in a direction.
The problem is that it will still go in the original direction it used to.
That's where the anti-intertia (From now on AIn) comes into play. During the turn it eliminates most of the momentum utilising the momentary thrust that accelerates the craft in the opposit direction compared to the original vector of movement.
Now, as you said, this solution is ridiculous.
Indeed; but having a dozen fans and fuel pipes in a miliary crafts hull is just as ridicolous - one stray bullet...
This system allows the whole drive to be truly reinforced.
Finally FS does have something right - if subspace was discovered, long distance missle attacks would be impossible. The target would simply jump out. (I know this is agains all escort missions, but let's assume you can't just jump into a node, 'cause it's interference makes calculations too hard; and you wouldn't jump out if you knew you'd have to come the same way later - and the attacker could chase you.)
So it's down to close combat, and in such an environment, harder armor, and better agility (instead top-speed (which is actually delta-speed)) are the no.1 requirements.
-
maybe their boots, coffee cup ect are all magnetic LOL.
(see above)
-
Hmmmm... looking at that 'slopping liquid' idea. So basically, you convert nuclear energy into kinetic energy, then convert the kinetic energy back into electrical potential energy, then back to kinetic energy in a different direction? Problem: only the liquid's kinetic energy would be converted. You would loose the kinetic energy of the container, because you'd have to use thrust to slow down the container to make the liquid 'slop'.
Consequently, why not do away with the liquid entirely? It's just extra mass that plays no useful part, and because the energy conversions described are not 100% efficient, it actually has a negative effect.
Container and liquid are stationary. Container accelerates, moving the magnetic coil relative to the liquid thereby generating electrical energy. This means that there is a resistive force to the motion of the coil relative to the liquid (the accelerating force on the container must work against this force to generate power as well as giving kinetic energy to the container). This resistive force remains in effect until the liquid is moving at the same velocity as the container. The thrust energy has therefore been converted into:
* electrical energy in the magnetic coil
* kinetic energy in the container
* kinetic energy in the liquid
When thrust is applied in the other direction to counter the kinetic energy of the container the same thing happens again, except the kinetic energy gains in the two opposing directions cancel each other out. This is what happens with a conventional spacecraft. However, this one's thrust has twice generated electrical power in the magnetic coil. Because of this, its engine has delivered more energy than a standard spacecraft. The extra energy delivered has been converted into light and heat (as usual in a chemical rocket) and also electrical power.
So, the liquid system would have no effect whatsoever except to generate power from rocket thrust. There are more efficient ways of producing electricity from the chemical energy in rocket fuel.
Nice try, though. Took me some time to spot the flaw. The trick is to remember that energy is always conserved. If you think you're getting something for nothing, go through the energy equation with vector quantities, not scalars.
-
Actually it doesn't work at all and never should.
Thank you for your comments Descenterace.
I was a fool to have thought so in the begining: all inertial system's original impulse must remain the same if only internal forces are acting.
So there's no way a system inside the craft would change its momentum without expelling something.
BTW if you used nuclear engines and only nozzles to balance the craft, that way you wouldn't need any machinery except a couple of valves for the additional thrusters.
You're right about one thing: the flight model of FS hasn't nothing to do with reality.
(I did have an explanation for shields as well, I thought it was a very thin subspace layer around the craft, that made projectiles and radiation steer-off the craft. But, still I wonder how the radio works...)
-
That would explain why shields don't work in subspace.:nod:
-
BTW, could you tell me what exactly is an MHD genarator Descenterace?
-
*throws in a random solution*
Maybe the engines somehow create an area of intense gravity and bend space-time and that somehow propels the ship forward? Once the distortion is turned off, the ship slowly stops bending space time and the ship is slowed (without a warped "bump" pushing the ship, there is not thrust). Ships turn by manipulating this bump in space time, or something like that.
Ok...go back to the fusion drives and inertial dampeners...
-
Originally posted by Descenterace
And finally: Atlur, I understood exactly what you meant by 'inside the torus', but I can't think of any reason for having moving parts anywhere near a Fusion torus except for fuel insertion. The whole point of Fusion is that it's mostly solid-state. Magnetohydrodynamics replaces the old coolant-and-turbine system, the reaction is self-controlled, and containment is achieved with a big electromagnet.
Cold Fusion is a common source of confusion. Fusion reactions require temperatures of 10 million degrees C, but the word 'temperature' always seems to confuse. Temperature is simply atomic energy, and hence a vaccuum is not at absolute zero because it has no particles in it to which the term 'temperature' can be applied. The plasma in a Fusion torus is extremely low-density. The ions in it are at very high energies, but the total energy is low. If you put your hand in it (disregarding radiation damage), then the plasma would come down to body temperature without raising the temperature of your hand noticably. 'Hot' nuclear reactions, such as the bog-standard Fission we're all used to, generate massive amounts of heat energy which is transferred to some sort of coolant which drives turbines. This means lots of shielding, and lots of wasted energy.
Magnetohydrodynamic generation is more efficient then the conventional coolant-turbine approach when electrical power is your only goal, but what about when the purpose of the reactor is to ionize a propellant? Wouldn't the energy radiated from trapped fusion products be more effective in superheating a propellant than electrical energy from a MHD generator?
-
Fusion, hot or cold, generates little radiation. If you're trying to ionise a propellant, use nuclear Fission. Uranium fuel can be synthesised from Thorium-232, which is one of the more abundant dense elements in space.
