The "what-the?" thread got me thinking about Superman.  I've probably got 150 or so issues of the guy, but there are some basic questions I'm not sure I know the answers to.  I'm sure JB or someone here can help me out?

Does Superman need to eat?  I know the sun gives him all kinds of powers and sustenance, but does he need to consume nutrients (I imagine he burns a lot of calories whenever he faces off against a supervillain or "bends steel in his bare hands" or "changes the course of mighty rivers")?

If the answer to that is yes, does he require trips to the restroom to eliminate waste products from those meals?  I know that sounds juvenile, but I've so rarely seen Superman eating and I'm not sure that it's not just a social thing.  If it is just a social thing and he doesn't absorb the food, what happens to the food in his stomach?

If everything on Superman is invulnerable, how is it that his heat vision can shave his beard / hair?  I've also read at times that he just doesn't grow a beard; is that canon and if so, is there any scientific explanation for why?

How does Superman fly?  I assume his molecular structure is super-dense to be so invulnerable, and yet he can make himself lighter than air.  Is there any (psuedo?)-scientific explanation to justify this ability?

Does Superman sweat?  I ask because he can swim in molten lava and bathe in the fireball of the sun, so obviously keeping his body temperature at a constant 98.6 is not of paramount importance.

I'm not trying to poke fun or holes in the Superman persona... just genuinely curious if these issues have ever been spelled out / addressed.

Usually, my feeling is that once you start sking these types of questions, it's time to move on from reading comics!

...or start writing for M*****

I don't know, Bob, these questions are kinda fun to ask. JB himself has addressed some of those issues in his Superman run, so maybe your response is a little extreme.

According to my memory and understanding of JB's Superman stories then (if something in the list below doesn't match what JB had written in the stories, I apologize in advance):

Superman doesn't really have to eat but he likes food, which he consumes 100% leaving no waste products.

Superman is described as invulnerable, whereas he is actually too hard to hurt. A lot of things can cause pain, his heat vision being one of those things that can hurt him, and, obviously, shave him. JB had shown that an uncontrolled, full force, extra packed heat vision beam (which I considered at the time the peak of the power's potential) burned hot enough to burn his hands and eyelids! He does grow a beard, though.

About the sweat, I guess the electrochemical aura around his body, the same aura that allows his skintight costume to remain intact and his skin to remain dirty, probabaly takes care of that as well.

About the flight, I have no real theory nor do I remember JB addressing the issue directly, I would consider though, that levitaiton through latent psychic abilities is a possible theory. Those same psychic abilities are what allows him to fly buildings and bulky masses over his head without them crumbling around him or manifest heat vision through pyrokinetic agitation of the target's molecules.

This applies to JB's post-Crisis version. What happened in the pre-Crisis versions, I have no idea, nor do I know what works and what doesn't in the current version.

I believe "JB's Superman" did eat, but used whatever he took in with total efficiency.  He could eat anything now and his body would process it perfectly without any waste product. 

As for flight, I think post-MOS many of Superman's powers, strength, speed, and flight definitely were a form of telekenesis. 

Please correct me if I'm wrong.

> Does Superman need to eat?  I know the sun gives him all kinds of powers and sustenance, but does he need to consume nutrients (I imagine he burns a lot of calories whenever he faces off against a supervillain or "bends steel in his bare hands" or "changes the course of mighty rivers")?

According to Action Comics 800, Superman doesn't need to eat.  Clark to Lana: "I don't need to eat."

> If everything on Superman is invulnerable, how is it that his heat vision can shave his beard / hair?  I've also read at times that he just doesn't grow a beard; is that canon and if so, is there any scientific explanation for why?

Superman is comic book invulnerable, not invulnerable invulnerable.  He can be hurt, it just takes a LOT to do it.

> How does Superman fly? 

According to John's work?  "Through sheer force of will."  Nowadays?  Lex hypothesized that Superman's body produces anti-gravity particles (in Birthright).

> Does Superman sweat?  I ask because he can swim in molten lava and bathe in the fireball of the sun, so obviously keeping his body temperature at a constant 98.6 is not of paramount importance.

I don't think I've ever seen him sweat under full power, no.  Unless some freaky magic is involved.

> I'm not trying to poke fun or holes in the Superman persona... just genuinely curious if these issues have ever been spelled out / addressed.

Some have been, some haven't been.  No comic has EVER answered, or even so much as asked, the question: DOES SUPERMAN POOP?

And, uh, that's fine for me.

_Frank Robert