Why is Superman affected by kryptonite?

I am not a fanboy so forgive me I this is common knowledge. I've never gotten why Superman is affected by kryptonite, either fatally by green or in any numbers of ways by the other colours. If kryptonite is so deadly to them, how did Kryptonians ever live on their own planet?Why is Superman affected by kryptonite?On a literary level, Kryptonite represents the remains of Kal-el's homeworld. It's a literal statement--he can't go back home. He has to be Clark Kent of Earth and live in the here and now.



On the science fiction level, it implicitly goes like this. It's been in continuity for a while that with your modern Superman (not the 1930s, Golden Age version), most of his powers are fueled by sunlight, or by a metabolism that absorbes solar radiation.



The sun is a naturally occurring nuclear fusion reaction.



This is important because it's _Always_ been in continuity (if not stated often enough) that Krypton exploded thanks to a runaway nuclear _fission_ reaction from the core of the planet. It literally blew up like an atom bomb, after local years (apparently) of smaller reactions producing massive tremors and earthquakes all over the world (the stuff Jor-el picked up on, but was ignored and ridiculed over).



So basically, what Kryptonite represents in terms of the science fiction of Superman is: it's a hack. It's saying, "Ok, his metabolism is open to nuclear radiation from the sun--that gives him life and powers. So....by extension, the radioactive waste from the death of his homeworld is _also_ going to affect him, in the opposite way, it will poison him and maybe kill him thanks to his metabolism's being implicitly sensitive to radiation".



That paragraph up there, that statement, is mainly conjectural, by the way, and based off of circumstantial evidence in the comic books. It might not _be_ in official continuity. Even though it makes totally perfect sense, the truth is, that biological link has never _been_ established in comic books that were considered _in_ continuity. Just to give you fair warning.



However, in all fairness, this isn't just my idea either. Frank Miller came up with it first in his _Dark Knight_ graphic novel, as a way to explain why a nuclear bomb could hurt Superman (and how, of course, the nuclear winter's shutting out of the sun could weaken him too). Several other writers working for DC Comics (including one Brad Metzler, who writes Justice League comics occasionally), consider it canon.



So there's that. In simple terms: If Superman's going to be sensitive to anything, it's radioactivity. Put the good stuff in, from the sun, and you get good stuff--his life and powers--out. Garbage in--debris and toxic waste from Krypton--also means garbage out, in terms of disease and death.



Hope this helps.Why is Superman affected by kryptonite?basically the assorted colors of Kryptonite are specific elements (just like we have the entire periodic Table of 1-118) one assumes that they have (know of) at least as many if not more on Krypton



Red, Blue, Green, Gold and Black could apply any 5 of those 118+ and considering the Radioactivity and rarity of most of those over 89 the specific elements could have messed with them on Krypton



this doesn't even take into account that they could have been harmless elements on Krypton... no people there had superpowers like they do here... so its feasable that the same processes that affect Superman giving him powers also affect the previously harmless elements making them toxic



the primary issue is that several continuities would often make Kryptonite so abundant that if you assume it was drawn to scale and added up every chuck it'd combine to form an entire planetWhy is Superman affected by kryptonite?Kryptonite was created by the process which caused Krypton to explode. In other words it may have existed in the last days of the planets (I believe the first Christopher Reeve movie suggested as much) but not before.