One of the greatest achievements of the twentieth century is undoubtedly the creation of cosmology - the science of the universe on its largest scale, both spatial and temporal . The universe has always been interested in the man, but until the beginning of last century the knowledge of him drowning in speculation and uncertainty. When he began the twentieth century, not known for sure whether there are galaxies, and whether Newtonian physics can be used outside our solar system without any "additional amendments." Then there is a rapid development - in parallel in the theory and observations. Substantial progress was the general theory of relativity, and built on the basis of the first cosmological models. They predicted that the cosmos is not a static creature, but extends from the super-dense state, which - perhaps too hastily - utożsamiono the beginning of the universe. At about the same time began to study first identified beyond any doubt, galaxies, and soon Edwin Hubble found that they run away from each other with ever-increasing speeds. It was the first important fact about the cosmological significance - The Universe is expanding.
second half of the twentieth century brought about further developments, both theoretical and observational. The theory was used more and more sophisticated mathematical methods and, thanks to the enormous technological progress (the era of computers, electronics, and artificial satellites) may have also become increasingly precise observational studies of the universe. The influx of data - both theoretical and observational - became so big that he formed a reliable picture of the large scale structure and evolution of the universe. The breakthrough was the discovery in the mid-sixties, the microwave background radiation, interpreted as a remnant of the Big Bang. Examination of physical properties of this radiation has allowed cosmologists to reconstruct the processes that have occurred in the very early universe. The seventies and eighties witnessed the consolidation of the standard cosmological model. The last decade of the century brought advances in observational techniques, which passed all expectations. COBE satellite mission and the Hubble Space Telescope - the first major observatory in orbit around the earth - have become even symbols of progress. COBE satellite made very precise measurements of the cosmic microwave background, which helped draw up a map of the universe with much of the period of pre-emergence of the first galaxies. Hubble still provides superb images Cosmos, is among them the famous "Hubble Deep Field, where they can see the formation of the oldest galaxies. With a great sense of security we can say that pass the following centuries of well-established image of the universe's largest scale available to us from very dense, early stages, when such decided to Nuclear, Chemical and portions of today's Universe, by phase, in which a space dominated by the electromagnetic radiation, the epoch of galaxy formation and their clusters, until the era. which we call "space today" - that it created the planet and was initiated biochemical evolution.
Fascinations cosmology typically involve the visual side. Just look closely photograph distant galaxies, to experience the philosophical delight - who are we compared to the millions of light years. A view images submitted by the orbiting Hubble Space Telescope, also provides a profound artistic experiences associated with beauty, but also the power of the cosmic abyss. Looking farther, we see what has happened in the more distant past. There are only a step to the Beginning ...
WHAT IS THE UNIVERSE?
Reflection on the philosophical problems of cosmology must begin with the question, what is the Universe [the word "universe" I write a capital letter as a proper name if it means our universe, in other cases, it writes a small point, as was adopted to write "Our Galaxy" and "other galaxies."] Or a little more modestly: What is meant by the word "universe" when it appears in texts or in the statements of cosmological cosmologists? As usual when it comes to understanding the words, in any setting is a large element of convention. However, this time from the convention too much depends, not to worry about its consequences. Let the following example will be justification for this claim.
From the thirties of last century's theory of relativity, relativistic cosmology were in the Soviet Union banned the teachings. Famous Russian cosmologist Yakov B. Zeldowicz once casually mentioned to me that Alexander A. Friedman, which many times we meet in the pages of this book, "was lucky, because he died before the plague, the ruling in St. Petersburg." Note that I understood much later, when the Soviet Union was no longer allowed to write about this and when I learned that two other scholars, colleagues, Friedman, also dealing with the theory of relativity and cosmology, Matwiejowi P. Bronsztejnowi and Wsiewolodowi K. Frederiksowi was not judged to survive a tragic border of 1938. Bronsztejn was shot in 1938, and Frederiks died in prison. Long years in the camps will spend! Yuri A. Krutkow well, who in the history of cosmology, inscribed by the fact that in 1923 during a long conversation with Einstein convinced him of the correctness of the famous work of Friedman in 1922 (at work the first time Friedman found solutions to Einstein's equations describing the expanding universe models.) The problem was that the then-known cosmological models present the universe as spatially finite (closed) and time (starting from the so-called evolution. Initial singularity), which was contrary to the claims of Marxist-Leninist philosophy above, according to which the universe must be infinite and eternal. Political repression effectively inhibited the development of cosmology in the Soviet Union for several decades.
