The Width of Narnia

As is revealed in Voyage of the Dawn Treader, the world of Narnia is a flat earth.  Characters can literally fall of the edge of the world.

I started wondering, at one point, how thick is that edge?

Characters from our world report no differences in the gravity (or whatever) on Narnia; they don't feel any greater or lesser weight walking around.  Arguably, if Narnia had a lower gravity, then the Pevensies might have had, at least, an easier time crossing through the snow.  And contrariwise, if Narnia had a much higher gravity, then the adventure would have mostly been about aching knee joints.

Further, when the Pevensies stay in Narnia as kings and queens, they eat the food there, and this does not make them sick.  The food they eat they report as tasting equivalent to earth food.  When they grow up, they marry dryads and naiads and other mythological things and have children.  Weird as this is, it all proves pretty much conclusively that Narnia is made of the same kind of "stuff" as Earth; this is important.

So we know three things.  We know Narnia has the same overall downward-pulling force as Earth's gravity, we know that Narnia is made of the same kind of stuff as Earth, and we know that Narnia is a flat earth with a literal edge that you could fall off.

This is enough to calculate, to a very good approximation, how thick Narnia is.

No, I Don't Like BBC's Sherlock

I get asked this maybe once a week, on a good week.  On a bad week, more.  I think so far, every person that I know has asked me at least twice.  I think friends from middle school that I haven't spoken to for over a decade have called me -- looked up my number and called me -- to ask if I like BBC's Sherlock. Then they hung up and called again to ask a second time.

The answer is no, I don't like it.

The Literature Review Process, or So I Understand It

I'm in the bookstore, and a book catches my eye.  More often than I'd like to admit, it's because it has a pretty cover illustration, or a very respectable binding.   Or maybe it was misplaced on the shelf by a previous browser, or maybe it had a special display rack for itself.

Anyway, somehow, by some means, I've got the book in my hand, and I want to know: should I bother reading this?

Of course, I can't trust the reviews on the back of the book.

Time Travel is Creepy

The other day, an idea dawned on me.  It took several hours before the full weight of it began to sink in.  It's an idea that has enjoyed constant employment by the human imagination, so much so that the terror of it has been weakened from banality.  When I was forced to take it out of fantasy books and in to reality, I wasn't so sure I liked it.

It occurred to me, that it might be possible to make a device that causes light to travel in closed causal curves.  As in, I could do some calculations and tell you how to make it and someone with a nanolab could build it in a year or so. This would allow communication with the future through radio waves; you broadcast them in to the machine and into the future, the future responds by broadcasting into the past.

Vectors are Not 1-Forms

So, I recently moved in to a new research area.  It's new to my advisor, too.  Actually, generally speaking, it's pretty new period, first appearing some ten years ago or less.  Anyway, this new field deals fairly heavily with Maxwell's Equations in curved spacetime, so to understand it we are needing to review differential geometry and general relativity, two fields which are not in the normal purview of my advisor's expertise.  I was asked to prepare a chalk-talk that would introduce the key concepts of differential geometry to them, and another talk to segue in to Maxwells Equations in curved spacetime.

Not like I'm an expert on differential geometry, but I've studied it some privately and as an undergraduate.

While studying for this, it dawned on me suddenly, like the storm clouds that pile higher and higher until the first bolt of lightning strikes the ground, that vectors and 1-forms are different.

Every thing I have ever read in physics equates them.  Or not really.  Everything I have ever read in physics doesn't even demonstrate that it understands why those two should occupy different semantic domains.

What the heck am I even talking about?

Happy Nice Guy Schadenfreude Day!

The title is actually all I wanted to say :P

Kingkiller Chronicles Speculation: Why Can't Kvothe Do Magic?

There's a certain type of book series that offers the reader the chance to be a detective; the entire world of the series is a mystery whose origins lie shrouded in a mist of narrative, yet enough light pierces that veil to allow the attentive reader to glimpse the nature of things.

The Kingkiller Chronicles is just such a series, perhaps the best such series.  It is written by a very talented writer, and it is already finished; every twist in the plot is already written in a manuscript, and Rothfuss is largely just fixing diction at this point (which is still taking him agonizingly long).  Further, the future of the series is already known; we know the end of the story, where Kvothe becomes the humble innkeeper of Nevarre and the world is torn apart by demon spiders, and we know that the rest of the story is going to explain how all of this happened.

So, as I have done in the past, I would like to take a moment to wildly speculate about the series.

There are, of course, SPOILERS.  Please do not read this until you have read the first two books, and thoroughly.  Try to piece things together for yourself, or you're missing half the fun of the series.