The interstellar space opera epic Star Wars uses science and technology in its settings and storylines. The series has showcased many technological concepts, both in the movies and in the expanded universe of novels, comics and other forms of media. The Star Wars movies' primary objective is to build upon drama, philosophy, political science and less on scientific knowledge. Many of the on-screen technologies created or borrowed for the Star Wars universe were used mainly as plot devices.
The iconic status that Star Wars has gained in popular culture and science fiction allows it to be used as an accessible introduction to real scientific concepts. Many of the features or technologies used in the Star Wars universe are not yet considered possible. Despite this, their concepts are still probable.
Tatooine's twin stars
thumb|300px|A [[NASA depiction of a theoretical viewpoint from Kepler-16b's orbit of its two stars]]
In the past, scientists thought that planets would be unlikely to form around binary stars. However, recent simulations indicate that planets are just as likely to form around binary star systems as single-star systems. Of the 3457 exoplanets currently known, 146 actually orbit binary star systems (and 39 orbit multiple star systems with three or more stars). Specifically, they orbit what are known as "wide" binary star systems where the two stars are fairly far apart (several AU). Tatooine appears to be of the other type — a "close" binary, where the stars are very close, and the planets orbit their common center of mass.
The first observationally confirmed binary — Kepler-16b — is a close binary. Exoplanet researchers' simulations indicate that planets form frequently around close binaries, though gravitational effects from the dual star system tend to make them very difficult to find with current Doppler and transit methods of planetary searches. In 2011 it was reported by The Guardian that NASA space telescope Kepler had discovered a planet, named Kepler-16b, with twin suns as seen in the Star Wars films.
Certified astrophysicist and Star Wars fan Jeanne Cavelos explains that scientists have been skeptical about the likelihood of binary star systems such as Tatooine since the gravity of one star may prevent planets from developing around the other. Two stars of different masses orbiting one another would cause gravity fields to shift, causing potential instabilities in the orbits of any planets in their system.
According to her, even planets in more stable orbits of a binary star system would suffer other kinds of problems such as climatic problems. As an example, a planet in a binary star system orbiting the larger star would be drawn closer to its gravitational field, causing the planet to endure heat of great temperatures during this period. As the planet passes its larger star and reaches the orbit of its smaller star, the gravitational field of that star would give the planet more distance from it. The distance (perhaps along with the smaller solar projection of the star) would send the planet into extreme frigid temperatures. Due to that, it is reasonable the blaster fire would pass like a sparkle, and hit its target. Sometimes, characters will call the bolts "laser bolts" that, while they do not travel at light speed, are made of intense light energy.
However, many official canonical Star Wars sources state that blaster technology is different from real lasers. According to official canon, they are a form of particle beam. This is supported by how "magnetically sealed" walls deflect them.
The Polish Academy of Sciences in collaboration with the University of Warsaw managed to film an ultra short laser pulse by using cameras that produce billions of frames per second. These laser pulses were so powerful that they almost instantly ionized the atoms they encountered, resulting in the formation of a plasma fiber filament.
The effects of a blaster on a live target were portrayed more or less the same in every part of the Star Wars series. Since blaster bolts consist of light or particle based energy, the bolts would burn through the flesh of a target, with some even exploding against their target, exerting great force. The latter effect was usually from a blaster with greater size. Blasters have even been shown to have plasma energy as ammunition, which is portrayed as blue bolts. As of The Force Awakens, these blue bolts rupture and damage flesh with little to no burning, which causes bleeding injuries, as Poe shot a Stormtrooper with a blaster that caused him to bleed until death. Another instance of a blaster causing bleeding was when Chewbacca shot Kylo Ren with his Bowcaster, the small explosion against his body causing a bleeding injury coupled with burns. In many modern showings of blaster fights, someone hit by a blaster has cinders and soot outlining the area where they were shot. Also blasters hit with great amounts of friction and kinetic energy, enough to cause sparks to fly off the target, make the target burst into flames, or kill a target on impact, even if the target is not penetrated by the bolt, as it is when some targets are armored against blasters.
