Is this the stuff scientific revolutions are made of

The WMAP satellite recently confirmed that only 4% of the universe is made of ordinary matter. Against the background of this finding, which causes some discomfort to some astronomers, could an alternative, less "dark" cosmological theory develop?

Judith Anton, "Copernicus"

A few weeks ago, the results of the research project - NASA's WMAP satellite that measured the cosmic background radiation - were published on the front pages of many newspapers in the world. This radiation, originating in the very young universe, reaches us from all directions. Based on the precise measurements of the changes in the background radiation, the researchers were able to estimate the magnitude of several important parameters in astronomy. Thus it turned out, in accordance with expectations, that the universe consists of 73% "dark energy", 23% "dark matter" and 4% normal matter (and normal energy).

In the articles about the discovery, very little was said about the fact that the composition of the universe, as it is explained today by astronomers and cosmologists, and as it also emerged from the results of an experiment, WMAP is actually shrouded in mystery. According to the picture of the world accepted by science today, the entire universe known to us, all the visible galaxies, all the suns and all the planets are only four percent of everything in the universe. Foam on the surface of the water in a great ocean of things that are not matter and are not energy, at least not in the usual sense.

Dark matter and energy are not arbitrary factors. Their existence arose as a learned hypothesis of astrophysicists due to the need to give theoretical answers to observational findings and to confirm the theory of relativity and the big bang theory. The hypotheses were tested again and again, tested in the light of new observations and passed a series of critical tests by the scientific community before they were accepted as the accepted theoretical explanations. But despite this, it is impossible not to feel a certain discomfort in the face of the explanation that 96% of the universe is nothing more than a combination of factors that have never been directly observed, factors that are described as "mysterious" even by scientists. But the scientific discussion revolves, naturally, around specific questions about the observations and the data and does not deal with a super-scientific critique that examines the complexity of the world picture resulting from the theories and its meaning. One of the exceptional scientists in this regard is Prof. Paul Schechter, a renowned astrophysicist from the Massachusetts Institute of Technology, who was interviewed a few months ago by the online magazine, "Slate" in an article that dealt with NASA's gravity experiments. Shechter said that "a change of perception regarding the force of gravity is requested" and added that "the last person who succeeded in bringing about a change in the theory regarding the force of gravity was Einstein." This change caused a tremendous revolution in physics and astronomy.

When theoretical explanations in a certain scientific field reach a point where discomfort is felt in relation to the picture of the world they paint, a point where there is a lot of conceptual reluctance, this may indicate a crisis point where the conditions for a scientific revolution are created. Is it possible that modern astronomy is currently in such a pre-revolutionary stage?

According to Prof. Menachem Fish, from the Cohen Institute for the History and Philosophy of Science and Ideas at Tel Aviv University, science reaches a turning point when the explanations it offers cease to be reasonable. "But what would be considered the limit of plausibility in this context?", asks Fish, "How much should a scientific hypothesis exceed the limits of common sense so that the scientists find it appropriate to re-examine the basic assumptions of the theory?"

Scientists hypothesized the existence of dark mass after measuring the rotation speed of various galaxies. The observed speed did not correspond to the amount of material contained in those galaxies, and according to the laws of physics it was impossible to explain their movement - according to the calculations, they should have been torn apart quickly and disintegrated everywhere. To provide an explanation for the fact that galaxies continue to move for billions of years and are not torn apart, the hypothesis was put forward that apart from all the matter we can observe - the various stars and the huge clouds of dust and gas - there is another matter in space, dark matter, which is not visible in observations but exerts a gravitational force and preserves the structure and movement of the galaxies. The currently accepted explanation is that dark matter consists of different particles than those that make up normal matter; that it does not consist of atoms but of "exotic" matter particles that will be able to be distinguished only with special detectors.

The dark energy was born twice. Albert Einstein first assumed its existence, when he formulated the theory of general relativity; He called it the "cosmological constant". Einstein added the cosmological constant to an earlier version of his equations after realizing that it follows from them that the matter in the universe should strive to unite due to gravity and therefore a universal collapse process should take place. According to the prevailing worldview at the time, the universe was static and motionless, so Einstein had to incorporate an additional factor into his equations that would balance the force of gravity. Years later, when it became clear from observations that the different galaxies are moving away from each other and the big bang hypothesis was put forward, Einstein canceled the cosmological constant and called it "the biggest mistake of my life". In the XNUMXs, observations were made using high-powered telescopes that showed that the various galaxies are not only moving away, but also accelerating their speed, and the cosmological constant was reborn as a factor that explains the acceleration.

Science is greatly assisted by supplementary additions, which are combined with theories as needed. The additions are used by scientists to reconcile the accepted scientific worldview with new findings that do not align with this worldview. At the end of the 19th century, the British physicist James Maxwell formulated the laws of the propagation of electromagnetic waves, thus laying the foundation for electronics and modern communication. Maxwell's equations show that the electric field and the magnetic field propagate in waves. The question that immediately arose was what is the medium in which these waves move, since there can be no sea waves without the sea just as there can be no sound waves, which move through the air, without air. But the electromagnetic waves also move in a complete vacuum - this could be tested experimentally. The scientists needed another theoretical factor that would allow them to include the electromagnetic waves in the accepted world picture. The gap in the theory was filled by the ether, the same concept that appears in the phrase "airwaves" which was used until a few years ago to describe radio transmissions (which are electromagnetic waves). The concept, which has existed since ancient Greece, suited the needs of the time. The ether has been described as a medium found everywhere and is a conductor for the electromagnetic waves. Today it is clear to physicists that there is no ether. The contemporary worldview speaks in terms of photons and attributes to light (and other electromagnetic phenomena) a dual character: waves and particles. The site was an unnecessary conjecture.

