One day in August 1493, the palace of Barcelona, a secret room. Ferdinand, with the assistance of two watchmakers and a carpenter, was building a timekeeping device that was more than 150 years ahead of its time.

Compared with the hardships of detonating the technology tree before, Ferdinand is now very relaxed, without the fatigue of insomnia at all, and there is no pressure to master each process skillfully. The craftsmen were only puzzled for a moment at first, and then it dawned on them that they were wise enough to finally say something that would make them understand.

This timekeeping device is the pendulum clock.

Before making a pendulum clock, it is first necessary to prove the isochronism of the pendulum by a single pendulum experiment.

The single pendulum ability does not need to be made at all, pull up a non-extendable rope, fix the upper end, and tie a small copper ball to the lower end to make a single pendulum. By hanging copper balls of different masses for oscillation, the isochronism of the pendulum can be obtained, and it is proved that the period of a single pendulum varies with the square root of the length of the pendulum.

From this principle, Huygens made the pendulum clock, and Ferdinand looked at the drawings of the first pendulum clock, and with the assistance of a skilled watchmaker, he effortlessly completed the invention and gave a successful practical lesson in popular science. The first generation of pendulum clocks had a large error of up to 20 seconds per day. But compared to the 15th-century clocks, the accuracy has been greatly improved, and there is still a lot of room for improvement.

Of course, pendulum clocks are still of no use for navigation. If the navigation wants to determine the accuracy, it can only honestly calculate the distance of the moon, compile the nautical calendar, and at the same time develop the nautical clock.

……

On September 9, 1493, three figures stood in the empty Alhambra Palace in Granada. In front of them were three pendulums—a single pendulum, a pendulum clock, and a heavy "Foucault pendulum", which should now be called the "Ferdinand pendulum".

It took Ferdinand a month, with the help of craftsmen, to come up with these three pendulum collections.

Now, the isochronism of the pendulum, which will be proved by Galileo in the future, has been verified by him in advance. Mr. Huygens's invention was also embarrassingly copied by him.

On the dome of the Alhambra, a large guy hangs, more than 200 feet of rope is more than 200 meters long, dozens of pounds of pendulum, and below it is a huge sand table.

Whenever the pendulum passes over the sand table, the pointer on the pendulum will leave a trajectory on the sand table. According to the experience of daily life, this huge pendulum should draw the only trajectory on the sand table. However, after each cycle of oscillations of this huge pendulum, the trajectory drawn on the sand table deviates slightly from the original trajectory.

"The earth is really turning." Juana was also a well-read Bible who "says that the earth is immovable......

"Oh God...... What does this mean......" The watchmaker, who realized the meaning of it, found that for the first time, he had such a very real doubt about the contents of the Bible.

"This means that the Bible cannot be taken literally," Ferdinand said, glancing at the bewildered watchmaker, "and it also means a new era of science......

"Of course, for now, it means you can't say what you see and think today!"

The watchmaker slammed his spirit: "Don't worry, I won't say a word, you know that my daughter and wife are in Sardinia...... I will forget everything I saw today. ”

"Huh? Forget? Ferdinand raised an eyebrow, "I'm just telling you not to say it." Don't forget, never forget, you should remember everything you see, this is not a tricky magic show, and it is not a heresy of ghosts. It's the truth, it's the science, it's the truth. ”

"It will be the last major scientific achievement of the 15th century."

Ferdinand was a little sad, as a king, he naturally could not immerse himself in the world of scientists.

Ferdinand had the illusion that he could be Newton in the 15th century, and he would bring out all the well-known scientific systems of classical mechanics, optics, thermal, electromagnetism, etc., and become a famous scientific giant through the ages.

Now it seems that it is not possible. Or rather, it can be done, but not as simple as he thinks.

First of all, he didn't have time. For the king, this is not the main business, just a side business.

Secondly, he has no conditions. It was also a time when Catholicism was dominating the intellectual and academic sphere. As a king, it is not impossible for him to challenge the Catholic order, but it will not benefit him, but it will harm his interests. For example, the Treaty of Tordesillas was imminent, and thanks to the papal support, Castile had a considerable advantage, and was not prepared to make concessions as it has historically. Why bother with the Pope? In any case, it is necessary to wait until the "Ninety-Five Theses" have been issued before they can act on their own, and by no means to abandon Catholicism, but to support Catholicism in exchange for the free development of scholarship.

Third, it is impossible for him to open science without restrictions. Ferdinand had already planned to establish a secret scientific research base and a secret intelligence agency in the future, and all his most shocking and time-ahead scientific theories and techniques could be secretly developed for a long time by people and organizations that were absolutely loyal to Spain, but many of them could not be made public. This is not to say that he has any black technology, but it involves the development correspondence between science and technology, science and industry.

For example, mechanics and optics in classical physics, he can throw them all out and promote the progress of Spain and even the whole of Europe. He could copy "The Mathematical Principles of Natural Philosophy" and "Optics" as they were, without worrying about what other countries were making. Anyway, if he could make a Jenny spinning machine, a Watt steam engine, and a railway locomotive with this thing, he would not be able to do it himself, and he would not dare to believe it at all, let alone the people under the feudal state system. The key to the first industrial revolution is the transformation of the social system, the establishment of the economic foundation, the encouragement of national policies (patent law) and the accumulation of technical experience, which are not fundamentally different from the empirical technological progress of ancient China.

But he didn't dare to publish heat and electromagnetism at will, which directly related to the basic theory of the second industrial revolution, especially electricity, is by no means just a famous American politician doing part-time kite flying. As soon as the Ford stack came out, Ferrari was born, and magnetism generated electricity, electricity generated magnetism, and magnetic force was generated...... Such a theoretical innovation will definitely turn European scientific theories upside down, and then it will inevitably affect the field of technology, who knows if Edison will be born in advance? This situation would have a huge impact on Spain's predominance, and then the whole course of history would be in shambles......

So Ferdinand decided that he would never set foot in scientific invention again until the 16th century, and this was the last time, the last tribute to the science of the 15th century.

In fact, it wasn't until 24 years later that Ferdinand really re-entered the realm of science.