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Woke up this morning thinking about gravity. It happens.
In particular, I was thinking about the "rubber sheet" model of gravity. The idea is that what gravity really is is a bending of space-time. Imagine a stretched-out rubber sheet. Like, say, a trampoline. Let's say that trampoline represents the universe. Or, rather, the two-dimensional surface at the top of the trampoline represents the universe.
Now, what happens when you put a weight somewhere on the trampoline? Gently, mind you. I'm not talking about bouncing it up and down. You put a weight down slowly, and the trampoline sags under it. Any other object on the trampoline's surface will naturally begin to slide towards it. And the closer you are to the weight and the heaver it is, the more the other object will be drawn in that direction.
That's what gravity is like. Mass bends space-time. The more mass there is, the greater the effect. And the closer you are, the more you feel it.
The thing is that the effect goes on infinitely in all directions. It drops off exponentially with distance, but it's still mathematically there. The same thing happens with, say, a lightbulb. The amount of light you see from it drops off exponentially the further you get from it, but the light rays go out from it infinitely in all directions. Even if you get far enough that it's too dim for your eyes to see, more sensitive equipment can still theoretically pick it up.
All of which is pretty cool because, among other things, it means that you, just by existing, are bending space and time around you in a way which can be felt across the entire universe. And every time you move, you're changing the curvature of the universe.
But it also means that if you know the exact shape of the gravitational field at a given point, down to the nth derivative, you can theoretically extrapolate from that the shape of the entire universe. Which means you'd know the mass and location of every object in existence. By studying exactly what's right here (wherever your "here" may happen to be), you can know where everything in the universe is.
The same goes for magnetic fields. They extend infinitely across the universe, so if you the exact shape of the magnetic field where you are, you could figure out where everything with any kind of electromagnetic charge is.
So, if you were looking for a specific distant object with a magnetic field and you could either know everything about that object's magnetic properties or know everything about the field where you are, you'd be better off with the latter. There are all sorts of electromagnetic fields coming from every direction. Knowing what you're looking for won't help so much because the effects would be miniscule. More importantly, you'd be getting interference from everything else. But if you know the field where you are, you can extrapolate from that where everything is.
I was thinking about that, and I suddenly realized something.
In Robert Jordan's Wheel of Time series, someone with the proper knowledge and sufficient magical power can Travel, opening up a Gateway from one place to another. The thing is that to do it you have to truly, deeply know the place where you are. Not where you're going. Where you're leaving from. You have to really study it. It can take days.
It always seemed like an odd magical quirk. A whim of the writer. But today it clicked for me. It's true. When you're dealing with the fabric of the universe, it really can be more important to know everything about where you are.
ETA: "Every time you move, you are changing the curvature of the universe." This might explain why it's so hard to get out of bed in the morning.
In particular, I was thinking about the "rubber sheet" model of gravity. The idea is that what gravity really is is a bending of space-time. Imagine a stretched-out rubber sheet. Like, say, a trampoline. Let's say that trampoline represents the universe. Or, rather, the two-dimensional surface at the top of the trampoline represents the universe.
Now, what happens when you put a weight somewhere on the trampoline? Gently, mind you. I'm not talking about bouncing it up and down. You put a weight down slowly, and the trampoline sags under it. Any other object on the trampoline's surface will naturally begin to slide towards it. And the closer you are to the weight and the heaver it is, the more the other object will be drawn in that direction.
That's what gravity is like. Mass bends space-time. The more mass there is, the greater the effect. And the closer you are, the more you feel it.
The thing is that the effect goes on infinitely in all directions. It drops off exponentially with distance, but it's still mathematically there. The same thing happens with, say, a lightbulb. The amount of light you see from it drops off exponentially the further you get from it, but the light rays go out from it infinitely in all directions. Even if you get far enough that it's too dim for your eyes to see, more sensitive equipment can still theoretically pick it up.
All of which is pretty cool because, among other things, it means that you, just by existing, are bending space and time around you in a way which can be felt across the entire universe. And every time you move, you're changing the curvature of the universe.
