by Jason L. Thompson

It can be argued that the type of literature which is both uniquely modern and uniquely definitive of the modern world is science fiction. Often what seems like improbable, wild speculation turns out, after scientific understanding has a chance to catch up with imagination, to be cold hard fact. In this regard, the names of Jules Verne (who predicted, amongst many other things, the invention of scuba gear, the nuclear powered submarine, neon signs, and the Eiffel tower) and Arthur C. Clarke (amongst whose predictions number the exact shape and nature of the lowest-energy traversible worm-hole and the existence of water on the Jovian moon Titan) come first to the forefront. But there are other places to look in the realm of science fiction, and comparisons with modern science can be most interesting.

Robert Heinlein stated, in his short story Elsewhen, that "Most people think of time as a track that they run on from birth to death as inexorably as a train follows its rails - they feel instinctively that time follows a straight line, the past lying behind, the future lying in front. Now I have reason to believe - to know - that time is analagous to a surface rather than a line...."

The characters in this story use this fact to travel in time in a most peculiar manner. By learning how to 'step off' the line they are on, they each find a time line that is discontinuous from that of the world in which they started. One dies and finds a world that is the Christian afterlife. Another finds a strange war on an alien world. Still another finds a home in a fairytale land.

This was not the only time Heinlein presented this picture of time. In his novel, The Number of the Beast, his protagonists invent a time machine which travels to different time lines and results in the characters' finding worlds corresponding to those of books they have read: Barsoom, Oz, Wonderland, the galaxy of the Lensmen, etc.

Heinlein believed that it was only our (that is, we humans') limited perceptions that prevented us from realizing this, that our cultural prejudices cause us to find other ways of defining "reality". He gave his fullest statement of this in his novel The Cat Who Walks Through Walls.

"The World as Myth is a subtle concept. It has sometimes been called a multiperson solipsism, despite the internal illogic of that phrase....For many centuries religion held sway as the explanation of the universe - or multiverse. The details of revealed religions differed wildly but were essentially the same: somewhere up in the sky - or down in the earth - or in a volcano - any inaccessible place - there was an old man in a nightshirt who knew everything and was all powerful and created everything and rewarded and punished...and could be bribed. The Almighty God idea came under attack because it explained nothing; it simply pushed all explanations one stage farther away. In the nineteenth century atheistic positivism started displacing the Almighty God notion in that minority of the population that bathed regularly. Atheism had a limited run as it, too, explains nothing, being merely Godism turned upside down...The physicists of the twentieth century made short work of that idea. Quantum mechanics and Schroedinger's cat tossed out the clockwork world of 1890 and replaced it with a fog of probability in which anything could happen. ...They did indeed visit the fairyland dreamed up by L. Frank Baum. And the Wonderland invented by the Reverend Mr. Dodgson to please Alice. And other places known only to fiction. Hilda discovered what none of us had noticed before because we were inside it: the World is Myth. We create it ouselves and we change it ourselves."

Heinlein's view of time is unique (or at least very uncommon). The world he pictured would look just like the physical world - the "real" world - in all respects. But, to someone who made the proper effort of perception, the world is many - the world is all the worlds that are, were, and ever would or could be. All that can be imagined (and all that can't) is true on SOME timeline. And more, these timelines of Heinlein's affect our physical world in small but important ways. But this can only be seen by those who know where to look.

Einstein's view of time is also unique. It was very different from any that had gone before (or, indeed, after - few nonscientists even now understand it). To put it in simplified layman's terminology, Einstein said that time is what we measure on clocks. In other words, time is defined by perception. Ergo, time is relative to who is doing the measuring and how they are doing it. It's different for observers in different reference frames. (It should be kept in mind here that the most basic form of a clock is a beam of light: time is marked by the passage of the peaks of its waves past a certain point in space.

This is even what is happening with that mecanical device called a clock - it is the light from the clock's hands, reaching our eyes, that tells us how the hands are moving) The other important part of Einstein's view of time was that all observers, no matter what their frame of reference, will measure the speed of light to be the same. If you are standing still you will see light travelling at 2.998*10^8 m/s. If you are traveling at 2*10^8 m/s you will still see light moving at 2.998*10^8 m/s. Its time and space that must warp and bend to allow this to occur. The idea seems most strange, but it's been experimentally verified time and again.

From these and other principles, Einstein developed the special and general theories of relativity. Just how he did this is beyond the scope of this paper, but the relevant thing is what the general theory of relativity has to say on the subject of black holes and time.

Einstein's theory of general relativity predicts that stars of a certain mass will eventually collapse down to the size of a point due to their own gravitation. When this occurs nothing, not even light, can escape their awesome gravitational pull (hence the term black hole). But Einstein's theory predicts one other interesting thing about them as well; they have another "side" to them (side here being used in a four-dimensional rather than a two-dimensional sense). Anything passing into the black hole passes through it and into a region of space and time that is completely disconnected from our space and time. Another universe.

