An elegant weapon … of a more civilized era. So the lightsaber was presented to the audience about 40 years ago. An invariable element in the surroundings of any Jedi, the glowing sword has been preserved for thousands of years in the galactic republic. Along with the first public appearance in 1977, when the first Star Wars movie was released, the characteristic lightsaber hum and the epic battle between Darth Vader and Obi-Wan Kenobi have long remained in the memory of viewers. A senior scientist at Fermi Lab is working on realistic options for bringing the lightsaber to life. And, as Don Lincoln says, he will definitely show up.
Build a lightsaber
Given the impact of the Star Wars franchise on society, it was inevitable that a segment of society would emerge that wanted to make a lightsaber and even train with it. But what kind of technology could form its basis? From here began the first attempts to reverse engineer this device. Reverse engineering, in this context, is thinking about how it can be done … rather than building one such sword.
Admit it, it would be nice to get such a sword as a gift for the New Year. But Star Wars, whatever one may say, is science fiction. What could scientists and engineers do to build such a sword (of course, it is beautiful on the screen, but it is almost impossible to limit the laser beam in this way).
Image: es.clubpenguin.wikia.com
In the film, the blades of lightsabers are shown to extend 1.2 meters in length. They definitely contain colossal amounts of energy and can melt huge amounts of metal. This weapon clearly has a powerful and compact energy source. They can cut through flesh without any difficulty, but their handles are not particularly hot to burn the hand that holds them. The two lightsabers don't go right through each other, and the blades also come in different colors.
Promotional video:
Given the name and appearance, the first obvious thought arises: These lightsabers must be using some type of laser. But this hypothesis is easy to rule out. Lasers do not have a fixed length, which is easy to check with a simple laser pointer. Also, unless the light is scattered in some way, the laser beam is essentially invisible. None of these characteristics describe our sword.
Plasma blades?
Plasma would be a more realistic technology. Such material is created after knocking out electrons from gas atoms, in the process of so-called ionization. Plasma is the fourth state of matter, after the well-known solid, liquid and gaseous. You, too, have seen many examples of plasma in your life. The glow of a fluorescent light is plasma, and so are neon lights.
This plasma appears to be very cold because you can touch the tube without burning your fingers. But usually the plasma is hot, with a temperature of several thousand degrees. However, the density of the gas in the fluorescent light tube is so low that even at high temperatures, the total heat energy is very low. An additional complication is that the electrons in the plasma have energies much higher than the ionized atoms from which these electrons emerged. The heat energy of a cup of coffee (which is much colder) is significantly higher than the energy contained in fluorescent light.
Some plasma, however, generates significant heat. In plasmatrons. The principle of their operation is the same as that of a light bulb, but with a large amount of electric current. There are many ways to make a plasmatron, but the simplest involves two electrodes and a conductive material, usually a gas like oxygen, nitrogen, or something. High voltage across the electrodes ionizes the gas, converting it into plasma.
Image: frikiamigo.com
Since plasma is electrically conductive, it can transmit a powerful electrical current to the target material, heating and melting it. Such a device is called a plasma cutter, but in reality it is an electric arc (welding), and the plasma acts as a conductor of electric current. Most plasma cutters work well when the material being cut is conductive because the material can then complete the circuit and send electrical current back to the device through the cable that connects the torch to the target. There are also double cutters that allow electricity to pass between them, they allow you to cut non-conductive materials.
So, plasmatrons can generate areas of intense heat, but require an enormous amount of electric current, and lightsabers don't seem to be able to provide that current. Maybe then the lightsabers are just tubes of super-hot plasma? Also not, because plasma acts as a hot gas that expands and cools, like ordinary fire (which is also often plasma, if only because it glows). Thus, if the plasma is to underlie the lightsaber, it will need to be contained in something.
Fortunately, there is such a mechanism. Plasma, made up of charged particles (at high speed), can be controlled by magnetic fields. In fact, some of the most promising fusion technologies use magnetic fields to confine plasma. The temperature and total energy contained in the synthesized plasma are so high that even a metal vessel containing them would melt.
Maybe a lightsaber will do. Strong magnetic fields coupled with super-hot and dense plasma offer a possible way to create a lightsaber. But we're not done yet.
If we take two plasma tubes that are magnetically held, they will go right through each other … there will be no epic duels. So we need to figure out how to make the swords have a solid core. And the material of which it will be composed must be resistant to high temperatures.
A ceramic that can be exposed to high temperatures without melting, softening, or warping may be suitable. But the hard ceramic core has a problem: when the Jedi does not use the sword, it hangs from his belt, and the handle is 20-25 centimeters long. The ceramic core should jump out of the handle like the devil from a snuffbox.
Brute force
This is how I (Don Lincoln) envision building a lightsaber, even though my project has problems. In Star Wars: Episode IV - A New Hope, Obi-Wan Kenobi cuts off an alien's hand with a light, casual motion. This moment silently indicates how hot the plasma should be.
Image: carlos92.deviantart.com
In Star Wars: Episode I - The Phantom Menace, Qui-Gon Jinn inserts his lightsaber into a heavy door, first making a deep cut and then simply melting it. If you look at this sequence and assume that the door is steel, take into account the time spent on heating and melting the metal, you can calculate the energy that such a sword should possess. It turns out somewhere around 20 megawatts. Considering the average consumption of household electricity - about 1.4 kilowatts - one lightsaber can power 14,000 ordinary houses until the battery runs out.
A power source of this density is clearly beyond the scope of modern technology, but perhaps we can assume that the Jedi know a secret. After all, they travel faster than the speed of light.
But there is a physical problem. This energy implies that the plasma will be incredibly hot and only a few inches away from the sword wearer's hand. And this heat will be radiated in the form of infrared radiation. The Jedi's hand should be charred instantly. This means that some kind of force must keep the heat. Again, sword blades use optical wavelengths, so the force field must contain infrared radiation but transmit visible light.
Such technical research inevitably leads to the need for unknown technologies. But we can at least just say that a lightsaber is composed of some kind of concentrated energy trapped in a force field.
Memory tells me how Michael Okuda, technical consultant for the Star Trek franchise, explained the new technology that made transporters possible. He said there were "Heisenberg compensators" supposedly needed to correct problems caused by the Heisenberg uncertainty principle. This is the famous quantum mechanical principle that you cannot simultaneously know the location and speed of a particle with high precision. Since a person is made up of many particles (atoms and their constituents), if you ever try to scan someone to find out the location of all of their atoms, you will not be able to accurately measure their position and movement. This means that when you try to reassemble someone, you will not be able to accurately collect protons, neutrons and electrons together. On a deep and fundamental physical level,Heisenberg's uncertainty principle says that such transporters are impossible. But who is Heisenberg to the creators of Star Trek? When Time reporters asked how such a device works, they said "very good, thank you."
Still, it was interesting to know how close modern science is to creating iconic science fiction technology. In the case of a lightsaber, the best that modern technology is capable of is a plasma weapon enclosed in a magnetic field. Yes, it will also have a ceramic core that uses a very dense energy source, as well as a force field that blocks infrared, but not visible radiation. Ugh, just spit.
It remains to ask the engineers how difficult it will be to do all this. But they can, right?