Vibration in vacuum
Star Wars is famously known for its epic space dogfights. Blaster, engine, and explosion sounds can be heard in those space scenes. Space is a vacuum, however, and since sound requires matter to propagate, the audience should not hear any sound.
This has been explained in some Star Wars media as the result of a sensor system that creates three-dimensional sound inside the cockpit or bridge matching the external movement of other vessels, as a form of multimodal interface, although the audience is still able to hear sound even from a perspective that is in space. In the canon novel Lords of the Sith it is explained that the characters in a galaxy far, far away indeed do not hear any sound in space if no longer confined by their vessels:
Therefore, the ability to hear sound in a vacuum by the audience is not heard by the iconic characters, but only to the audience as an interpretation to imagine what sounds we hear in the films as out-of-universe artifacts.
In contrast to Star Wars, the ship featured in 2001: A Space Odyssey, Discovery One, had a course that took it directly through the asteroid belt in the novel, without real fear of collision on the part of the mission organizers. However, the Solar System's Asteroid Belt is far less dense and several real spacecraft have passed through it without harm.
By banking, the center of gravity would be maintained so up is still up but the g forces generated at such speeds would surely injure the occupants. This is handled in the films by devices known as "inertial compensators".
In order to turn in non-atmospheric flight, some force must still be applied to the craft, presumably by some sort of thruster or generated force field wave, the location of which (in relation to the craft's centre of gravity) will dictate the orientation of the ship, or bank angle, required to make the turn.
The phenomenon has been around supposedly since 1997 following a number of comic book productions on Star Wars beyond the original trilogy (of unknown canonicity, although like most other works it has been declared non-canonical and part of the distinct Star Wars Legends continuity in 2014) and has been known as "The Endor Holocaust". It came about from a rational analysis in multiple commentaries of the aftermath of the second Death Star's destruction and its hypothetical effects on the forest moon and its living inhabitants. Based on all the information from the stories, it has been concluded that a nuclear fallout would cause radioactive contamination on the surface of the planet (or moon), leading to widespread death and destruction.
Studying and analyzing the second Death Star's destruction, physicists hypothesize its results and consequences. Astrophysicist and Star Wars fan Dave Mosher covers the film's events in a 10,000 word essay. His first argument is the Death Star explosion resulting from the rebel attack on its nuclear reactor, the whole space station would be reduced to a large number of fine metallic pieces raining down on Endor. The debris would burn up in Endor's atmosphere turning into toxic soot and spark planetary firestorms.
Another scientist, Sarah Stewart, reanalyzes the situation and theorizes the moon's previous state after some environmental cleanup from the Death Star's fallout.
This would make Endor slightly larger than Mars but about 15% the size of Earth. He also notes that in diameter, Endor would still be smaller than Mars, but denser in mass by his measurement formula. Endor's composition being smaller would be unusual, but not impossible according to him.
Minton therefore concludes there would be little vaporization of remaining material and that the explosion would move a lot slower than what is required to keep them in orbit, which he estimates is about 212 miles per second. Using the equation representing orbital velocity of the Death Star, he theorizes the fragments would need to be orbiting at about 4.5 kilometers per second to maintain orbit at the same altitude the Death Star had been. Since this does not happen, he argues the remains of the former Death Star would fall straight into the area where the shield generator has been on the moon's surface.
Hyperspace travel has also been noted to have some form of air resistance, as seen in "Deal No Deal", an episode of the Star Wars: the Clone Wars TV series. Trace Martez – smuggler and friend of Ahsoka Tano – apologises for flight turbulence on her heavily modified Nebula-class freighter, nicknamed the "Silver Angel", having "left the air brakes on". This would be normal, if Martez was encountering air resistance in the atmosphere of Coruscant - the planet she had just left. However, she only encountered turbulence once she entered hyperspace, which suggests that hyperspace has some form of gaseous atmosphere, for lack of a better term.
Planets, moons and planetoids
thumb|300px|Map of the Star Wars galaxy
In the Star Wars franchise, almost everyone can breathe and move on many planets, and these, as well as the star systems, are treated as small places. Both defects have an accurate explanation.