According to the classical conception of the structure of science, put forward by the philosopher of science Karl Popper, an experiment or observation that contradicts the theory must lead to its refutation and cancellation, but in practice the process is more complex. When a theory is a fertile ground for research or technological development, the community of scientists is not in a hurry to discard it and declare it invalid just because of the existence of observations or experiments that contradict it. Instead of replacing the theory, concepts, factors or explanations are added to it that allow it to contain the unruly discovery and move on. Only rarely, when a collection of phenomena accumulates for which the explanation does not satisfy the mind, the door is opened for a revolutionary change and the formation of a new worldview.

The Copernican revolution

This is what happened in the astronomical revolution of Copernicus. Since the days of the ancient Greeks, astronomers have explained the movement of the planets, the sun and the moon using a system based on circular motion around a central point where the earth is located. At some point, observational findings were discovered that conflicted with this world picture. To deal with the new observations, the ancient astronomers added additional small circles, called epicycles, which move on top of the large circles at different speeds so that the observed movement is finally obtained. The system became more and more complicated over time, and arduous calculations were required in order to calculate the operation of the dozens of integrated circuits it included. At the beginning of the 16th century, Copernicus proposed to give up the resulting theoretical awkwardness and explain the movement in a simpler way. The picture of the world he proposed included fewer hypotheses and assumptions and was simpler to present, but according to it the sun is at the center of the system and the various planets, including the earth, move around it.

Are we indeed witnessing a conceptual awkwardness and an excess of theoretical corrections that reveal fault lines in modern astronomy? Do dark matter and dark energy deserve to be thrown into the dustbin of science like the ether and epicycles? It is still too early to determine.

It is possible that in the future it will turn out that the scientists were indeed very accurate in their hypotheses and that the factors whose existence Shuar does exist in the form they were described. Perhaps one day a research spacecraft will return to Earth with samples of dark matter or measure dark energy directly and clearly. But it is also possible that these days the physicist, the astronomer or perhaps the patent clerk is sitting in his room who will one day publish another explanation for the cosmic phenomena; An explanation that will illuminate the universe in a new light.

"Dark energy" is an enigma

Dr. Noah Brosh

In mid-February, the first results obtained by the MAP satellite for the study of the cosmic background radiation were published. The findings - at a much higher level of sensitivity and sharpness than those provided by the COBE satellite a decade ago - showed that the universe is 13.7 billion years old (that is, since the Big Bang), plus or minus - that is, a possible error in the calculation - 200 million years.

The first stars lit up in the universe "only" 200 million years after the big bang. Most of the universe is not ordinary matter as we know it, but only 4% of all the matter from which we are also built.

The MAP satellite launched in 2001 achieved this after only one year of activity in space and in the following years its results will be improved and compared to the theoretical predictions. Its developers entrusted it with an important task: to measure the cosmic background radiation with an unprecedented level of precision.

The background radiation was released into the universe when free electrons, created in the Big Bang, combined with the first nuclei that appeared in the universe and created neutral atoms of hydrogen, helium, and a small amount of heavier chemical elements. The date of connecting all the components to create neutral matter in the universe was determined about 380 thousand years after the big bang. From that moment on, the background radiation spread through the universe without interruption - until it was now picked up by the measuring instruments.

In the last moments before it was released from the "bear hug" of the ionized material, the background radiation picked up the signature of the material in which it was found, in the form of tiny changes in temperature.

In the place that appears to be the coldest on the map, provided by MAP, the temperature reaches 2.7249 absolute degrees, while in the hottest place it is 2.7251 degrees. In such a tiny difference, of less than a thousandth of a degree, the great structure of the universe is hidden: the densest regions that then began to form as small concentrations of matter that gradually grew as they attracted and absorbed matter in their surroundings.

Over the years, these regions have become rich clusters of galaxies, each similar to the Milky Way of which we are members.

To achieve the required level of accuracy, the unmanned spacecraft MAP was placed in a "quiet" place in space, where the heat load from the sun is constant. This region, known as the "second Lagrange point", is at a distance four times greater than our distance from the moon. A spaceship in this place feels the gravitational force of the Sun as well as that of the Earth.

Under the weighting effect of the two forces, the spacecraft moves on an orbit around the sun and circles it every year, like the earth itself. The spacecraft stays in the same area all the time, relative to Israel - and therefore it is easier to communicate with it (with computer and radio communication from Israel) thanks to the solar cells in it that produce electricity uniformly.

One of the most interesting results provided by MAP is the recalculation of the contents of the universe. It turns out that the results show that only a tiny part - only 4% of the contents of the universe - is ordinary matter, made of atoms and molecules as we know them on Earth. But, about 23% is "dark mass" - an unidentified component of the universe, which creates a force of attraction and gravity that affects the movements of ordinary matter.
Today it is thought that the "dark mass" consists of an unknown type of particles, which have not yet been found in the most powerful accelerators. The rest of the cosmic content is a new type of material (or "product") whose existence has only been identified in recent years, and is called "dark energy". Dark energy probably causes the expansion of the universe to accelerate. Today, scientists have no idea what its origin is and what its nature is.