Origen_universo_Intereses_El Big Bang y la Creación

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Origen_universo_txt_El Big Bang y la Creación

The Big Bang and Creation

Author: Eduardo Peláez
Published in: Salvador Mérida, ed. Conjugando Ciencia y Fe. Argumentos en el año de la fe. Madrid. CEU Ediciones
Publication date: 2014

One of the most exciting scientific adventures of the 20th century has been the study of the Universe: the achievement of knowledge of its origin, its shape and its development. It is an astonishing odyssey for the human being: that from his corner in the Cosmos he has been able to get a global idea of its history going back to his birth. It is difficult to find anyone who has not heard of the Big Bang theory. But how reliable is it? And if it is experimentally verifiable, do we therefore arrive at the finger of God in his creation? Is this vision a confirmation for the believer of what his faith teaches? To these questions I will try to answer, in a few pages, with this article. To do so, I will follow closely, in large part, the exhibition of Michio Kaku, Full Professor of Theoretical Physics at the City University of New York.

There are two major protagonists to whom I will devote special attention: Einstein and Lemaître, the father of the Big Bang.

The Big Bang and CreationAt the age of 26 - during his "annus mirabilis" of 1905 - Einstein published three scientific papers of great importance for physics. In one of them, he will expound the Theory of Special Relativity. After almost ten years of work, with the help of a mathematician, Marcel Grosmann, he succeeded in formulating the General Theory of Relativity, which he published in Annalen der Physik in March 1916.

According to his own account, he had the initial idea for the new theory of gravity when he was still working at the patent office as a simple civil servant in 1907: "I was sitting in my chair at the patent office in Berne when an idea suddenly occurred to me: if a person falls freely, he does not grade his own weight. I was startled. This simple idea made a deep impression on me. It led me to a theory of gravitation". It was the foundation of what was to become his theory: the laws of physics are indistinguishable in an accelerated framework or in a gravitational framework . He thus established the so-called "equivalence principle" between inert mass and heavy mass and a conclusion, as Pais recalls, "if all referential systems are equivalent, they cannot be Euclidean".

Einstein's theory reformed Newton's gravitation by asserting that gravity is caused by space-time being curved. The first empirical verification of this metric view of gravitation was to be carried out by another physicist, Sir Arthur Eddington, on Principe Island in the Gulf of Guinea. Eddington was the secretary of the Royal Astronomical Society of England and was well acquainted with Einstein's work. Eddington himself recounts this in his book Space, Time and Gravitation.

To explain his theory, Einstein had posited a hypothetical situation in which the line of sight between an observer on Earth and a star was blocked by the edge of the Sun. If Newton were right, the star would remain invisible, but Einstein calculated that something much more surprising would happen. The solar gravitational force would curve the space around it, the star's rays would follow that curved path - its geodesic - to go around the Sun and reach the observer on Earth without any problems. The timely eclipse would allow this hypothesis to be tested at test by obscuring sunlight; thanks to the Moon, British scientists would be able to photograph stars close to the Sun that are normally hidden by the Sun's glare.

Measurements made by Eddington during the total solar eclipse of 29 May 1919 in Principe showed that his calculations of the bending of light in the presence of a gravitational field were accurate. Solar gravity had caused a deflection of light of about 1.6 arcseconds. The result matched the prediction of the Theory of General Relativity. Einstein was right. The news spread around the world.

Two years later, in 1921, he received the award Nobel Prize for his contribution to theoretical physics and for the development of the theory of the photon. But not for his general relativity, as there were still physicists who doubted that it was correct.

One of the most important applications of general relativity has been in cosmology. Einstein himself first suggested that the Universe was a three-dimensional spherical surface, and therefore of constant curvature. However, the field equations imply a dependence on time, but, as there was no evidence for this, Einstein added a further term to the equations to eliminate this dependence. This term was called the "cosmological constant". In this way he defended a static model of the Universe.