MHD works on the idea that electric current is just a moving charge. In a transformer, a changing EMF in a primary coil induces a changing EMF in a secondary coil.
The plasma in a toroidal Fusion reactor has an electric current flowing in it. I'm not exactly certain of the dynamics of plasma, or why this current is an alternating current, but this ring of plasma can be treated as a transformer's primary coil. The secondary coil of the MHD generator-transformer is wrapped vertically, so the wires run parallel to the plasma. The current in the plasma induces an EMF in the coil, generating power.
Because the plasma is only a single 'turn' coil, the current generated is low. Typically, the voltage is low as well. It is likely that many small torii, each about 2 metres in diameter, would be stacked up in towers like the cells in a voltaic pile.
-
The GTVA fleet is powerd by C++ code and doesn't need to be refueld, upgrades of engines/weapon systems/targeting systems etc are done by patches that you download or by using the launcher:p
*runs*
-
Originally posted by Darkage
The GTVA fleet is powerd by C++ code and doesn't need to be refueld, upgrades of engines/weapon systems/targeting systems etc are done by patches that you download or by using the launcher:p
:D:ha:
-
Originally posted by Atlur
Magnetohydrodynamic generation is more efficient then the conventional coolant-turbine approach when electrical power is your only goal, but what about when the purpose of the reactor is to ionize a propellant? Wouldn't the energy radiated from trapped fusion products be more effective in superheating a propellant than electrical energy from a MHD generator?
That's what I proposed in the first space.
However Descenterace commen once again struck a nerv, for I have to admit he has superioir knowledge of fusion compared to me.
However I do have one doubt: how come a fusion reaction creates so little radiation? After all the sun works the sae way :)
The reason I thought of a fusion nuclear drive was, that the fusion reactor is quite clean, while it still produces an enormous ammount of power.
-
In Fusion reactions, more energy is released per escaped neutron. In Fission, a very large number of neutrons escape the material compared to the amount of energy produced.
Most of my physics knowledge is the result of weapons design projects. Such as the Ion Cannon I designed when I was in Secondary school. And the Railgun I designed about seven months ago.
OK, so these projects would never work, but you can learn a lot by doing things like this. Like why they don't work. Oh, and I read a load of Quantum Physics stuff too, and it's crystal clear to me... where people go wrong is trying to imagine quantum particles as objects. Because Quantum Theory is maths, these particles can only be described in terms of how they interact with each other. So it is possible to understand Quantum Physics without being confused by it.
-
Per escaped neutron?
I understand what escaped neutron means, however I don't understand than what's the problem. In this case its not the reaction's waster radiation that I'd like to use.
Is it possible to use a fusion reactor for a nuclear drive?
-
In a nuclear reaction, atoms break up or join to produce new atoms and free neutrons. These neutrons usually go on to trigger (and take part in) further atom-smasing/combining. Neutron radiation is comprised of neutrons that escape the material instead of being absorbed in a reaction.
The only radiation you can use is the waste radiation. The rest is consumed in the reaction.
Unless you're using a 'hot' fusion reaction, in which case the 10 million degrees C plasma temperature becomes VERY significant, I don't think it would be possible to build a Fusion-based nuclear drive. The Fission-based nuclear drive involves a big cylinder of Boron with holes drilled through it, leading to a parabolic combustion chamber/thruster. Water with dissolved Uranuim salts is pumped through the Boron block into the thruster, where the Uranium eventually exceeds critical mass and creates a slow nuclear explosion. This reaction is far more violent than in a power station, and is only kept in check by the rate of fuel flow and the Boron block. Basically, a nuclear drive involves detonating a stream of small A-bombs behind the ship.
-
Originally posted by Descenterace
In a nuclear reaction, atoms break up or join to produce new atoms and free neutrons. These neutrons usually go on to trigger (and take part in) further atom-smasing/combining. Neutron radiation is comprised of neutrons that escape the material instead of being absorbed in a reaction.
The only radiation you can use is the waste radiation. The rest is consumed in the reaction.
Unless you're using a 'hot' fusion reaction, in which case the 10 million degrees C plasma temperature becomes VERY significant, I don't think it would be possible to build a Fusion-based nuclear drive. The Fission-based nuclear drive involves a big cylinder of Boron with holes drilled through it, leading to a parabolic combustion chamber/thruster. Water with dissolved Uranuim salts is pumped through the Boron block into the thruster, where the Uranium eventually exceeds critical mass and creates a slow nuclear explosion. This reaction is far more violent than in a power station, and is only kept in check by the rate of fuel flow and the Boron block. Basically, a nuclear drive involves detonating a stream of small A-bombs behind the ship.
http://pwg.gsfc.nasa.gov/stargaze/Snucfly.htm
I suggest you take a look at the link above.
What you say is apropiate, but not a 100% true.
IIRC the first nuclear drive to be devised simply used the heat from the reactor to accelerate the propellant agent.
Then there was project Orion which indeed works as you described, however that project is lot more hideous and dangerous than the original idea.
My FS engine uses the first system, so it's not the reaction itself that propels the craft.
I always thought in a "hot" reaction as you put it, however I have my doubts now.
There are a lot of rumors about cold fusion - you've enlightened me, so know I don't necessarly think only of the meson catalysed humbug that the science community had to stomach about 10 years ago.