Galileo Galilei made many discoveries that changed the face of science as we know it today, but along the way he made several mistakes and drew wrong conclusions. Even the smartest scientists make mistakes! What can be learned from mistakes?
Written by: Zvi Atzmon
of: Young Galileo, issue 200 September 2020
Galileo Galilei is considered the father of modern science. He made many important and revolutionary discoveries, invented and perfected many research instruments and laid the foundations for the scientific method used to this day, which relies on conducting experiments and conducting observations.
Galileo was a rebel by nature - if the results of the experiments and observations he made and his common sense indicated that he was right, he did not submit to an authority that claimed the opposite, even if that authority was as powerful in his time as the Catholic Church. This tendency of his to examine and test and not submit to authority caused him difficulties and conflicts, including house arrest until his death and a complete ban on the publication of science books (Galileo found a way to circumvent this ban - printing his book in Holland, which was not subject to the Catholic Church).
Galileo's achievements
falling Free: When bodies fall in free fall, without any foreign factor (such as air resistance) interfering, all bodies, light and heavy, fall at the same rate.
pendulum: The duration of the oscillation of a pendulum depends on the length of the string to which the pendulum weight is tied, but not on the degree of deflection (amplitude) of the weight - this discovery allowed Galileo to accurately measure short times, for example for the purpose of studying free fall, and is the basis of pendulum clocks.
persistence: If there is no intervention of an external factor (such as friction), a body in motion at a certain speed will continue to move forever at the same speed, and there is no need for an external factor (such as an engine) to push it. This principle allowed Galileo to explain how the Earth continues to orbit the Sun, and like it the other planets orbiting the Sun (the heliocentric concept - the Sun in the center), and not that the Sun orbits the Earth.
telescope: The telescope, which had been invented a short time before, was considered an amusement by the public; Galileo perfected the use of the telescope as a tool for studying the celestial bodies - something that had never occurred to anyone before him.
Identifying terrain features, such as surfaces and craters, on the surface of the moon, and hence the conclusions that the structure of the moon is essentially similar to the earth and that it is not made of some special celestial material, subject to special laws of nature, as was thought before him.
Identify four bodies (moons) that orbit the planet Jupiter Named after him - Galileo's moons (Io, Europa, Callisto and Ganymede). They were also proof that not all celestial bodies revolve around the Earth.
Identifying sunspots: Galileo discovered spots on the surface of the sun with his telescope. This discovery made him very angry because it testified that the sun is made of "earthly" materials, and not of "pure" materials, different in essence from those of the earth; The spots also indicate that the sun itself rotates on an axis.
Discovery of Venus shows and its apparent size: Galileo discovered that the planet Venus has appearances (like the moon; sometimes it is full, sometimes it appears as a semicircle, and sometimes as a thin sickle) and that the appearances are related to its apparent size: when it is full it appears small, and as a sickle it is large, and this proves that the planet Venus orbits not Earth but the sun. This is further evidence of the heliocentric concept.
Discovering the structure of the Milky Way galaxy: Galileo discovered through his telescope that the Milky Way is not a mysterious and continuous band of light across the sky, but is made of many separate stars - this is our galaxy, the Milky Way galaxy.
Discovery of Saturn's rings: Galileo saw that the planet Saturn has appendages on both sides. Today we know that he discovered the rings surrounding Saturn.
microscope: Galileo invented the microscope consisting of two lenses, not one.
thermometer: Galileo invented a thermometer (actually an early model of a thermometer, called a thermoscope). Galileo's thermoscope was based on the expansion of air and the rise in temperature.
These are outstanding achievements. Many of them would have awarded him Nobel Prizes, if there had been such a prize in his day... but alongside his glorious achievements, Galileo also made some mistakes. Some of them can certainly be justified, and important conclusions can be drawn from all of them.
Saturn's earrings?
Galileo discovered through his telescope that the planet Saturn has two appendages, like earlobes. How did Galileo make a mistake between the rings surrounding Saturn and between appendages like ears? It turns out that this mistake resulted from a combination of two factors: although the telescope he built was the best in those days, it was very weak compared to modern telescopes.
