Miscellaneous Technicalities

This page collects thoughts about interesting facets of the technology and consistency of the STAR WARS universe. This is intended to be a temporary collection of miscellaneous topics that don't yet have fully realised commentary pages.

Battle Overviews

This section will eventually be expanded to decompose the sequence of events in some important battles seen in the visual media. It will begin with listings identifying the warships involved in the particular clashes. Notes on the fates of the various ships will be added later.

Thanks are due to:

Battle of Hoth

Battle of Endor (Space)



identifying Imperial warships

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Partial images of a Imperial fleet pincer at the start of the Battle of Endor. Twenty-two warships are visible, including the Executor. Rebel craft are in the foreground. There are 13 warships to the left (starboard) of Executor. Since Executor is probably the centre of the formation, symmetry suggests that there would be 13 more warships on its port side, which would give a total of 27 Imperial ships.

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View of the initial Imperial formation from the Millennium Falcon. The bilateral symmetry about the Executor is obvious in this shot.

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Imperial destroyers and the Executor advance rapidly upon the Death Star II as seen on the monitors in the base on the sanctuary moon. Every second they moved a distance of at least one interval. There were at least 22 vessels, without accounting for possible superimposition of ships. battle station. The last link is to a 24fps QuickTime animation of the onscreen motion.

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The illumination and shadows on the spheres of the Death Star and sanctuary moon indicate the orientation of the battle zone with respect to the fixed position of the Endorian suns. The shadows on the battling starships could also be used to determine the orientations of all major components of the battle.

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Three interesting things can be discerned in the Emperor's view of the early part of the battle: (1) the apparent positions of the stars change, implying that the Death Star is rotating; (2) the Imperial ships exhibit motion relative to the stars at an angular rate slower than the station's rotation; (3) some Imperial ships' angular positions move at different rates, due to a difference of velocities and/or a difference of distances from this vantage point. These images precede Ackbar's order to engage the Imperial fleet at point-blank range; the rebels are probably offscreeen.

A Nebulon-B frigate (bottom right) does not appear to have a suitable fighter-size aperture on its starboard side.

Battle of Endor (Surface)

As suggested by Bill Nee:

Organisation of the Imperial Garrison

Command of the garrison

The garrison command structure is puzzling. In his disguise as a walker pilot, Han Solo addressed the base "commander" via a flat-screen communications system. The confident young man who dispatched squads to "help" Solo was is far too junior to be in charge of the entire base. He wore a black uniform like that of a stormtrooper officer, but his lack of officer insignia means that he must be some kind of NCO. His closest subordinates are two more NCOs and four naval security crewmen. Judging by his age, he is too junior to command an entire legion of the Empire's best troops.

This man has local responsibility for a control station in one part of the power system for the shield projector. Specifically, his the part of the base was invaded by rebels twice. His supervision may extend to the area around the back door. He probably wasn't the intended recipient of Solo's request, which may have been shown on many of the base's monitors.

The base probably has a larger control centre in a more central location. The commanding officer, unseen in the movie, would be found there.

In the outdoor scenes several mid-ranking officers were present. Some of them had the insignia of naval commanders or army colonels. [Of course, the infamous ROTJ Imperial costuming blooper means that all Imperial officers wear the same badge. In intra-textual terms, some of the officers may have been higher or lower than a colonel's rank.]

* * * * * * * *
Various views of the clearing at the back door, as the rebel captives are led outdoors. One AT-ST stands guard over a mix of army, navy and stormtrooper personnel; another AT-ST circles the area.

Three squads sent out in response to Han Solo's decption. The troop types are mixed.

* * * * * * *
A small control room inside the base near the back door. Imperial forces recapturing the room come from the passageway leading outdoors, as well as the left and right sides of the gantry over the crackling tunnel.

Battle of Calamari

Inspection of the careful and fascinatingly detailed renderings in Dark Empire should provide minimum counts on the types of vessels present at the Battle of Calamari. The Imperial blockade included the following ships:

Other notes:



Thanks are due to:

Combat Physics

Question: What does the blast consist of?

