### Earth’s Gravity

Why do all the material things on the earth fall towards the center of the earth? For example, we jump from a great height and come down. You can’t jump ten feet and reach a height of ten feet. why like this? Due to weight? (Of course it is important to understand the definition of weight)

What is weight? The earth pulls everything to its center. I, you and all the material things on the earth are stable because of the same gravity of the earth. If this gravity of the earth is removed, then the weight of Mount Everest on earth will be equal to zero. Weight is not a thing in itself, it is the gravitational pull of the earth, which we call weight. The more mass an object has, the more the gravity of the earth will affect it. What is gravity? Gravity is one of the secrets of nature, which makes us feel at home every moment, but hidden from view.

• Matter consists of four basic types, they are solid liquid gas and plasma. Matter is a mixture of different types of atoms.
• The amount of matter inside something is called the mass of that thing.
• Is called the volume of anything. As you take an area that is one kilometer long, one kilometer deep, it is called one cubic kilometer. The volume of the Earth is 1,083,206,916,846 cubic kilometers (the volume of the Sun is equal to 1.3 million Earths).
• Density is called density or density. Divide the total mass of a material by its volume and find out how dense the substance is. For example, to find out the total volume and mass of the earth and how much of the earth’s mass is contained in one cubic kilometer / cubic meter or cubic centimeter of the earth.
• Gravity is the force that any material body exerts when it pulls another material body towards itself. For example, “Earth’s gravity is 9.81 meters per second. An object dropped freely towards the earth increases its speed with each passing second by 9.81 meters per second. That is, if you hit a ball from a height. In the first second the falling speed of the ball will be 9.81 meters per second, in the second second the falling speed of the ball will be 19.62 meters per second and in the third second the falling speed of the ball will be 29.43 meters per second. As the falling ball gets closer to the ground, its speed (due to the reduced distance from the center of gravity) will increase by 9.81 meters per second. “

A body with more matter also has more gravity, just like our sun. The gravity of the sun is 28 times greater than the gravity of the earth. The falling speed of an object falling freely on the sun will increase by 274 meters per second. The greater the gravity of any material body, the harder it will be to escape. A speed of 11.2 kilometers per second would be required to free the earth from gravity. This is called escape velocity. A spacecraft traveling from Earth to space cannot be free from the gravity of the Earth without reaching a speed of 11.2 km per second.

The gravity of this body can be increased by reducing the volume of any material object and increasing its density. This is because the distance of the object from the center of gravity decreases.

“The diameter of the earth is 12742 km. If all the mass of the earth were made so dense that all the mass of the earth would be absorbed in a diameter of eighteen 18 millimeters, any body would have to travel as fast as light to escape the earth. And if the mass of the earth is trapped in a diameter less than 18 millimeters, then light will not be able to escape from the earth. The same thing happens in a black hole. As it becomes denser, its gravity increases exponentially, resulting in an increase in the escape velocity of the black hole. According to Albert Einstein, no material object can travel at the speed of light.

It doesn’t take us long to get to know gravity. There are many theories about gravity, which scientists have come up with from time to time in the past. Among these theories are the British scientist Isaac Newton’s Law of universal gravitation and the German scientist Albert Einstein’s General theory of relativity. In the seventeenth century (1666) Isaac Newton first considered why all things fall to the earth. Later Isaac Newton worked on it and introduced his thinking under the name of law of universal gravitation. “Gravity,” Isaac Newton told us. How and why is gravity? We learned this from Albert Einstein two and a half centuries later.

In November 1915, Albert Einstein introduced the general theory of relativity to the world. In 1916, the theory was published in the German scientific journal Annalen der physik. In this theory, Albert Einstein stated that:

• The universe is a “cloth” made up of time and space, that is, time and space.
• When something is placed on the cloth, which is made of material, the cloth will bend or deepen in that place.
• This cosmic sheet made of time and space is not permanent or static in its state, but due to the material it becomes soft / curved. That is, material bodies also affect time and space. The material body will bend in the cosmic space and the cosmic time will also change its direction.
• The more mass and density the material body has, the slower it will be in time. Even a very dense material body can force time to stop (an example is a black hole. The first black hole was discovered after Einstein’s passing in 1971, and Einstein’s statement proved true.)
• The heavier the body will be placed in this universal sheet, the more bend will be created in this place in this sheet. Due to this elbow, other material objects around this material object (in this curved area) will fall towards this elbow.

As time went on, Albert Einstein’s theory became clearer. Albert Einstein’s theory is considered one of the most important pillars of modern physics.

Everything on earth also attracts the earth because everything made of matter has gravity, even a human being pulls the earth towards itself by its own gravity, but anything on the earth is attracted to it. The mass of an object or a human being is not large enough to produce more gravity than the gravity of the earth. As a result, the earth’s gravity is pulling all the material objects on the earth towards its center. The same gravity of the earth keeps the moon in its orbit (but the orbital motion of the moon does not allow it to collide with the earth). The gravity of the moon causes the earth’s oceans to flood twice a day. The part of the ocean that is closest to the moon, in this part of the moon’s gravity waves rise high, the force created by the moon’s gravity is called tidel force.

Every material thing in the universe is dominated by gravity over a material thing smaller than itself. The moon revolves around the planets, the planets revolve around the stars. Most stars are bound to each other by gravity in clusters. Galaxies made up of billions of stars hold all the stars together by gravity. Even galaxies are not alone, but exist in clusters due to each other’s gravity (scientists have divided these clusters of galaxies into different groups).

Does gravity affect only us? Not only that, but gravity also affects light, time and sound. Changing the energy of light or turning the light, slowing down the time by creating a curve in space time and changing the behavior of sound waves are the mischief of gravity. Whatever it is, gravity is a great masterpiece of nature. Thanks to this, our satellites are in orbit around the earth. It is because of these satellites that we are taking advantage of the Internet, mobile phones and many other such important facilities.

Gravity is invisible, but it can be felt at every step.