Since 1917 the "cosmological constant" has caused rivers of ink to flow. Einstein went so far as to say that it was the biggest mistake of his life. This factor created a repulsive anti-gravity that was balanced by the attractive force of gravity. This is what made the universe static. The cosmological constant assigned energy to empty space. This anti-gravity term, now known as "dark energy", is the energy of the absolute vacuum. It can pull galaxies apart or bring them closer together again. Einstein chose the value of the cosmological constant to exactly counteract the contraction due to gravity, so that the universe would be static. Eighty years later - as we shall see - evidence would be found for the cosmological constant, which is now considered to be the dominant source energy of the universe.

Also in the same year of 1917, Willem de Sitter, a Danish physicist, saw that it was possible to find a strange solution to Einstein's equations: a completely empty universe from subject that was expanding! All that was needed was the cosmological constant, the energy of the vacuum, to move an expanding universe. Dark energy would propel it forward.

The decisive final steps were taken by Alexander Friedmann in 1922, and independently by the Belgian priest and astrophysicist Georges Lemaître in 1927. Both showed that an expanding universe is a direct consequence of Einstein's equations, in which the cosmological constant disappears. Friedmann obtained a solution of Einstein's equations on the basis of a homogeneous and isotropic universe whose radius expands or contracts. grade Before publishing it, he sent a copy to Einstein, who did not reply, but when it appeared in print in the Zeitschrift für Physik, Einstein hastened to write to the German publisher criticising Friedmann's solution and pointing out a mathematical error. He would later rectify this by sending another grade in which he retracted his objection. However, he continued to consider that, even if the calculations were correct, his equations did not describe reality. Something similar was to happen with Lemaître. Einstein remarked to him, in 1927, when he tried to present his model: "I have read your work, your calculations are correct but your physics is abominable". Lemaître had published his calculations and arguments in Annales de la Société scientifique de Bruxelles that year. Friedman had died a few years earlier, in 1925, without having seen the problem solved. It was Einstein who sent a copy of his work in English to Lemaître.

The discussion remained active until 1929, when astronomer Edwin Hubble obtained results that would revolutionise astronomy. He first demonstrated the presence of galaxies outside the Milky Way. Moreover, in 1928 he made a momentous trip to the Netherlands, where he met De Sitter, who claimed that Einstein's relativity predicted an expanding universe with a proportional relationship between redshift and distance. The further a galaxy was from Earth, the faster it would move away from us.

When Hubble returned to the Mount Wilson observatory near Pasadena in California, he began a systematic study of the redshifts of the galaxies he had found, to see if the correlation was true. He knew that, in 1922, Vesto Melvin Slipher had shown that some distant nebulae were moving away from the Earth, creating a redshift in their spectrum. Hubble systematically calculated the redshift of the spectra of distant galaxies and discovered that these galaxies were moving away from the Earth, i.e., that the universe was expanding at a dizzying rate. He then discovered that his data confirmed De Sitter's conjecture, now known as "Hubble's law": the rate at which a galaxy is moving away is directly proportional to its distance (and vice versa).

In 1930 Einstein visited the Mount Wilson observatory, where he met Hubble. As Hubble presented the results he had painstakingly obtained from studying a multitude of galaxies, all moving away from the Milky Way, his idea of a static universe began to crumble. In that year Lemaître turned to Eddington, with whom he had worked years earlier, and sent him his findings. Eddington was convinced of the hypothesis of the expansion of the Universe and discussed it with Einstein in Cambridge.

We now know that, if Einstein's equations are taken to their logical conclusion, they show that the universe had a singular beginning. This is what Lemaître did in 1931 by claiming that the universe had originated in a big explosion. If the universe expands at a certain rate, one can reverse this expansion and calculate approximately when the expansion started. In other words, the universe not only had a beginning, but we can also calculate its age.

Lemaître first presented this model, i.e. the "hypothesis of the primitive atom" as he called it, in that year, in an article published in the Revue des Questions Scientifiques, and months later he defended it at the British Association for the Advancement of Science in a controversial atmosphere. It must be considered that the description that general relativity gives us of the expansion of the Universe is such that it is space itself that expands, and it is not, therefore, a simple ordinary explosion where the objects that participate in it move away from each other without altering the space-time structure. Moreover, from agreement with the cosmological principle, it occurs at all points in the same way, so that we cannot locate the centre of the expansion in any particular place. This fact has been called by some the new Copernican revolution of the 20th century.

