I invite you to do a little thought experiment with me, and you’ll need a prop to help you along. Get yourself a sheet of paper. Draw an X toward one end and another X toward the other end. It should look something like this:
I want you to imagine that the surface of this sheet of paper is a miniature world, with living creatures that are completely flat. I mean completely flat, only visible from above. In this case, you can think of yourself as a very advanced being, like a god, and you can see what’s going on in the world of the sheet of paper.
Of course, these flat creatures are capable of motion. Suppose a group of them wish to move from the X at one end of the paper to the X at the other end. The shortest route would be distance d1, as indicated in the image.
Now, bend the sheet of paper as shown in this image. While the distance between the Xs is still the same for the flat creatures on the paper, you’ve created a new path between the two that is shorter. What you have done is created a 3-dimensional curve in 2-dimensional space. The flatlings, unless they are sufficiently advanced, will have no idea.
You may not be able to visualize this (and I don’t encourage you to try), but there are more than three dimensions to the space we live in. You’ve heard of time being the 4th dimension, and in many physics applications this is held to be true. Physicists currently believe there are ten or eleven dimensions, maybe even 26. Like I said, don’t try to visualize it. If you’re inclined to examine the science behind the multi-dimensional model of the universe, click here; otherwise, let’s continue.
That shortcut created by the folding of space is called a wormhole. A wormhole is a theoretical construct in which two points in space separated by distance d1 also have a more “direct” route, distance d2; wormholes are usually envisioned being similar to a tunnel. Such a thing would not be possible in space with only three dimensions. You can consider 3D space to be a surface, with the higher dimensions making up a volume. We can again illustrate this with a simplified example.
The cylindrical container has a surface area and an internal volume. Flatlings are free to move around the surface of the container. On a curved surface, the shortest distance between two points is called a geodesic. It’s the path of least curvature, meaning it has the same curvature as the space it exists on. But when you allow paths that exist in the next higher dimension, you have paths that are even shorter; they have much less curvature.
Theoretically, wormholes appear on the quantum level (translation: VERY small) all the time, but then collapse tiny fractions of a second later. But a traversable wormhole would be one that is large enough, and lasts long enough, to allow macroscopic bodies (translation: people, equipment and spaceships)to pass into one end and out the other. We lack the technology to find traversable wormholes, or any wormholes at all, and we don’t have the means to create them ourselves. Some kind of matter, an exotic kind that we haven’t discovered yet, could be the key to holding a wormhole open and keeping it stable.
Now, if such a thing were possible, then all those cool things you see in sci-fi, populating the galaxy, visiting neighboring galaxies, cosmic commerce–they could all become reality. Don’t count on it happening in your lifetime, either way, though.
But the wormhole could answer another question in physics, and it’s a doozy. That question is: what is action at a distance? Action at a distance, basically, is the ability of one body to influence the motion of another body without being in contact with it. In physics, it has to do with the behavior of subatomic particles. A phenomenon called entanglement causes that very thing to happen, and happen a lot. In fact, nearly all matter is entangled. I’ll give you a basic example.
Suppose you have a single, solitary atom of helium. Now, you don’t find a whole lot of ionic helium in nature, so you’ll be looking at a nucleus with two protons and two neutrons. Two electrons will be in orbit about this nucleus. Electrons, like all subatomic particles, have a property called spin. It’s not a spin in the classical sense; it doesn’t refer to any rotational behavior of the particle. Read about it if you want, as it is a pretty important process (for example, it’s the secret of the success behind MRI scanning, and it’s the theoretical mechanism behind Hawking radiation) but you don’t need to know any more about it for the purposes of this article. Because of a rule in quantum physics called the Pauli exclusion principle, the electrons in orbit about the helium atom’s nucleus cannot have the same spin; one will have to be spin-up while the other is spin-down. Helium is not an easy element to ionize, so you’d need to apply a great deal of energy into the atom to shake the electrons loose. But once you do, that’s when entanglement shows itself: the electrons each somehow “know” what its counterpart is doing. If you put enough energy into the spin-down electron to make it become spin-up, the spin-up electron will instantaneously give off that same amount of energy and become spin-down. It will happen instantaneously no matter how far apart the electrons become, even if they wind up on opposite sides of the universe. That, my friends, is action at a distance.
Einstein himself was alarmed by this phenomenon and denounced it, but there is plenty of evidence that it occurs. The thing that really kicks physicists in the ass, though, is that the change in spin is something that takes place instantaneously. That shouldn’t be possible, since the information traveling from electron A to electron B should not be able to propagate faster than the speed of light, which is pretty fast; it’s not fast enough to allow for an instantaneous change, especially when the electrons get to be very far apart. Something has to give though, and if it’s not speed, it’s distance. And if distance is what has to give–I think you know where this is going, it’s possible that entanglement IS a wormhole. If that’s true, then the universe is overrun with wormholes, like a telephone network that is far larger than any of us can comprehend.
If we lived in a reality with only three spatial dimensions (height, width and depth) none of this would be possible, and by that I mean literally none of this would be possible: there would be no reality at all, no way for matter or energy to exist. In the three dimensions we are aware of, the universe is an expanding sphere. In higher dimensions, it could be shaped entirely differently from a sphere. It could be a doughnut, a saddle, or something we can’t even imagine, but in an case, we’re talking about geometries that allow points in space to become close together that would never do that in three-dimensional space. There’s even the possibility that the space itself in higher dimensional space is in motion. But whatever the case may be, entanglement and wormholes being one and the same is an idea worth serious consideration.
Spooky, isn’t it?