Inertia: What is Thine Origin?

God I am such a geek, but this sort of thing is so FUN. I am not an expert at this, and I’m not claiming it’s truth, untruth, real, imagined (well, imagined, ok), or anything. Just looking for a conversation with anyone who gives a rat’s patooty. If you want to respond to this, I’d LOVE to hear from you, but keep it fun.

What is inertia? No, I know the classical party line… object at rest stays at rest, object in motion stays in motion. But WHY?

Hence, the gedankenexperiment.

Imagine you are the Omnipotent Universal Quantum Cowboy (riding the free spectral range… ok, bad joke). You zip into normal space-time and fire a bullet at an errant lawbreaking apple, which has started to fall from a tree, when you clearly told it to ignore that a-hole Newton’s silly laws. You’re the new sheriff in town and they’re your laws, dammit.

You fire the bullet, zip back into Omnipotent Universal Quantum Cowboy frame (hereinafter OUQC) and you observe said bullet as it traces it’s path towards the no-account apple. Halfway through the bullet’s transit you decide to mix things up a bit, so you stop time <zap>. Pause, and admire yourself in the saloon window…

You walk… errr… you mosey up to the normally 1000 fps bullet, reach out with your immaculately white OUQC gloves, and EXACTLY turn that bullet around 180 degrees. You go back to your OUQC frame, tip back your immaculately white OUQC hat, have a smoke - so a few galaxies burn out sooner, so what? Then you start time again <zap> (having timed it so that time starts when the butt hits the ground - gotta look cool ’cause someone could be filming this).

Which way does the bullet go? Does it kill that mongrel dog of an apple? Is inertia a vector or a scalar? Obviously it acts like a vector as it moves in a certain direction in the meatspace frame (that of the entities who are not OUQC’s), that is, the one in which the impulse was initially given. Is inertia bound up in the matter comprising the bullet itself, or is it a feature of space-time which is curved around the bullet?

As far as I have been able to tell, people either fall back on Laws of Motion and sit out the dance there, or, they go so far as to admit that there must exist some balancing yet unknown force (see http://www.geocities.com/physics_world/gr/inertial_force.htm) It is enough to drive me batty.

But wait… I just now found this, a short blurb by Einstein which supports where I was going with thoughts (the unformed thought in my head stuff)…

Albert Einstein -That the relation of gravity to inertia was the motivation for general relativity is expressed in an article Einstein wrote which appeared in the February 17, 1921 issue of Nature [28]

Can gravitation and inertia be identical? This question leads directly to the General Theory of Relativity. Is it not possible for me to regard the earth as free from rotation, if I conceive of the centrifugal force, which acts on all bodies at rest relatively to the earth, as being a “real” gravitational field of gravitation, or part of such a field? If this idea can be carried out, then we shall have proved in very truth the identity of gravitation and inertia. For the same property which is regarded as inertia from the point of view of a system not taking part of the rotation can be interpreted as gravitation when considered with respect to a system that shares this rotation. According to Newton, this interpretation is impossible, because in Newton’s theory there is no “real” field of the “Coriolis-field” type. But perhaps Newton’s law of field could be replaced by another that fits in with the field which holds with respect to a “rotating” system of co-ordinates? My conviction of the identity of inertial and gravitational mass aroused within me the feeling of absolute confidence in the correctness of this interpretation.

Frankly, I want to believe that the model is broken or at least could use a bit of sprucing up, and does not accept additional dimensions required to explain it. Oh, such hubris! Vanity, get thee behind me.

It’s like… “Well, we essentially are gonna say that inertia and gravity are kind of linked mind you.”

Ok. Nice. But how does something know to move in a certain direction? Suppose it comes near a massive object - a gravity well certainly acts upon it - damned outside forces! Could an object want to move in a certain direction due to the direction of the curvature of the space that it creates by being something of mass and it’s velocity, which relativistically does increase? (think: riding a wave) If I went to the edge of the Universe and stood at the edge of the Abyss (while my tired and obviously not-omnipotent-class-equine-material steed keels over), and fired a bullet, what happens to the bullet? Does it now go just so far and then slow down? If one supposes that space-time and curvature of spaces is really just a construct that works in the presence of many bodies of mass, then it could be said that the universe is self-regulating.

Hopefully I’ll see some responses from people who enjoy this sort of thing and not from those who enjoy making fun of others in order to pump up their ego. If you know the answers just shout them right out!