Absolutely all bodies that have a finite mass interact with each other due to the so-called force of attraction or gravity. Let's give a definition of gravity in the article, and also consider what role it plays in nature and space.
What is gravity or gravity?
In physics, the definition of gravity or gravity is given as follows: it is the force with which two bodies that have mass are attracted to each other. This means that every person is attracted to any object that he encounters in his life. However, this power is so small that it is not felt.
The manifestation of gravity is noticeable when among the interacting bodies there is an object with a huge mass, for example, our planet. In many problems in physics, the definition of gravity is reduced to the concept of the attraction of objects to the Earth. In the latter case, they talk about body weight, which is calculated by the formula P \u003d mg. Here m and g are the mass of the body and the acceleration due to gravity, which is approximately 9.81 m/s2.
Sir Isaac Newton and gravity
For the first time exhaustiveThe definition of gravity was given at the end of the 17th century by the great English scientist Isaac Newton. He was able to combine the disparate knowledge and empirical observations that existed at that time (Galileo's concept of the inertia of bodies and Kepler's laws) and formalize them in the form of a coherent theory, called "Celestial Mechanics".
According to Newton, all bodies are attracted to each other with a force that is written by the following formula
F=Gm1m2/R2 where
m1 and m2 - body masses, R - distance between them, G=6, 67410-11Nm2/kg2is the universal gravitational constant.
The force of gravity (gravity) F acts at absolutely any distance, is directed towards the center of mass of bodies and quickly decreases with increasing distance between them.
If we substitute the value for the mass and radius of the Earth into the marked formula, then we can get the above-mentioned acceleration g.
Effects due to the existence of gravity
Gravity has been defined above, but it has not been said what role it plays in our lives. Firstly, thanks to its existence, we do not float in the air, but stand firmly on the surface, and the air itself does not fly into outer space. Secondly, any thrown body falls back to the ground. Thirdly, when calculating the flight trajectories of free bodies, taking into account the influence of this force is fundamental. Finally, the force of gravity is the main factor that determinesfeatures of the movement of our planet around the Sun, and in general the movement of any space bodies.
Currently, scientists around the world are trying to combine gravity with other fundamental forces to create a unified physical theory of our universe.
