Whilst you suppose of Megastar Wars, you bring to mind lightsabers. Proper? What might be higher, from a movie-making point of view, than a futuristic sword that allows you to create superior fencing duels like in old-time Errol Flynn swashbucklers. (Such a lot higher than observing Stormtroopers hearth their blasters into partitions and ceilings and anything with the exception of their goals.)
Lightsabers are available in a cosmic rainbow of hues (color-coded blue or inexperienced for excellent guys, pink for unhealthy) and numerous shapes. There’s even a double-bladed model in Phantom Threat. (I don’t wish to get started a nerd combat—but—however the most productive lightsaber combat within the canon needs to be the “Duel of the Fates” in that film, due to the abilities and scariness of Darth Maul actor Ray Park.)
So … precisely what are lightsabers? After all, they aren’t actual, so no one in point of fact is aware of how they paintings. Even the characters within the films appear a bit of puzzled about it. In Phantom Threat, Anakin calls it a “laser sword.” Yeah, he used to be a child, however each Din Djarin (the Mandalorian) and Luke Skywalker additionally consult with it as a laser sword—even though I think Luke used to be being sarcastic.
Anyway, that’s simply mistaken: It may well’t be a laser. For starters, lasers beams are invisible from the facet, so that you wouldn’t see a factor except you staged the duels in a disco with fog machines to scatter the beams. 2d, the beams move on endlessly; they don’t have an finish. 3rd, laser beams can’t clank in combination like swords—they’d simply move thru every different whilst you attempt to parry.
However what’s it then? We will very much slim the chances via asking if the blade has mass. If it’s some roughly gentle (as you’d suppose from the identify “lightsaber”), then the solution is not any—gentle, or electromagnetic radiation, has no mass. If we will decide that it has mass, then it’s no longer gentle.
This can be a query we can solution, via examining how lightsabers transfer whilst you wave them round. In different phrases, it’s time for some physics!
Mass and Movement
Don’t confuse mass and weight. Mass is a measure of ways a lot “stuff” like protons, neutrons, and electrons are in an object, and weight is the volume of gravitational pressure appearing on an object. Right here we wish to see what have an effect on the mass of a lightsaber would have on its movement. However let’s get started with one thing more practical.
As an alternative of a lightsaber, say now we have a “lightball” product of the similar buzzy substance. Because it’s symmetrical, we will describe its movement with out being worried about rotation. If we wish to transfer this ball from side to side, we name on Newton’s 2d regulation of movement. This says the acceleration (a) of an object is dependent upon its mass (m) and the volume of pressure (F) carried out to it.