In those years Einstein reconsidered his attitude towards Lemaître's thesis, and in 1933 in Pasadena and in 1935 in Princeton he became much more open. His resistance to the Big Bang theory because it seemed to him to be made to support Creation vanished. When the Belgian scientist and priest made him realise that God could not be reduced to a scientific hypothesis, he abandoned his distrust.

In 1948, two rival positions were clear. On the one hand, H. Bondi, T. Gold and F. Hoyle proposed the model of the steady state of the Universe, with the hypothesis of a continuous creation compatible with relativistic theory. Our galaxies and stars would be born over time. Thus the Universe would be eternal and self-sufficient, with no beginning in time.

At the other extreme was the Ukrainian physicist G. Gamow and his team, R. Alpher and R. Herman. Gamow approached the evolution of the world from a thermodynamic point of view, and proposed that the universe at its initial instant, besides being very dense, as Lemaître pointed out, must have been very hot, and that, during expansion, it cooled down. This new theory, the hot "primitive atom", harmonised cosmology with elementary particle physics.

In addition, they predicted a cold cosmic background radiation that should be detected everywhere in the Universe, as an "echo" of the initial "big bang". This would be a test final in favour of the Big Bang - as Hoyle called it in a BBC radio programme - against the steady-state theory.

Lemaître's hypothesis of the "primitive atom" was still a long way off. The background radiation, the fossil remnant of the big bang, was not easy to discover. The opportunity was provided by a fortuitous finding by two engineers in 1965, Robert Wilson and Arno Penzias. These two researchers had built a radiometer at Bell Laboratories at Crawford Hill in New Jersey which they intended to use for radio astronomy and satellite communications experiments. The instrument had an excess noise temperature of a few Degrees Kelvin that they had not counted on. The two scientists were unaware of the work of Gamow and his collaborators, and it was Princeton physicist R. H. Dicke who correctly identified this radiation as Gamow's background wave radiation. Penzias and Wilson received the award Nobel Prize for their work and the Big Bang theory received the boost it needed. Lemaître read the news in the Astrophysical Journal of 13 May 1965. He was seriously ill. He died on 20 June 1966.

Years later, the COBE (an acronym for Cosmic Background Explorer) satellite, launched by NASA in 1989, has given us the most detailed picture yet of this surprisingly smooth background radiation. When physicists led by George Smoot of the University of California at Berkeley carefully analysed the tiny ripples in this uniform background, they were able to produce a stunning photograph of the background radiation from when the Universe was only 400,000 years old.

This image sample shows that the irregularities probably correspond to tiny quantum fluctuations in the Big Bang. According to the uncertainty principle, the Big Bang could not have been a perfectly uniform explosion, since quantum effects should have produced irregularities of a certain size. And this is what Berkeley's group found. These small anisotropies in the background radiation correspond to temperature variations of the order of a hundred millionths of Degree. These small variations would be "gravitational seeds" that enable the formation of galaxies and stars, clusters and superclusters. This is the biggest breakthrough and support in the study of the background radiation since Penzias and Wilson detected it.

Then, in 2001, another NASA mission called WMAP (Wilkinson Microwave Anisotropy Probe) was launched with a satellite set up to study the properties of the cosmic background radiation throughout the sky, using temperature differences measured in Kelvin. In 2003, WMAP scientists obtained a more detailed map of the cosmic background radiation that reflected the state of the young Universe, starting about 300-400 thousand years after the Big Bang, when the first atoms formed. The age of the Universe was calculated quite accurately at 13.7 billion years.

The universe is currently thought to be composed of 4% ordinary subject , 23% dark subject and 73% of the mysterious dark energy, which thus constitutes the largest source of subject/energy in the entire Universe.

By analysing supernovae in distant galaxies, astronomers have been able to calculate the rate of expansion of the Universe over billions of years. To their surprise, they have concluded that the expansion of the Universe, rather than slowing down as most thought, is actually speeding up. The explanation has not yet been discovered. It is as if there are "negative masses" causing gravitational repulsion. The cosmological constant that Einstein initially introduced in his 1917 equations reappears.

