While reading a fic, I again came across the statement that Superman can fly with objects at much faster speeds than with humans. Why? If that speed would vaporize a human, why would it not also vaporize luggage or any other object? And while we're at it, why can he zip from one place to another in a second without disturbing the atmosphere, yet when returning from nightfall he created a fireball? Yet more incongruities from the show we love...

The first one is not really a incongruity, I think. consider this: If a plane crashes, you can find the passengers clothes and even their suit-cases. Often, they don't look particularly harmed - and still, there are no or near to no survivors. Obviously, baggage (as in fabric and other non-fragile objects) can take quite a beating without being vaproized, as you put it. Human, on the other hand, are very fragile living beings. Especially when the inner organs get too much of a shove (like from the crash), they suffer fatal internal injuries. In many cases, the body looks outwardly unharmed to boot - or so I read somewhere.

About the second one: I think you're right there, it is a contradiction. But since a man defying gravity on a regular basis isn't any more logical than this, I decided to go with it.

The answer to the second question has more to do with the atmosphere actually. Think of how a meteor burns up in the atmosphere when it enters and it looks like a fire ball. The principle is the same thing with Superman's re-entry when Nightfall happened. It is this reason why thermo shielding is so important for space shuttles otherwise something like what happened to the Space Shuttle Columbia would occur.

Crazy Babe, I understand why he could have made a fireball coming back. They are caused by friction with air. But when he is going much faster, like when he was getting all those things for Lois, why doesn't create a fireball then? The air is denser closer to the earth. The only explanation I can think of is how his body is turned when flying, like diving through the air, whereas in Nightfall, he might have ended up in a ball or sideways.

Another possibility is that since he normally flies while conscious, he is subconsciously extending his personal field to minimize the friction through the air (so his cape won't burn.

During the fall in Nightfall, since he was unconscious, he was unable to compensate and his personal field went into survival mode - stopped at his skin - which also explains the suit burning off.

And yes, living things are much more fragile than non-living things, plus there's the matter of temperature and air pressure.

Maybe his entry angle was a factor too? When he flies fast, doesn't he angle himself to cut through the air like a dart, with hands straight out, maybe like he's diving, tiny splash? If he was unconscious, he would have been tumbling, right? wound up like a ball or a rock, big splash?

As far a vaporization, couldn't you take the density of some objects into account? say a block of iron as compared to a block of wood?

You got me thinking of the Phoenix affect in the 3rd X-men, how Wolverine's skin peeled off as he approached Jean Grey, but his adamantium skeleton remained solid against her "wind" of power.

Well, Woody, I'm not sure that Superman would make a fireball in any case, when he is either falling or flying very fast through the atmosphere. Meteorites create fireballs when they fall through the atmosphere because they heat up so much that they partly or completely vaporize. That is not something that would happen to Superman, since he is invulnerable... on the other hand, his cape should burn up every time he flies really fast.

And Superman really should create sonic booms. There is no excuse for him not to. Anything sizable moving sufficiently fast through the atmosphere will create sonic booms, and to my knowledge there is no way you can avoid it.

But like Olympe pointed out, the laws of nature as we know them simply don't allow a living being with a human's weight, size and build to fly under its own power, much less fly incredibly fast. If we accept that Superman can fly at all, and fly unbelievably fast at that, then there is no reason why we shouldn't believe that he can fly without burning up his cape or creating sonic booms. It's called suspension of disbelief, and we need it in order to enjoy all fantastic stories about what is scientifically impossible.

Ann

You're referring to ablation - where heat is dissipated by pieces falling off, and oxidation - burning up (rocks don't actually burn all that well.) BUT, you see the air compressing and getting red-hot even around things like space capsules and shuttles returning to Earth that aren't ablating or oxidizing - that's what causes ionization and radio blackout.

As to the sonic booms - sonic booms are created by the creation of air pressure building up in front of an object moving so fast the air can't get out of the way fast enough, creating a shock wave. In theory, if there was a way to prevent or minimize the shock wave as an object approaches and exceeds the speed of sound, you could prevent the sonic boom.

We need a nerd icon.

I agree with your statements that it is impossible to avoid a sonic boom, but it sure can be minimized. Some time ago I read something about planes and the wall of sound. If a plane lags barely below the speed of sound for too long, it causes the plane to vibrate and, if nothing is done to prevent it, it will be shattered. If it accelerates too slowly, the sonic boom will be very loud indeed.

So, if you accellerate extremely quickly while reaching Mach 1, the sonic boom should be minimized.

Well. I guess it depends on the dynamics behind Superman's flight.

The one fanboy science explanation I've seen suggests that Superman flies by manipulating gravitons with his mind. Down is essentialy were he want's it to be. And like Dandello suggested when he is unconscious this process stops working and his body will be subject to the gravity well and all the usual natural laws. (except that he is indestructable of course)

How that interact with atmospheric friction I don't know, perhaps he can dispel or bend it as well. Considerng the speeds he can achieve there almost must be something else