The Star Wars Expanded Universe states that many of the planets of the galaxy were colonized and adapted to the atmosphere and gravity of the most populated species, and there are also many species—such as Kel Dor and Skakoans—that need to use devices like breathing masks or pressurized suits. In the other case, since the Star Wars franchise develops itself to the intergalactic level, it is assumed that almost all the planets on it are planetary civilizations, a theory well-based in reality and that could possibly happen in a distant future.
The novelization of A New Hope, ghostwritten by Alan Dean Foster, mentions that humans colonized Tatooine in the section introducing the Tusken Raiders. The section implies that humans colonized the planet and settled in the more remote areas of the much sparsely populated planet, which did not give much chance of contact between the Tusken Raiders and the human colonists, who settled on the planet in small numbers.
Also in the same novel, the section introducing the planet Yavin describes it as uninhabitable. Its satellite moons are described as planet sized. The fourth moon called "Yavin IV" as it was named by early human colonizers is described rich with plant and animal life. It describes an ancient civilization that once existed in the jungles of the moon but disappeared centuries before human explorers ever set foot on the moon. The only evidence of their existence the ancient architectural sites and monuments they left behind (as seen in the film), most of which were mysteriously built. At the time the Rebel Alliance used territory on Yavin as their hidden base, the only thing left on the moon was plant, insect and animal life.
Jeanne Cavelos points to the Tales of the Jedi comic book series that document the early colonization of much of the populated Star Wars galaxy. Her argument is that the humans in the Star Wars galaxy being a single species, as well as appearing and living like human beings on Earth, likely originated from a single Earth-like planet, though the exact origin or home world of the human species in the Star Wars universe is not exactly known. She suggests that to be able to colonize other planets, the humans of the Star Wars galaxy could not have been genetically altered. She points to the fact that Luke Skywalker lived his life on Tatooine but did not require any genetic altering to adapt to Hoth, a planet with a climate estimately the opposite of Tatooine.
There are also problems with the possibility of humans altering the climate of the planet they colonize. She mentions the fact that there are native species on planets that humans live on, such as the Jawas alongside the Tusken Raiders on Tatooine who survive in the same climate as humans live on. If they lived in another climate prior to human colonization and environmental modification/alternation, such as terraforming, they are unlikely to survive. However, using lasers raises several issues:
- The necessity of something to reflect the end of the beam.
- Having a compact and powerful enough power source.
- Lasers do not clash when their beams cross.
- Lasers are silent.
- There are some materials that can withstand a lightsaber, and some can even deactivate one upon contact.
Earlier forms of the weapon were known as "protosabers" in the Star Wars galaxy that required battery packs which were connected to the lightsaber hilt through a power cord. The battery pack was attached to a belt worn by the Jedi using the lightsaber, similar to how a flamethrower is worn, but was not ideal as it restricted the Jedi's movements during combat.
Lightsabers have been generally explained as plasma kept in a force field, usually an electric or magnetic field. The force field could not be magnetic, because the field contains heat, something a magnetic field is incapable of doing. Thus, the force field must be a shield not known by modern technology. Additionally, when two plasma blades would come into direct contact, it would almost certainly result in magnetic reconnection, causing an explosive release of the plasma contained in both sabers.
The problems with lightsabers that use actual light blades mentioned at the beginning of this section are not all insurmountable. For instance, it is mentioned that "Lasers do not clash when their beams cross", which is a statement based on our day-to-day experience with light. But Euler and Heisenberg have shown in 1936 that, for sufficiently high intensities, light can actually interact with itself (an effect due to quantum fluctuations of the vacuum). Given this, then it is possible to imagine a scenario of two lightsabers clashing in which photons coming from the hilt of one lightsaber are scattered toward the hilt of the other lightsaber (the scattering is done in the region where the two lightsabers overlap). Since photons have momentum, those scattered photons would exert radiation pressure on the hilt of the other lightsaber. Using techniques from ultrahigh intensity lasers, it has been shown that for lasers with an electric field strength of the order of 10<sup>15</sup> V/m, the force felt in the hilt of each lightsabers is approximately 10 N (roughly the weight of a one kilogram object). This force due to scattered photons would give an impression of blade solidity when the two lightsabers clash.