Physics and Star Wars

The space opera interstellar epic Star Wars uses science and technology in its settings and storylines, although its main focus is not necessarily on science. 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 aim is to deliver 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 or as aesthetic elements, and not as elements of the story in their own right.

The iconic status that Star Wars has gained in popular culture 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. However their concepts are still probable.

Tatooine's twin suns

NASA's Kepler mission spacecraft has discovered a world where two suns set over the horizon instead of just one. The planet, called Kepler-16b, is the most "Tatooine-like" planet yet found in our galaxy and is depicted here in this artist's concept with its two stars. Tatooine is the name of Luke Skywalker's home world in the science fiction movie Star Wars: A New Hope. In this case, the planet is not thought to be habitable. It is a cold world, with a gaseous surface, but like Tatooine, it circles two stars. The largest of the two stars, a K dwarf, is about 69 percent the mass of our sun, and the smallest, a red dwarf, is about 20 percent the sun's mass.

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 778 Exoplanets currently known, about 20 or so actually orbit binary star systems. 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 studies looking for dusty disks—where planet formation is likely—around binary stars, such disks were found in wide or narrow binaries, or those whose stars are more than 50 or less than 3 AU apart, respectively. Intermediate binaries, or those with between 3 and 50 AU between them, had no dusty disks. In 2011 it was reported by The Guardian that NASA space craft Kepler had discovered a planet, named Kepler-16b, with twin suns as seen in the Star Wars films.

Blaster Bolts

Star Wars makes heavy use of blaster and ion weaponry, attributed to laser, plasma or particle based bolts of light. Characters can be seen escaping, or even dodging those bolts, and the blaster bolts themselves can be seen flying at a moderate-fast speed. Dodging a laser bolt would be nearly impossible, as it would travel at the speed of light. Due to that, it's reasonable the blaster fire would pass like a sparkle, and hit its target. Sometimes, characters will call the bolts "laser bolts" that while they don't 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 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 where 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 possibly best 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. Although it has never been clarified whether the sound was inserted to add more drama for the audience or whether the characters also hear this space 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.

Asteroid field in Episode V

In The Empire Strikes Back, after the Battle of Hoth, the Millennium Falcon is pursued by imperial ships through a dense asteroid field. The chunks of rock in the field are moving at rapid speeds, constantly colliding, and densely packed. Ordinarily, an asteroid field or belt is unlikely to be so densely packed with large objects, because collisions reduce large objects to rubble. About the only way for an asteroid belt to maintain itself would be to "balance destructive high-speed collisions with constructive soft collisions", but it is unclear whether this is happening in the film.

In contrast to Star Wars, the ship featured in 2001: A Space Odyssey, Discovery One's course took it directly through the asteroid belt in the novel, without real fear of collision on the part of the mission organizers. However, our asteroid belt is far less dense and several real spacecraft have passed through it without harm.

On the other hand, the so-called Trojan asteroid fields, named after the asteroids found in Jupiter-Sun Lagrange points, are known to be packed much more densely. The Solar System contains two such fields, the Greek Trojans and the Trojan Trojans, and two more (Neptune's trojans) are discovered recently but little is known about them currently.

Flight dynamics

Unlike the true flight dynamics of space, those seen in Star Wars closely mirror the familiar dynamics of flying in Earth's atmosphere. For example, fixed-wing aircraft must make banked turns because they use air pressure to operate. Yet, in the airless vacuum of space in Star Wars, the spaceships are always (unnecessarily) banks when turning. Physicist Lawrence M. Krauss says this is for a simple reason: "it looks good." By banking, the centre of gravity would be maintained so up is still up but the g forces generated at such speeds would surely injure the occupants.

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.

Hyperspace travel

The hyperspace travel in the Star Wars franchise requires two elements, light speed travel and Hyperspace. Ships in the Star Wars Universe have engines capable of propelling them to the speed of light. However, current physical theory states that it is impossible for any physical object to attain that speed, as long as the object has a non-zero mass. Doing so would require infinite energy, which is also impossible to generate in our universe. Even if one was traveling at the speed of light, it would still take thousands of years to travel the galaxy, unless the galaxy is smaller in size, possibly the case in Star Wars; therefore the Star Wars ships use a "hyperdrive".

