all you explained about the imaginary number is how it is used. What you haven't eplained is how it does it. -4 squared is 16. the Square root of -16 is an undefined concept. So they throw in this imaginary number because there is no real number that can perform the task. You can also use the absolute value of negative 16, the square root of which is 4. Which, if you were calculating the field strength of an electrical or magnetic field when you imput negative sixteen units and you want to know how the force changes, in accordance with inverse square you use the absolute value of negative sixteen to avoid the mucking about in imaginary numbers. Sort of how change in velocity is always a positive number, making the term deceleration archaic and meaninless, like centrifugal force. Though I recently read an blog by astronomer Phil Plait defending his use of cetrifugal force. Of course centrifugal force is innertia attempting to carry a mass in a strait line, and the centripital force is acting on a spiining opbject forcing it to move along a curved path which can be calculated as acceleration because that is what any change in inertai is. Inertia is a property of matter and not a force, like hardness and color. But what you call it doesn't really effect how you aim a telescope at it, so to an astronomer it doesn't matter. No pun intended.
Where was I? Blah blah blah, there is no god, yadda yadda yadda. Right Gravitons! This is another partical of dubious veracity. See, our understanding of gravity comes from Einstein's general theory or reletivity. Simpler then it seems, but more counter intuitive then you would expect. However there are no particals or waves in the general theory of relativity. The speed of light is absolute, and every thing else changes to keep it the same. Light is an information carrier you see, so until the light gets there it hasn't happened yet but relativity addresses how observers comparing notes after the fact could descrieb the same event as occuring differently.
Now here's the problem with gravitons and gravity. The quantum world functions in probabilistic terms. This is called "Uncertainty." Now the strong force, which uses gluons, If I'm rebering it right, and the electromagentic force uses photons to transmit the information about the force. But gravity is the weekest force, while the other three are nearly equall. Gravity isn't a little bit weeker, like half as strong, or a tenth as strong, or a one hundreth or even a one thousandth. Gravity is Quintillions of times weeker then the electromagnetic force. That looks a little like 1,000,000,000,000,000,000. English call that number something different because they have thousand millions, but you get the idea. Gravity is so week in fact that it would never overcome its own uncertainty under the "Standard Model". I use qoutes to point out that that is the Name of the model, and not to imply that it is unworthy. Anyways, quantum physics, which explains how your cell phone works, the computer your reading this onfunctions, and infact couldn't have been built without the knowledge that came from this very theoretical back ground. This lynch pin of modern technology predicts that THERE IS NO GRAVITY! Or that there could be gravity but it would never be able to amount to anything, certainly not stars and galaxies, and clusters of galaxies. The priciple of uncertainty means that gravitons would be so week and pitiful that they would be unable to affect matter in any noticable way. At that level it can't and is often discounted all together.
But it can't be helped that the two great achievements of 20th century physics are in contraditon with one another. Oh yah, the quantum entanglemnt which is where tacheons come from is the result of information passing between two particals instantaniously at any distance. Since Relativity is built on nothing traveling faster then light, Relativity has a problem. You've heard about tacheons because sci-fi writers are always trying to go faster then light, so it seems to be made to order. But tacheons are only virtual particals that only affect the universe under specific conditions, so not really useful. Being a virtual partical it has no mass and no energy. And apparently no velocity as well. Not much of a partical. At least virtual photons have velocity.
They don't talk abouth these things not because they think no one will understand, they don't talk about it because NO ONE UNDERSTANDS. The universe does appear to work, and contradiction seems to be a problem only to us. The universe seems to have discovered double think long before George Orwell put it into his novel 1984.
So like the imaginary number there are some concepts that it doesn't matter how old you are. So saying some one doesn't understand because they are too young is just a smoke screen.
Also, there is no God.
(a statement that makes a prediction about the universe that can be refuted by example. No examples being forthcomming I shall accept the statement as provisionally true. This means the statement is scientific in its nature and can be included in science class rooms, while Intelligent design can't.)