Learning About C# for Beginners

Learning About C# for Beginners C# is a general purpose object-oriented programming language developed at Microsoft and released in 2002. It is similar to Java in its syntax. The purpose of C# is to precisely define a series of operations that a computer can perform to accomplish a task. Most C# operations involve manipulating numbers and text, but anything that the computer can physically do can be programmed in C#. Computers have no intelligence- they have to be told exactly what to do, and their actions are defined by the programming language you use. Once programmed, they can repeat the steps as many times as needed at high speed. Modern PCs are so fast they can count to a billion in seconds. What Can a C# Program Do? Typical programming tasks include  putting data into a database or pulling it out, displaying high-speed graphics in a game or video, controlling electronic devices attached to the PC and playing music or sound effects. You can even use it to write software to generate music or help you compose. Some developers believe that C# is too slow for games  because it is interpreted  rather than compiled. However the .NET Framework compiles the interpreted code the first time it runs. Is C# the Best Programming Language? C# is a highly ranked program language. Many computer languages are written for a specific purpose, but C# is a general purpose language with features to make programs more robust.   Unlike C and to a lesser extent Java, the screen handling in C# is excellent on both desktops and the web. In this role, C# overtook languages such as Visual Basic and Delphi. Which Computers Can Run C#? Any PC that can run the .NET Framework can run the C# programming language. Linux supports C# using the Mono C# compiler. How Do I Get Started With C#? You need a C# compiler. There are a number of commercial and free ones available. The professional version of Visual Studio can compile C# code. Mono is a free and open-source C# compiler. How Do I Begin Writing C# Applications? C# is written using a text editor. You write a computer program as a series of instructions (called statements) in a notation that looks a little like mathematical formulas. This is saved as a  text file and then compiled and linked to generate machine code which you then can run. Most applications you use on a computer were written and compiled like this, many of them in C#. Is There Plenty of C# Open Source Code? Not as much as in Java, C or C but it is starting to become popular. Unlike commercial applications, where the source code is owned by a business and never made available, open source code can be viewed and used by anyone. Its an excellent way to learn coding techniques. The Job Market for C# Programmers There are plenty of C# jobs out there, and C# has the backing of Microsoft, so is likely to be around for a while.   You could write your own games, but youd need to be artistic or need an artist friend because you also need music and sound effects. Perhaps youd prefer a career as a business software developer creating business applications or as a software engineer.

