Optical Absorption

For one of the classes that I teach the students use a device called a spectrophotometer. Basically this device works by shining a light through a sample and measuring the amount of light that gets through the material. This device is more than a fancy light meter which simply measures intensity. This device can break down the transmitted light into specific wavelengths and thus measure the amount of light transmitted for each wavelength. By measuring the amount of light transmitted we can figure out the the absorption which can tell us something about the specific properties of the material.

In this case my students are trying to determine the band gap energy for different semiconductors and also whether or not the band gaps are direct or indirect. I plan on posting about this lab at some point, but for now I just wanted to mention one thing that I measured. While I was in the lab one day I put my glasses in the detector and measured the absorption of the plastic lenses. The results I got are shown in the graph below (click on it to view it bigger).
The wavelengths that I measured extended from 800 nm (infrared) to 200 nm (ultraviolet). In the graph I only show down to 400 nm because below that my glasses absorbed too much light and the detector could not get accurate readings. Still you can see a sharp increase in the the absorption as you approach 400 nm. Other than the region below 400 nm my glasses did not absorb much light. This can be seen by the low measurements that are all below 0.05. To give you an idea of what this means, all throughout the visible spectrum ( ~400-720 nm, except for the tiny bit close to 400 nm) my glasses absorbed less than 10% of the light. An absorption rating of 1 would mean that an object absorbs 90% of the light, a rating of 2 would mean it absorbs 99%, 3 99.9% and so on. Typically an absorption rating of 7 (99.99999% absorbed, yes that can be measured) or higher is considered fully opaque.

As you might notice the absorption of the plastic in my glasses is not constant. There are small bumps or waves in the graph. These bumps are a result of the the thickness of my glasses and some slight internal reflections inside the material. These bumps are useful because from the size and shape of the bumps we can figure out the index of refraction for the material that my glasses are made from. That would be useful information to know if I were the one designing the glasses since the index of refraction determines the corrective ability of the lenses, and the curvature needed to make them work. Unfortunately I did not put my glasses in straight in the detector which meant that the path of the beam was not normal (perpendicular) to the surface of the lens. This makes the measurement more difficult (i.e. it would take more work than I'm willing to put into it) so I was not able to figure out the index of refraction for my glasses.

My Favorite Christmas Song

There are many Christmas songs and carols out there and while I like many of them that I like there are a few that I really enjoy. But there is one Christmas song that I would have to say is my favorite. It is called "Mary's Lullaby" written by Bertha Kleinman with music by Wanda West Palmer [Update 12/25/13: You can purchase the sheet music here]. Most people who read this blog may recognize the song from the Mesa Easter Pageant but it was written long before it was used in the pageant. Below are two videos of performances of the song.



The accompanying text for this video reads: "This recording was made in 1980 at a church Christmas program. Mary was holding her nine-day-old son, Kristopher. She was first privileged to perform this song in the early 1970s before it was even published and has been invited to sing it many times since, so she almost feels like it is her song. The music was written by Wanda West Palmer and the words by Bertha Kleinman."



The accompanying text for this video reads: "This recording was made in 2003 at a church Christmas program. Mary was holding her 2 month old grandson Kevin. 23 years earlier, she sang this song to Kevins father, Kristopher, who was nine-days-old at the time. (See [The first video]). Mary considers this is her songs as she was first privileged to perform it in the early 1970s before it was even published. The song was written by Wanda West Palmer and the words were written by Bertha Kleinman. It has been a part of the Easter Pagent at the Mesa Arizona Temple for many years."

