TechTheDay

For 2014, many of the posts on this blog featured 3D-related topics. Somehow, 4D tech has been ignored. This post serves as an introduction to the idea of 4D technology. What is it all about? Is it going to become as hot as 3D technology? What is the extent of its applications?

Overview

4D, in simple terms, is 3D + the time dimension. It is mathematically defined as a geometric space with four dimensions, usually referring to the four-dimensional Euclidean space. In modern physics, however, it is not considered as a Euclidean space. 4D in physics definition can be considered as the unified existence of physics, space, and time in a four-dimensional continuum more popularly known as spacetime. Although there’s this difference in definition, 4D is for laypeople basically something more advanced than 3D. If 3D has the X, Y, and Z axes, 4D has an additional axis that is orthogonal to the other three.

Tesseract Example

To better understand the concept of 4D, the tesseract is often used as an example. A tesseract, also known as a tetracube or cubic prism, is a four-dimensional analog of a cube. If a cube has 6 faces, a tesseract has 8. A tesseract is created by combining two cubes. The idea is similar to constructing a (3D) cube out of (2D) squares. Cubes are created by piecing similarly sized squares together. Similarly, tesseracts are formed by juxtaposing two of the lower-dimensional cube and connecting the corresponding vertices. A tesseract can be unfolded into 8 cubes in 3D space, just like how a cube can be separated into 6 squares in 2D space.

Projections and Perspective

To explain the idea of 4D further, consider the tesseract example again If a (3D) cube is seen as square from one of its sides, a tesseract is seen as a cube from one of its sides. If a cube can be seen from an edge as two squares meeting on a common side (with two of the squares’ edges or corners connected), the corresponding image for a tesseract would be two cubes meeting on a common side (with four square edges or corners connected). The rest of projections and perspectives are better explained by the following images:

Visual Scope

It is important to remember the perception of dimensions is rather not what most people would probably be thinking. For humans, who are three-dimensional creatures, everything is perceived in 2D. What humans see is only one side of everything. 3D creatures need to move to another location to be able to see the other sides of a 3D object. If a 4D creature existed, it would be able to see all sides of a 3D object without having to move to see a new angle of the 3D object being observed. In short, 3D creatures (humans for example) only see 2D, while only (hypothetical) 4D creatures would be able to appreciate 3D objects in full and only (hypothetical) 5D creatures would be able to see 4D objects in their entirety, et cetera.

The Idea of 4D Technology

So what does 4D technology mean? Basically, just like how 3D technology works, 4D tech involves the use of already existing 3D tech with an additional dimension. For the most part, 4D applications are simply a matter of marketing. The idea of coming up with something with a real 4th dimension or something that supposedly only 5D creatures are able to appreciate is still not possible. For now, a real 4D object, as defined in mathematics or physics, does not exist.

4D in 4D cinemas is simply 3D plus an additional dimension or element. This additional element is usually a simulation or group of simulations of environmental occurrences based on what is being projected. Examples of which are wind effects, rain and water jet effects, smoke, strobe lighting, air bubbles, scents, and vibration. There is no established or consistent standard as to what a 4D cinematic experience really means. Others may even offer 5D, 6D, and even more “D’s” to emphasize the amount of additional effects they offer. Nevertheless, there are established brands such as Smell-O-Vision and 4DX for creating a “fourth dimension” in films.

In the case of 4D printing, the 4th D is typically just another layer of computational power. The idea of which is to create something that unfolds into another thing. It makes use of software-based methods or tricks to produce something that can create the illusion of transformation.

4D and the Future

At present, the best of what 4D effects can offer is the hype and illusion. It’s unclear at this point whether or not 4D based technologies can provide practical benefits in the future. The earlier applications demonstrated haven’t been impressive nor practically viable to be worth pursuing. In the movies, 4D is even just a marketing term. Still, it’s exciting to see new technologies unfold. We are not sure how 4D will be relevant to us and that may make it exciting.