Computer

A computer is a machine for manipulating data according to a list of instructions known as a program.Computers are extremely versatile. In fact, they are universal information-processing machines. According to the Church–Turing thesis, a computer with a certain minimum threshold capability is in principle capable of performing the tasks of any other computer. Therefore, computers with capabilities ranging from those of a personal digital assistant to a supercomputer may all perform the same tasks, as long as time and memory capacity are not considerations. Therefore, the same computer designs may be adapted for tasks ranging from processing company payrolls to controlling unmanned spaceflights. Due to technological advancement, modern electronic computers are exponentially more capable than those of preceding generations .

Computers take numerous physical forms. Early electronic computers were the size of a large room, while entire modern embedded computers may be smaller than a deck of playing cards. Even today, enormous computing facilities still exist for specialized scientific computation and for the transaction processing requirements of large organizations. Smaller computers designed for individual use are called personal computers.

Volcano

A volcano is a geological landform usually generated by the eruption through a vent in a planet's surface of magma, molten rock welling up from the planet's interior. Volcanoes of various types are found on other planets and their moons as well as on earth. Roughly defined, a volcano consists of a magma chamber, pipes and vents. The magma chamber is where magma from deep within the planet pools, while pipes are channels that lead to surface vents, openings in the volcano's surface through which lava is ejected during an eruption.

Though the common perception of a volcano as mountain spewing lava and poisonous gases from a crater in its top is not wrong per se, the features of volcanoes are much more complicated and vary from volcano to volcano depending on a number of factors. Some volcanoes even have rugged peaks formed by lava domes rather than a summit crater, whereas others present landscape features such as massive plateaus. Vents that issue volcanic material and gases can be located anywhere on the landform

Lighthouse of Alexandria

The Pharos of Alexandria was a lighthouse built in the 3rd century BC on the island of Pharos in Alexandria, Egypt to serve as that port's landmark, and later, a lighthouse.With a height variously estimated at between 115 and 135 metres it was among the tallest man-made structures on Earth for many centuries, and was identified as one of the Seven Wonders of the World by classical writers.It ceased operating and was largely destroyed as a result of two earthquakes in the 14th century AD; some of its remains were found on the floor of Alexandria's Eastern Harbour by divers in 1994. More of the remains have subsequently been revealed by satellite imaging.

Constructed from large blocks of light-coloured stone, the tower was made up of three stages: a lower square section with a central core, a middle octagonal section, and, at the top, a circular section. At its apex was positioned a mirror which reflected sunlight during the day; a fire was lit at night. Extant Roman coins struck by the Alexandrian mint show that a statue of a triton was positioned on each of the building's 4 corners. A statue of Poseidon stood atop the tower during the Roman period.

Solar System

The Solar System or solar system is the stellar system comprising the Sun and the retinue of celestial objects gravitationally bound to it: the eight planets, their 162 known moons, three currently identified dwarf planets and their four known moons, and thousands of small bodies. This last category includes asteroids, meteoroids, comets, and interplanetary dust.
The principal component of the Solar System is the Sun astronomical symbol ; a main sequence G2 star that contains 99.86% of the system's known mass and dominates it gravitationally.

Because of its large mass, the Sun has an interior density high enough to sustain nuclear fusion, releasing enormous amounts of energy, most of which is radiated into space in the form of electromagnetic radiation, including visible light. The Sun's two largest orbiting bodies, Jupiter and Saturn, account for more than 90% of the system's remaining mass.The currently hypothetical Oort cloud, should its existence be confirmed, would also hold a substantial percentage.