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Friday, December 30, 2011

An Experiment from Archimedes

One of the famous stories of Archimedes is the basis for this experiment. Archimedes was a Greek scientist and mathematician. He worked for the king of Syracuse in Sicily. The king suspected that a goldsmith had cheated him by mixing silver with the gold for his new crown. He asked Archimedes to test the crown. Archimedes decided to compare the volume of the crown to a piece of pure gold that was the same weight as the crown. He knew that gold is heavier than silver, so if the goldsmith cheated, the identical weights would not have the same volume. The problem was how could he determine the volume of gold in the crown? One day he filled his tub with water to take a bath. When he entered the tub, water spilled over the sides. Archimedes realized that the water that spilled over was the same volume as his body! He was so excited that he jumped out of the bath and ran through the streets yelling "Eureka!" which means "I found it!" He measured the volume of the crown and an equal weight of pure gold and found that the goldsmith had cheated. His research led to more experiments, which in turn led to "Archimedes Principle." You can find the full story of Archimedes in your encyclopedia or through research at your library. This is an excellent research opportunity for students!

Here's the experiment:
The goal of using the lab sheets is to introduce the student to the scientific method. Do not be discouraged if the hypothesis or even the interpretation is incorrect. The hypothesis should simply be an educated guess, and it is fun to see how one's guess was incorrect.

If the interpretation is incorrect, this is a good opportunity to explain how even the best scientists have some error in their methods which can lead to incorrect interpretations. For example, the interpretation from this experiment should be that the amount of water displaced weighs the same amount as the object that floats. If the cup was not filled with water, or if the displaced water was not poured carefully into the cup to be measured, there will be error. The conclusion should be his famous principle:

"When a body is placed in a liquid, the weight it appears to lose is equal to the weight of the liquid it displaces."

Name of the Experiment: Archimedes' Experiment

Performed by:________________________________________

Date:_________________________________________

The Problem: How does the weight of an object compare to the weight of the water it displaces when it floats?

The Hypothesis:

The Experiment: You will need a postage scale (or other scale that measures ounces), a cake pan, a plastic bowl, a plastic cup, aluminum foil, 25 pennies, and water. Set a plastic bowl full of water in the cake pan. Dribble extra water into the bowl until it is so full that the water heaps up. Mop up any water that spilled into the cake pan. Make a "wide-bottom boat" with high sides from aluminum. Carefully float the boat in the bowl and add about 20 pennies. If the boat sinks, begin again and add only the number of pennies that will allow the boat to remain floating. Remove the boat from the bowl, then remove the bowl from the cake pan without spilling any water. Pour the water from the cake pan into the plastic cup, and record the weight of the cup and water on the chart below. Empty the cup, dry it, and weigh it again with the boat and pennies inside. Record this weight on the chart below. Repeat the experiment several times until you get consistent results. (Three spaces are given for repeating the experiment.) You may change the number of pennies as well.

Observations:

Weight of the Cup that is filled with Water: ________ ________ ________

Weight of the Cup, Pennies, and the Boat: ________ ________ ________

Interpretation:

Conclusion:



Friday, December 23, 2011

A Word from Calvin on Hymns

SINGING WITH UNDERSTANDING REQUIRED

As for the rest, it is necessary to remember that which St. Paul hath said, the spiritual songs cannot be well sung save from the heart. But the heart requires the intelligence. And in that (says St. Augustine) lies the difference between the singing of men and that of the birds. For a linnet, a nightingale, a parrot may sing well; but it will be without understanding. But the unique gift of man is to sing knowing that which he sings. After the intelligence must follow the heart and the affection, a thing which is unable to be except if we have the hymn imprinted on our memory, in order never to cease from singing.

From John Calvin's Preface to the Psalter, 1543

Friday, December 16, 2011

Durer and the Bible

“For he has repented of and made atonement for the sins of the whole world, and has obtained of the Father Everlasting Life. Therefore Christ Jesus is the Son of God, the highest power, who can do all things, and He is the Eternal Life.”

