### Facts and Open Questions of Fundamental Physics

Since the dawn of humanity, we have lived with the paradigm that our universe is the alpha and omega of reality, a unique and smooth space. However, while working within this paradigm science has accumulated many questions to which no one has yet found, and may never find, the answers.

What are the true natures of space, time, elementary particles, and gravity? Will the photon’s dual nature or the physical nature of quantum spaces ever be explained? Is it possible to unify gravity with the other three fundamental forces?

Although modern science has made astounding strides, discovering many well-kept secrets of the world, the fundamental open questions mentioned above are just a few of those resolved by the new multispace paradigm. This discussion prepares the reader for the explanations given in the book’s third part, which describes the multispace model in detail.

In 1905, Einstein discovered the special relativity of reference frames. As a result, researchers in relativity spent the last century following the path that Einstein set with his special and general theories of relativity, which explain reality from the perspective of a single space-time framework that encompasses the entire observable universe. And while Einstein’s theories provide a set of tools that describe the relationships between our observations, they do not address the physical nature of reference frames, or of space-time itself.

During the last decades, some physicists have understood the need to draw a clear distinction between mathematical coordinate systems and physical frames of reference. As noted by Patrick Cornille:^{1}

… [A] distinction between mathematical sets of coordinates and physical frames of reference must be made. The ignorance of such distinction is the source of much confusion … the dependent functions such as velocity, for example, are measured with respect to a physical reference frame, but one is free to choose any mathematical coordinate system in which the equations are specified.

Similarly, Graham Nerlich made the following assertion:

The idea of a reference frame is really quite different from that of a coordinate system. Frames differ just when they define different spaces (sets of rest points) or times (sets of simultaneous events). So the ideas of a space, a time, of rest and simultaneity, go inextricably together with that of frame.^{2 }

Moreover, recent progress in cosmology and string theory has led many physicists to revisit the idea of multiple spaces. In string theory, for example, the universe is a higher-dimensional framework that encompasses many independent “spaces,” each a subset of the dimensions comprising an independent domain with unique properties.

As Brian Greene puts it: ”We keep banging into the possibility that we are one universe of many.”^{3}

But before we start counting universes, let us discuss an aspect of reality directly influenced by the distinction between coordinate systems and reference frames: *elementary particles*.

For years, researchers in quantum mechanics and string theory have been attempting to explain what elementary particles really are.^{4} Despite significant progress in discovering the laws that govern interactions between particles and fields, no one has yet adequately explained how an apparently dimensionless object can possess physical properties or create a field that fills the space around it. While in classical mechanics and electromagnetism the properties of a point mass or a field are described by real numbers (e.g., charge) or by functions defined on two- or three-dimensional coordinate systems with direct spatial meaning (e.g., potential energy), neither of these two branches of physics provides such interpretations for elementary particles.

Nevertheless, quantum mechanics and string theory offer a compelling argument for the existence of a multispace: An elementary particle only *seems* to be dimensionless because its physical substance exists in a space that is separate from the space of our universe.

Quantum mechanics describes elementary particles in terms of “quantum spaces,” sets of mathematical variables having no direct correspondence with the physical space of the universe. The particles themselves are “filled” with nothing other than energy, momentum, angular momentum, and a handful of discrete quantum numbers. Thus, particles are believed to have a structure completely different from our familiar physical space, and indeed to be “external to” the space we inhabit. In our universe, each particle appears as a dimensionless singularity – a mathematical point – surrounded by a field. It is via their fields that elementary particles interact with one another and with the universe in which they exist.

Even if quantum spaces are well defined in mathematical terms, quantum theory does not provide clear and satisfying insights into their properties. Indeed, it cannot even answer the seemingly simple question of where these spaces are located physically (outside the mathematical realm). This disconnect from our classical, macroscopic view of the world has haunted quantum physicists for decades.

Now, elementary particles are physically explained as dimensionless singularities that “ride” on a wave-like field, but the very existence of these particles is problematic. Do particles have an independent existence beyond their probability fields, or does some unknown dynamical property of the particles create the field? This is only one example of the many open questions for modern physics. The bottom line, though, is that quantum spaces are clearly different from the physical space of the universe in which we live.

