Physics on 4/18/13By honorsphysics12o, April 18, 2013
By honorsphysics12o, April 18, 2013 | | Honors Physics (1-2 O)
Shields started the day with a warm up involving the distance of the planets from the sun against their velocity. After we had all plotted the data, and then tried to put an equation to the data, Shields explained to us the true type of equation of the data—a power function. A power equation is an equation whose form is V=D1/2. As we learned back in the gravity unit, mv2/r=GMm/r2, which can be reduced to V=G (1/√r), this is good because they are orbiting a center of gravity. And so we have used data to plot a behavior that follows a function. For our group, the power curve fits the data with an r2 value of .9998 (For those of you who haven’t taken stats, the closer to 1, the better the function fits the curve, in this case, it fits very well).
Shields then instructed us to go to a link on his website to get data on the Milky Way. After we had plotted the data, it was obvious that the actual data does not fit the actual curve. As a special bonus, Shields had us plot what theory would predict, and that is a drastically different plot. Finally, after we had finished that, he had a second special bonus, which was to do the same as above, only for the Andromeda Galaxy (NGC 224).
After we had finished this, Shields then put on a movie about gravity, dark matter, and why everything is not following the patterns we thought it would, the same videos we have been working through over the past few days. We started with Professor Frenk, a man whose job description was to figure out the universe. This man and his colleagues through their research looked at the amount of the amount of matter and dark matter of the universe, they found even less dark matter than they thought, and they were puzzled, and a hole appeared. Then they found out that the universe was not expanding slowly as they thought, but actually quite quickly. And, because of the energy required, they believed that they thought that they found what could fill the gap, and what was needed for the big bang theories—dark energy. They believed that they found cosmology’s standard model, 4% matter, 21% dark matter, and 75% dark energy. Then the movie consulted a skeptic, who doesn’t believe the standard model. The professor they consulted earlier used the proposals and used that to create a computer simulation of the universe. This simulated universe was virtually indistinguishable from the real universe, and gave Prof. Frenk what he thought he needed.
There is nothing due next class.
By Richard and Wade