…this coming Tuesday there is a fractions quiz:
– mixed to improper
– improper to mixed
STARTING WITH BEN FRANKLIN
Many people think Benjamin Franklin discovered electricity with his famous kite-flying experiments in 1752. But, electricity was not discovered all at once. At first, electricity was associated with light. People wanted a cheap and safe way to light their homes, and scientists thought electricity might be a way to do it.
Learning how to produce and use electricity was not easy. For a long time there was no dependable source of electricity for experiments. Finally, in 1800, Alessandro Volta, an Italian scientist, made a great discovery. He soaked some paper in salt water, placed zinc and copper on opposite sides of the paper, and watched the chemical reaction produce an electric current. Volta had created the first electric cell. By connecting many of these cells together, Volta was able to “string a current” and create a battery. It is in honor of Volta that we measure battery power in volts. Finally, a safe and dependable source of electricity was available, making it easy for scientists to study electricity.
A CURRENT BEGAN
An English scientist, Michael Faraday, was the first one to realize that an electric current could be produced by passing a magnet through a copper wire. It was an amazing discovery. Almost all the electricity we use today is made with magnets and coils of copper wire in giant power plants. Both the electric generator and electric motor are based on this principle. A generator converts mechanical energy into electricity. A motor converts electrical energy into mechanical energy.
MR. EDISON & HIS LIGHT
In 1879, Thomas Edison focused on inventing a practical light bulb, one that would last a long time before burning out. The problem was finding a strong material for the filament, the small wire inside the bulb that conducts the electricity. Finally, Edison used ordinary cotton thread that had been soaked in carbon. The filament didn’t burn at all—it became incandescent; that is, it glowed. These light bulbs worked, but they were batterypowered and expensive. The next challenge was developing an electrical system that could provide people with a practical source of energy to power these new lights. Edison wanted a way to make electricity both practical and inexpensive. He designed and built the first electric power plant that was able to produce electricity and carry it to people’s homes. Edison’s Pearl Street Power Station started up its generator on September 4, 1882, in New York City. About 85 customers in lower Manhattan received enough power to light 5,000 lamps. His customers paid a lot for their electricity, though. In today’s dollars, the electricity cost $5 per kilowatt-hour! Today, electricity costs a little over eight cents per kilowatt-hour.
AC OR DC?
The turning point of the electric age came a few years later with the development of AC (alternating current) power systems. With alternating current, power plants could transport electricity much farther than before. In 1895, George Westinghouse opened the first major power plant at Niagara Falls. It used alternating current. While Edison’s DC (direct current) plant could only transport electricity within one square mile of his Pearl Street Power Station, the Niagara Falls plant was able to transport electricity more than 200 miles! Electricity didn’t have an easy beginning. Many people were thrilled with all the new inventions, but some people were afraid of electricity and wary of bringing it into their homes. Many social critics of the day saw electricity as an end to a simpler, less hectic way of life. Poets commented that electric lights were less romantic than gas lights. Perhaps they were right, but the new electric age could not be dimmed. In 1920, about two percent of all the energy in the United States was used to make electricity. Today, about 37 percent of all energy is used to make electricity. As we continue to use technology powered by electricity, that figure will continue to rise.
The 2016 Canada Day Challenge is Here! – Le Défi de la fête du Canada 2016 est lancé! The 2016 Canada Day Challenge launched last week! The Challenge will be a great opportunity for Canadian youth between 8 and 18 years of age, inviting them to express their creativity. Canadian youth are invited to start thinking about the Challenge now and how they can demonstrate pride in Canada. There are three exciting categories: DRAW IT! Draw, paint, and sketch! Youth can draw inspiration from Canada’s past and present to create a colourful poster design. SNAP IT! Youth can use their smartphones or digital cameras and submit their best photograph. That captures Canada through their eyes. WRITE IT! Youth can express their thoughts about what Canada means to them and capture Canada’s amazing spirit in writing. The original work can be a short story, a poem, or an essay. Please visit the website at http://www.challenge.pch.gc.ca for more contest details and to see the exceptional works of the 2015 winners.