String theory goes one step further: Particles are seen as vibrating loops that occupy a separate universe of *six, *or more, spatial dimensions hidden in the fabric of space-time itself. In fact, according to string theory, these matter spaces are not actually *hidden*, but rather the extra dimensions are curled up into small loops by Mother Nature – *compactified* in mathematical terms. However, it is only because they are thought (in string theory) to be small – and not because they are intrinsically different from our familiar spatial dimensions – are they explained as being dimensionless (invisible).

The good news is that string theory provides a better means than quantum theory to represent elementary particles as independent physical spaces, albeit invisible to us. The difficulty lies in trying to explain how physical phenomena arise from the complementary characteristics of independence and invisibility that these spaces possess. On the other hand, many physicists assert that string theory is ill defined and based on crude assumptions. Rather than describing one universe, the theory describes 10^{500} possible universes, each with its own constants of nature, or even different laws of physics.^{ }

Taken together, the insights of quantum mechanics and string theory suggest that elementary particles, while appearing dimensionless from our perspective, may in fact have a rich internal structure and any physical size. If that is the case, then “quantum spaces” are not mere mathematical abstractions, but actual representations of the particles’ true nature. We need only find the *correct* way to explain their existence.

Let us consider the second example: *gravity*. Despite being a force we all think we know about and understand, gravity has proven to be the most puzzling of the four fundamental forces of nature.

In his theory of special relativity, Einstein assumed that a single space-time suffices for describing the entire universe; in his theory of general relativity, he explained gravity by allowing this space-time to curve. Erroneously believing that he had correctly explained the nature of gravity, Einstein spent the rest of his life chasing a chimera: trying to formulate a unified theory of gravity and electromagnetism. Thus far, the pursuit of “grand unification” has been a complete failure, not just for Einstein, but also for everyone after him who made such an attempt.

However, Einstein’s lack of success in unifying gravity and electromagnetism is easy to explain with the multispace model. In the 3rd part of the book, we will see that gravity is a force not of attraction but of repulsion – a kind of cosmic pressure.

Some physicists, even while unaware of the multispace paradigm, have already begun to suspect that the true nature of gravity has yet to be discovered. Paul Wesson of the University of Waterloo in Ontario, Canada says: “*We don’t know that gravity is strictly an attractive force.*“^{5} He points to the “dark energy” that seems to be accelerating the expansion of the universe, suggesting that gravity can work both ways. Although Wesson’s latter idea is debatable (because gravity is a pressure, and as such is repulsive on all scales), his insight is remarkable.

To learn more about the hidden secrets of reality, see the companion article “Predictions of the Multispace Model.” But only in the upcoming book, *The New Paradigm of Reality: The Multispace Universe*, will you finally get the clear and satisfying explanation that we have all been searching for.

^{1} Patrick Cornille, *Essays on the Formal Aspects of Electromagnetic Theory*, World Scientific (1993), p. 149. ISBN 9810208545.

^{2} Graham Nerlich, *What Spacetime Explains: Metaphysical essays on space and time*, Cambridge University Press (1994), p. 64. ISBN 0521452619.

^{3} Anil Ananthaswamy, “How to map the multiverse,” *New Scientist*, issue 2706 (2009), pp. 35–37. Available athttp://www.newscientist.com/article/mg20227061.200-how-to-map-the-multiverse.html?full=true.

^{4} The terms *particle*, *elementary particle*, and *matter particle* are used interchangeably throughout this website in reference to *fermions*. In the *Standard Model* of particle physics, these particles are the fundamental constituents of matter, as opposed to *bosons*, which are force carriers.

^{5} Michael Brooks, “Seven things that don’t make sense about gravity,” *New Scientist*, issue 2712 (2009), pp. 28–32. Available at http://www.newscientist.com/article/mg20227122.600-seven-things-that-dont-make-sense-about-gravity.html.