There is no sure answer in terms of real life science; so far we can only place constraints on the nature of the beam by making careful observations about the filmed behaviour. The shots create light which is emitted sideways, otherwise the bolts would not be seen. The visible bolts appear to travel at various velocities, which usually appear to be slower than the speed of light. However there is an invisible component of the beam which often propagates far ahead of the visible bolt. The invisible forerunner is probably an aspect of the fundamental beam itself, and the luminosity of the bolt is a side-effect. The forerunner beam is known to damage targets before the visible bolts arrive, and this component of the shot may actually propagate at lightspeed.

Question: can a lightsabre block a turbolaser shot?

Probably. It depends on whether the damaging part of the bolt is thinner or thicker than the lightsabre beam. Even if it Even if the shot can be deflected, it might not be completely safe or comfortable for the lightsabre wielder to be close to the turbolaser shot. Luke Skywalker deflected fire from an AT-AT walker in the Dark Empire comic, which means that the effectual propagating part of an AT-AT laser cannon shot is thinner than a lightsabre. There remains an open question about whether or not Skywalker used a special Jedi power to dissipate side-effects of close proximity to the bolt. comic.

Qualification: In TESB we see that AT-AT guns have variable power settings (small shots for eliminating troops, "maximum firepower" for destroying structures like the power generator). We don't know what setting was used to attack Skywalker in Dark Empire; it might be the lower setting. Furthermore, we don't know whether the effective diameter of a bolt changes depending on the power level (for the shot against the power generator, the bolts were brighter, longer and greater in duration, but not necessarily wider).

Actually it has not been determined whether or not the effectual part of a blaster bolt has any thickness at all. It is possible that all bolts are microscopically thin, whether they come from a pistol or a Death Star. The apparent visible width may be due to nothing more than the glare spread on the observer's retina and/or movie film.

Question: How much momentum does a blaster bolt have?

Probably very little. When blaster shots are deflected off a lightsabre, the change of the bolt's momentum would be felt as a force on the lightsabre, which the wielder would feel through the coupling of the 'sabre beam to the hilt. Consider it like bullets being deflected off a sword: if blaster bolts had as much momentum as an Earthly bullet then Luke Skywalker's lightsabre would have been jarred visibly in his grip. Therefore shots from a blaster carry much less momentum than material shots from a primitive slugthrower weapon.

The fact that blaster shots are momentumless (or nearly so) does not mean that they lack energy. A beam of light, or low-mass elementary particles, can carry intense energy without having much momentum. (Many an insect has discovered this at the hands of a cruel child with magnifying glass.) The explosion when a blaster bolt hits a solid object is not due to impact. It is primarily due to the sudden heating and explosive vaporisation of the opaque matter. The small puff of violently expanding vapour (from the blaster wound or crater) pushes out in any unobstructed direction. That motion exerts a force on the surrounding solid object, like a recoil kick or the reaction of a rocket expelling burning fuel from its exhaust. That is why people and objects shot with blasters may be knocked over.

There is one interesting morbid consequence of all this. A person who is shot with a low-powered blaster shot (or who is wearing armour that absorbs the shot partially) has a crater wound only on the side nearest the firer, but a sufficiently high-powered shot will affect a column of flesh from one side to the other. The person in the former case may feel a more violent kick because the blasted material only expands in the forward direction, whereas the person who is shot right through has hot matter blasting out from both the entry and exit wounds.

Sometimes a recoil is felt in the firing blaster weapon, especially in the case of turbolasers where part of the cannon mechanism springs backwards with every shot. This would best be explained by some kind of explosive event inside the weapon. Flashes or air-bursts are indeed seen near the barrels of some blasters of the movies, especially stormtrooper blasters in ANH.

Question: can a lightsabre operate underwater?

In The Phantom Menace, Obi-Wan Kenobi's lightsabre was rendered inoperable when it became wet in the Naboo swamps. In the roleplaying game adventure Battle for the Golden Sun, provision was made for the use of lightsabres under the oceans of the planet Sedri, and their performance characteristics (in game terms) were altered. In Splinter of the Mind's Eye Luke Skywalker used his father's lightsabre underwater to cut the stems of raft-like waterplant leaves. In Vision of the Future, lightsabres were again used underwater.

