Forces and movements

Forces and movements

The gravity It is the force of attraction between objects. In the Universe all matter moves because of it and other forces.

Gravity depends on the mass of the objects and the distance that separates them. The more mass they have and the closer they are, the greater the force. When the double is separated, the force is reduced to a quarter.

Gravity acts as if the entire mass of a body is concentrated in a single point, the center of gravity. The spherical area around a body where its gravity acts is the gravitational field.

The law of universal gravitation was formulated by British physicist Isaac Newton in the year 1684.

If we left two bodies with mass and at rest, without any other force acting except their attraction, they would inevitably collide. But in the Universe there are many "seriousnesses", other forces act and the bodies are in motion.


A gravitational collapse is when a body becomes smaller as a result of its own gravity, for example, a gas cloud to form a star, or a star to form a black hole. The atoms are broken and the building crumbles.

Atoms are empty boxes where a force maintains the structure. But, if gravity exceeds this force, the central structure does not hold and matter initiates a chain reaction.

The density increases (the body becomes small without losing mass), the gravitational field intensifies and collapse occurs.

Fundamental Forces of the Universe

There are four fundamental forces, which determine all forms of interaction of matter:

- Strong nuclear interactions,
- Weak nuclear interactions,
- Electromagnetism and
- Gravity or gravitation.

Gravity is the weakest of the four and the only one that only acts in one direction. Scientists speculate on whether the complementary one exists. In 2015 the first were detected gravitational waves of history, which opened a whole universe of new possibilities.


Stars, galaxies and the entire Universe move. Another thing is to detect the movement of some bodies, especially the most distant.

The movement of many objects in the Universe has been measured. Thus we know that, to move an apparent distance equal to the diameter of the moon, the closest star Alpha Centauro, needs 506 years. Arturo needs 815; Sirius, 1,410; Altair, 2,830; Capella, 4270 and Fomalhaut, more than 5,000.

The trajectory of an object that revolves around another is called an orbit. The orbital period is the time it takes for the object to complete an orbit. It seems that all objects, in space, orbit around others with more mass.

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