Added to this was the fact that Saturn's rings sometimes point their wide area towards the Earth, and then it is easy to notice them with a telescope, but sometimes they turn their side, the profile, towards us, and then it is difficult to notice that they are rings and not appendages on both sides of Saturn. This was the case when Galileo observed Saturn, that is, Galileo discovered the rings of Saturn, but he had no way of distinguishing that they were indeed rings.
Where are the comets?
Galileo was wrong to think that comets are a phenomenon that occurs inside the Earth's atmosphere (like the aurora borealis) and not that they are far outside the atmosphere, as we know today. This is indeed an embarrassing mistake, especially considering that even earlier the renowned Danish astronomer Tycho Brahe claimed, based on observations he made of a comet seen in his day, that comets are far beyond the orbit of the moon.
Persistence only in a straight line
Galileo had another mistake regarding the phenomenon of persistence, even though Galileo's discovery of persistence was a huge revolution in mechanics - the field of physics that deals with the forces acting on bodies and the movements of bodies.
In ancient times and the Middle Ages there was the concept that in order for a body to move something must continue to push it. Only the celestial bodies (such as the entire dome of the sky, as well as the moon and the planets), so they thought, have a constant, circular motion, by virtue of being celestial, without the need for a factor to push them. If all movement requires a constant push, the heliocentric view has to answer the question of what can constantly push the giant Earth around the Sun.
Through a thought experiment that Galileo devised and which was based on actual experiments that he conducted, he concluded that there is a persistence of motion. This explained the question of how the Earth could continue to orbit the Sun without something pushing it.
The phenomenon of persistence was therefore, both in terms of mechanics and in terms of the heliocentric view of the structure of the universe, an important and revolutionary discovery.
But this revolutionary discovery was accompanied by a mistake. Later it became clear that persistence takes place along a straight line, while the movement of the earth around the sun is not a straight line. Therefore, another factor is required, apart from persistence. This factor was deciphered by a genius physicist who followed Galileo - Isaac Newton. Newton (born a few months after Galileo's death) found that persistence occurs only along a straight line.
The Earth's orbit around the Sun depends not only on persistence but also on the existence of gravity. The phenomenon of persistence and the sun's gravity are together responsible for the orbit of the earth and the other planets around the sun. Since Newton corrected Galileo's mistake, the phenomenon of persistence is also called "Newton's first law of motion".
What do the tides come from?
Galileo's most striking mistake is the explanation he gave for the phenomenon of tides. A tide is the phenomenon in which the coastline advances towards the land, while a low tide is when the coastline recedes towards the sea.
Galileo tried very hard to convince his contemporaries that the concept that the sun is in the center and the earth goes around it once a year is the correct one. He also tried to convince them that our feeling as if the dome of the sky, including the sun, circles the earth once a day is an illusion that comes from the fact that the earth completes one revolution on its axis once a day.
To find convincing evidence for this, Galileo turned to the phenomenon of tides. It was based on an actual observation he made. When he sailed in an open tanker carrying drinking water, he saw that when the tanker suddenly stops (for example, when it encounters a sandbank), a "tide" is formed on its front side - the water accumulates there and its height rises, while the surface of the water at the stern (back side) falls. Here, he thought, is a real tidal phenomenon.
Galileo was so anxious to find proofs of the earth's motions that he did not give his mind to the fact that the phenomenon of tides returns almost twice a day, and not just once; He also did not carefully consider the proposal of the genius astronomer of his generation Johannes Kepler, that the moon affects the phenomenon of tides and tides.
Galileo was, in addition to being an astronomer, also a physicist who studied motion and relied on experiments, while Kepler, who was a genius astronomer, did not deal with physics, and sometimes tended to mysterious explanations. Galileo preferred to rely on his observations in a water tank rather than on explanations he could not test, such as the influence of the moon.
However, even though Galileo thought he had found the explanation for the phenomenon of tides and that this explanation fits well with the heliocentric concept, he left room for the possibility that he was wrong, and thus wrote: "I hope that the explanation I offer for the phenomenon of tides will not turn out to be a dream hallucination... This is me I leave it to the judgment of talented researchers."
