History of Science

Cao Tianyuan’s Column

As for Galileo, the next step is naturally to talk about his world-famous story: the ball-throwing experiment from the leaning tower. In a 2002 selection by Physics World magazine, it ranked second among the most beautiful physics experiments ever. And if we talk about popularity, I believe that in the history of science, there is no other physics experiment that is as famous as it is and is a household name.

In August 1971, the Apollo 15 astronauts even repeated the experiment using a feather and a hammer on the lunar surface and broadcast it live to the public. Galileo's glory still shines on the moon. In fact, everything in the world has to obey his command obediently and fall on the ground tamely and at the same time under the same acceleration of gravity.

However, as skeptics, what we always have to ask is, did this famous story really happen in history?

Looking back at history, the first person to record this incident was a student and assistant of Galileo in his later years named Vivani. He wrote a biography of Galileo, mentioning that when the scientific giant was 25 years old and still a professor at the University of Pisa, he conducted this experiment on the famous Leaning Tower in front of many students and professors, which made him an instant success. This breaks Aristotle's misconception that heavy objects fall faster than light objects. What’s embarrassing is that, apart from this solitary piece of evidence, there are no descriptions or records from contemporaries that can verify this major event. If it was as big a hit as Vivani claimed, why wasn't there a single word left anywhere else?

Unfortunately, historians have discovered n loopholes in the biography Vivani wrote for his mentor. In order to elevate his status as a teacher, he always intentionally or unintentionally added luster to Galileo between the lines. As a result, many records were seriously inconsistent with history, which made the reliability of the material itself a big problem. What's more, Vivani himself never witnessed this experiment. He did not become Galileo's student until nearly 50 years after the incident. Even if he did not take the initiative to create, there is no guarantee that Galileo's own recollections were correct. You must know that Galileo was already in his late teens, blind, and only 4 years away from death.

Also, we are now fairly certain that Galileo was not the first to make the mistake of pointing out that heavy objects fall to the ground faster than light objects. Byzantine scholars had made this clear more than ten centuries before him. Not long before Galileo climbed the Leaning Tower, Italian scholars published detailed experimental results showing that there was no big difference in the landing time of objects of different weights. It seems that Galileo's demonstration, if it really existed, did not have such epoch-making significance as we usually understand it.

Object analysis: Young students are in the stage of physical and mental growth and development, and are full of curiosity about everything in nature. This text will take students into the field of science, listen to the rhythm of scientists' determination to explore, and taste the ground-breaking ideas, thereby stimulating the enthusiasm to climb the peak of science. Teaching ideas and goals: This is an article introducing the scientist Galileo. The author truly describes the scientist Galileo's continuous exploration on the road of science, showing the scientists' determination to explore and their endless struggle. When teaching, students should be guided to understand the relevant knowledge involved in the text, such as: the background of Galileo's life, the Leaning Tower of Pisa, the influence of Aristotle, etc., so that students can increase their knowledge; students should also be guided to conduct inquiries and inspire their classmates In addition, we should guide students to understand the importance of knowledge innovation and strive to innovate. Teaching focus: 1. Understand the relevant knowledge involved in the class and enrich the knowledge background. 2. Understand the importance of scientific knowledge and inspire the enthusiasm to climb scientific peaks. Teaching process: 1. Introduction 1. Show projection. Do you know Newton? (Brief description of the person: Newton was a great British mathematician, physicist, astronomer and natural philosopher. The apple fell to the ground.) Evaluation: He is a bright pearl in the history of science, and promoted the development of our mankind. Progress, but his greatness comes from ordinary life.

(Show fill-in-the-blank questions) After reading "Experiments on the Leaning Tower", I learned about Galileo. For example: scientists who are not afraid of threats, have the courage to explore, pay attention to practice, do not believe in authority, and love science. Ask students to analyze corresponding passages in the text. (Emphasis on students' main body reading) Example: (1) Some professors also scolded him to the point of scolding him. What does this ignorant young boy want to do? Analysis: "Ye" and "scold" show that students are so harsh towards their teachers. Even professors and thoughtful people are firmly opposed to Galileo's actions. "Blood-spraying" shows that the scolding is very fierce. "The sky is high and the earth is thick" refers to the complexity of things, and "the sky is high and the earth is thick" shows that in the minds of these people, Galileo was a naive and ignorant person. These words are derogatory, indicating the huge opposition that Galileo faced at that time. (2) The performance took place at the Leaning Tower of Pisa. The professors wore their purple velvet robes and walked in front of the tower. The students and the townspeople walked in front of them. Everyone was noisy and happy, ready to watch. Galileo made a fool of himself and was sentenced to death for his character. Analysis: The "performance" shows that this is just a public demonstration for Galileo. On the other hand, it reflects that Galileo is very confident that this is no longer an experiment. The professors wore robes to reflect their solemnity about the matter. On the other hand, it can be seen that they wanted to see what kind of absurd "game" Galileo would play on this representative building - the Leaning Tower of Pisa. The students "Unceremonious ridicule" made them most want to see how this ridiculous teacher would make a fool of himself. (3) His purpose was to re-examine Aristotle’s teachings on science, rather than accepting these teachings as gospel truth. His way of discovering the truth was not by memorizing Aristotle’s works, but by reciting Aristotle’s works. It is through studying the treasure book of nature. "Re-examination" means re-examination, and it also reflects that someone has tested it before, but failed to overturn Aristotle's conclusion, indicating that Galileo did not regard the previous conclusions as truth, but wanted to use experiments to prove it. It reflects Galileo's spirit of focusing on experimentation and practice and not superstitious about authority. (4) Galileo refused to stop his experiments. Galileo was happy to accept this challenge. "Refuse" shows Galileo's persistence, and "happy" shows Galileo's willingness to use experiments to prove his conclusions. Wait 2. Then, the title of the text can be changed to "The Life of Galileo"? (Learn how to write articles) Clarity: This is different from ordinary biographies written in chronological order? Master the ingenuity of conception. Group discussions, exchanges between teachers and students. (Teacher’s summary: The full text is developed along the lines of “The Enlightenment of the Swinging Hanging Lamp—Experiences of Students and Children—Experiments on the Leaning Tower of Pisa.” The text first describes how Galileo discovered the law of swinging. The writing is fascinating. This catches the reader at once, and then briefly describes Galileo's childhood and student years, and then focuses on Galileo's discovery of the law of free fall. This way of structuring the whole text not only gives readers a clear understanding of Galileo's life and two important events. Discovery. And it feels exciting and interesting to read.) (Teaching tips: The teacher should guide students to go deeper and solve them one by one. On the question of "What is the clever idea?" Students can freely discuss and express their own opinions, and encourage them to express their unique opinions.) 3. Extend and learn from Galileo. The students must have been deeply inspired by Galileo. You can summarize the experience of knowledge innovation from Galileo's deeds. I believe that as long as you do this, you will also succeed. Blackboard design Experiment on the Leaning Tower Love science Pay attention to practice Perseverance Challenge authority