This is explained by having the ships warp to another "dimension", presumably a brane universe with different physical laws. Gravity supposedly reaches between branes. In Star Wars, gravity in real spaces forms gravitic "mass shadows" in hyperspace. Hyperspace in Star Wars is unrelated to the presumed space between universal "bubbles" in real life physics.

The hyperdrive when started, presumably contracts the space in front of the starship and expands it behind the space vessel. According to scientists, this concept is very vague and only probable in theoretical physics, but could become a possibility in the next three centuries.

Planets, moons and planetoids

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, however.

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.

Lightsabers

Often, lightsabers are said to be composed of lasers. 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, 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. Plasma would require the energy that can only be produced by something along the lines of a nuclear reactor, making the power source, again, a problem. Also, 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.

In the documentary "Can you build a real lightsaber?" physicist, futurist and science fiction enthusiast Dr. Michio Kaku discusses the basic functions and technicalities of lightsabers as well the possibilities and problems of creating them. Dr. Kaku explores the various power sources for lightsabers including lasers, crystals and plasma. Amongst the problems, Dr. Kaku points out the lightsaber blades if produced using modern technology, would not clash when meeting together as seen in the films during lightsaber dual scenes, because light has no mass or substance like matter. Instead the blades would pass through one another as normal light beams do. Another discussed problem is how to hold the beams of light in place to produce a blade limited in size as opposed to the endless reaches of normal light if not obstructed by any hard surface or object. If part of a laser beam, the light will simply cut/burn/melt through just about any mass that blocks it.

Dr. Kaku tries to resolve this problem by applying the relatively new practice of trapping light. This is done by firing laser photons into a small container filled with gas atoms. A gas atom would grab the light for a very short instant and then pass it onto the next gas atom. Slowing down the light would work, but would create another problem of having a light energy blade with extreme sun-like heat, possibly exposing its hilt and wielder to extreme temperatures and the risk of causing destruction in its environment.

Another suggestion is that if the extremely hot lightsaber beam could somehow be contained within a protected space using the same concept of modern laser cutters which use oxygen and heated air as a fuel source that is supplied through tubes and then ionized before being released as plasma beams. Amplifying the amount of energy used for producing these plasma beams while at the same time keeping them in a magnetically controlled space would be ideal for creating a lightsaber. He proposes ceramics as a useful container of heat energy which can withstand up to 4000 degrees of heat without being affected, also which is used by NASA to build spacecraft in order for them to pass through planetary atmospheres without getting burned.

There is still the problem of producing so much energy in such a small mass that a reliable power source would be needed such as a battery, but limited in size to fit the lightsaber handle. One possibility according to Dr. Kaku is a nanotube, while small in size could produce large scales of energy by the use of carbon atoms that can conduct electricity.

Kaku's vision of a lightsaber is a blade of super hot plasma. The handle would be a plasma torch with the base of a dyetanium fan that would shoot about one hundred feet of cubic air per second into the hilt where it would be heated to twelve thousand degrees of plasma which would be kept intact by an electro-magentic coil. A telescopic ceramic handle would exit the hilt and contain the plasma beam with the energy coming from nano batteries stored within the hilt. Dr. Kaku argues such an energy beam/blade would also clash with its own kind without being able to penetrate one another. At the end of his analysis and lightsaber design in (computerized) blueprint format, Dr. Kaku concludes that lightsabers are theoretically possible, but still require some scientific/technological advancement to function in the same or similar manner as the ones in the Star Wars universe. According to Dr. Kaku, it is only a matter of a few decades until the technology can be developed.

A team of scientists from Harvard University claimed to have accidentally produced lightsabers during a physics experiment. While the concept of these "lightsabers" is similar to those as in the Star Wars universe, there are some still significant problems and differences. The photons used in these devices repulsed each other and caused an energy beam, but are still able to pass through one another when two separate beams come into contact, unlike the ones in Star Wars.

See also

• Technology in Star Wars
• Star Wars: Where Science Meets Imagination

External links

• Star Wars Technical Commentaries
• First Planet Orbiting Twin Suns Discovered
• One Planet, Two Suns
• Students prove real-life Star Wars deflector shield is possible
• Star Wars 'hyperdrive' space flight explored by physicists
• Science of Star Wars: why the Force could be with us
• NASA discovers real-life ‘death star’ ripping apart and vaporizing tiny faraway planet
• TIE Fighter Physics