Tuesday, February 28, 2012

How objects become electrically charged

Before I start explaining, you should know these vocabulary words:
Charging by conduction- charging an object by allowing it to come into contact with an object that already has an electrical charge.

Charging by induction- charging an object without direct contact between the object and the charge.

Like charges repel each other:
This means that two positively or negatively charged objects will repel, not attract each other. The first object will exert a repulsive force on the second, and Newton's Third Law shows that the second object will exert an equal and opposite force on the first.

Opposite charges attract one another:
This means that when a negatively charged particle is in proximity to a positively charged particle, a mutual attractive force will develop. The first will exert a force on the second, and according to Newton's Third Law, the second will exert an equal and opposite force on the first.

Principles of Gravitational Force:
1. All electrical charges attract or repel one another: charges repel, while opposite charges attract.
2. The force between charged objects is directly proportional to the amount of electrical charge on each object.
3. The force between charged objects is directly proportional to the square of the distance between the two objects.

These two photos show the positive and negative attractions that I have posted about!

 static electricity.jpeg


Resistance

Resistance -- the ability of a material to impede the flow of charge


For example, the wires on the inside of a toaster or the coil on an electrical stove or a space heater are all objects that have electrons and resistance. 


"One way we get electrons to do something useful in an electrical circuit is to use a metal's resistance to convert the energy of the electrons speeding through the circuit into heat and light." 
--Exploring Creation with Physical Science by Dr. While (chapter 12 pg. 301) 

Thursday, February 23, 2012

A Brief History of Our View of the Solar System

Most of what we know about the  solar system and how it works was known before humans ventured into space. Even in ancient history, people were very fascinated by the moon and the stars. People who lived long ago also knew that by keeping track of the moon and stars, they could have a fairly easy way of knowing dates and times. The Greek's view on the solar system was geocentric. Geocentric has the idea that the earth is the center our galaxy and that all the other planets and stars orbit around it. This remained the most popular view until the 16th century. A man named Nicolaus Copernicus started changing this idea in 1543. He wrote a book called On the Revolution of Heavenly Bodies. His idea was that the sun was at the center. This is what scientist call heliocentric. This is the way we now know the earth orbits. Two men made what are called the "Kelper Laws". These didn't explain why the planets moved as they did, only how they moved. Sir Isaac Newton was the man who found the Universal Law of Gravitation. The main difference between all these people is the amount of technology they had helping them. What we know in science is always growing and changing...who knows what we will know tomorrow.

Wednesday, February 22, 2012

The Gravitational Force at work in our Solar System

Take a look at this photo of the Solar System to help  better educate yourself over the following information!
Look at the different sizes, colors, features, and distance of each planet:



The orbit of the planets in our Solar System determines the length of the year, and when the seasons change. Relative to the sun, earth moves 70,000 miles per hour (FAST)! The sun supplies centripetal force to the earth. This makes the earth travel in a circle.

Why do planets orbit the sun?
Planets orbit the sun because of the gravitational attraction between each planet and the sun.

Each planet exerts gravitational force on every object in the Solar System, as a result, planets having moving objects that rotate around them. For example, the moon orbits the earth. Did you know that Jupiter has not just one, but 60 satellites! The four biggest satellites were discovered by Galileo, thus getting the name "Galilean Satellites".

Saturn, Uranus, Jupiter, Neptune have planetry rings.

Force and Circular Motion

Centripetal Force- The force necessary to make an object move in a circle. It is directed perpendicular to the velocity toward the center of the circle. This the special force required by circular motion.

According to Newton's First Law, an object that is not acted upon by an outside force will travel at a constant velocity. Since velocity includes direction, this means the object will travel in a straight line. The only way you can change this, is to apply a force/forces. If that force happens to be perpendicular to the velocity of an object, the object will curve, but if a force continues to direct perpendicularly to the velocity, the object will move in a circle.

Centripetal Acceleration required centripetal force, which also comes centripetal velocity.

