How can you prove that the Earth is rotating? 5

Foucault pendulum experiment.

Foucault pendulum refers to a pendulum that moves in a fixed plane of inertial space only by gravitational and hanging wire tension. In order to prove that the earth is rotating, the French physicist Foucault made a successful swing experiment in 1851, thus strongly proving that the earth is rotating, hence the name Foucault's pendulum.

This pendulum inertia and momentum are large and the oscillation time is very long. In the Foucault pendulum experiment, it is seen that the swing plane slowly rotates in a clockwise direction during the swing, and the swing direction is constantly changing. According to the law of inertia, the spatial direction of the swing does not change, so it can be seen that the change in the direction of the swing direction is the result of the rotation of the earth where the observer is located in the counterclockwise direction, and the observer on the earth sees the relative motion phenomenon, thus strongly proving that the earth is rotating.

In 1851, in the State Funeral Home (Pantheon of the French Republic), Foucault hung a 67-meter-long rope from the dome of the hall, underneath which was a pendulum weighing 28 kilograms. Underneath the pendulum is a huge sand table. Whenever the pendulum passes over the sand table, the pointer on the pendulum leaves a trail of movement on the sand table.

According to the experience of daily life, this huge pendulum should draw the only trajectory on the sand table. The experiment was named one of the "most beautiful experiments in physics".

Refer to the encyclopedia "Foucault pendulum").

Steering of the water in the toilet bowl.

With the development of science and technology, there are many ways to prove that the earth is rotating.

1."Foucault pendulum.

When the swing occurs, the dial on the ground shifts from the swing direction of the pendulum.

In the Foucault pendulum test, it is seen that the plane of oscillation is clockwise during the swing.

The direction rotates slowly, and the direction of the swing is constantly changing. Analyzing this phenomenon, the swing plane direction is not affected by external forces, according to the law of inertia.

The spatial direction of the swing does not change.

Therefore, it can be seen that this change in the direction of the oscillation is due to the observer.

As a result of the Earth rotating in a counterclockwise direction, observers on the Earth see the phenomenon of relative motion, thus providing strong evidence that the Earth is rotating.

2.The sun, moon and stars rise in the east and set in the west every day. All of these phenomena prove that the Earth is rotating.

3.Toothpick method

First fill a basin with water, put it in a horizontal and non-vibrating place, after the water is still, gently put down a thin wooden toothpick, and make a mark at one end of the toothpick, remember the position of the toothpick, after a few hours (preferably more than 10 hours), when you look again, you will find that the toothpick has rotated at a certain angle, it looks like the toothpick is rotating, in fact, it is not rotating, but the earth is rotating.

In the Northern Hemisphere, toothpicks are rotated clockwise as the Earth rotates.

In the Northern Hemisphere it appears to be counterclockwise, in the Southern Hemisphere.

The opposite is true for the Northern Hemisphere.

In the 16th century, "heliocentrism."

The founder of Copernicus.

The rotation of the earth is proposed.

theories. However, this theory was not confirmed by the French physicist Foucault until the 19th century.

Foucault was a famous French physicist, born on September 18, 1819 in Paris, France. He spent his early years as a doctor and later turned to physics. In 1853, Foucault received a doctorate in physics and became a professor of physics at the Paris Observatory.

In 1851, on the dome of the Pantheon in Paris, France, Foucault used a Foucault pendulum designed by himself.

The rotational motion of the Earth is demonstrated. Foucault's pendulum is mainly composed of a metal wire and an iron ball, and the wire that is the length of the pendulum is more than 67 meters long, which is very fine. On top of the wire hangs a 28 kg iron ball with a diameter of about 30 cm as a pendulum.

Based on the theory of the rotation of the earth, Foucault proposed that the rest of the earth except the equator, a single pendulum.

The vibration surface will rotate. He hung the Foucault pendulum from the dome of the temple** so that it could swing freely in any direction, with a sand table with a diameter of 6 meters and a starting bolt placed underneath.

If the earth rotates, then the oscillating surface of the pendulum will rotate; If the Earth had not rotated, the oscillating surface of the pendulum would have remained the same. The experiment began. It is astonishing to see that with each vibration of the Foucault pendulum, the tip of the pendulum moves 3 mm on the sand table and deflects 11° 20 per hour'After 31 hours and 47 minutes, it returned to its original position.

The direction and speed of the Foucault pendulum correspond to the Parisian dimension, which is 31 hours and 47 minutes for one rotation. Later, the experiment was redone at the Paris Observatory with the same conclusion.