Only in the sixties the situation started to change for the better thanks to ... skillful maneuver terminologicznemu, invented by the influential Soviet physicist, Abram L. Zelmanowa. Writing about cosmology, instead of "universe" he used the term "Metagalaktyka. Metagalaktyka according to him only a part of the observable universe, and it only deals with cosmology. The universe is the domain of Marxist philosophy. Some "progressive" Western cosmologists picked up a new appointment, considering it to be less burdened philosophical connotations, but more aware of things their Russian colleagues immediately returned to the term "Universe" as soon as political conditions allowed it. Today, the term "Metagalaktyka 'goes into oblivion.
(On the pic. Fr. Michael Heller)
A glance at the history of cosmology, to find out that the concept of universe, evolving, expanding its scope. That's what the universe was yesterday, tomorrow will be only a small part of it. Newton even our solar system called the "world system" soon after this system became an insignificant detail, lost in the starry skies. And when in the twentieth century discovered the world of galaxies, the current universe, which is a collection of stars, it became the only "our galaxy." Today we know that galaxies escape from each other. The universe is expanding, but much earlier you could say that extends to the very concept of the universe. The expansion of this concept is a measure of the growth of our knowledge.
But the laws of physics are immutable? Do extrapolating our laws of physics to remote areas of space and time, do not commit human error, which it considers its backyard typical for the whole continent? For a long time there were speculations about the volatility of the laws of physics, but one of the first, a more physically reasonable inference of this supposition comes from Paul Dirac.
Dirac remarked that after all if the universe is expanding is the radius of the observable part (it is equal to approximately the speed of light multiplied by time elapsed since the Big Bang) is growing and is indeed a matter of For that we live in an age in which the ratio of the radius of the observable universe to the radius of the proton is just 10 39 . But if you assume that the gravitational constant (and consequently the gravitational field strength) decreases inversely with the age of the universe, the randomness of it no longer exists: in any age, these "strange" relationship figures, in which there are number 10 39 , will be preserved.
Can we therefore define the Universe as the largest system in which Our physical laws are valid if we know right now were not necessarily always the same in the future may also change? Perhaps you can, provided that our physical laws shall be construed accordingly broad - as a team to be the evolution of regularities in the current era of overlapping with those regularities, which today we call our physical laws which we discover in the laboratories.
There is still a valid argument to the effect that our laws of physics are representative for the universe. Well, today you can no longer argue that by observation we control only our immediate neighborhood astronomical. We see very distant objects as they were in an era when the emitted beam of light now blowing in our detector (telescope, radio telescope). This feature allows you to still watch the nascent galaxies, and study the cosmic microwave background gives us insight into the physical processes that take place in the universe a few hundred thousand years after the Big Bang, when the beginnings of future clusters of galaxies existed in the form of minor clumps hot, uniform plasma.
If noted that the current age of the universe is nearly 10 10 years, it is easy to say that we met up to ninety percent of the total number of cosmic history (from the Big Bang .) If in the course of cosmic history, the laws of physics have been changing, that it must reveal the inconsistencies in our picture of the world. If, for example, some physical constants changed only about one part per hundred billion, it will even be noticed, taking into account today's accuracy of observation. History of the Universe turns out to be extremely sensitive to changes in some of the important parameters, such as physical constants. You can talk about the "argument from compliance" from the known laws of physics, we reconstruct the earliest states of the universe, deduces from them - again referring to the laws of physics - the conclusions about the current state of the universe, and it turns out that these conclusions agree with the results of observation.
Among theoretical physicists of today, there is convinced that the basic physical effects: gravity. Strong and weak nuclear and electromagnetic symmetry breaking are the result of the initial impact, which reigned supreme in the Big Bang. Subsequent violations of the original great-syrnetrii phase transitions in nature, similar for example to move the liquid to the solid state or gas. This time, however, phase transitions related to the space or the "vacuum", which as far as temperatures fall rapidly disintegrates into various "phases" (impact), which also define the mass of fundamental particles associated with these phases. Phase transition process itself is carried out in accordance - f. use a priori laws of physics, but the effects of this process also depend on some accidental circumstances, as well as patterns of ice on the glass depend on purely random factors, although the freezing process is subject to strict laws of physics. This raises the question whether the fact that we have today and not just those four other physical effects (and eventually this and no other physics), is not entirely the result of some accidental circumstances that have occurred in the early Universe? l, or if those circumstances were just a little bit different, we would have completely different physics?