This must indicate a difference of design. It could be a fashion innovation, perhaps devised to suit conditions of the Clone Wars (after TPM and during which Anakin built his weapon). It could could be a design trade-off: Kenobi's first weapon might emphasis efficiency, while Anakin's is better protected and more robust. It could be that Anakin's craftsmanship was superior. Other possibilities are imaginable; the question will probably remain open until/unless it is treated specifically in the upcoming prequels.

Question: How does a blaster bolt inflict damage?

The bolt from a personal blaster is visible because some part of the energy beam emits (or decays into) light directed transverse to the blast ray. The emission appears to be monochromatic and non-thermal. (This is proven by the existence of green blaster bolts, because there is no temperature at which an incandescent surface appears subjectively "green.") Nevertheless a bolt propagating from a hand blaster appears to emit at least several dozen watts of luminous power. When that light falls upon an opaque, absorbing surface its energy is thermalised. The energy loss from the bolt ought to be faster in an opaque medium (eg. human flesh) than in open air, so this may be one way in which the entire energy of the bolt is deposited in a target.

There are other possibilities which cannot yet be eliminated. Maybe blaster bolts do have a high characteristic temperature, in terms of the disordered energy component of the beam's constituents? If the beams are innately "hot" the temperature can not be high enough for blackbody emission to outshine the transverse luminousity described above. The energy of a blaster bolt may be highly concentrated in non-thermal forms; there may be a spin or shear or circulation of whatever particles or massless quanta comprise the beam.

If spontaneous (or stimulated) decay of the blaster bolt into transverse light radiation is important to the bolt's damaging effects, then one aspect of stormtrooper armour is explained. A white surface would help reflect the decay light, and may even slow or ameliorate the light-conversion of blaster energy.

Question: How do blaster bolts affect light from other sources?

The visible part of a blaster bolt creates obvious monochromatic emission, but it is less obvious how the destructive beam affects ambient light from other sources. Lightsabre beams have an opaque core cylinder which casts shadows in strong ambient light (eg. in the Emperor's throne room aboard the second Death Star). There are other circumstances in which the beams of energy weapons are not totally opaque. As shown in the indoor and ground battles of the movies, the long, invisible forerunner of the visible trace bolt is blatantly transparent and has negligible effect on natural light. Some bolts from personal blasters are sufficiently transparent for background objects to be seen through them. It's harder to tell in other cases where the bolt is luminous enough to saturate the recorded image. The opacity of blaster (etc) beams is probably dependent on the energy density, with a threshold that is higher than the threshold for spontaneous emission of visible light.

Question: What might be the practical importance of the length of a blaster barrel?

Several speculative possibilities come to mind, by analogy with projectile guns or by considering the distinction of energy weapons. The advantages might include:

Question: What are the properties of shots from an ion cannon?

The nature of the ion cannon shots is as unobvious as the shots from blaster weapons. With "turbolaser" blasts, it is uncertain whether the dangerous energy is supposed to involve or merely create "lasers", and similarly it is not certain what the role of ions might be in ion cannons. Roleplaying game sources stated that ion cannon shots disrupt electronics in a target vehicle. This would be understandable if the shots carry or cause the creation of ions — electrically charged atomic fragments of matter.

Some sources indicate that ion cannon shots can pass freely through shields [eg. Star Wars Roleplaying Game: 2nd edition]. However this can't be entirely true, or else marauding starfleets could inflict untold havoc upon planets sheltering under global shields. The conquest of Coruscant would have been much more straightforward [X-Wing: Wedge's Gamble]. Furthermore it seemed that the rebel shield over Hoth had to be lowered to allow the egress of departing ships and the ion cannon shots against the Imperial blockade [The Empire Strikes Back]. The fact that the star destroyer Tyrant was struck and disabled without any sign of effective shielding means that the ship's shields were very much weaker than the rebels' shield.

An instance of damage before the visible bolt: a Naboo canon fires upon Trade Federation battle droids in TPM. Is the transparent bolt a lower-powered shot?

