String physicists assume that energetic pieces of threads are the keys to quantum gravity and to everything else of our perceived reality throughout the universe. The basic elements of this theory are "strings" or membranes, i.e. subatomic one-dimensional energy threads and built areas. The vibrations of these strings generate everything out of a vacuum, like the different characteristics and features of subatomic elementary particles and all elements of the periodic system. Ten and more dimensions are needed to describe a perceived reality, but only Einstein's four dimensions of three-dimensional space and one-dimensional time seem to be sort of "rolled out". The latest attempts to totally describe nature and the universe by energy strings is the very complex "M-Theory", with staggering amounts of possible mathematical solutions.
A tiny little string, about a hundredth of a billionth of a billionth of the size of an atomic nucleus, could form, for example, an electron by its special kind of oscillation. All kinds of particles are unified by a "Super String Theory" because each particle differs only by the oscillation pattern of a string. Even space and time are supposed to be subject to vibrations of strings. The string theory is a breathtaking mathematical approach of highest complexity, but, at least so far, with neither a concrete result for all the existing elementary particles, nor a feasible construction of space-time. One distinctive feature of the string theory is the assumed existence of multidimensional spaces within any single point of space and time. Endless string solutions are the result, by far too many variations to find the suitable ones just by accident. Powerful computers support string scientists to shorten the time towards a feasible result to embrace physics and all wonders of our existence in each of their aspects.
A basic obstacle of string specialists are the insufficient explanations of seemingly clear physical phenomena. Electromagnetism is one example. The effects of electromagnetism are described in great detail by physicists and widely used in daily life by engineers, but the real origins and true nature of electricity and magnetism are undiscovered. Scientists figured out that electricity and magnetism are two sides of the same coin, although they appear with very different features like an electrical particle charge and a magnetic particle spin, indicating an asymmetrical observation with the result of a reciprocal impact in formulas for electromagnetic oscillations. Electrical engineering of electronic oscillation circuits is possible because of the inverted resistances of capacitances and in parallel connected magnetic induction coils; the resistances of electric charge capacitances drop with rising alternating current frequency whereas the resistances of magnetic induction coils increase. Usual electronic circuits use this peculiarity to generate oscillations and radiations. Such electromagnetic waves and particles can be transformed into matter, for example shooting highly energized photons at atomic nuclei to initiate the energy conversion from light, which is an electromagnetic phenomenon, into matter. This process is state of the art and used to produce electrons and positrons in specialized laboratories. This kind of matter generation can be mathematically reformulated by string vibrations and forced string transformations into matter.
The basic theories for elementary particles need getting used to because each material particle is described as a distinguishable excitation state of basic energy strings and areas with quantum mechanical aspects. The classical observations of nature completely fade in the imagination of theoretical physicists, but the quantized approach to all forces and energies of nature challenges these scientists already from the very beginning, looking at a simple electron: Like any photon, any electron either behaves as concentrated particle or as a spreading wave, only depending on the set-up of the experiment. Scientists speak about "the unsolved dualism of wave and particle". Quantum physicists try to handle this inexplicable contradiction by the superposition of several possible states and conditions. There is only a probability that one of these states and conditions actually takes place. The whole of possible states is mathematically expressed by so called wave functions. Any single result of an observation appears accidentally. This way, quantum physics became able to predict atomic processes with extraordinary high precision, fully in accordance with experimental examinations.
Some physicists consider quantum mechanical results to be completely subject to observations. This means that the wave function contains all possible results in an indefinable intermediate state and only the actual observation itself decides upon the selection from possible results. This brings us to the question of necessary repetition sequences to constantly interact with the space-time construction of our perception. A single event cannot be predicted, but many events of the same kind should appear with certain probabilities exactly because of these repetition sequences. The observed system appears to accidentally move on to a new state, never in total chaos, but usually determined by a degree of probability. Repeating such a transition process many times shows different following states, based on a calculable probability. One best example is the decay of atoms: The radioactive decay of a Uranium atom may happen in an instant or only after many millions of years. Its decay is not predictable. The radioactive decay of a certain quantity of Uranium, however, follows proven decay laws of probability.
Accepting these peculiarities of quantum physics, it is possible to calculate the probabilities and whereabouts of events, particles and energy states with astonishingly precise results. The actual measurement causes a seeming collapse of the wave function of probabilities, extracting only one possibility out of the given repetition sequence. The process of measurement and evaluation is considered to represent an active disturbance of this wave function that leads to the then actual and noticeable result. In the phase before the actual measurement, everything still was in a state of uncertainty. The unknown origins of quantum physical aspects of the microcosm lead to the major dilemma today's string physicists are faced with, trying to reformulate classic physics with energy strings and quantum physics. New super gravity approaches introduced one or even more additional dimensions on top of the 10 dimensions of classic string theories, partly not being any more subject to quantum mechanics. Proponents believe that one or more additional dimensions on top of those 10 will open the way to unite all string theories.
This wave function approach seems much more plausible than the alternative interpretation by multiple parallel universes that host all of the possible measurement results, one in each. The latter imaginations describe a complex reality, split into multiple parallel universes. There is no communication facility between these multiple parallel universes and we cannot notice that we follow only one possible path through permanently splitting universes. Nevertheless, this view is another mathematical possibility, beyond all doubt.
