In olden days, people used to draw circles with the help of a compass. But they could not draw a square equal in area to the circle. Since then, “squaring the circle” has been the name for the task of constructing a square, using a compass and a ruler, whose area would be equal to the area of a given circle.

Space exploration is a very complex and expensive undertaking. From our earlier days, mankind has dreamed of flying to the stars. But it was not until the 20th century that we were able to realize this dream- the first satellite was built, the first astronaut was sent into space, the first flight apparatuses was sent to the moon and Venus, and the first space station was sent into orbit.

Our daily habits affect our appearance, well being and state of health. Healthy eating habits help to a healthy lifestyle each day. A healthy person sleeps 7-8 hours per night, at which the body spends a lot of energy on recovery and growth. To replenish the level of glucose in the blood, which serves as fuel for the muscles and nervous system a healthy meal is very important.

Matter is everything that surrounds us, and we ourselves consist of may atoms, called chemical elements. In order to understand the origin of this diversity, one has to look into the distant past. According to the big bang theory the universe came into existence 13.7 billion years ago from a tiny point called the singularity. Calculations show that its density and temperature were infinitely high. At some point in time, the point began to grow and cool down- its energy began to dissipate through the expanding universe with great speed.