~Albrecht Durer

Albrecht Durer helped to bring the Bible to a wide audience through his brilliant illustrations of the book of Revelation and other themes. His woodcuts were meant to be affordable for ordinary people. Durer wanted to show the supremacy of the Bible while using his art to preach sermons to those who could not read. For an interesting foray into art, search "images" on the internet for artwork by Durer.

Friday, December 9, 2011

Blaise Pascal and the Torricelli Experiment

This experiment is based on actual experiments performed by Blaise Pascal, one of the foremost scientists and Christian apologists of the 1600's. Pascal once wrote: "According to the doctrine of chance, you ought to put yourself to the trouble of searching for the truth; for if you die without worshipping the True Cause, you are lost." He also wrote: "Not only do we know God by Jesus Christ alone, but we know ourselves only by Jesus Christ."
You can copy the lab sheet below into a word processing program and use for your own experiment.

The Torricelli Experiment:

Performed by:_____________________________

Date:________________

The Problem: What happens to the water in a water-filled tube that is turned upside-down and submerged in water?

The Hypothesis:


The Experiment: You will need a test tube or a medicine spoon that is shaped like a test tube, and a glass. Completely fill the test tube or medicine spoon with water. Fill the glass half full of water. Put your finger over the top of the test tube and quickly turn it upside down and submerge it in the water in the glass. Remove your finger. Does the column of water in the test tube run out? Now lift the test tube up above the water in the glass. Does the water run out now? Try the experiment several times until you get consistent results. Record your results under "Observations" below. You may not be sure what to write as the "conclusion", but you can find more information in the encyclopedia under "Torricelli" or read A Piece of the Mountain: the Story of Blaise Pascal to learn about the experiment that he performed. Can you guess why the Torricelli tube acted as it did?

Observations:


Interpretation:


Conclusion:

Friday, December 2, 2011

An Experiment to Use with "The Ocean of Truth: The Story of Isaac Newton"

What is light? This question has interested scientists for hundreds of years. Isaac Newton discovered that light is made up of a spectrum of colored light. He used a prism in his research, but you can use a pan of water to "refract" or bend light. The lab sheet is provided so that you can record what you discover!
There is a story about Isaac Newton that he chanced upon a prism at a book fair during his college years. Despite his thrifty nature, he purchased the curiosity and proceeded to invent dozens of experiments with the light and prism. When he observed how the prism cast a "rainbow" on the wall, he hypothesized that the prism was splitting the light into bands of many different colors of light. To test his hypothesis, however, he had to wait for another fair so that he could purchase a second prism to put all the colors back together!
Isaac Newton went on to make many important discoveries in the fields of physics and mathematics. He wrote: "This most beautiful system of the sun, planets, and comets, could only proceed from the counsel and dominion of an intelligent and powerful Being." Few people know that the man who discovered the "Laws of Motion" also wrote about God: "We must believe that he is the father of whom are all things, & that he loves his people as his children that they may mutually love him & obey him as their father."

You can copy the lab sheet below into a word processing program and use for your own experiment.

An Experiment on Light

Performed by:________________________________________

Date:_________________________________________

The Problem: What happens to light that is reflected from a mirror which is submerged in water?

The Hypothesis:

The Experiment: You will need a pan of water, a hand mirror and a piece of white paper. Place a mirror in a bowl of water so that the handle of the mirror rests on the edge of the pan and the other end rests on the bottom of the bowl. Find a pool of light on the floor of a room in your house, and place the pan in the sunlight. If you catch the light of the sun on the mirror just right, there should be a reflection on the wall. You may have to move the pan several times to get it just right. Wait for the water to become still. Place the piece of white paper in the place where the spectrum reflects and mark the results on the paper. What do you see?

Observations:




Interpretation:

Conclusion: