FLIPPED CLASSROOM!!

In recent times, a series of teachers have been encouraged to record their classes so that after we can see them from home; here I leave some videos related to the contents we have studied.

NEWS GROUP 2 - UNIT 1

Thundershocking discovery

Benjamin Franklin invents the lightning rod 

Yesterday, 15th of June of 1752, Benjamin Franklin, scientist born in Boston in 1706, made a discovery, which helped him to invent the lighting rod, after various years of investigation.

 

Yesterday there was a storm in Philadelphia and Franklin went out to the field. The scientist saw the perfect opportunity to test his investigation. Across the floss all the electricity was coming to the key. So it had clear that if the beam was going out of the clouds and in its way to the land it was finding a metallic conduit in the one that to get, was remaining there. Of this form it managed to domesticate what it was calling the "electrical fire".

 

 

Benjamin Franklin dominates the "electrical fire"

The lightning rod consists of a metallic mast with a compress captator. The compress has many forms depending on its first functioning: it can be in top, multitops, semispherically or spherically and must stand out over the highest parts of the building to prevent that a great quantity of electrical load provoques damages to buildings,  fires or even the death of animals or people.

Franklin spent the summer of 1747 conducting a series of groundbreaking experiments with electricity. He wrote down all of his results and ideas for future experiments in letters to Peter Collinson, a fellow scientist and friend in London who was interested in publishing his work. By July, Ben used the terms positive and negative (plus and minus) to describe electricity, instead of the previously used words "vitreous" and "resinous." Franklin described the concept of an electrical battery in a letter to Collinson in the spring of 1749, but he wasn't sure how it could be useful. Later the same year, he explained what he believed were similarities between electricity and lightning, such as the color of the light, its crooked direction, crackling noise, and other things. There were other scientists who believed that lightning was electricity, but Franklin was determined to find a method of proving it.

By 1750, in addition to wanting to prove that lightning was electricity, Franklin began to think about protecting people, buildings, and other structures from lightning. This grew into his idea for the lightning rod. Franklin described an iron rod about 8 or 10 feet long that was sharpened to a point at the end. He wrote, "the electrical fire would, I think, be drawn out of a cloud silently, before it could come near enough to strike..." Two years later, Franklin decided to try his own lightning experiment. Surprisingly, he never wrote letters about the legendary kite experiment; someone else wrote the only account 15 years after it took place. 

Two years before the kite and key experiment, Ben had observed that a sharp iron needle would conduct electricity away from a charged metal sphere. He first theorized that lightning might be preventable by using an elevated iron rod connected to earth to empty static from a cloud. Franklin articulated these thoughts as he pondered the usefulness of a lightning rod.

lightinig rod

We think that this discovery made by Franklin will be very useful, because it will be able to save a lots of people´s lives and make them much safer.