But how can you determine which features of the universe are random and which are essential, since the universe is given to us in one piece and we do not have to compare it with what? Remains thought experiment: can there other universes, in which the same original great-symmetry is broken in a different way, leading to a totally different physics and a completely different from our cosmic history?
the early eighties, was born up, and soon became fashionable, the idea of \u200b\u200binflationary cosmology. The originator was Alan H. Guth, but the concept was relatively quickly adopted and developed by other researchers. According to the inflationary scenario, when the universe was very young, around 10 -35 seconds after the Big Bang, the expansion has suffered a sharp acceleration, with the result that the Universe has increased its size 10 30 times (or much more, according to later, improved scenario). This is called a phase of inflation (distension). The reason for this distension would be the energy contained in a vacuum, before the latter has passed the phase which gave rise to present a strong nuclear impacts. Einstein's equations allow for such a process and it is undoubted merit Guth. it drew attention to this. Inflation process ends when the vacuum goes into more normal state (more normal today from our standpoint) then emit huge amounts of heat. It is possible that this process is testimony to the cosmic microwave background temperature of 2.7 K, filling out the entire space.
inflationary universe idea remains highly speculative. For many cosmologists, however, the concept is attractive (although it is also strong opponents), mainly because it solves several problems of the standard model. These difficulties are associated with the fact that our universe is very "synchronized": the density of matter contained in it is very similar to the so-called. critical density (characteristic of the model space plane) so that its expansion is almost exactly such a rate that is necessary to ensure that might occur in galaxies and their clusters, a remote area of \u200b\u200bthe universe have a lot of the same features, though - if not for inflation - never in the past, there would be a causal relationship between them. Inflationary model overcomes these difficulties in one fell swoop: "synchronize" the universe is a consequence of the unprecedented distension; ever before distension, the whole universe seen today occupied a tiny volume, within which all combined causal relationship (more extensively on this subject will be discussed in Chapter 11, there also will be offered another solution to these difficulties.)
discussion on this topic as one of the first Russian cosmologist Andrei took Linde. His proposal called chaotic inflation. According to his idea of \u200b\u200binflation did not have to be something one-off. Each singularity resulting from collapse of a massive object can be regarded as a "little Big Bang", which gives rise to a new universe. Inflation trends in this universe --child may expand it to large sizes. Phase transitions of a new vacuum in each new universe - a result of random factors involved, such phase transitions always depend on - lead to the other fundamental interactions and, hence, to other cosmological scenarios. The set of all universes is eternal, although individual universes may last for a limited time. Our universe is the result of a detachment from the mother of the universe. Budding in this way the universes are very different: some are short-lived, almost immediately sank to the final singularity, other There are tens of billions of years or even longer, the pace of expansion is some small, others large, some are homogeneous, while others are rich in structure. Our universe is so "good" performance to one of his planets life could have arisen because, in other universes, which record the adverse conditions are met, not zaistnielibyśmy and we could not explore such universes (which is an example of anthropic reasoning).
idea Linde developed the Lee Smolin. Lead is still the question of why our universe is the way it is, in particular, why it is such that it could grow and evolve. Biological evolution is governed by the law of natural selection. Does a similar law can not be applied to the process of giving birth to new universes? According to Smolin is possible, but you have to accept this new assumption. It is namely assumed that the laws of physics in every newborn baby universe-slightly different from the laws of physics force in the universe, the mother (similarly, condition for occurrence of biological evolution is small changes in a set of genes in the offspring compared with a set of genes of parents). This mechanism ensures that after many generations in the set of all universes will dominate those universes that seem the most offspring, the ones that create most of the black holes that could be an zaczątkami new universes. Smolin is trying to prove that the universe must resemble our universe. So we are not only the effect of natural selection in the biological sense, but also of natural selection acting on a scale all the universes.
To prove his cosmological vision, Smolin points out that it does contain at least an empirical prediction. Well, our universe must contain many black holes. If it turned out that it is not. It belonged not to the universe, which seem to many offspring. It goes without saying that this kind of empirical prediction differs significantly from the empirical tests, which typically require the physical theories.
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