natural phenomena in space

1. Collision Between Galaxies

Apparently galaxies can also eat each other. Even more surprising is the Andromeda galaxy is moving closer to our own Milky Way galaxy, and the picture above it is a simulation of colliding galaxies.

2. Quasar

Quasar glistened on the edge of the universe that we can see. Quasars release energy equivalent to the energy of hundreds of galaxies combined. It could be that quasars are a very large black hole in the hearts of distant galaxies. This image is the quasar 3C 273, which was photographed in 1979.

3. Dark Matter (Dark Matter)

Scientists think that dark matter (dark matter) is the largest constituent of the universe, but can not be seen and detected directly by current technology. Candidates range from heavy neotrino to invisible black holes.

scientist

 For the scientist (or aspiring scientist), the question of why to study science doesn't need to be answered. If you're one of the people who get science, then no explanation is required. Chances are that you already have at least some of the scientific skills necessary to pursue such a career, and the whole point of study is to gain the skills which you don't yet have.
However, for those who are not pursuing a career in the sciences, or in technology, it can frequently feel as if science courses of any stripe are a waste of your time. Courses in the physical sciences, especially, tend to be avoided at all cost, with courses in biology taking their place to fill necessary science requirements.
The argument in favor of "scientific literacy" is amply made in James Trefil's 2007 book Why Science?, focusing on arguments from civics, aesthetics, and culture to explain why a very basic understanding of scientific concepts is necessary for the non-scientist.
  
Sir Isaac Newton's law of universal gravitation (i.e. the law of gravity) can be restated into the form of agravitational field, which can prove to be a useful means of looking at the situation. Instead of calculating the forces between two objects every time, we instead say that an object with mass creates a gravitational field around it. The gravitational field is defined as the force of gravity at a given point divided by the mass of an object at that point, as depicted to the right.

You'll notice that here both g and F_g have arrows above them, denoting their vector nature. The source mass M is now capitalized. The r at the end of the rightmost two formulas has a carat (^) above it, which means that it is a unit vector in the direction from the source point of the mass M. Since the vector points away from the source while the force (and field) are directed toward the source, a negative is introduced to make the vectors point in the correct direction.

This equation depicts a vector field around M which is always directed toward it, with a value equal to an object's gravitational acceleration within the field. The units of the gravitational field are m/s².

teaching of me

LESSON PLAN

                                                                                            

School                                   : Senior High School

Class / Semester                   : X / 2

Subject                                  : PHYSICS

Allocation of time                 : 10 minutes

 Competency Standards       : 6. Understanding the concepts and principles of electromagnetic   waves.

Basic Competency               : 6.1. Describe the electromagnetic wave spectrum.

Indicator                              :1. Describe the concept of electromagnetic waves.

  2. Sort the array of electromagnetic waves by frequency or wavelength.

A. Learning Objectives

After the learning activities students can:

1.       Explaining the electromagnetic wave.

2.       Explaining the spectrum of electromagnetic waves.

3.       Describe the characteristics of each of the electromagnetic wave spectrum.

                                                            

B. Learning Materials

Electromagnetic Waves

James Clerk Maxwell said that a change in magnetic field might generate electric field.Maxwell concluded that the speed of the electromagnetic wave depends on two properties, they are electrical permittivity and magnetic permeability. In vacuum where the electrical permittivity and magnetic permeability, the speed of the electromagnetic wave satisfies the formula:

 

                           

c= speed of the electromagnetic wave

ε₀ = electrical permittivity = 8,85418 x 10^-12C²N^-1m^-2

μ₀ = magnetic permeability = 4π x 10^-7 wbA^-1m^-1

The electromagnetic wave propagation speed is often written as = 3,0 x 10⁸ m/s

Therefore, Hertz experiments fully supported Maxwell’s hypothesis on electromagnetic wave. Hertz also showed that electromagnetic wave has properties which are owned by light. It undergoes reflection, refraction, polarization, diffraction, and it is able to propagate in vacuum.