Question 1: How to prove that the earth is rotating The earth is rotating and revolving around the sun. How can we prove that the Earth is rotating?

It is said that Galileo once did such an experiment: on the balcony of the top of the tower, there were many lead balls of different diameters, he pushed two lead balls of different weights down at the same time, observed their falling, and found that the large and small balls hit the ground at the same time, and they did not fall vertically, but slightly to the east.

Objects thrown from towers or mine mouths are slightly easterly when they land.

What kind of object will the appearance of the ground be biased? It turns out that the size of the arc formed by the top of the tower and the base of the tower when the earth rotates is different, and the arc at the top of the tower is larger than the arc at the base of the tower, and the linear velocity is also larger. In this way, the object that falls freely from the top of the tower, according to the law of inertia, will definitely maintain its original speed, therefore, the object will walk in front of the bottom of the tower, fall a little off, the higher the tower, or the closer the test place is to the equator, the more obvious the deviation will be.

In the lobby of the Beijing Planetarium**, there is a "Foucault pendulum" that proves the rotation of the earth, and the direction of the swing is about 37 hours and 15 minutes.

Other natural phenomena caused by the rotation of the earth can also prove that the earth is rotating, and the earth is an oblate sphere, which changes its shape due to the centrifugal force generated by the rotation of the earth. Under the influence of the Earth's rotation, objects moving horizontally on the Earth, regardless of which direction they move, will undergo deflection. In the Northern Hemisphere, the right bank of rivers is always susceptible to erosion, and when the air flow moves horizontally, it deflects to the right, and the shells fired also deviate to the right.

In the same way, in the Southern Hemisphere, the left bank of the river is always susceptible to erosion, and when the air flow moves horizontally, it deflects to the left, and the shells fired also deflect to the left.

Question 2: Who proved that the earth is rotating and explained the method of proving the rotation of the earth In the 6th century, Copernicus, the founder of the "heliocentric theory", proposed the theory of the rotation of the earth based on the principle of relative motion. For a long time after he proposed this theory, it could only stay at the level of subjective acceptance, until the 19th century, when it was confirmed by a French physicist named Foucault with an experiment designed by himself.

Foucault experimented with a special pendulum. The pendulum consists of a 27-kilogram iron ball with a diameter of about 30 centimeters suspended from a slender wire more than 60 meters long. At that time, people called this never-before-seen "super pendulum" "Foucault pendulum".

Question 3: How to prove that the earth is rotating You only need to look at the difference between the morning and afternoon of the sun, if the earth only revolves but does not rotate, then the sun will always be fixed at the same angle.

Categories: Education, Science, >> Science & Technology.

Analysis: Methods of proving the rotation of the Earth:

1.Toothpick method

First fill a basin with water, put it in a horizontal and non-vibrating place, after the water is still, gently put down a thin wooden toothpick, and make a mark at one end of the toothpick, remember the position of the toothpick, after a few hours (preferably more than 10 hours), when you look again, you will find that the toothpick has rotated at a certain angle, it looks like the toothpick is rotating, in fact, it is not rotating, but the earth is rotating. In the Northern Hemisphere, the toothpick rotates clockwise because the Earth's rotation appears counterclockwise in the Northern Hemisphere. The Southern Hemisphere is the opposite of the Northern Hemisphere.

2.Cannonball method.

The earth is constantly rotating, and objects moving horizontally on the ground must have a continuous deviation to the right (northern hemisphere) or left (southern hemisphere).Based on this phenomenon, one can prove that the earth is rotating by analyzing the direction of the movement of the projectiles.

3.Gravitational acceleration method.

The earth rotates constantly at all times, and due to the action of inertial centrifugal force, the gravitational acceleration of the ground must be the smallest at the equator and the largest at the poles; The Earth cannot be a positive sphere, but must be a spheroid with a slightly bulging equator and slightly flattened poles. The results of gravity measurements and radian measurements confirm the correctness of these views, which also confirms the rotation of the earth from one side.

4.Deep well measurements.

The earth is constantly rotating, because the rotation speed increases with the height, the object must have a high eastward rotation speed in the process of falling from a height, and it will inevitably fall to the easterly location. To confirm this, tests were carried out in very deep mines. The results of the test were:

The object falling from the center of the wellhead always collides with the east wall of the mine at a certain depth, confirming the rotational motion of the earth from another side.