For those who are interested the lyrics read:
All mine in your loveliness, Baby, all mine;
All mine in your holiness, Baby Divine.
Sing on, herald angels, in chorus sublime;
Sing on and adore, For tonight you are mine.
The wise men are coming to worship their king.
The shepherds are kneeling, their homage to bring.
Out yonder, the star over Judah will keep;
No harm can befall thee, then sleep, Baby, sleep.
Oh, let me enfold thee, my baby, tonight;
While legions are singing in joyous delight.
A new star has risen to hail thee divine,
For you are a king, But tonight you are mine.
Away spectered future of sorrow and plight.
Away to the years that must follow tonight.
The pangs of Gethsemane, let them be dim;
The red drops on Calvary, not, Lord, for him!
Oh, let me enfold thee, my baby, tonight;
While legions are singing in joyous delight.
A new star has risen to hail thee divine,
For you are a king, But tonight you are mine.
All mine in your loveliness, Baby, all mine;
All mine in your holiness, Baby Divine.
Sing on, herald angels, in chorus sublime;
Sing on and adore, For tonight you are mine.

Moral Discipline

A few months ago I wrote a post about research done by a Dr. Dan Ariely. Part of the work done by Dr. Ariely showed that people tended to be more honest when they were reminded of their moral code (even if it was a nonexistent moral code). In my previous post I concluded that "In the absence of a moral code, or a consistent moral code, it would seem that the only way to keep most people honest would be through active regulation of their actions."

About a month after writing that post I watched a talk given by Elder D. Todd Christofferson of the Quorum of the Twelve Apostles. The talk was entitled Moral Discipline and I found it very interesting because he spoke on almost the exact same topic that I had covered, but with more insight and more advice as to what to do about the problem. Here are some excerpts from the talk that I found very interesting.

"The societies in which many of us live have for more than a generation failed to foster moral discipline. They have taught that truth is relative and that everyone decides for himself or herself what is right. Concepts such as sin and wrong have been condemned as “value judgments.” As the Lord describes it, “Every man walketh in his own way, and after the image of his own god” (D&C 1:16).

As a consequence, self-discipline has eroded and societies are left to try to maintain order and civility by compulsion. The lack of internal control by individuals breeds external control by governments. One columnist observed that “gentlemanly behavior [for example, once] protected women from coarse behavior. Today, we expect sexual harassment laws to restrain coarse behavior. …

“Policemen and laws can never replace customs, traditions and moral values as a means for regulating human behavior. At best, the police and criminal justice system are the last desperate line of defense for a civilized society. Our increased reliance on laws to regulate behavior is a measure of how uncivilized we’ve become.”2

In most of the world, we have been experiencing an extended and devastating economic recession. It was brought on by multiple causes, but one of the major causes was widespread dishonest and unethical conduct, particularly in the U.S. housing and financial markets. Reactions have focused on enacting more and stronger regulation. Perhaps that may dissuade some from unprincipled conduct, but others will simply get more creative in their circumvention.3 There could never be enough rules so finely crafted as to anticipate and cover every situation, and even if there were, enforcement would be impossibly expensive and burdensome. This approach leads to diminished freedom for everyone. In the memorable phrase of Bishop Fulton J. Sheen, “We would not accept the yoke of Christ; so now we must tremble at the yoke of Caesar.”4

In the end, it is only an internal moral compass in each individual that can effectively deal with the root causes as well as the symptoms of societal decay. Societies will struggle in vain to establish the common good until sin is denounced as sin and moral discipline takes its place in the pantheon of civic virtues.5"

Essentially the argument is that as societies fail to maintain and encourage moral codes the only other alternative to maintain a civil society is to increase the number and enforcement of laws, or as Elder Christofferson put it, "The lack of internal control by individuals breeds external control by governments." It is with these ideas in mind that I look at societies like those in France or Greece and find it odd that they accept or (as in the case of Greece) actively encourage protest and violent protest as a legitimate means of expressing political frustrations, and then they complain about living in a "police state". In my own experience with places where I have lived, the places where protest was not the first resort of political expression have tended to be more peaceful and less prone to be characterized as having a "police state" mentality. But in places (such as Argentina) were protest and violent protest was a societal tradition the people tended to complain more of government oppression and viewed police and other government forces as adversaries rather than protectors.

What I have learned from observing these different societies is that if people want peace then there needs to be more moral discipline and less unbounded personal freedom. More responsibility and less entitlement. More reminding and less enforcement. Only then can we be free.