The Nature of Time as the Fourth Dimension

In another Helium article on a similar topic, I described personal experiences with multiple mathematical dimensions. But that article didn’t offer any thoughts or opinions about the subject itself. So here goes!

There’s no single answer to the question “What is the 4th dimension?” or “What is the 5th?” In fact, there is no “THE” fourth dimension.

That’s because “dimensions” depend on what you’re studying. Take our visible universe. We think it’s three dimensional because we need three numbers to uniquely identify any location in it: (1) How far a point is to our left or right, (2) How far in front or behind us, and (3) How far above or below. And if we also want to identify how objects move and when events occur, then we get into the whole 4D thing, with “time” as “The Fourth Dimension.”

But not so fast there! If we only really want to identify the locations of points, objects, and events on the surface of our Earth, then we don’t need three dimensions at all. We’ll do quite nicely with just two: Latitude and Longitude (plus a GPS satellite to help us keep them straight). And if we add time to our “2D universe” of locations on the planet’s surface, then we’re up to only three dimensions . . . with time, in this case, being the third.

This is only one example of how the number of dimensions in a “universe” depends on what we are actually studying. Much like Heisenberg’s Uncertainty Principle in quantum mechanics, the whole area of dimensions is subject to its own uncertainty, where the “real” answer depends on how one looks at things. For example, the “Fractal Dimension” that defines the convolutions of a 3D English coastline is actually a single number between 1 and 2 . . . and its value is probably larger than the Fractal Dimension of Long Sands in York Beach Maine (if you study both coasts at the same level of detail). In addition, the Fractal Dimension of each coastline isn’t even an integer…it’s a real number between the dimension of a line and a plane.

If an ancient Greek philosopher were reading this topic, he’d raise his hand right now and urge caution in even using the word “dimension.” He and his colleagues knew the pitfalls that terminology can pose to thought and debate. The word “dimension” almost forces us to think in terms of numbers…and usually only integers. But if we’re analyzing the zigzagginess of a coastline, its Fractal Dimension isn’t an integer at all. And “dimensions” don’t even have to be numbers.

Take your living room floor, for instance. Let’s say you’re blessed with the gift of waving your hand and instantly making hundreds of spinning tops appear on it. The individual tops are colored red, green, or blue. Some spin about their axes clockwise, while others spin counter-clockwise, and still others rebel by spinning clockwise or counter-clockwise, but on their sides. A mathematician studying your tops might call them a “top space,” “set,” “group,” or even a “manifold” . . . depending on what they’re studying about them.

And there’s no single dimensional value for the simple “top space” that’s cluttering your floor. If we want to study just the distribution of the tops across the floor, then the two familiar X – Y dimensions suffice. But if we also want to analyze how the tops careen about the floor, we must up the ante to three dimensions…X, Y, and time. Factoring in their spin velocities raises this to four numeric dimensions (with plus values for clockwise spins and minus values for counter-clockwise). And if we then want to factor in each top’s color and precisely how it is spinning, we’re up to six dimensions. Dimensions 5 and 6 might be called “Color” (with the discrete non-numeric values “Red,” “Green,” and “Blue”) and “Spin Attitude” (with the discrete non-numeric values “About Axis” and “On Side”).

(Because of situations like this, you’ll hear quantum physicists discussing multidimensional “particle spaces” with “dimensions” like “Color” and “Spin.”)

Redirecting our view back to the visible universe, one can say that calling it 3D or 4D only considers locations and events within it. A complete understanding would call for an infinite number of “dimensions” (or perhaps a better term would be “descriptors” or “identifiers”). These would have to cover everything from quantum spins, “colors,” and energy/vibration states; through the energy emissions, visible colors, and electromagnetic fields of larger objects; and even up to the biological, emotional, and spiritual states of all the universe’s sentient beings.

So how many dimensions does our universe really have…and is “time” number 4? Only its Creator knows for sure. But it’s entirely possible that what we call “space” and “time” may be nowhere near numbers 1 through 4 on his or her list.