The popular story of astronomy is wrong
The old tale of the enmity of science and the church is far from reality
At the very beginning of the seventeenth century, Johann Kepler argued that there were thousands of huge bodies in the universe, so large that they themselves could be universes. The presence of these giant bodies, as Kepler said, argues in favor of incredible power, as well as personal attachments, the almighty creator god. The gigantic bodies in his view were the stars accumulated around the Sun, the central body of the Universe of relatively small size, around which a suite of still smaller planets moves in orbits.
This strange idea of the Universe, which Kepler adhered to, was an innovative astronomer who prepared the ground for Isaac Newton and the onset of modern physics, freed astronomy from the ideal circles of Aristotle and calculated the elliptical nature of the orbital motion, also adhered to several early followers of Nicolaus Copernicusand its heliocentric ("suncentric") theory. Science insisted on Kepler's theory - observations of stars with high repeatability and careful mathematical analysis of data obtained as a result of these observations. It was also the Achilles heel of Copernicus’s theory. Astronomers, who considered the Earth still located in the center of the Universe, expressed the absurdity of giant stars, invented by the supporters of Copernicus only so that their favorite theory coincided with the data. The story of the "giant stars" describing the universe has been forgotten.
These illustrations demonstrate the Coriolis effect, a force acting on almost all objects moving on the surface of a rotating sphere. They were painted by a 17th century Jesuit Claude Francis Millier Deschalswho used them as an argument against the movement of the Earth. The illustration to the left shows the F ball falling from the tower. If the Earth does not move, then the ball simply falls from point F to point G. If the Earth moves, then, since the top of the tower is farther from the center of the Earth than the base, the top will move faster when the ball falls than the bottom: the top is at H, and the bottom is at point I. Therefore, a ball moving at the speed of the top of the tower at the moment it is released must land not at I, but at L [apparently, there was an error, and it meant “not at G, but at I ”/ approx. trans.]. On a rotating Earth, the ball will not fall straight down. The illustration on the right shows the same idea, only for a shell. The gun shoots at a target in the north. If the Earth does not rotate, then the core flies straight and hits the target the gun is aimed at. If the Earth rotates, then the gun, being closer to the equator than the target, will move to the right faster than the target, when the core will fly out of it. Therefore, the core will not hit the target, but will go to the right. In both cases, it should be possible to detect the rotation of the Earth. And the opponents of the Copernicans were right. Only to detect these effects was much more difficult than it was then thought.
And it is very regrettable. The story of Kepler and the giant stars illustrates the dynamism inherent in science from its very birth. It contrasts with the usual stories that tell us about the birth of science, stories describing the controversy over the Copernican theory, as those cases where science was suppressed by a powerful, deeply rooted establishment. Stories about the suppression of science, and not about its dynamism, did not serve the science of good service. And the story of giant stars will be useful to her.
Johann Kepler outlined his ideas about giant stars in a book he wrote in 1606 and called " De Stella Nova“, or“ About a new star. ”The book told about a new star, just appearing for some time out of nowhere in the sky in 1604. According to Kepler, the new star eclipsed everyone else, even Sirius, the brightest of all stars, regularly appearing in the night sky. In the book, Kepler reflected on the size of the new star, and concluded that its girth far exceeds the size of Saturn's orbit (the most distant planet known at that time). Sirius should have been about as huge, and even the smallest stars his opinion should have been a pain beyond the orbit of the Earth. His
stars were generally the size of a universe. Former Kepler chief, Tycho Brahe, proposed the theory of the Universe, borrowed from Copernicus, according to which the Earth was motionless in the center of the Universe. Shortly before his death in 1601, Brahe personified the "great science" of his days - he had a huge observatory, the best tools, many wonderful assistants (such as Kepler), his own publishing house, and a lot of money. In the geocentric (“earth-centered”) Brahe model, the Sun, the Moon and the stars rotated around a stationary Earth, and the planets - around the Sun. The stars were located immediately beyond Saturn, marking the edge of the observable universe. The sizes assigned by Kepler to the new star and Sirius exceeded the whole Braga universe, while the sizes of the other stars were comparable to this universe.
Why did Kepler say that the size of the stars is comparable to the universe? Because the data talked about it - at least in the event that his heliocentric theory was correct. According to this theory, the Earth moved around the Sun in a circle, making a revolution in a year. Therefore, if at one time of the year she moved towards a certain star, then after six months she moved from this star. It was possible to expect that some stars will burn brighter in the spring when the Earth approached them, and then become dimmer in the autumn. This effect is called parallax. But no one watched any parallax. Copernicus explained it this way: the orbit of the Earth will seem like a tiny dot compared with the distances to the stars. The Earth's orbit was negligible for the stars, and the motion of the Earth could be neglected. As Copernicus himself wrote, “that
The problem is a negligible size and a huge distance. People with good eyesight, looking into the sky, will see the stars in the form of small round dots, with a small but measurable visible size. Astronomers in the time of Ptolemy in the second century AD, determined that the brightest stars are between one-tenth and one-twelfth of the diameter of the moon. In the book "On the New Star" Kepler wrote that bright stars are about ten times smaller than the moon in diameter, and Sirius is slightly larger than them. The problem is that a star, the apparent size of which is one-tenth the size of the moon, can be ten times smaller than the physical size of the moon in diameter, only if it is at the same distance from us as the moon. But the stars away from us. If the star were 10 times farther from the moon, then its real size would coincide with the Moon - and it would seem ten times smaller than the Moon only because of the distance to it. If the star were 100 times farther away, its true diameter would be 100 times larger than the moon. If she were 1000 times farther than the moon, her true size would be 1000 times larger [probably meaning 10 times and 100 times more, respectively / approx. ].