"So what?" the observant reader will be saying about now (that is, the observant reader who knows a thing or two about black holes). "Anything passing through a black hole will be crushed completely, so there is no way these other universes can ever be observed." And that is largely true. But the physicist Kip Thorne found certain solutions to Einstein's equations that say that there are certain types of black holes that don't collapse all the way to a point but still lead to these other universes. These black holes can be formed in such a way that a human passing into one is still alive and kicking when he emerges on the other side. And vice versa. Therefore, these universes are observable under the right conditions.

Now, to appreciate all of this, a little quantum mechanics must be understood. Werner Heisenberg, who many consider to be the father of quantum mechanics, formulated what is now called the Heisenberg Uncertainty Principle. This principle states that no energy measurement can ever be known exactly. There must always be a certain rigidly defined amount of uncertainty in every measurement. But zero is an exact number and therefore disallowed by Heisenberg. This means that even when observing empty space, no possible energy state can be seen to be zero. This means that all of space is filled with "vacuum fluctuations", virtual particles popping in and out of existence continuously. There are an infinite number of such particles covering the range of all possible energies (from zero to infinitely energetic). The reason we don't notice this in day to day life is that it is the same in every direction. A push to the left is cancelled by a push to the right and so forth. It is only energy differences that we notice, things that are sort of "on top" of this sea of infinite energy. The existence of this sea of energy, this quantum foam, was experimentally confirmed first by Sparnaay and then later by Lamoreaux, following Casimir's suggestion.

This gives an interesting picture of space, all space, even empty space. Look at it at a small, microscopic level, and you find it to be full of particles of energy that are as large as the space you are looking at and, over time, that tend to cancel each other's effects out. This region of space is also full of smaller, more energetic particles, but these cannot be directly observed easily. The smaller the particles, the more energetic they are, the quicker their actions cancel each other out. Look at an ever smaller region of space and these smaller energetic particles become easier to see, the cancelling action taking longer for a smaller scale. All the structure of space, time, and matter we observe at our scale of the universe are built up out of this infinite sea of energy. Our world is, in effect, the small differences in these energies that didn't quite cancel out all added up.

The important point here is that all possible energy states must be occupied at all times. That means that there are particles that are so energetic that they form miniature black holes. Since Thorne-type black holes allow for signals to pass from another universe into this one, every possible Thorne-type black hole must exist in the quantum foam, for each possible universe must send a different signal, for the energy states of any two universes must be different (Heisenberg again). Keep in mind that these signals need be nothing other than energy leakage from one side to the other.

The upshot of all this is best expressed in the following sorites:

1. Every Thorne-type black hole connects to a universe separate from this one. No one universe may have exactly the same energy state as any other, as this would be an exact determination of energy in violation of Heisenberg's principle. Therefore every Thorne-type black hole leads to a different universe (a universe with a different energy state).

2. All possible states of energy must be occupied at all points in space and time. Every Thorne-type black hole is connected to, and therefore has, a different state of energy. Therefore every possible Thorne-type black hole state is occupied (every possible Thorne-type black hole exists) at all points in space and time. Therefore:

3. Every possible Thorne-type black hole state is occupied. Every possible Thorne-type black hole leads to a different universe. Therefore every energy state that corresponds to a Thorne-type black hole leading to a different universe is occupied (every possible universe exists).

And lastly -

4. Heinlein's view of the world is based on the existence of all possible universes.

All possible universes exist.

Therefore Heinlein's view of the world is correct.

So C.S. Lewis' wardrobe really did lead to Narnia. Never-never Land is past the first star on the left and straight on till morning. But it must be kept in mind that the chance of a macroscopic observer (such as a person) observing any one particular universe in the quantum foam is so low as to be practically indistinguishable from zero. It's so small that the odds of someone winning the lottery every week for a year seem quite good by comparison.

But there are an infinite number of other universes. And any finite number multiplied an infinite number of times is itself infinite. So these other universes do exert an influence on our world. Why then is this not observable in day to day life? Well, because there are an infinite number of infinitely varied universes, they must be mostly self cancelling in effect. For every effect coming out of one, there has to be the cancelling effect coming out of another. But there is nothing to say that there are not local imbalances, where the cancelling effects are only observable over a larger area. In fact, certain scientific principles demand it. So how large an effect these other universes have on ours is impossible to say. Perhaps quite a large, but subtle one. Perhaps an inobservable one.

So maybe Heinlein's idea of traveling to these places is a dream that could not be realized for a long time to come, if ever. But the philosophical implications of the World as Myth are quite interesting. Does it not imply that every religion that ever was is, in its own way, true? Does it not imply that we are not alone? Does it not imply that there is far more to reality than what is readily apparent?