But it also means that if you know the exact shape of the gravitational field at a given point, down to the nth derivative, you can theoretically extrapolate from that the shape of the entire universe. Which means you'd know the mass and location of every object in existence. By studying exactly what's right here (wherever your "here" may happen to be), you can know where everything in the universe is.
The same goes for magnetic fields. They extend infinitely across the universe, so if you the exact shape of the magnetic field where you are, you could figure out where everything with any kind of electromagnetic charge is.
So, if you were looking for a specific distant object with a magnetic field and you could either know everything about that object's magnetic properties or know everything about the field where you are, you'd be better off with the latter. There are all sorts of electromagnetic fields coming from every direction. Knowing what you're looking for won't help so much because the effects would be miniscule. More importantly, you'd be getting interference from everything else. But if you know the field where you are, you can extrapolate from that where everything is.
I was thinking about that, and I suddenly realized something.
In Robert Jordan's Wheel of Time series, someone with the proper knowledge and sufficient magical power can Travel, opening up a Gateway from one place to another. The thing is that to do it you have to truly, deeply know the place where you are. Not where you're going. Where you're leaving from. You have to really study it. It can take days.
It always seemed like an odd magical quirk. A whim of the writer. But today it clicked for me. It's true. When you're dealing with the fabric of the universe, it really can be more important to know everything about where you are.
ETA: "Every time you move, you are changing the curvature of the universe." This might explain why it's so hard to get out of bed in the morning.
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That said, this is an interesting post. I've always appreciated books where the magic wasn't easy, where there was thought about the costs and the learning and the longer-term effects. I haven't read the Jordan books, but I like them better for reading this.
But it's okay to get out of the bed in the morning, and even okay of you step on that butterfly (in a cosmic sense). The future will be what it will be, but fear of motion generally works to make the future less interesting.
End my 0.02
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Jordan puts thought into everything. His world is vast and complex. Actually, the major criticisms I've seen of his work is that it's too much so. The series is comprised of over a dozen tomes (currently totaling just over 11,000 pages) with more characters and history than it's humanly possible to keep track of unaided. There's a whole wiki dedicated to trying to keep it all straight.
(I should perhaps mention that much of the background is a patchwork of snippets from existing mythologies. At first, I considered that lazy. Later, I came to appreciate the skill, knowledge, and thought it takes to combine all of that into a sensible whole. I still find it less impressive than, say, China Meiville's whole cloth, but I don't see it as the weakness I first did.)
That said, the magic system isn't quite as well-defined as this post may have implied. Traveling is introduced, and it's explained that the approach to it is different for men and women. It's explained that forming a Gateway requires intimate knowledge of the origin point, but after it's introduced that limitation doesn't come up very often. The people using them tend to stick to places they know well, at first. Although it's never explicitly stated, it seems that with experience you learn to know a place more quickly and/or need to know less in order to form the proper weaves.
But that's part of the progression of the books, which, on the surface, follow a very familiar pattern: Young farmboy from a small town in the middle of nowhere develops into the long-prophecied hero who will stand up to ultimate evil. There's a lot more to the story than that, and, as much as anything, it's about how the story is told. This is a story which continuously widens in scale and complexity. As the main characters go from rural children to living legends, Traveling goes from a lost art from the Age of Legends to something almost commonplace.
The magic system is defined. Its limits and abilities matter. Each thing it can or cannot do is discussed. There are big revelations along the way. But all of that is a small part of a very big story. Part of the background. The way the world is.
Am I making sense? The costs and the learning are part of it, but perhaps not as big a part as this post, which focuses on one small detail, might make it seem. Just wanted to make sure I wasn't giving you a false impression.
As for getting out of bed in the morning... that was something of a joke. I've got a pile of sleeping disorders. It's always hard for me to get up. I've woken up feeling refreshed only once that I can remember, and that was when I'd accidentally overdosed on my nighttime medications - something which greatly backfired later in the day. So it's fun to make the excuse that in getting up and moving, I'm actually changing the curvature of the entire universe. The Earth is pulling me towards its center. At the same time, I'm exerting an equal and opposite force, pulling the entire planet towards me. No wonder I'm so tired.
It's not that I'm afraid to move or to step on metaphorical butterflies. I want to change the world. What's the point of a life that doesn't?