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Universe, Matter, Condensed Matter and Materials

It is an accepted fact that our world is made of matter, a kind of objective existence (reality) independent of our consciousness; in this sense, both space and time are some kind of matter. Our world can also be called the universe, thus describing the coupling of space and time. What we call "space" is a three-dimensional sub-entity (leading to the real world in which we are living) of a larger four-dimensional entity that includes time. In this sense, space and time are two aspects of matter that cannot be separated. Depending on which generalized definition of matter (in the sense of a kind of existence) we use, consciousness or our thoughts can also be considered a form of matter. The final goal of our scientific analysis is to reveal how matter is formed - what sort of micro-, macro-, and cosmological structure it preserves, which intrinsic features these different sorts of matter exhibit, and which relationships exist between them. We need to pay close attention to the difference between time and space on one hand and their respective concepts on the other hand. The latter are the reflection of real time and space in people's minds, which is subjective. In addition, there is a conceptional difference between matter and materials with materials being one important type of matter. Materials are specific manifestations of matter that can be used or controlled by humans and can be physically touched or characterized.

Generally speaking, our three-dimensional space is filled with matter, and this matter exists in space while depending on the time coordinate of the larger four-dimensional space (or the temporal-spatial unity and consistency). If you are interested in the deeper features of time and space, please refer to the inspiring books by Hawking and Gamow et al. [1, 2]. We will not discuss the involved concepts in depth since out focus in this book is simply condensed matter - materials. It is well-known that there are three commonly occurring phases of matter: the solid phase, the liquid phase and the gas phase. There is also an additional phase of matter, however, the plasma, which constitutes a special type of gas phase that is also often mentioned in books. The term condensed matter is commonly used to jointly describe solid and liquid phases. In addition, when we talk of materials in physical science we typically think of substances that can be and are utilized practically by humans.

1.1 Features of the Universe and Fundamental Constants

One of the well-accepted facts in our scientific view of nature is that the whole universe and the matter in it are originated from the so-called Big Bang, an initial singularity of space and time, as shown in Figure 1.1. Since then, the universe has evolved (for about 13.8 billion years - up to now), in the course developing all existing matter, experiencing quantum fluctuations, inflation, the afterglow light pattern at 380 000 years, dark ages, the formation of the first star (such as our sun) after about 400 million years, the development of galaxies (such as our Milky Way or the Andromeda Nebula), planets (such as Earth or Jupiter) and their satellites (moons), and many more objects (such as, e.g., neuron stars or black holes) [3]. A black hole is a region in space where gravity is so strong that nothing - not even light! - can escape, a fact that can be deducted indirectly by detecting the super-high temperature, and large amount of ?-ray and/or X-ray radiation emitted by the black hole as it devours the matter around it [4].

The information depicted in Figure 1.1 has been collected by the Wilkinson Microwave Anisotropy Probe (WMAP), a NASA Explorer mission launched in June 2001 to perform fundamental cosmological measurements (cosmology describes the study of the universe's properties as a whole). WMAP has proven stunningly successful and played a major role in establishing the so-called Standard Model of Cosmology. The detailed all-sky picture of the infant universe created from nine years of WMAP data as shown in Figure 1.1 reveals 13.8-billion-year-old temperature fluctuations (shown as color differences) that correspond to the seeds that evolved to finally become the galaxies. The temperature range displayed in this image encompasses ±200 µK.

We can even image what happened during the long evolution history of our universe. The first beam appeared about 13.8 billion years ago, our Sun was born about 4.57 billion years ago, and finally our Earth was formed about 4.57 billion years before today. First life forms appeared on Earth about 3.6 billion years ago. Anomalocaris (a Cambrian species of shrimp, Figure 1.2) evolved their eyes and became the first species to see the light that had been around for about 10 billion years. Finally, ancient man finished the evolution from Australopithecine about 7 million years ago, starting the development of human society and the related science and technology that helps us to explore the magic universe that has already been existing for 13.8 billion years.

Figure 1.1 Start and evolution of our universe since the Big Bang singularity. WMAP: Wilkinson Microwave Anisotropy Probe.

Source: NASA/Wilkinson Microwave Anisotropy Probe (WMAP) Science Team. http://map.gsfc.nasa.gov/ [5].

Figure 1.2 Artistic illustration of Anomalocaris - the first species in the ancient ocean to perceive the light that already existed since the Big Bang about 10 billion years earlier.

Source: CHATCHAI/Adobe Stock Photos.

If we strive to understand the features of the universe we have to take into account two interactions related to matter: the first is the interaction between matter and electromagnetic waves and the second is the interaction between matter and fundamental particles. However, there are at present still two main problems with our understanding of matter: the first is antimatter and the second is dark matter and dark energy. These prove difficult to be studied by the above two methods.

In 1928, British physicist Paul Dirac wrote down an equation that combined quantum theory and special relativity to describe the behavior of an electron moving at a relativistic speed. The equation - which won Dirac the Nobel Prize in 1933 - posed a problem: Just as the equation x2 = 4 has two possible solutions (x = 2 or x = -2), Dirac's equation had two solutions, one for an electron with positive energy and one for an electron with negative energy. But classical physics (and common sense) dictates that the energy of a particle must always be positive. To solve this apparent contradiction, Dirac interpreted his equation to mean that for every particle there exists a corresponding "antiparticle", exactly matching the particle but with opposite charge. For example, for the electron there should be an "antielectron" (also called "positron"), identical in every way but with a positive electric charge. The fact that one of the solutions of his equations described the exact opposite of the particle that it was designed to describe might have been brushed aside as a mere curiosity. But it wasn't. Instead, Dirac interpreted it as a description of antimatter - and, four years later (in 1932), this antimatter in fact turned up in a real-life experiment as the antielectron (or a positively charged electron) was discovered. In the 1950s, with the subsequent discovery of the antiproton and the antineutron, researchers realized that any particle might have its corresponding antiparticle in the universe. Since then, antimatter - first, antielectrons, known as positrons, and then anti-versions of all other particles of matter - has become a staple of both real science and its fictional counterparts [6].

What has until recently not been available for study, however, were entire antiatoms. Many research facilities were built to synthesize atomic antimatter such as the anti-version of the simplest atom, hydrogen. However, since the prediction and discovery of the positron and the antiproton, atomic antimatter has neither been observed nor synthesized in a laboratory for about three generations. Finally, in January 1996, the European Center for Nuclear Research (CERN) in Geneva announced that its researchers had created a total of 11 antihydrogen atoms by using CERN's Low-Energy Antiproton Ring (LEAR). Physicists are intensely excited at the prospect of being able to study this entirely new atom, because it will provide a fundamental test for their understanding of nature. At CERN, physicists produce antimatter with the aim of studying it in experiments. The starting point is the Antiproton Decelerator (AD), which slows antiprotons down so that physicists can investigate their properties.

In the meanwhile, a sizeable number of them have been produced in various laboratories, and even held on to for a few seconds. But for a long time, none of them existed long enough to be examined in detail because, famously, antimatter and matter annihilate each other on contact. That has now changed, with the preservation of several hundred of these atoms over periods of several minutes achieved by Jeffrey Hangst and his colleagues at CERN. The reason why...