The Science of Star Wars: The Scientific Facts Behind the Force, Space Travel, and More!

by Mark Brake

“Laser” stands for “Light Amplification by Stimulated Emission of Radiation.” It essentially works by using energy to stimulate a substance into emitting photons. The aforementioned substance is known as the gain medium and can be made from a gas, liquid, or solid. The first ever laser used a solid ruby crystal as its gain medium. This produced a red light beam. Other gain mediums can produce other colors, depending on the particular wavelength of the emitted photons. For example, larger wavelengths have lower energies and produce red light, while the smaller wavelengths have higher energies, producing blue light. Other colors also exist, including green and yellow. So the kyber crystal in the lightsaber could make sense as a possible gain medium. Then slight impurities in the crystals could give a lightsaber its characteristic color. This would also mean that different colored lightsabers have different energies. However, as light waves are invisible, these beams could only be seen if they reflected off some surface or were scattered by particles in the surroundings. So a laser saber would actually be invisible, which isn’t what happens in the movies. This is not the only obstacle in the way of this method.