Pierr Simone Laplas (1749 - 1827).

"That what we know is so insignificant comparing with what we don't know."

(Pierr Simone Laplas.)

For his bright intellect and an outstanding achievements in several sciences (astronomy, physics, mathematics) Laplas was called "a French Newton".

He became a consistent follower of Newton and rut a task before himself of explaining the planets motion, the movement of their satellites, the ocean rising tides in the Earth and a complicated motion of the Moon. Laplas showed that the planets inequalities should be periodical (based on Newton's gravitation principal). For example Saturn's slowing down must change to its acceleration and so on. This means that the Solar system is stable.

In 1778 - 1785 Laplas continued to improve the theory of indignations. He used it for the comet's motion analysis. He showed that firstly the comet moved according the Sun on hyperbolic orbit, but coming near the Sun it would suffer a gravitation force. Its orbit might become an elliptical and periodically it returned to the Sun. In 1789 Laplas built a theory of Jupiter satellites' movement.

In 1795 Laplas wrote a remarkable book "The World system's exposition", where he put together all the astronomic knowledges of the XVIII century, without any formulas. He told about a calendar, eclipses, planets motion, ets. In his book Laplas came to the conclusion that there were so solid massive bodies in Universe, that the light could not leave them. Now they are called the black holes.