Chapter+4

How were we able to find out why our solar system is how it is?
photo from flickr.com picture of an elliptical galaxy :) ===Two men by the names of Halley and Newton are the answer to your questions. Halley was a captain, a cartographer, a professor, an astronomer, and an inventor. One day Halley, Robert Hooke, and Wren (other influential scientists) were having dinner, when one of them proposed that our solar system was in an elliptical shape. None of the three scientists understood why, so Wren offered 40 shillings to the scientist who came up with the answer. === ===Halley decided to ask for help. He then went to Cambridge in search of famous Sr. Issac Newton. In 1684 Halley visited Newton in Cambridge, and asked him "What would the curve be when described by planets supposing the force of attraction toward the sun to be the reciprocal to the square of their distance from it?" Newton replied "It would be elliptical." Halley questioned how he knew but Newton said " I calculated it but i think i misplaced the formula!" Halley then suggested to recalculate how he got to that conclusion and Newton abliged. after he went back and reworked everything he also made another dicovery. He developed his three laws of motion, which leads us to other discoveries about the universe today! ===
 * [[image:http://farm3.static.flickr.com/2118/2042977114_ceb7dbc926.jpg?v=1202619406 width="500" height="334" caption="M31_300SecISO800x20 by rudynix."]] ||
 * M31_300SecISO800x20 by rudynix. ||


===  How Big is the Earth we Live on? __raider-garrett10__ section 2&3 pg 80-86    ( __It's amazing how big the Earth really is. It's so hard to just grasp the concept of how extremely big it is!__) Newton's laws explained so many things, such as the following: the motions of planets, the slosh and roll of ocean tides,etc. One revelation, that the earth wasn't perfectly round, became almost immediately controversial. In Newton's theory he states the centrifugal force of the Earth's spin should result in a slight flattening at the poles and a bulginh at the equator, making the planet slightly oblate. Meaning the lenth of a degree would differ depending on where you were located. Newton said the length of a degree would shorten as you moved away from the poles. An English mathematician by the name of Richard Norwood was one of the first people to try and calculate the size of the earth. Earlier stories of ship's captains that had been set sail for Bermuda, a small island in the North Atlantic Ocean, and being hard to locate. Even the slightest miscalculations would set them off target, so Norwood decided to calculate the length of a degree using his first love trigonometry. He started at the London Tower and spent two years walking 208mi north to York, continously stretching and measuring a length of a chain and making adjustments to the different features he came across. Finally, Norwood measured the angle of the Sun at York at the same time of day and on the same day of the year as he made his first measurement in London. A mistake of the slightest fraction would throw the whole calculation off by miles, but he proudly proclaimed that he was accurate and announced that it was approximately 110.72 kilometers per degree of arc. About 15 years past and the momentum for calculating the Earth's circumference passed to France. Jean Picard, an astronomer, devidsed a complicated method of triangulation. After two years of triangulating his way across France he announced a more accurate measure of 110.46 kilometers per degree of arc which backed up the theory of the Earth being perfectly round. The father-and-son team of Giovanni and Jacques Assini repeated Picard's experiments, after his death, over a larger area and came up with results that suggested that the Earth was fatter not at the equator but at the poles. In other words, that's saying Newton was exactly wrong! The Academy of Sciences sent Bouguer and La Condamine to South America to take new measurements. To determine if there really was a difference in sphericity they chose the Andes near the equator. They also said the mountains would give them good sightlines. While on their journey to determine wether or not the Earth was a perfect sphere they got word that there was another French team taking measurements in northern Scandinavia that had found that a degree was, as Newton had promised, longer near the poles. When measuring the Earth's circumference the length is forty-three kilometers smaller than when measured from pole to pole. Bouguer and La Condamine had spent nearly a decade working to find that they weren't the first to find it. They completed there survey confirming that the first French team was accurate! ===

 ** Explorers Settle More Than a Dispute Section 5 ** ** By: Raider-Lauren ** This is the Mason-Dixon Line!
 * It was a clear, dark night, on a vessel in the Atlantic ocean near the country of Submarta, when two British scientists by the names of Charles Mason, and Jeremiah Dixon got attacked by a French Frigate. They were in the ocean on a voyage set by the Royal Society. The two scientists then sent a note to the society asking if they should just call off the long and dangerous voyage and proceed home. They got an immediate response stating that they had already gotten paid for they voyage and that the entire British community was counting on them, and they would lose their reputations in the community if they did not proceed. In route to Submarta they had gotten word that the country had fallen under French rule. They decided to proceed home. On the way back the ship stopped on the lonely island of St. Helena where Mr. Mason then met a man by the name of Maskelyne. They became good friends, and while they were there they became great friends. They spent many useful weeks collecting data and charting the tidal flows of the Atlantic. Maskelyne then became a royal astronomer. **
 * A little while later Charles Mason and Jeremiah Dixon set out on another voyage, but this time they were in the American wilderness, settling a boundary dispute between William Penn and Lord Baltimore. This was a four year journey that eventually led to the discovery of the Mason-Dixon Line. This line separated the slave states from the Free states. During the four years they were discovering this line they came to the found the most accurate measurements of the degree of the meridian. This discovery brought them more glory than the land dispute. **

==Caraline Section 6 Pg 93-101  ==

Summer 1774s Discoveries!
==In the beautiful summer of 1774 Mr. Maskelyn and a few of his land surveyors traveled through a great mountian to get some measurements on that mountain! They all had to live in some harsh conditions. Most lived in a tent on the Scottish glen. All that the team did was take measurments from every angle possible and do some calculations. The mathematician Charles Hutton "covered a map with scores and figures" where he marked elevation on its point on the map. Instantly, anyone could grasp what, overall, the mountain really looked like (as in shape and slope). From all this work Hutton could find the mass of the Earth! It was 5,000 million million tons. After all this excitement the summer ended and John Michell came into the picture. Michell found about like what the wavelength of earthquakes, and the magnetism and gravity of black holes. He was a pretty interesting guy, on top of that, he did all this two year before anyone else had even thought of it! Michell had built a machine used for measuring the mass of the earth, but he died before he could actually do the experiment. From then on Henry Cavendish took over the experiment. Cavendish was a rather odd man who was slightly a social outcast. He was also the first person to isolate hydrogen and the first one to combine two hydrogen and one oxygen to form water. Also, in this time frame Calvedish found that the earth weighed a little more than 13,000,000,000,000,000,000,000 pounds! Thats insane! Calvendish's findings helped other scientist find the length from the earth to the sun and also the dimentions of the earth and its shape! ==