Mad as a Hatter

Fri, 13 Apr 2012 11:30:34 GMT

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.

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Mon, 05 Mar 2012 04:16:14 GMT

Why would you need to shoot the fish if they're already in a freaking barrel?

Come to that, wouldn't that put holes in the barrel?

Actually, no. It wouldn't. Because bullets lose velocity amazingly fast when traveling through water. So the fish would probably be okay. And so would the barrel.

Also, water diffracts light, so you'd probably miss the fish, especially if you're as lazy as the expression implies.

This whole thing is like shooting fish in a barrel; it makes no sense at all.

ETA: Never mind. Mythbusters proved that the shockwave from the bullet will kill the fish even if you miss wildly. Huh.

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Fri, 05 Mar 2010 06:04:15 GMT

Just finished reading a cool book called The Warded Man. Found it in the library.

The book takes place in a world beset by demons. They arise every night from the core of the Earth. A lot of bad stuff happens to the main character, of course. To all three of them, actually. But the title character... well, it destroys any chance of him having faith. And he's talking about that to a priest, who is trying to convince him that there is a Creator and a reason for it all and a plan that could be understood if only the bigger picture could be seen.

It's not the first time I've seen a conversation like that in a book. But it brings up the same thought in me every time. Whatever I think of theology in our world, I know the truth of theirs. The priest is absolutely right. In their world, there is a higher power. There is a creator. No question. Their entire lives, their entire world... all part of a greater plan. The deaths of loved ones, the plague that rips through the town, the demons who slaughter anyone they can get their hands on, the betrayals and bandits and everything... all part of the plan. A plan that will eventually (almost) certainly bring triumph, glory, and (some measure of) happiness to the main characters. There is indeed a reason for all that pain and suffering and conflict and death.

That reason? Entertainment. For people like me who can pick the book up off the shelf and escape into it for a few hours.

Sometimes, I wish I could tell them. But it would be doing them no favors. Sort of feels like maybe I owe them something, though. And an apology isn't nearly going to cut it. Not after everything they went through.

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About last names...

Fri, 09 Oct 2009 07:21:26 GMT

Every once in a while, I wonder about last names.

There was a time, several hundred years ago, when people didn't have last names. You had a first name, and then some distinguishing fact. Maybe it was your father's name. You'd be Erik, John's son. Or maybe you were the acknowledged bastard of some local noble, in which case you'd be Brian, Fitz (bastard of) Patrick. Or maybe it would be the family business, particularly if it was a prestigious one, like Smith or Miller. Or maybe it was the place where you'd grown up - you were the Robert from the local village of Rosefield (or perhaps Rosenfeld), or you'd come from the prestigious and sophisticated city of Vienna (and thus were named "Weiner" - which is only a small part of how I got my family name, but never mind that just now).

And then something changed. Last names happened. I don't know how or why. Was it by royal decree? Was it that the king took on a last name in order to tout his lineage, which then, of course, became the noble fashion, and it spread from there? Was it just some cultural change? Something else?

Think of what it must have been like during that transition.

John, Erik's son, fathered Michael, John's son. He, in turn, fathered... Robert Johnson. Which must have been very confusing for the older generations. His name is Johnson, but he's Michael's boy?

Brian was born into a family of millers, but there wasn't really a place for him there. His older brothers did the work of maintaining the mill, and he'd never really gotten the hang of all that complex machinery (the pinnacle of power-generating technology). There was no way he could go off to some other town and build a mill of his own. But he was pretty good at working with the flour produced by the mill. So he became Brian Miller... the baker.

And what of David Rosenfeld, whose family had moved out of town a generation before, but who had himself been born and raised in Hamburg?

All these people with names that should have described something about them, but that didn't really fit. I guess it'd have helped that many others of their generation were going through the same thing... but not all of them would have. Not the ones born shortly before the change took place. Did Robert Johnson's oldest brother stay George, Michael's son? Did he become George Michaelson? Or George Johnson?

It just seems like it all would have been very weird. I wonder what it was actually like.

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Mon, 21 Sep 2009 20:37:43 GMT

Had a good weekend. Went to Cape May with Mom and Dad. Didn't sleep well (even for me), unfortunately, but otherwise it was good. Beautiful weather, charming little town, nice change of pace. Pretty tired now (even for me), though.

Did have an odd dream. Or an odd fragment of a dream:

Frodo and Bilbo were walking through the forest when suddenly Gandalf appeared. He ate the two hobbits with one cartoonish swallow each. There was a flash and a magical puff and he was instantly made moderately fat. So he changed his name to James Gandalfini.

Even odder is that I never read LotR (I took a crack at it when I was a kid, but couldn't slog through even half of the first book), never saw the movies, and never watched The Sopranos, either. This meant that the whole scene was glimpsed very vaguely, with the people involved having no distinct forms. No idea where any of it came from.

Also, random thought for those of you who don't read randomthoughts:

You know that expression "I put my pants on one leg at a time, just like everyone else"? Well you know who doesn't? Batman.^*

Also (even if they are sometimes The Wrong Trousers) Wallace.

^*The Adam West version, anyway.

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