In the spirit of my favorite childhood book, and out of jealousy of all those eccentrics who get a moment in the sun as creators of yet another "theory of everything," I decided to play my trump card. Here, for your afternoon entertainment, is a theory of everything so short, it fits within a single tweet.
Dark matter and dark energy are nothing more than gravitational bleed across multiverse branes.There. You're welcome. Join me after the jump for a slightly longer explanation and instructions on mailing my Nobel Prize.
Despite the brevity and (hopefully) the humor of my intro, I'm actually serious about this. I'm posting it here because I know that the community is blessed with some genuine, actual physicists who will not hesitate to tell me—a creaky old geologist, biologist, and general soft-science guy—where I failed at basic math. Note that I absolutely expect every aspect of this idea to have already been thought of, tested, and shot down. Besides, non-physicists tossing off crazy theories is a fine American tradition.
Here's the pieces of this modest little theory in my (very) modest little mind.
The idea that our universe is just one expression of a much more complicated (and well nigh infinite) reality has been around for a long time. It's not just implicit in quantum theory, it's requisite. Each universe contains not just its own matter and energy, but it's own space and time. There's also pretty good reasons to think that fundamental properties of physics may vary between these universes.
Many different ideas have been put forward as to how these many universes are arranged. A sea of foam. Bubbles within bubbles. However they are arranged, there's the question of what bounds them. What barrier seperates one set of spaces and rules from another? One idea that has grown out of string theory (itself a quest to clean up the ugliness of the standard model) is that of membranes or just "branes." Whether a brane exists as an actual thing, or a mathematical convenience, depends on the brand of membrane theory that tickles your fancy.
Crossing the bounds
So when I say that "gravitational bleed across multiverse branes" what I'm actually saying is that gravity is capable of passing information across a brane boundary. Which is enough to get me roasted on many a physics pyre. How does this happen? I think it happens because the structure of the brane is itself distorted by the space-time structure of the matter bounded by the brane. There are theories in which the contents of a universe are little more than projections of information stored on the brane. You can think of this as just the inverse of that same idea. It's the assumption that the information on a brane is not limited to being expressed only on the inside.
Dark matter, dark energy, and the rest of us
Ok, so what's all that have to do with dark anything? Both dark matter and dark energy arise from a simple conundrum: there's more gravity around than there should be. On a small scale, gravity works just as it should (within current bounds of measurement) on a larger scale of galaxies and galactic clusters, there's both more integral gravity holding structures together and an unexpected source of gravitation pushing things apart. No visible source can be seen for this spare gravity, though it accounts for 96% of all the gravity out there. The usual assumption is that there is something in this universe (composed either of ordinary particles or something more exotic) which is impossible, or at least very difficult, to detect except for the gravity it generates. My answer is: that's because the matter generating this gravitation is not in our universe.
Instead of thinking of it as energy slipping over the border, think of it as gravitation in the Einstein space-time sense. What we experience as dark matter and dark energy are hills and valleys generated by distribution of matter on the other side of "nearby" branes. Whatever the hell nearby means in this context.
The relationship we see between normal matter and its dark siblings is mostly what you'd expect if our universe represented a more or less average example. Most normal matter exists in a surrounding fog of the dark stuff—probablistic slop generated by all those little quantum level differences. On the other hand, there's not always a great alignment between normal matter and dark stuff, suggesting that sometimes our universe is something of an outlier.
Or that this isn't a particularly good theory.
OK, real physicists, kick me in the teeth. Obviously I've spent too much time on this brane fart already, stop me before I start to show off Gaussian distribution graphs.
Now I'm off to solve the origin of consciousness.