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Apparently opaque and transparent blaster bolts from Naboo weapons. Is the transparent bolt a lower-powered shot?

A curious instance of a bolt apparently bouncing off the ground, within the effective range of a Gungan theatre shield.

Weapon Ranges

The range of a warship's heaviest weapons is dictated by certain fundamental scales: practical geometric and dynamic constraints.

  1. Firstly, the range must be significantly greater than the length of the ship. A warship won't be very much good in combat if its guns can't strike far beyond its own hull.
  2. Secondly, the weapon range should exceed the turning circle for the ship's maneuvering. Otherwise the only kind of engagement possible would be point-blank battles in which opposing armadas happen to be at rest relative to each other.

These considerations imply that the range of the heavy weapons intended for use against other capital ships cannot be less than several hundred kilometres, a few dozen times the ship's length. Indeed the Imperial and rebel fleets at Endor were engaged over ranges much greater than the size of the second Death Star, and Imperial warships are known to bombard planets from orbit, implying ranges of thousands of kilometres.

Turbolaser shots attenuate with distance due to energy losses as the visible lateral light emissions. However the waste luminosity is small compared to the energy that a shot typically carries, and the attenuation range is generally longer than a solar system. Therefore attenuation is normally not a significant factor affecting weapons ranges in starship combat.

The most important limiters of the effective gunnery range are the mechanisms that aim the barrel. The tracking systems cannot be precise to indefinitely small angular resolution. The gun turret and barrel are massive objects, and the aiming actuators uost spend time and exert force to deal with mechanical inertia. Finally, no targeting computer can even pinpoint and anticipate target motion infinitely well. In principle, every attack anticipation device can be counfounded within some small margin of error due to the light-transit lag time of sensors and the target ship's opportunity to maneouver during that tiny fraction of a second.

Personal Shields

Shields in STAR WARS are usually associated with spacecraft, but there are several examples of devices involving shields on a smaller, personal scale.


Candy Fish asked:

There is one topic that has nagged at me for years, and I can't seem to get a straight answer out of anyone - How would hologram recording technology work?

In other words, how is Artoo able to record a full 3-dimensional hologram of Princess Leia, when it appears his holorecorder can only record one view, which is whatever is facing him? The only theories I've been able to come up with have to do with the holoprojector somehow generating some kind of invisible reflective field around Leia that the "recording waves" can bounce off of and return back to the holorecorder for assembly afterward.

There are different ways of recording and projecting holograms, however the result is pretty much the same. But some means, the complete wavefront of the light coming from the subject is recorded, including information about the phase of light at each point. Photography, on the other hand, only records the intensity of light and loses information about phase. A hologram contains all of the information about the original light waves, so that the light environment is reconstructed completely.

The fact that the back of Princess Leia is projected in R2-D2's message means that some light reflected off that side of her reached his holorecording system. Either he took advantage of a slave camera built into the wall of Tantive 4 behind the Princess, or the light from her back reached the holocamera on the droid's body.

This could be accomplished if there was a reflective surface behind her. Since a hologram of an object records all of its optical properties, a hologram of a mirror acts like a mirror. Similarly a hologram of a more complicated reflective surface records the glints of that surface. Thus if the glint is a reflection of the back of a Princess, the droid will have indirect information about her back.

Given this, the only remarkable thing is that R2-D2 was able to edit the reflective surfaces out of the image, leaving only the likeness of the Princess. Digital editing of holographic movies is beyond Earthly technology. However it is probably within the computing power of everyday devices of a society that has had transgalactic flight for countless millennia.

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This holographic image of Luke Skywalker includes the likeness of sides of his head and body that could not have been directly visible to the recorder.

Inertial Compensators

Even the most (seemingly) ponderous STAR WARS starships are able to engage in straight-line accelerations of hundress or thousands of G (Earth gravities). To sustain the crew and contents against the violence of such manoeuvres (the inertial forces would easily pulverise a human) starships employ devices called "inertial dampers" or "inertial compensators." These are gravitic devices which act invisibly on every particle in the ship's habitable volume. They apply force equal and opposite to the effect of inertia due to the ship's acceleration at any given moment.

