Physical Science, Module 11, The Forces in Creation - Part 1 (part A)

--Videos we watched for Module 11.
--Play  Quizlet.  Just scroll down and click on Physical, then scroll to find the Module you want.

This module briefly introduced the four fundamental forces of Creation, then focused on gravitational force.
*the gravitational force - the force of gravity
*the electromagnetic force - the force that exists between particles with an electrical charge
*the weak force - governs certain radioactive processes in atoms.  Physicists have said that this is a different facet of the same force as the electromagnetic force, and have combined the two names and called this force the electroweak force.  However, in this course, they are discussed separately as the mathematics required to understand how they are the same is rather intense.
*the strong nuclear force - the force that holds the center of the atom (the nucleus) together
These are called "fundamental forces" because all forces in Creation can be traced back to one of them.

Experiment 11.1, Force and Circular Motion
The kids had an empty pen tube, string, and metal washers.  They threaded the string through the pen tube, and tied one washer to the top, and two to the bottom.  They pulled out 6 inches at the top, and marked the string with black marker so they could keep it at that distance while swinging the top washer around in a circle.  It took a few tries and adjustments to get the hang of keeping it going steady so that the top washer stayed 6 inches out, but they did pretty good.

When each kid got it going and was ready, they would say, "Go!" and one of the others would use the stopwatch.  We wanted to see how long it took the washer to make 20 rounds.  We did several trials for each kid, to get an average number of times.  It was around 11 seconds, give or take.
Then we added 2 more washers to the bottom for more weight.  We discovered that with more washers, the downward pull was stronger, and we had to twirl more quickly to keep the string out at 6 inches.  It only took around 7-8 seconds.  The stronger the pull, the faster the top washer would need to go to stay 6 inches out.

Then the last thing we were supposed to do, and I forgot! was to go outside, wear safety goggles, stay away from the windows, and get the washer twirling.  Then one of the kids was to cut the bottom string with the 4 washers, allowing the top washer to fly free.

This was to be an example of centripetal force - the force that is always directed perpendicular ⊥ to the velocity of an object.  Centripetal force pulls toward the center of the circle.
When the washer flew free, it began traveling in a straight line, in the direction of it's velocity as it had been trying to do all the time, but was prevented since it was tied to a string.  The 4 washers hanging on the bottom of the string provided the centripetal force.  The force was in the center, and at any given moment, the direction the top washer was trying to go was perpendicular ⊥ to the center of the circle.

← Generally, objects try to travel in a straight line from in whatever position they currently are.  That can be changed by applying force.  If the force is perpendicular to the velocity of the object, the object's path will begin to curve.  If this continues, the object will move in a circle.  But to stay moving, force must be applied continually.  An acceleration must occur.  Just like if you are driving up a hill, you must keep your foot on the gas.  You may go at a steady speed, but you are still giving the car gas (accelerating).

The acceleration that must occur to keep an object traveling in a circle is called centripetal acceleration.

General principles of circular motion:

1. Circular motion requires centripetal force.
2. The larger the centripetal force, the faster an object can travel in a circle.
3. The larger the centripetal force, the smaller the circle of motion.

Here is a picture of how centripetal force works in our solar system.  Instead of traveling in a straight line, the moon travels in a circle because of the earth's gravity.

Consider the orbits of the different planets; they all travel at different speeds.  The ones that are closer to the sun take less time for their orbit.  Mercury, the closest planet to the sun, takes 0.24 years to orbit the sun.  Neptune, the farthest planet from the sun, takes 164.79 years!  Pluto, no longer considered a planet, takes 247.7 years.

We didn't do experiment 11.2, The "Bent Space" Theory of Gravity (Einstein's General Theory of Relativity) since I didn't have a bowling ball or other suitable really heavy object, as well as the simplicity of the experiment.  If you placed a heavy bowling ball on a couch cushion and rolled a marble around in the circle the dent created, that is Einstein's picture of gravity.  (You'd really have to read the book to grasp this!)  ETA:  We actually DID do the experiment later, LOL!!!!!


I tend to believe in the theory of gravity!  Yes, it's still a theory.  =)
But for some reason, I forgot about experiment 11.3, The Graviton Theory of Gravity.
Boy, my mind was not with me that day!  I've also had a hard time getting back into writing the science posts.  I've done other posts, but they required very little thinking!  =D

Joshua 10:12-13 (KJV)  
¹² Then spake Joshua to the LORD in the day when the LORD delivered up the Amorites before the children of Israel, and he said in the sight of Israel, Sun, stand thou still upon Gibeon; and thou, Moon, in the valley of Ajalon.
¹³ And the sun stood still, and the moon stayed, until the people had avenged themselves upon their enemies. Is not this written in the book of Jasher? So the sun stood still in the midst of heaven, and hasted not to go down about a whole day.
This doesn't mean the sun revolves around the earth.  It just means that Joshua and the children of Israel thought it did!  This is simply telling us what happened from the people's perspective.
The Bible is the single most accurate historical document of its time.  As a historical document, it must quote its subjects accurately, and tell what happened from the perspective of those who made or watched it happen.