In a nutshell, we have covered the following in this post:
1. Circular motion required centripetal force.
2. The larger the centripetal force, the faster an object travels in a circle of a given size.
3. At a given speed, the larger the centripetal force, the smaller the circle.

What Causes Gravitational Force?

For a long time, no one knew what caused gravitational force, but Albert Einstein changed that. This idea is known as the General Theory of Relativity. His idea states that the way we view space may not be how it really is. For example, some used to think the world is flat because if feels flat to us. Einstein's theory shows that the reason the planets orbit the sun is because the sun's mass pulls the planets in a circular motion. The other theory of gravity says that two massive objects tend to exchange tiny particles called gravitons. This theory has never been proved as gravitons have never been observed. One of the reasons that some people believe this is because all the other forces are explained by particle exchange. 


This is a picture of General Theory of Relativity 

Tuesday, February 21, 2012

Is Pluto a Planet?

Pluto is no longer recognized as a planet. Pluto is known as a dwarf planet. Since Pluto has become a dwarf planet, other planets have been recognized as dwarf planets as well. Pluto is very small and has few characteristics of the other planets. There are several smaller objects, similar to Pluto, orbiting the sun beyond Neptune. Eris and Ceres are the other two.

For an object in space to be recognized as a planet is must meet the following criteria:
1. A planet must be in orbit around the sun.
2. A planet must be nearly round in shape
3. A planet must have "cleared the neighborhood" around its orbit.

The definition of a dwarf planet:
1. A dwarf planet must be orbit around the sun.
2. A dwarf planet must be nearly round in shape.
3. A dwarf planet has not "cleared the neighborhood" around its orbit
4. A dwarf planet cannot be a saltelite. (such as a moon)

Comets




Gravity, one of the four forces in creation also has effect on comets also. Comets are sometimes known as "dirty snowballs". The ice on these comets isn't just from water...it is also from frozen carbon dioxide.
When a substance turns from a solid to gas we say it has sublimated. The nucleus of a comet is is the dirt and ice and the coma of a comet is the atmosphere around it. There are particles being emitted from the sun and when these particles pushed away it causes a wind called, solar wind.

There are short period comets and long period comets. Short period comets take less than 200 years to orbit. Long period comets take more than 200 years. Scientists have found many comets, the shortest orbit is 3.3 years and some of the longest go over 5,000 years.

Force 1: Gravitational Force

You experience gravitational force everyday, but what actually causes this force? Believe it or not, even scientists are not completely sure of where gravity comes from, inspite of their theories.

Sir Issac Newton was the man who was able to present with valid information that gravity is a universal force that applies to small things near the earth's surface.

For example:
An apple falls from a tree because it is attracted to the earth.
The moon stays in it's orbit around the earth because gravity attracts it to the earth.

These examples tell you a few different things:

  • All objects with mass are attracted to one another by gravitational force.
  • The gravitational force between two masses is directly proportional to the mass of each object. 
  • The gravitational force between two masses is inversely proportional to the square of the distance between two objects. 

The Four Fundamental Forces in Creation

Physicists believe that there are four different forces in creation. Each force has it's own attributes, which you will learn throughout our posts. Below is a shallow outline of each force, but more depth will be added to each force in later posts.

The Four Fundamental Forces in Creation:

  • Gravitational Force-  the force of attraction between all masses in the universe; especially the attraction of the earth's mass for bodies near its surface.  
  • Electromagnetic Force-  electrical force by which an electron is attracted to an atomic nucleus but repelled by another electron.
  • Weak Force-  a very short-range force responsible for particle decay, also similar to electromagnetic force.
  • Strong Force- the strongest force in creation; responsible for holding the nucleus together.

Welcome to "The Forces in Creation" Science Blog!

In each post, you will learn in depth about the different forces in creation. We will go into detail about each force, explaining it's meaning, what it does, and why it is here. You will learn Physical Science vocabulary and add to your knowledge of the different forces in creation.

Thank you for reading, and be sure to click "follow".

Sincerely,
Olivia and Kathryn