This picture of an accelerating Universe seems to confirm the idea of an "inflationary Universe" proposal first proposed by MIT physicist Alan Guth, which is a modification of the original Big Bang theory of Friedmann and Lemaître, where there are two phases of the expansion process. Therefore, we now have a fairly reasonable understanding of the history of the Universe from a certain initial instant. Our reconstruction of cosmic history backwards in time goes up to the moment when we begin to ignore the physical laws that determine the relevant processes. That moment occurs when the age of the Universe is of the order of the "Planck time" (10-44 seconds) and quantum-gravitational effects would be dominant.

Thus we have come to a convincing conclusion: during the 20th century our knowledge of gravitation and the structure of the subject has made the Universe accessible to human reason. Numerous scientists - we have seen only the most outstanding ones - have been involved in this gigantic history of the Universe since its formation, finding . One of the greatest, without a doubt, has been Georges Lemaître, the father of the Big Bang, as he has been called in various works.

This believing scientist was a passionate and competent scientist researcher and saw no conflict between his discoveries and his faith; on the contrary, he thought they complemented each other harmoniously. In 1935, on receiving an award from King Leopold III of Belgium, he said something he had kept in mind from an early age: "Science is beautiful, it deserves to be loved for its own sake, because it is a reflection of God's creative thought". And in February 1933 in an interview with the New York Times Magazine he confessed on the other hand: "I was interested in truth from the point of view of salvation and from the point of view of scientific certainty. It seemed to me that both paths lead to truth, and I decided to follow both. Nothing in my professional life, nor in what I have found in science and religion, has ever induced me to change my mind".

Lemaître never used science for the benefit of faith by making science say more than it is capable of. He saw the model of the Big Bang as congruent with Creation, but at the same time he was convinced that both were autonomous, different and complementary paths that converge in the ultimate truth. John Paul II in his speech to the Pontifical Academy of Sciences on 3 October 1981 put it this way:

"Any scientific hypothesis about the origin of the world, such as that of a primitive atom from which the whole of the physical universe would come, leaves open the problem of the beginning of the universe. Science alone cannot resolve this question: we need that knowledge of man which rises above physics and astrophysics and which is called metaphysics; we need, above all, the knowledge which comes from the revelation of God. Thirty years ago, on 22 November 1951, my predecessor Pope Pius XII, speaking on the problem of the origin of the universe on the occasion of the Week of Studies on the Question of Micro-earthquakes, organised by the Pontifical Academy of Sciences, said: "It would be useless to expect an answer from the natural sciences, which, on the contrary, faithfully declare that they are faced with an insoluble enigma. It is equally true that the human spirit given to philosophical meditation penetrates more deeply into the problem. It cannot be denied that an enlightened mind, enriched with modern scientific knowledge and calmly investigating the problem, is led to break through the hedge of a wholly independent and autonomous subject - either because it is uncreated or because it has created itself - and to rise to a creative Spirit. With the same clear and critical eye with which it examines and judges the facts, it comes to glimpse and recognise in them the work of the creative Omnipotence, whose virtue, aroused by the mighty 'fiat' uttered billions of years ago by the creative Spirit, unfolded itself within the universe, calling into existence, in a gesture of generous love, the subject overflowing with energy".

Faith is not on a collision course with science, for the two are on different levels. God does not act on the level of created chance but on the transcendent level. Lemaître understood this well and explained it clearly by delimiting these fields. Science can point to the solution without resolving it. agreement Perhaps this is why he was not entirely in agreement with Einstein, when at a lecture he gave at the California Institute of Technology on 7 May 1933, in which he described the expanding universe, the German physicist stood up at the conclusion, applauded and said "This is the most beautiful and satisfactory explanation of creation that I have ever heard". Words that the Belgian professor would find nuanced.

This is what he did on 10 September 1936 at the 6th Catholic congress in Mechelen, halfway between Brussels and Antwerp, devoted to "Catholic culture and the positive sciences":

"The Christian scientist (...) has the same means as his non-believing colleague. He also has the same freedom of spirit, at least if the idea he has of religious truths is on a par with his scientific training. He knows that everything has been made by God, but he also knows that God does not replace his creatures. The omnipresent divine activity is everywhere hidden. The supreme Being can never be reduced to a scientific hypothesis. Divine revelation has not taught us what we were capable of discovering for ourselves, at least when these natural truths are not indispensable for understanding supernatural truth.

