Kepler's LawsThese three laws concerning the movements of the planets made by the German astronomer Johannes Kepler in the early seventeenth century. Kepler based his laws on planetary data collected by the Danish astronomer Tycho Brahe, who was assistant. His proposals broke with a centuries-old belief that the planets moved in circular orbits.
First law: The planets orbit the Sun in elliptical orbits in which the Sun occupies one focus of the ellipse Law.
Swept by the line joining the Sun to the planet (radius vector) areas are proportional to the times used to describe them. Consequently, the closer the planet from the Sun faster moving Law.
The squares of the sidereal periods of revolution of the planets around the sun are proportional to the cubes of the semimajor axes of their elliptical orbits. This allows to deduce that the farthest planets orbit the Sun more slowly than nearby; says that the period of revolution depends on the distance to the sun.
These laws have played an important role in the work of the astronomer, English mathematician and physicist Isaac Newton seventeenth century, and are fundamental to understanding the orbital paths of the Moon and satellites artificial.
Gravitation is the property of mutual attraction possessed by all objects composed of matter. Sometimes it is used as the term "gravity", but this refers only to the gravitational force exerted by
Earth's gravity is one of the four basic forces that control the interactions of matter. So far have had no attempts to detect gravitational waves, as suggested by the theory of relativity could be observed when the gravitational field of a massive object is disturbed.
The law of gravitation, formulated by Isaac Newton in 1684, states that the gravitational attraction between two bodies is directly proportional to the product their masses and inversely proportional to the square of the distance between them.
The Doppler effectVarying the wavelength of light, electromagnetic radiation and sound of bodies reports its movement.
When a vehicle approaches its sharpest hear when engine goes away. Similarly, when a star or galaxy is approaching, the spectrum shifts to the blue, and if they walk away, toward the red.
For now, all observed galaxies are shifted towards the red, ie, away from here.
Translated from the website: http://www.astromia.com/