True North VS. Magnetic North

 

True north and magnetic north are not  on one point.

 

True North

True north, which is also called geodetic north, is the direction along the earth's surface towards the geographic North Pole. It is the direction of a meridian of longitude which converges on Pole. In maps, we conveniently use what is known as the "gird north".True north is marked with a line terminating in a five-pointed star.

Magnetic North

The North Magnetic Pole is the point on the surface of Earth's Northern Hemisphere at whcih the planet's magnetic field point vertically downwards.The earth's magnetism is caused by the flow of electrons in its fluid metallic core.

reference:

1) Yu, J. (2005). True north vs. magnetic north. Retrieved from http://www.astro-fengshui.com/fengshui/truenorth.html 
2) Meeus, Jean (1997). Mathematical Astronomy Morsels. Richmon

The energy ball report

By Charlotte Ge                                                                                                        Feb.7th,2013

 

series circuit and parallel circuit:

Series circuit and parallel circuit are two basic types of circuits.

Series circuit is a circuit in which all the loads are connected. If one load burns out or short circuit, then the whole circuit will be broken. The same current flows though all the components.

Parallel circuit is a circuit in which each component forms a separate branch though the circuit. If one load has some problems, it will not effect the whole circuit.If two or more components are connected in parallel, they have the same potential difference across their ends.
 

The energy ball:

To make the energy ball work, a complete circuit is needed. We should connect two metal contacts. Human body is conductive, because it is mostly water which is polar covalent bonds.There is also salt in our body. Water and salt are the electrolyte, so when we touch the metal on the ball, it makes a circuit though our body. Then the ball will shine.

Self-Reflection:

     From the experiment, I have learned that it is important to do an experiment in order to understanding. The experiment makes the theory more vivid. During the experiment, I figured out some problems, and it made me think more. It improved my communication skill also, although I am an ESL student, I can still communicate with my group.

Reference:

LaPlante, Ron. (n.d.). What are "series" and "parallel" circuits?
Retrieved February 7, 2013, from

http://www.allaboutcircuits.com/vol_1/chpt_5/1.html


(n.d.)Difference between series circuit and parallel circuit?
Retrieved February 7, 2013, from

http://wiki.answers.com/Q/Difference_between_series_circuit_and_parallel_circuit