Indeed, Galileo was wrong. Newton proved that the phenomenon of tides is largely due to the effect of the moon (and to a lesser extent the effect of the sun) on the oceans and seas of the earth, through the force of gravity - a force that Newton revealed and which Kepler and Galileo did not know about.
What can be learned from the mistakes of a genius?
You can and should learn from mistakes, especially when it comes to the mistakes of a genius like Galileo Galilei. One of the conclusions is that every person, even the best of the best, and even if he is one of the most intelligent scientists of all generations and has a magazine for curious children named after him, is ultimately a person, and as a person he can make mistakes. The attempt to present a certain person as if he is immune from mistakes is a very dangerous attempt, and we can learn about this from many examples in history.
And a more personal conclusion: even if you were wrong about this or that, it is important to remember that you still have a chance to make an important, and perhaps even a revolutionary, contribution to science, technology and humanity in general.
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Regarding dear,
Allow me to seriously doubt your words, since they stem from a worldview that is clearly anti-religious.
You claim that tyrants and murderers used Judaism, Christianity and Islam as a basis for their behavior, and apparently the problem is with "religions", but remind you that the Nazis used "science" to justify the degeneration of the Jews and the "evolutionary" need to get rid of them.
The problem is not religions but fanaticism and evil, that evil factor will use everything at his disposal to commit immoral acts - for some religion and for others science.
Therefore, the solution is values before rituals and labels on people - the values represented by Judeo-Christian morality are values that most people should adopt, the spirit of skepticism and asking questions is without a doubt a Jewish value (you are invited to look in the bookcase for a publication called Gemara), and about liberalism?
Liberalism also needs limits, like everything in nature, and as soon as you release the brakes completely, you get an anarchy that consumes the open and free society that we all want.
In a certain sense you are right, the tide is when the water line advances and penetrates more into the land and the sea level rises, the low tide is the opposite, the water line recedes and the sea level falls, but to an observer on land it looks exactly the opposite, so both are right and both are wrong. The important lesson is, never accept anything as Torah from Sinai, meaning you must doubt even the words of the wisest, because every "truth" can have another "truth". This is the foundation on which humanity evolved from a state of tyrants and slaves, from merciless murderers to liberal regimes and granters of equal rights, all other truths, Judaism, Christianity and Islam were used at one stage or another as an ideological infrastructure for tyrants greedy for power, power and rule, no good has grown for humanity from all these religions.
Really nice article. But another mistake in it: Galileo did not invent the microscope. In the Galileo Museum in Florence there are three microscopes previously attributed to Galileo. Later research showed that two of them made of brass are probably unfinished experiments from the 18th century (long after his time) and one still attributed to him was created by the microscope maker Giuseppe Campani of Rome (1715-1635). Galileo probably only used such a microscope. The first compound microscope was probably invented in Holland at the beginning of the 17th century, but there is no agreement on this.
You are right, the water does not advance or recede, the height of the water simply rises at high tide and since the coastline is rising construction, it looks as if the water is advancing towards the coast and at low tide it recedes, but it is simply a matter of the height of the water and the coastline will be sealed
Our ancestors already knew that it was the moon that affects tides and those who lived for example near the Dead Sea therefore believed in the moon god. It turns out that they were much smarter than you think.
it is the same thing. When balding, the forest recedes or the forest advances. The new situation can be described in two ways.
Nevertheless, keep moving!
In every physical or philosophical parameter this theorem attributed to Galileo is his true legacy to humanity, beyond any discovery to his credit.
Interesting and "nice" article
with a glaring error (1),
Write:
"A tide is the phenomenon in which the coastline advances towards the land,
Whereas low tide is when the coastline recedes towards the sea.
is that so ?
And for Tommy, I always thought that what moves, advances and recedes is the water,
The water rises/advances and falls/retreats,
The beach is a stable line (even if not permanent),
Is this a mistake in the wording or my mistake?