Although some different incarnations of superman are more vulnerable than others, the main stream concept of superman is only vulnerable to a few things like kryptonite and EXTREME force, but he has easily withstood nuclear weapons, and could probably easily withstand a lightsaber.
The truth of the matter is that Superman is invulnerable when the situation calls for it. Is he immortal and impervious? as long as he sells comics.
I have a question and wasnt sure where to ask it. diddnt want to start a thread for one question. What comic series of superman leads up to him leaving to sleep in the sun? Why did he leave in the first place? much appreciated if any help can be given?
__________________ "If you tell the truth, you never have to remember anything" -Twain
(sig by Scythe)
That happened over 70,000 years in the future from mainstream DC continuity.
As for his invulnerablity, he has easily survived nuclear bombs, he does that all the time. He's even taken supernova - level explosions or higher. However if you have enough force you can put him down without utilizing one of his weaknesses (Kryptonite, red sun radiation, or magic). Examples are Darkseid (at least back when he wasn't a joke), Mageddon, Imperiex, Doomsday....
It was only explained in the dc 1million arc by Supes 1million. He left because all his loved ones had long since past away and felt as though the earth was in safe hands. I think he spent thousands of years traveling the universe, fighting gods and demons and apparently breaking through the gates of heaven all in search of Lois. He returned to earth at some point a few hundred century's down the line and granted his Superman dynasty with powers beyond any metahuman and 10 new extra senses I think. This is the point where he decides to go hibernate in the sun for oh I dunno a few hundred thousand years. The story behind Superman Prime is vague at best but DC 1 Million is a really good read.
He's taken a direct nuclear blast while being in kryptonite more than once.
__________________
Humans are afraid of the dark.
And yet… At the same time, we’re fascinated and bewitched by it.
Maybe that’s why humans drink the darkness that is coffee.
It likely wouldn't effect him. He can fly through red suns (which drain his power) without a burn and take heat vision from other Kryptonians to the face. Superman has very high energy resistance.
As a casual fan of Superman and mildly hardcore fan of SW movies, I will bite. We all know that Superman's skin will easily turn a knife and is resistant to temperature extremes. Because lightsabers behave like swords, one could assume Superman would easilydeflect a blow.
No, correct me if I'm wrong, but lightsabers use various crystals to focus the beam of light, hence, the different colour blades. Supposing some managed to use a chunk of Kryptonite as the focal crystal? Would the resulting beam cut through his skin or would the hilt just make him sick?
Food for though.
__________________ "I'll be around in the middle of the song to visit with you individually." - Joe Walsh
Well a kryptonite sword would most likely impale him with enough force behind it so yes I imagine a k-nite lightsaber would. Though I don't think a normal one would do shit.
A lightsaber can slice things apart on an atomic level so it might hurt him, but then again it is repelled by forcefields, and Superman has his own forcefield....