I'm going to side with Narsrim, but you can't simply dismiss the nitroDragon explanation that easily. You seem to be taking it one process at a time, and showing how nitrogen base won't work, when in fact a lifeform based on nitrogen would have an entirely different evolutionary path, rendering it too different to really compare to our organic lifeforms in any way.

Why do you think all forms of known life is organic (carbon based)? Was it chance? Not hardly, it has to do primarily with the chemical nature of carbon... and everything stems for it. Talk to any organic/biochemist and ask them if this nitro-dragon (or even a single celled nitrogen based creature) would even be possible. They are going to tell you it just doesn't work that way. Hell, I want to see someone come up with a feasible theory for a singled celled nitrogen based creature let alone a dragon.

I like my proof.

Dragons aren't real, they're magical - imaginary.

Therefore science can't adequetly explain why they do what they do.

Therefore trying to is an exercise in futility.

In sum, I win.

Natural napalm makes the most sense.

The hydrogen theory was selected by all the biologists because it also helps explain the flight issue. By having a huge hydrogen bladder, it helps keep them aloft as well as breathe fire.

Sciene cannot fully explain gravity either. In fact, if you study quantum physics and delve deep into the scientific world, you will learn that the "law of gravity" actually has less support than many other disputed ordeals such as the theory of evolution. However, does that make it futile to explore it scientifically?

Of course not.

But just by dropping something you can see that gravity exists.

Can you show that fire breathing, flying dragons actually exist? Can you get a dragon and point at it and say "Here's a dragon" and then have that dragon actually eat someone after roasting them from the air?

I thought not.

So what about a silicon based lifeform? I'd think that would make a bit more sense than a nitrogen base. Though I'm still not ruling that out completely until you prove that nitrogen can't possibly, in any world with our physical laws, support life.

Trolls how are a silicon based lifeform slow down the hotter they get, thus they appear really stupid to people who see them away from thier very cold caves.

Go Terry Pratchett! That's science at its best, explaining how dragons fly, and where did all those fossils come from.

Ummmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm. Where's your evidence?

You can prove something exists, but you can never prove something does not exist.

We don't know if dragons existed or not, but there has to be a little evidance to support their existance, if it was later made to scare little village boys. Honestly, I believe they do exist. Just look at the Dracnari, Lord Draconis was known as the dragon god and his childern are lizards (not dragons)

Notice that this thread has been placed in "The Real World" category.

I know that, i'm using an example from Lusternia. I will speak in easier terms for you. Perhaps Dragons changed from the thousands of years, and became animals like the Komato Dragon

edit: Or better yet, the Komato Dragons are the great great grand childern of orginal dragons. I don't know!

That's Komodo Dragons, and Shiro, you are making yourself look like a fool.







Again.

Bah, so I spelt the first name wrong... and I am not!!

I will now show one way that a nitrogen based creature might be able to work (Warning: long ).

As the reader may or may not know, nitrogen has 5 valence electrons, meaning that any large nitrogen-based compound would end up being a chain, such as H-N-N-N-N-N-N-H, or some such thing, with other compounds branching off. This would mean that the bonding between strands occurs when the ends of other strands attack to points midway through the original strand. With combinations of strands in this way, simple yet sturdy membranes could be created that are, while strongly interconnected, also permeable to allow for osmosis. This creates the basic structure of the dragon, the skin and tissue. Now, the inflow of nitrogen comes from two sources: nitrogen fixation in the lungs or similar organs, and digestion of proteins. Both would be high, because around 80% of the atmosphere is nitrogen, and also because dragons are almost always shown as carnivorous, so this can be seen as an explanation of that, too.

Moving on, we can see that the dragon would need a form of respiration. How this works is that the dragon breathes in air, with its mix of nitrogen, oxygen, hydrogen, carbon dioxide, and other things. The nitrogen, I have already said, is fixated through either specially adapted enzymes or through bacteria which live in symbiosis with the dragon. This nitrogen is attached to the structure that is the dragon, by either turning it into a protein or by attaching it to some other parts of the system. Also, other things, mainly oxygen and hydrogen, could be taken in by various respiratory organs. Carbon that had previously been ingested could then be expelled in whichever form, perhaps in small carbon rings, perhaps as floating hydrocarbons, whichever type, though, it would be sure to burn easily, because of the nature of carbon and combustion reactions.

Now, to the digestion. Proteins are naturally found in the meat of other animals, and these could be broken down into smaller parts and then reassembled to provide the chemical workings of the dragon. Carbohydrates in the animals could be split through the removal of outer elements, due to stronger nuclear forces in nitrogen than in carbon. The excess carbon rings could, as was previously said, be expelled in the breathing of the dragon. Fats in the animals could also be stripped of their excess hydrogen and oxygen, but the remaining carbon chains would most likely be removed in the excrement of the dragon, which while it may seem like a cheap explanation, does however match with the common description of dragon excrement. Just as clarification, what happens is that the bond between the carbon and the (for instance) hydrogen is broken, and the energy is used to bond the hydrogen to a nitrogen, with the excess energy perhaps bonding an oxygen too, to make NOH, like O=N-H with a covalent N to O bond and an ionic N to H bond. This is for now the specified energy carrier, similar in function to ATP(that's right, isn't it?).

Moving on some more, we look at the circulatory system. Now here's where a special convention could appear; the dragon does not use liquids to circulate, instead it uses gases. So, there are these complex gas molecules that various other molecules can attach to. This is one of the main reasons that the dragon can fly. Also there is the reason that the webbed/membrane style of tissue is much lighter than the heavily compacted cellular style of carbon-based lifeforms. Anyways, the smaller gasses are able to pass through smaller holes in the membranes, while larger ones stay to make up the mainstream. This is how the spread of nutrients and the like is managed: by selective osmosis. Only the right type of gas molecules are able to osmosize(?) through certain membranes.

Where do these nutrients go? They go to the organs. First there is the heart, which is similar to a normal heart, in that it pushes circulation through the use of ventricles. Next there is the brain, which I don't know how it works, because that's just too complex (scientists are mostly at a loss as to how are brains work too, so it's not just me). Also there is the kidney-type organs, which draw out of the system anything that doesn't belong.

Then there are the muscles. Muscles are tricky, because they normally work through contraction. Dragon muscles work through a similar system, but they involve a complex bunching of nitrogen strings, which when released in the correct way, spring in a certain way to create motion. I would detail it but it is difficult without visual aids. Anyways, this is part of why many large dragons of yore spent most of their time without moving: many muscular movement requires that they be rebonded before being repeated, however, this system also allows very sudden bursts of rapid action, which would greatly aid the dragon as a predator.

The nervous system is also somewhat similar, in that it is a result of complex pullings and realeasing of string tensions that cause things to happen. This, however, means that dragons could never really advance in intelligence very fast, which is a fact that often led to their demise when they were being hunted by humans, who are much faster at learning and adapting. Lastly, the dragon's immune system is simple enough: it employs complex proteins that attack and disseminate invaders. Besides, most bacteria and viruses are designed for attack on the classis carbon-based creature, and there would not be enough dragons in the world to facilitate the evolution of a dragon-targeting disease, so that part really isn't important. Anyways, there it is!
(Note that any of these ideas could be inconsistent or impossible, but also note that they are only each one of many possibilities. This is merely to be a demonstration of how a dragon could be.)