I agree that it is simpler, less extravagent, and more practical, probably cheaper, to arm standard soldiers with ranged weapons like guns and blasters.
You can jsut look at todays army. No one uses swords on the battlefield. I mean, people might if they had the reflexes to block bullets with them, but they don't!
By the same token the average being in star wars would not have the reflexes to block blaster bolts, even if they are slightly slower than bullets (but not all that much). They couldn't do the saber boomerang throw either among other things.
There have been stormtroopers trained to use lightsabers, I think vader trained them himself, thats right, but they eventually turned on him, Vader dispatched them easily.
Regarding making the lightsaber. I think there are parallels between the construction of a lightsaber and the forging of a samurai sword or similar weapon. Samurai swords are constructed with MANY folded layers of steal over a soft iron core, a skilled swordsmith will often spend months creating one. It is considered a kind of spiritual ritual, fasting during the construction of the swords was not uncommon.
When you make a lightsaber, the housing is fine, but the focusing crystal is the key, i think the focusing lens is important as well.
You can have a natural crystal (usually an Ilum crystal that is blue or green) or use a synthetic crystal (like those used by the sith). Creating synthetic crystals is tricky, some jedi and sith manipulate the forming of these crystals with their own force influence while it is in the forge.
For natural crystals I dunno. Perhaps natural crystals still need some kind of force touch to manipulate the molecular structure of the crystal in order for it to work properly. It is said that some try and fail to make a lightsaber many times over.
Luke used components and a synthetic crystal forge he found in Obi Wan's dwelling on tatooine to construct his own lightsaber. He uses a synthetic crystal he created in a special forge.
The crystal is what determines the color. Lightsabers came in all colors before the battle of Ruusan (1000 BBY). After that there were only blue and green for the Jedi, and red for the Sith (these were Ilum crystals, but the sith used synthetic ones.)
Other sources of crystals were lost after that Battle. Ruusan was a source of those crystals, but that planet was lost and forgotten for a thousand years until it was rediscovered by Jerec and Katarn - (Valley of the Jedi).
As far as General Greivous (who was an amazingly dexterous cyborg anyway), and others using a lightsaber, sure they can! But for the untrained, ancient weapons are no match for a good blaster at your side.
Now why do Jedi in the NJO era have lightsabers of all different colors? Well one theory is that some planet that has more useable crystals was discovered. The other is that creating synthetic crystals is a relatively new technology, which allows some crystals to come out a variety of different colors.
About red representing evil - nah. Its true that sith pretty much only use red crystals, but Luke made a red lightsaber for Leia. Later on I can only presume she made a green one of her own. But some other picture shows her using a blue one!! I think it was a cover picture for Legacy of the Force series. So i dont know what color lightsaber she has now.
That is all...
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