Week of January 18, 2010

This week in science class we continued our study of Astronomy. In the beginning of the week we learned about direct and indirect light. Direct light is at a perpendicular angle , is smaller, and stronger. Indirect light is more spread out and has less strength. We also learned that we only see fifty percent of the moon, and no more than fifty percent is lit up. We see the moon phases because the moon revolves and rotates around the earth. This week we also learned the terms solstice and equinox. A solstice is when the sun reaches it's highest point (summer solstice) or lowest point (winter solstice) in the sky at noon, marked by the longest ( summer) and shortest (winter) days. This takes place on June 27 and December 27. An equinox is the time and date (twice a year) at which the sun crosses the celestial equator, when day and night are of equal length. This takes place on September 22 and March 20. Later in the week we took a quiz (ahhhh!) and watched a video. In the video David pushed a rolling bowling ball with a hammer to make it move in a circular shape. This brought us to the study of why the earth orbits the sun or why the moon orbits the earth without crashing into it. There are several that need to happen to get something to orbit another thing. First, the object or satellite has to be in motion. (Initial Velocity) If the initial velocity is too small it will crash into the object it is orbiting, but if it is too big the object that is orbiting will fly away (escape velocity). Second, Distance effects the amount of initial velocity necessary to orbit. The farther you are from the object you are orbiting the less initial velocity needed to put in orbit. But the closer you are to the object you are orbiting the more initial velocity needed to put in orbit. Lastly, the arrow direction (direction of velocity)should be perpendicular to the object you are orbiting. to learn this we practiced on our two imaginary planets Turtle and Juego!

Week of January 11, 2010

This week in Science class we took the placement test for honors science. It was two days long. When we weren't taking the test we were learning about seasons. We came up with four hypothesis' for why we have seasons:

1.) Mark- depending on how long the sun is out during the day.

2.) Mickey- depends on where we are around the orbit compared to the sun (if we are close to the sun it is summer)

3.) Emily- it has to do with the tilt of the earth.

4.) Jackie- it depends on the direct and indirect rays.

One by one we tried to prove them wrong. We used the simulation to discover that when the earth is farthest away from the sun it is summer. So Mickey's hypothesis is wrong. We thought about Mark's hypothesis and concluded that his was wrong because the seasons changing is the cause and the change in how long the sun is out is the effect. He had it the other way around. So that left Jackie and Emily. Their hypothesis' were correct. The final answer to the question WHY DO WE HAVE SEASONS?is:

We have seasons because the angle of the tilt of the earth makes direct and indirect light and we are revolving and rotating around the earth, so different parts of the earth get different kinds of light and that is what makes the seasons change.

We also learned five important facts about seasons;

1.) The earth is tilted and stays in that one tilt.

2.) We are revolving and rotating around the sun.

3.) The hemispheres face the sun at different times.

4.) The light is direct and indirect.

5.) Some places don't get much light at all. (Alaska)

Week of January 4, 2010

This week in science class we learned about Astronomy. We learned that the moon revolves and rotates around the earth. We also learned that rotating means changing in orientation but not position and revolving is a complete turn or change in position but not orientation. I learned that the moon and the sun rotate counterclockwise and that it takes 29 1/2 days for the moon to go through all of it's phases. I made the phneumonic device; Nanny Wilson Froze Watermelons For Willie Till Winter to help me remember the phases of the moon. The phases of the moon are New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, and Waning crescent. These phases keep repeating. Lastly, we started making force diagrams for the earth in relation to the location of the moon and sun. This lead us into learning about the tides on earth. The moon pulls on the surface of the earth and since the surface is mostly ocean it pulls the ocean and creates tides and waves. It is important to know these things if you want to be an astronomer, or are interested in anything that has to do with the different waves and tides of the ocean.