Thus the Christian scientist goes forward freely, secure in the knowledge that his research cannot conflict with his faith. He has perhaps even a certain advantage over his non-believing colleague; indeed, both are striving to decipher the manifold complexity of nature in which the various stages of the world's long evolution are overlaid and confused, but the believer has the advantage of knowing that the riddle is solvable, that the underlying scripture is after all the work of an intelligent Being, and that therefore the problem posed by nature can be solved and its difficulty is certainly proportionate to the present and future capacity of mankind.

This will probably not provide him with new resources for his research, but it will help to foster in him that healthy optimism without which a sustained effort cannot be maintained over a long period of time. In a sense, the scientist dispenses with his faith in his work, not because that faith might hinder his research, but because it is not directly related to his scientific activity".

I have underlined in the text what seems to me essential to bear in mind when making a philosophical and theological reading of the data of science. These words clearly summarise the compatibility between science and faith, in a mutual respect that avoids undue interference, and at the same time show the encouragement that faith gives to the Christian scientist to advance in his hard work. As W. E. Carroll has written: Thomas Aquinas would have no difficulty in accepting the present cosmology, even with all its recent variations, while affirming the doctrine of creation from nothing. And he would, of course, distinguish between advances in the natural sciences and the philosophical and theological reflections on those advances.

What is not defensible - neither from science nor from faith - is to deduce from science a naturalistic vision in which the Universe explains itself, as has happened with some of Hawking's interventions, who maintains: "The universe could be self-contained and completely determined by the laws of science"; he has even spoken of a "self-creation", trying to include the Big Bang in a broader theory that avoids the initial singularity. It must be said that this theory has no experimental support and is a contradiction in terms, since the Universe does not have in itself the reason for its being and cannot "create itself".

Soler has shown in depth how the naturalistic attempt to offer a model of the universe that contains a 'closed' and merely physical explanation of its own existence does not and surely cannot work.

The model of the Big Bang, like all scientific model , is a model provisional that can be improved eventually, Sánchez Cañizares tells us. All these are physical or natural explanations of the universe. They explain it on the basis of a series of natural transformations (from one evolving reality to another). However, these explanations fail to answer a more radical question we can ask ourselves: Why does something exist instead of nothing existing? If we try to answer this question by resorting to natural laws, we would not find an answer, because we could still ask: Why do these laws exist? We say that the universe needs an explanation "outside" itself, not in terms of physical laws, but to answer this radical question. The ultimate reason for the existence of the universe is studied by philosophy and theology. Following the rational path proper to these fields of knowledge, distinct from and complementary to that of science, we come to know that the universe has a necessary cause (which exists by itself and cannot not exist) outside of itself; and that this Cause is God, who has created the universe, with its natural laws.

As Lorda writes, we can conclude that arriving at the idea of a Creator God is beyond scientific data. But it is a possible deduction, of a philosophical nature, when contemplating the whole of reality. For us Christians, that deduction is reinforced by our faith.

The ultimate explanation of the Universe, of its internal order, of the emergence of Structures and of its very laws, is that it has been thought up by an intelligent Being. Benedict XVI liked to think of the same "mathematical core" of the Cosmos. Galileo said that nature has a mathematical core, but that marvellous order deserves an explanation. Einstein was amazed that its workings could be described in elegant mathematical equations. I find it almost unbelievable," says the German Pope in a meeting with young people in April 2006, "that an invention of the human intellect and the structure of the universe coincide: the mathematics invented by us actually gives us access to the nature of the universe and enables us to use it. Therefore, the intellectual structure of the human subject and the objective structure of reality coincide: subjective reason and objectified reason in nature are identical. I believe that this coincidence between what we have thought and the way nature is realised and behaves is an enigma and a great challenge, because we see that, in final, it is 'one reason' that unites them both: our reason could not discover the other if there were not an identical reason at the root of both" The ever more precise knowledge of the Universe, which flees from all reductionism, speaks to us patently of a Creator Logos who, through faith, we know is Love.

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