Copernicus is nowadays an exuberantly honored person in Poland, considering the post stamps, taxi companies, T-shirts and cafeterias, all bearing his name. You cannot avoid it when visiting Torún, his hometown, or Olsztyn, the town where he worked as canon. A salient detail is, that in the days of the German-speaking and Latin-writing Copernicus, Poland did not even exist as a nation.
The Italian scholar and skilled experimenter Galileo Galilei (1564-1642) bought a Dutch spyglass on the market and improved it considerably. A spyglass presenting an upright image is called a 'Dutch spyglass'. This type of spyglass was invented simultaneously in 1609 by two lens grinders and polishers, Sacharias Jansen and Hans Lipperhey, both citizens of the Dutch city of Middelburg. Lipperhey was the first one applying for a patent for his invention 'voor de buyse waarmede men verre kan sien'('a tube for seeing things far away as if they were nearby'). Lipperhey's request for a patent was rejected however, because 'just everyone should be able to fix two pieces of glass behind each other'. Instead of its intended use, the early detection of ships at sea, Galileo looked straight up with it and discovered four moons circling around Jupiter.
Figure 2.3: Dialogo di Galileo Galilei Lincio
On the basis of his observation of the moons of Jupiter and of the moonlike phases of Venus, Galileo concluded that it was the sun that should definitely be at the centre of the solar system and that Copernicus had it right. He published his "Dialogo" in 1632 for which he had managed to obtain the church's imprimatur by stating in the preface, just like Copernicus, that its message was purely hypothetical. The book contains four dialogues conducted between three persons of which one, Simplicio, is the stupid fool. The arguments for the earth in the centre are expressed by him. Simplicio's arguments were easily recognizable as the same arguments that the then pope Urban VIII expressed. Although the pope was, until then, on friendly terms with Galilei, both being from the same region in Italy, and had protected Galilei thus far against the alarming attention of the Inquisition, the pope in his indignation then unleashed the Inquisition on Galilei. In order to protect his life and limbs Galilei had to withdraw his hypothesis publicly and thus kept his life but was under house arrest for the rest of his life. In 1992, only after 450 years, the church of Rome offered her apologies. The Vatican even considered placing a bust of Galilei in its gardens, but to date this has not been realized.
Galilei was well acquainted with the publication of Johannes Kepler (1571-1630) - "Astronomia Nova" - which appeared in 1609. Kepler had studied the observations of Tycho Brahe intensively, which were the most accurate registered measurements given the technology of the time. Kepler discovered, by his study of Tycho's tables, that the orbits of the planets were not God's perfect circles, but that they were elliptical. He discovered also that the planets did not move at uniform velocities along their trajectories. Which is Kepler's first law.
Figure 2.4: Kepler's second law.
Kepler's second law, the law of equal areas, is the best known by far. See figure 2.4. When a planet moves from A to B in the same time as from C to D, the grey marked areas in figure 2.4 are equally large.
Kepler's third law is also called the harmonic law [4]. The square of the orbital time of a planet is proportional to the third power of average distance from the sun.
Kepler formulated a mathematical equation, now called the Kepler's equation [5], with which the deviation of a fictitious circular trajectory of the planet in its orbit around the sun can be calculated.
Kepler's three laws [6] together with his equation formed the basis of Isaac Newton's law of gravitation in 1687.
The publications of Copernicus, Kepler and Galilei marked the end of an era of more than 1400 years during which the geocentric Ptolemaic model had been supreme. Until that moment, almost every respected scholar had committed himself to the Ptolemaic model, at least publicly. These conservative scholars, stubbornly holding on to their trusted old views, even refused to look through Galilei's telescope because they knew 'how the world was' and called it an instrument inspired by the devil which only showed you hallucinatory misleading images. This is cognitive dissonance, a common human behavior, avoiding world view disturbing facts. Proclaiming in those days that the earth was not at the centre of the cosmos was at the very least a bad career choice and could even be risky for your neck.
Sir Isaac Newton (1643 - 1727)
In the first two thirds of the twentieth century the physics taught in high school, and for an important part of that century also at universities, was still 100% Newtonian physics, also known as Newtonian mechanics. This foundation of Newton mechanics on which physics education nowadays is still resting for a large part is a great and rightful compliment to its original creator, Sir Isaac Newton [7].
In favorable contrast with Galileo, Newton did not live under the oppressing shadow of the Catholic church when compared to the unlucky Inquisition hounded Italian scholar. His was a country that had founded, by a king's whim, its own independent Christian church in 1534. In that respect he had little to fear from the Inquisition, still a fear instigating institution on the European continent. So, he had few godly qualms when putting the sun in the centre of the planets bound in their elliptical trajectories by indifferent gravity instead of by caring angels. Incidentally, Newton was a very godly man, however entertaining very private ideas concerning biblical correctness and its Roman Catholic dogmatic interpretations.
In the field of mathematics Newton developed, among other things, the differential calculus and the integral calculus (simultaneously with and independently of Leibniz), the binomial theorem and various approximation methods.
In his most important and influential publication in 1687 'Philosophiae Naturalis Principia Mathematica' [8] Newton explained, among other things, his law of gravity and the three laws of mechanics, with which he created the foundation of classical mechanics.
In 1704 Newton published Opticks [9], an as a standard in optics considered work. He invented the Newtonian mirror telescope to overcome the chromatic aberration problems of glass lenses, and developed a theory about the colors of light, based on the way a prism separates white light into a visible spectrum of colors. He also studied the speed of sound, thermodynamics and hydrodynamics.
According to a 2005 poll, members of the British Royal Society then regarded Newton as the greatest scientist in the entire history of science. Unlike Albert Einstein, Newton was not only a theoretician but also a brilliant experimenter.
The driving reason for the enormous success of Newton's theories and formulas was its predictive power. The day when a comet, we know now as Halley's comet, would reappear in the heavens was accurately predicted by Edmond Halley in 1705 by applying Newton's gravity theory. Halley didn't live to see his prediction verified. It was 16 years after his death that - right on schedule, in 1758 - the comet did return. With this success,