Discussing about wave, beside its propagation speed, you should also remember frequency and wavelength. The relationship of propagation speed(c), frequency(f), and wavelength(λ) is:

c = λf

The Spectrum of Electromagnetic Waves from small to large is:

1)      Radio Wave

2)      Microwave

3)      Infrared Ray

4)      Visible Light

5)      Ultraviolet Ray

6)      X-Ray

7)      Gamma Ray

C. Learning Strategy

1. Model               : Contextual Teaching and Learning

2. Approaching          :  Inquiry, concept  and learning objectives

3. Method             : Lectures, Question and answer

          

D. Learning Procedures                                                    

Steps	Teacher Activities	Student Activities	Time Allocation
Open Activities	1.      Teacher greeting and check attended student 2.      Motivation and Aperception: how do I categorize the spectrum of electromagnetic waves? 3.      Prerequisite knowledge: what is the spectrum of electromagnetic waves? 4.      Information of learning objectives: explaining the electromagnetic wave, explaining the spectrum of electromagnetic waves, describe the characteristics of each of the electromagnetic wave spectrum.	1.      Pray together to begin the lesson. 2.      Listening and paying attention to the motivation.	2 minutes
Main Activities a.       Exploration b.      Elaboration c.       confirmation	1.      Learners pay attention to teachers' explanations about the magnitude of electromagnetic waves. 2.      Learners pay attention to teachers' explanations about the characteristics each of the electromagnetic wave spectrum. 1.      Teachers guide students in forming groups. 2.      The teacher gives some problems determining the electromagnetic wave spectrum to be done by learners. 3.      Teacher points one of group for forward at front brazes 4.      Teacher comments to usufruct discussion of student 1.      Teacher corrects students' answers to whether it is correct or not. If there are still students who have not been able to answer correctly, the teacher can provide direct guidance. 2.      Teachers respond to students' answer discussions and provide real information. 3.      Evaluated of each group based on the presentations, as well as understanding the concept of cooperation in groups. 4.      Giving rewards for the best group presentation.	1.      Answering questions from the teacher. 2.      Listening to the teacher's explanations about electromagnetic waves 1.      Students ask questions about the material that the student did’t understand. 2.      Students (supervised by teachers) discuss the notion of electromagnetic waves.       3.      Students (supervised by teachers) discuss the terms of the electromagnetic wave spectrum. 4.      Present the result of the group discussion in front of the class. 5.      Questions and answers between groups. 1.      Student asks to learn about material which was understood 2.      Student listens explanation of teacher	5 minutes
Closing	1.      Teachers give awards to student that have good answered. 2.      Students (supervised by teachers) to create a summary of discussions. 3.   The teacher gives a homework assignment in the form of exercises.	1.      Mention to the  conclusions. 2.      Answer the greeting.	3 minutes

E. Learning Media

Ø  Sources:

1. Kanginan, Marthen.2002.Physics X.Jakarta:erlangga.

2. Team MGMP Physics Senior High School.2006.Worksheet Senior High School Physics X.Jakarta:multigrafika.

Ø  Media:

1.      Powerpoint Template

2.      Handphone

F. Assessment of Learning Outcomes

a. Assessment techniques:

- Written test

-Assignment

b. Shape Instrument:

-multiple choose of Test   

c. Example Instruments:

-Examples of multiple choose of test

The order of the frequency spectrum of electromagnetic waves from small to large is..

a. infrared,visible light, UV, x-rays, gamma-ray

b. UV, infrared, visible light,gamma-ray,infrared ray

c. visible light, UV, infrared,  radio waves, microwaves

d radio waves, microwaves, infrared ray, visible light

e. x-ray, gamma-ray,UV, light, infrared

- Sample test description                       

State the characteristics of electromagnetic waves.

Semarang, 4 January  2012

Signed by

Head Master,                                                                                  Teacher,

Mr.Taufik                                                                                       Heti Kurniawati

STUDENT WORKSHEET

Group              :

Groupmaster   :

Person             :

Propagation of Electromagnetic  Wave in Cell Phone

       I.            Learning Objectives    : Explaining the spectrum of electromagnetic waves.

    II.            Learning Materials      :

Electromagnetic wave is not the name for a single frequency wave. It has a   wide frequency range. Hence, it includes many waves with different  frequencies. This group of electromagnetic waves with different frequencies forms the spectrum of electromagnetic wave.   The Spectrum of Electromagnetic Waves from small to large is : Radio Wave, Microwave, Infrared Ray, Visible Light, Ultraviolet Ray, X-Ray, and Gamma Ray.

Electromagnetic waves  follow the formula  c = λf

Where : c= electromagnetic propagation speed(m/s)

f= frequency (Hz)

λ= wavelength  (m)

 III.            Procedure                    :

1.Putone cellphoneinside atransparentplastic bag and tie the plastic tighly so there is no air which allowed to get in or out

2.Use the cell phone outside to call the cell   phone   inside the plastic bag. Observe whether   the call is successful or not.

3.   Use the cell phone outside to plastic bag to  call the cell   phone outside. Observe whether   the call is successful or not.

 IV.            Question

What is your conclusion?