The Formation of Planet Earth

The Formation of Planet Earth The formation and evolution of planet Earth is a scientific detective story that has taken astronomers and planetary scientists a lot of research to figure out. Understanding our worlds formation process not only gives new insight into its structure and formation, but it also opens new windows of insight into the creation of planets around other stars.   The Story Begins Long Before Earth Existed Earth was not around at the beginning of the universe. In fact, very little of what we see in the cosmos today was around when the universe formed some 13.8 billion years ago. However, to get to Earth, its important to start at the beginning, when the universe was young. It all started out with only two elements: hydrogen and helium, and a small trace of lithium. The first stars formed out of the hydrogen that existed. Once that process started,  generations of stars were born in clouds of gas. As they aged, those stars created heavier elements in their cores, elements such as oxygen, silicon, iron, and others. When the first generations of stars died, they scattered those elements to space, which seeded the next generation of stars. Around some of those stars, the heavier elements formed planets. The Birth of the Solar System Gets a Kick-start Some five billion years ago, in a perfectly ordinary place in the galaxy, something happened. It might have been a supernova explosion pushing a lot of its heavy-element wreckage into a nearby cloud of hydrogen gas and interstellar dust. Or, it could have been the action of a passing star stirring up the cloud into a swirling mixture. Whatever the kick-start was, it pushed the cloud into action which eventually resulted in the birth of the solar system. The mixture grew hot and compressed under its own gravity. At its center, a protostellar object formed. It was young, hot, and glowing, but not yet a full star. Around it swirled a disk of the same material, which grew hotter and hotter as gravity and motion compressed the dust and rocks of the cloud together. The hot young protostar eventually turned on and began to fuse hydrogen to helium in its core. The Sun was born. The swirling hot disk was the cradle where Earth and its sister planets formed. It wasnt the first time such a planetary system was formed. In fact, astronomers can see just this sort of thing happening elsewhere in the universe. While the Sun grew in size and energy, beginning to ignite its nuclear fires, the hot disk slowly cooled. This took millions of years. During that time, the components of the disk began to freeze out into small dust-sized grains. Iron metal and compounds of silicon, magnesium, aluminum, and oxygen came out first in that fiery setting. Bits of these are preserved in chondrite meteorites, which are ancient materials from the solar nebula. Slowly these grains settled together and collected into clumps, then chunks, then boulders, and finally bodies called planetesimals large enough to exert their own gravity.   Earth Is Born in Fiery Collisions As time went by, planetesimals collided with other bodies and grew larger. As they did, the energy of each collision was tremendous. By the time they reached a hundred kilometers or so in size, planetesimal collisions were energetic enough to  melt and vaporize  much of the material involved. The rocks, iron, and other metals in these colliding worlds sorted themselves into layers. The dense iron settled in the center and the lighter rock separated into a mantle around the iron, in a miniature of Earth and the other inner planets today. Planetary scientists call this settling process  differentiation.  It didnt just happen with planets, but also occurred within the larger moons and  the largest asteroids. The iron meteorites that plunge to Earth from time to time come from collisions between these asteroids in the distant past.   At some point during this time, the Sun ignited. Although the Sun was only about two-thirds as bright as it is today, the process of ignition (the so-called T-Tauri phase) was energetic enough to blow away most of the gaseous part of the protoplanetary disk. The chunks, boulders, and planetesimals left behind continued to collect into a handful of large, stable bodies in well-spaced orbits. Earth was the third one of these, counting outward from the Sun. The process of accumulation and collision was violent and spectacular because the smaller pieces left huge craters on the larger ones. Studies of the other planets show  these impacts and the evidence is strong that they contributed to catastrophic conditions on the infant Earth.   At one point early in this process a very large planetesimal struck Earth an off-center blow and sprayed much of the young Earths rocky mantle into space. The planet got most of it back after a period of time, but some of it collected into a second planetesimal circling Earth. Those leftovers are thought to have been part of the Moons formation story. Volcanoes, Mountains, Tectonic Plates, and an Evolving Earth The oldest surviving rocks on Earth were laid down some five hundred million years after the planet first formed. It ​and other planets suffered through whats called the late heavy bombardment of the last stray planetesimals around four billion years ago). The ancient rocks have been dated by the uranium-lead method  and appear to be about 4.03 billion years old. Their mineral content and embedded gases show that there were volcanoes, continents, mountain ranges, oceans, and crustal plates on Earth in those days. Some slightly younger rocks (about 3.8 billion years old) show tantalizing evidence of life on the young planet. While the eons that followed were full of strange stories and far-reaching changes, by the time the first life did appear, Earths structure was well-formed and only its primordial atmosphere was being changed by the onset of life. The stage was set for the formation and spread of tiny microbes across the planet. Their evolution ultimately resulted in the modern life-bearing world still filled with mountains, oceans, and volcanoes that we know today.  Its a world that is constantly changing, with regions where continents are pulling apart and other places where new land is being formed. These actions affect not just the planet, but life on it. The evidence for the story of Earths formation and evolution is the result of patient evidence-collecting from meteorites and studies of the geology of the other planets. It also comes from analyses of very large bodies of geochemical data, astronomical studies of planet-forming regions around other stars, and decades of serious discussion among astronomers, geologists, planetary scientists, chemists, and biologists. The story of Earth is one of the most fascinating and complex scientific stories around, with plenty of evidence and understanding to back it up.   Updated and rewritten by Carolyn Collins Petersen.