The force must be applied to each elementary particle separately. Otherwise the force differential across tissues, cells or molecules would stress, compress and destroy the crew at that level. For instance, if the compensatory forces were applied at a macroscopic level then the crew would be squashed; if they were applied at a cellular level then the crew would turn into putrified meat. Therefore the inertial compensator must apply its forces at a level where there is no permanent structure: at the atomic level or lower. Furthermore the forces exerted by the compensators must permeate and act equally throughout the entire interior of the ship. It may in fact be an ambient effect resembling gravity, or perhaps a disconnection of local spacetime from the universe at large.

The force compensation adjusts in realtime to match the changing accelerations of the ship, but the regulatory mechanism is not yet known. The effect might be controlled by accleration data from the ship's propulsion systems (but this would not help protect the ship from external forces). Alternatively, the compensation might be controlled by a network of independent inertial sensors. For all we know, the intertial compensator mechanisms may have inherent negative-feedback to stiffle inertial forces almost instantly.

Observational History

In STAR WARS, history must have become an observational field of research, rather than exclusively a matter of retrospective scholarship frought with problems of vague relativistic philosophies. As mentioned in some novels (eg. The Courtship of Princess Leia) it is possible to construct a sufficiently powerful and expensive telescope to observe the people on an inhabited world, from a vantage point far away in interstellar space.

However since light emitted or reflected during these events travels through the galaxy much slower than hyperdrive travel, it is possible to launch and expedition to overtake or meet the images of events from the distant past. If there is sufficient justification, equipment could be arranged to allow observation of events years, centuries or millennia after they happened. Great interstellar battles and galactic events are subject to observation and review by astronomical historians, so long as they took place under at least a partially open sky (allowing reflected light to escape into space).

Light from the twenty-five millennia of the history of unified government under the Galactic Republic is still mostly within the 120,000 light year diameter of the galaxy. All periods of the Galactic Republic's history are potentially observable, especially if the astro-historians venture above the plane of the galactic disk, away from the obscuring dust and gas clouds that may limit visibility to a few thousand light years (and hence a few thousand years of time) within the main spiral.



Sate Pestage

There is controversy over the fate of State Pestage, the Grand Vizier of the Emperor's court. He was alive on Byss at the time of Dark Empire, according to the Dark Empire Sourcebook. According to this account, other members of the court had him tried for treason after he refused to allow access to Palpatine's personal archives and the Imperial Seal. These items would have helped resolve the problem of succession in the Galactic Empire. He took these assets with him into exile on Byss, into the hands of Palpatine's Clones (unbeknownst to his persecutors on Coruscant).

However he appeared to meet his end at the hands of one Admiral Krennel several years earlier in Mandatory Retirement, the last story of the X-Wing comic series. His flight from Coruscant is consistent with the circumstances revealled in Dark Empire, and it reveals a pretext for the charge of treason. His chief enemy in the court is identified as Ysanne Isard. The problem is that the comic implies that he died.

The problem is soluble. In fact if we examine the comic closely it is not a problem at all. We do not actually see him dying; he is mistreated painfully but not killed. The situation is referenced in the novel Isard's Revenge, where several characters assume that he died, and Krennel did not condescend to offer any correction. Obviously Pestage must have survived, otherwise the Imperial Seal and Palpatine's archives would not have reached Byss. The Sate Pestage who fled Coruscant was captured by Krennel but must have made his escape at some point.


There are several representations of writing in the galactic Basic language in STAR WARS:

The "aurebesh" was invented by West End Games for use in the Star Wars Roleplaying Game. Some of the characters of this alphabet look slightly similar to some of the letters seen on computer screens in Return of the Jedi. However they are not the same. I don't know whether this is intentional or just a matter of untidy work on WEG's part. If you try to use the WEG aurebesh to decipher the computer screens in ROTJ you'll obtain unspeakable gibberish. Since the text has spaces and the words clearly must belong to some kind of speakable language, I choose to ignore the WEG version.

A definitive interpretation of the true written form of Basic must await the release of Return of the Jedi on DVD, when the computer screens will be readable in complete clarity.

STAR WARS Technical Commentaries.
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