The History of the Compass and Other Magnetic Innovations

The History of the Compass and Other Magnetic Innovations A compass is an instrument containing a freely suspended magnetic element that displays the direction of the horizontal component of Earths magnetic field at the point of observation. Its been used to help people navigate for many centuries. Located in the same part of the public imagination as sextants and telescopes, its actually been in use for a lot longer than the sea voyages that discovered North America. The use of magnetism in inventions doesnt stop there, though; its found in everything from telecommunications equipment and motors to the food chain. Discovery Large deposits of magnetic oxides were found in the district of Magnesia in Asia Minor thousands of years ago; their location led to the mineral receiving the  name of magnetite (Fe3O4), which was nicknamed lodestone. In 1600,  William Gilbert published De Magnete, a paper on magnetism that details the use and properties of magnetite. Ferrites, or magnetic oxides, are stones that attract iron and other metals. These are natural magnets and are not inventions. However, the machines that we make with magnets are inventions. Magnetic Compass The magnetic compass is actually  an old Chinese invention, probably first made in China during the Qin dynasty (221–206 B.C.). Back then, the Chinese used lodestones (which align themselves in a north-south direction) to construct fortune-telling boards. Eventually, someone noticed that the lodestones were better at pointing out real directions, which led to the creation of the first compasses. The earliest compasses were designed on a square slab that had markings for the cardinal points and the constellations. The pointing needle was a spoon-shaped lodestone device with a handle that would always point south. Later on, magnetized needles were used as direction pointers instead of the spoon-shaped lodestones. These appeared in the eighth century A.D.- again in China- and between 850 and 1050. Compasses as Navigational Aids In the 11th century, compasses use as navigational devices on ships seemed to have become common. The magnetized-needle compasses used in navigation could be wet (in water), dry (on a pointed shaft), or suspended (on silk thread) and were used by voyagers, such as those traders who traveled to the Middle East, and were used by early navigators to locate the magnetic North Pole or pole star. Electromagnetism In 1819,  Hans Christian Oersted  reported that when an  electric current  in a wire was applied to a magnetic  compass  needle, the magnet was affected. This is called  electromagnetism. In 1825, British inventor William Sturgeon (1783–1850) displayed the power of the electromagnet by lifting nine pounds with a seven-ounce piece of iron wrapped with wires through which the current of a single-cell battery was sent. This device laid the foundation for large-scale  electronic communications, as it led to the invention of the telegraph. It also resulted in the invention of the electric motor.   Cow Magnets U.S. patent #3,005,458 is the  first patent  issued for a cow magnet. It was issued to Louis Paul Longo, the inventor of the Magnetrol Magnet, for the prevention of hardware disease in cows. If cows happen to consume scrap pieces of metal, such as nails, when theyre feeding, the foreign objects can cause internal damage to their digestive tract. Cow magnets keep the metal pieces confined to the cows first stomach, rather than traveling to the later stomachs or intestines, where the fragments can cause the most damage.

How to Plan a Game Development Project

How to Plan a Game Development Project One of the most complicated aspects of game development is planning. Some would argue that small indie projects don’t need this step; they simply need to work on the project until it’s done. This is far from true. Initial Planning The design framework laid at the project’s origin will determine the course for the entire project’s development. Its important to remember at this step that nothing is set in stone, but you should attempt to be as accurate as possible. Feature List First, analyze the design document and determine the game’s requirements. Then, split out each requirement into a list of features that will be needed to implement the requirement. Breaking Down the Tasks Take each feature and work with your leads in each area (art, animation, programming, sound, level design, etc) to break it down into tasks for each department (a group or person, depending on the size of your team). Assigning Tasks The lead of each group should then create initial time requirement estimates for each task and assign them to team members. After this is complete, the lead should work with the team to ensure that the estimates are correct and reasonable. Dependencies The project manager then must take all the task estimates and place them into a project management software package, either Microsoft Project or Excel (the two long-time industry standards) or any of the newer choices available for agile project management. Once the tasks are added, the project manager must look at the tasks and match dependencies between teams to ensure that the timing of creating a feature doesn’t have impossible relationships that prevent it from being completed within necessary time frames. For example, to fully implement a racing game, you wouldnt schedule the coding of tire durability before the completion of the physics system. You would have no framework to base the tire code upon. Scheduling This is where things get particularly complicated, but where the need for project management in the first place becomes more apparent. The project manager assigns estimated start and completion dates for each task. In traditional project planning, you end up with a cascading â€Å"waterfall† view, which shows the timeline for completion of the project and the dependencies that link the tasks. Its critical to remember to factor in slippage, employee sick time, unexpected delays on features, etc. This is a time-consuming step, but it will quickly give you an idea of exactly how much time the project will take to complete. What to Do With the Data By looking at this project plan, you can determine if a feature is going to be costly in time (and, therefore, money) and make decisions about whether the feature is necessary for the game to succeed. You might decide that delaying a feature to update- or even a sequel- makes more sense. Also, tracking how long you’ve worked on a feature is useful in determining if its time to either try a new technique to solve the problem or cut the feature for the good of the project. Milestones A frequent use of project planning involves the creation of milestones. Milestones indicate when a certain element of functionality, a time period of working on the project, or a percentage of the tasks has been completed. For internal project tracking, milestones are useful for planning purposes and for giving the team specific goals to aim for. When working with a publisher, milestones frequently determine how and when the developing studio is paid. Final Notes Project planning is regarded by many as a nuisance, but youll almost always find that developers who plan projects well in advance and hit their milestones are the ones who succeed in the long run.