Better understanding of all physical disciplines, like electromagnetism, particle physics, nuclear physics, gravitational physics, nonlinear field theory and ultrahigh pressure physics will be the important key to elicit more secrets from nature and to pave the way for the string theory or even a new theory to capture the entire universe with only one picture. Many research centers around the globe work on these fundamental research issues and many more centers are planned.
Practical evidences of the existence of strings will be the ultimate challenge for string scientists, because sooner or later powerful computers will be able to complete the theoretical calculation and to describe a complete universe of strings just by inventing as many dimensions as necessary to capture all processes of nature, including the startling peculiarities of quantum physics, with its uncertainties and probabilities, and culminating in the still unsolved integration of gravitation.
Modern cosmology will strongly influence the further development of the string theory, because of the recently found phenomena of dark energy and dark matter. Attempts of cosmologists to describe cosmic processes few moments after an assumed big-bang led during the past 3 decades to a model of an inflationary universe. Driving force of the inflation are postulated scalar fields. The introduction of such scalar fields follows the unifying theory for elementary particles called Grand Unified Theory, "GUT". Fields of this kind serve in GUTs for a description of changing symmetries that have their origin in one single type of initial force. These fields determine the development of the hierarchy of today's fundamental forces of nature. The existence of these postulated scalar fields could not yet be confirmed experimentally, but a majority of scientists see the early universe filled up with such scalar fields and our cosmos starting with an initial high symmetry and high energy density of scalar fields and heading towards low symmetry and low energy density of scalar fields because of progressive expansion and cooling.
The theoretical transition of a highly symmetrical state of vacuum into an asymmetrical state has one peculiar feature that is different to anything physics could observe and describe so far: the energy density of a vacuum bubble that has been filled up with any of today's known types of matter and energies decreases during the expansion phase of this bubble, whereas the energy density of a symmetry-asymmetry transition vacuum seems to stay constant without a dilution. The pressure within such a transition vacuum equals a negative density. The expansion of the universe means for such a type of vacuum the necessity of a scalar quantity of work against the negative pressure. This implies the gain of energy. Such peculiar characteristics of symmetrical origin and peculiar vacuum towards asymmetry can be combined with the modern string theories. One result is the observable accelerating expansion of the universe against the forces of gravity, i.e. against Einstein's mass caused curvatures of space-time.
Despite the logical fact that any observer throughout the entire universe perceives an own central position, because of looking from any place into any spatial direction the same 13.7 billion years into the past, the universe appears inhomogeneous and asymmetrical. The question comes up, whether this is the true picture or the distorted view from the observer's asymmetrical anchoring in space and time and other rolled up dimensions of the string theory.
Astrophysicists today use sophisticated statistics to interpret the forms and distributions of galaxies, including their average speed through space. The complex processes of gases, birth and death of stars makes it difficult to precisely extract the phenomena of dark matter that keep all galaxies stable. Current computer models use the critical energy density factor 1, applying about 23 percent of energy density contributions by dark matter and about 72 percent of energy density contributions by dark energy, the latter interpreted as a cosmological constant for an accelerating expansion of the universe. String physicists have to integrate these new cosmological aspects into their theory to hopefully come to a meaningful mathematical description of the entire universe.
The String Theory and the Grand Unified Theory get additional valuable impulses from another exciting direction of modern theoretical physics and practical research: Super symmetry concepts for Einstein's space-time and known forms of energies turn the asymmetrical energy distribution picture into a symmetrical set-up. This way it is possible to widen Einstein's four space and time dimensions with opposing, relatively rolled up space-time dimensions and to correctly describe a rotational symmetry for this space-time grid and all energies within. Opposing energy values then astonishingly behave like the inverted resistances of magnetic induction coils versus capacitances of electric oscillation circuits and complete the missing puzzle pieces for strings, dark energy and its postulated scalar energy fields. Relatively rolled up but turned or opposing dimensions, either appear with the relative standstill of time, or with extremely accelerated processes, or reciprocal development. All peculiarities of quantum physics become explicable by the relative acceleration sector and its repetition of energy processes just until one solution is selected by the disturbance of the wave function, realizing the following state.
Wormhole engineering by an innovative kind of space-folding theoretically becomes possible by the use of this rotational symmetry. This is not yet a physical reality, but more than pure science fiction; it is a mathematical possibility. This way, mankind might become able to cover light years across deep space within moments, which might open the gate for a survival on the long run and perhaps to extraterrestrial civilizations. Well-known mathematicians confirm the correctness of the so far purely mathematical concept. Accelerating an evacuation spaceship close to the speed of light and slowing it down for the arrival at any habitable planet seems to be currently the only, certainly extremely difficult, but physically possible solution. This one-sided view of practicable space-travel could completely change within the next decades if the postulated symmetry becomes provable by practical experiments. This cosmic super symmetry is also most important for particle physicists and their currently assumed super symmetrical and weakly interacting massive particles (WIMPS) that are today supposed to form the extensive dark matter halos that stabilize all galaxies throughout the entire universe.
Despite all discoveries in physics and mathematical formulations of nature ahead, one ultimate question will remain: who invented and possibly still pulls all these energy strings that possibly form our universe?