And what if this star, whose apparent size is ten times smaller than the moon, would be at such a distance that Copernicus's theory requires so that we do not notice parallax? This star, Kepler claimed, would have been the size of Saturn’s orbit. And absolutely all the stars visible in the sky would be no less than the orbit of the Earth. Even the smallest stars would be several orders of magnitude larger than the sun. Today, this statement may seem strange to us, because we already know that stars are of different sizes, and if few stars are larger than Earth's orbit (a bright example of such a star would be Betelgeusefrom the constellation Orion), most of the stars are red dwarfs, much smaller than the sun. However, in the days of Kepler, the question consisted only in simple observation, measurement, and mathematics — ordinary scientific matters. An astronomer of the time, who believed in Copernicus, measurements and mathematics, had to believe that all the stars were huge (we will discuss later what they were wrong about).
The argument in favor of the huge stars was so convincing that the details of their measurements did not matter. Johann Georg Loher and his mentor Christopher Scheinerbeautifully summarize the problem of giant stars in the astronomical book of 1614 “Disquisitiones Mathematicae”, or “Mathematical Surveys”. They wrote that, according to the theory of Copernicus, the orbit of the Earth is similar to a point in a universe full of stars; but the stars, having measurable dimensions, are larger than points; consequently, in the Copernican universe, each star must be greater than the orbit of the Earth, and, naturally, greater than the Sun.
Because of the giant stars, Loher and Scheiner rejected the Copernican theory and supported Brahe’s theory. This theory coincided with the latest discoveries made with a telescope, for example, with the phases of Venus, confirming that it moves around the sun. According to the theory of Braga, the stars were not located so far away - right behind Saturn. The astronomer at the time of Kepler, who believed Brahe, measurements and mathematics, was not obliged to believe that the stars are huge. (Brahe calculated that their sizes varied from large planets to the Sun). Loher and Scheiner were not alone - for many astronomers, including Brahe himself who studied this problem, the theory of giant stars was something out of the ordinary.
But Kepler had no problems with giant stars. They were for him part of the general structure of the universe; and Kepler, who saw ellipses at orbits andcorrect polyhedra in the organization of the movement of the planets, always looking for the whole structure. For him, gigantic stars were both an illustration of the power of God and his striving to create a whole universe. Discussing parts of the universe — the stars, the solar system (the system of “movables”, as Kepler called them), and the Earth — the text of the book On the New Star becomes almost poetic, even in translation.
Other followers of Copernicus shared the views of Kepler. People like Thomas Digges , Christoph Rothman and Philip Lansberg, they talked about giant stars as an example of divine power, as a divine palace, or angels palace, or even as warriors of God. Copernicus himself mentioned the power of God, discussing great distances to the stars, noting "how precise the divine work of the greatest and best of artists is."
But opponents of Copernicus did not lose their point of view. Loher and Scheiner noted that the Copernican "sycophants" did not deny the fact that the stars in the Copernican universe must be gigantic. “Instead,” wrote these two astronomers, “they spread about how, based on this, everyone can better feel the greatness of the Creator,” and called this idea “ridiculous.” One opponent of Copernicus, astronomer Giovanni Battista Riccioli, wrote that the appeal to divine power to support the theory "can not satisfy more intelligent people." Another one, Peter Kruger , commented on the size of the stars: “I don’t understand how the Pythagorean or Copernican system of the universe can survive.”
Opponents of Copernicus did not simply deny his theories. Loher and Scheiner reported on their discoveries. They encouraged astronomers to engage in systematic observations with telescopes in order to use the eclipses of Jupiter’s moons to measure the distance to Jupiter, and the “accompanying” Saturn (then they did not understand that these were rings) to study its movement. They worked on explaining how the Earth can move around the Sun: constantly falling on it, just like an iron core can constantly fall on Earth. (This idea appeared several decades before the birth of Newton, which could give us a modern explanation of how orbit is a kind of fall, and illustrate orbits using the example of a cannon firing from a mountain). They also investigated the question of how the rotation of the Earth can affect the trajectories of falling bodies and shells.
When at school we studied the Copernican Revolution, we did not hear anything about the arguments concerning the size of stars and the Coriolis effect. We were told where the less scientifically dynamic story in which such scientists as Kepler tried to defeat the omnipotent, ingrained and recalcitious establishment with the help of scientifically correct ideas. Today, despite the progress of technology and knowledge, science is rejected by people who claim that it suffers from hoaxes, conspiracies and a lack of data that is caused by a powerful establishment.
But the history of the Copernican revolution demonstrates that science from the very beginning was a dynamic process, there were successful and unsuccessful moments in it, moreover, on both debating sides. Only after a few decades after Kepler’s “About the New Star” and Loher and Shayner’s Mathematical Surveys, did astronomers begin to find evidence that the dimensions of stars they measured, both by eye and through telescopes, were exaggerated by the optical effect, and that the Copernican universe did not have to be so huge.
If clear discoveries in the customary history of the Copernican revolution confront the omnipotent establishment, it is not surprising that some people expect quick and clear answers and discoveries from science, and they see the hand of secreted influential forces in scientific obscurity. We would all have more realistic expectations from science if we instead found out that the Copernican revolution contained dynamic mutual concessions, that there were reasonable people on both sides of this process, and that discoveries and progress go unevenly, with hesitation, and sometimes lead to dead ends - such as giant Kepler stars. When we understand that the simple question of whether the Earth is moving has been a very complex scientific problem for quite a long time, then we will understand that today's scientific questions can give us complex answers, and then only with time.