Louis Essen was born in 1908 in a small city in England called Nottingham. His childhood was typical of the time and he pursued his education with enjoyment and dedication. At the age of 20 Louis graduated from the University of Nottingham, where he had been studying. It was at this time that his career started to take off, as he was invited to join the NPL, or National Physics Laboratory.

It was during Louis’s time at the NPL that he began working to develop a quartz crystal oscillator as he believed they were capable of measuring time as accurately as a pendulum based clock. Ten years after joining the NPL Louis had invented the Essen ring. This was an eponymous invention which took its name from the shape of the quartz which Louis had used in his latest clock and which was three times more accurate than the previous versions.

Louis soon moved on to newer areas of research and began to study ways to measure the speed of light. During World War II he began to work on high frequency radar and used his technical ability to develop the cavity resonance wavemeter. From 1946 it was this wavemeter which he used, along with a colleague by the name of Albert Gordon-Smith, to make his lightspeed measurements. It has been acknowledged recently that Louis’s measurements were by far the most accurate to have been recorded up until that time.

During the early part of the 1950’s Louis began to take an interest in research which was being carried out at the National Bureau of Standards (NBS) in the United States of America. He learnt that work was being carried out to invent a clock which was more accurate than any other. The American scientists were using the idea of maintaining a clock’s accuracy by using the radiation emitted or absorbed by atoms. At that time the Americans were using a molecule of ammonia but Louis felt that this was not working as well as if they were using different atoms, such as hydrogen or caesium, and so he began working on his own clock using these materials instead.

1953 saw Louis and a colleague, Jack Parry, receiving permission to develop an atomic clock at the NPL based on Louis’s existing knowledge of quartz crystal oscillators and other relevant techniques he had learned from the cavity resonance wavemeter he had previously designed. Only two years later Louis’s first atomic clock was running, Caesium I, designed by the UK scientists. Development in the United States had all but stopped due to political difficulties.

Louis continued to work on his atomic clock and by 1964 he had managed to increase the accuracy of the atomic clock from one second in 300 years to one second every 2000 years! The continued success of Louis’s work resulted in the definition of a second being changed from 1/864000 of a mean solar day to being calculated as the time it took for 9192631770 cycles of the radiation in an atomic clock.

Louis Essen died in 1997 and before his death had been honoured with, amongst others, an OBE and the Tompion Gold Medal of the Clockmakers’ Company.

The United Nations, an international organization dedicated to keeping peace among the world’s nations, was created on October 24, 1945. This month, then, would be an excellent time to focus on how to settle disagreements and learn something about the U.N. Here are a few suggestions:

1. Read this excerpt of the U.N. Charter and discuss what it means:

We the peoples of the United Nations determine…to live together in peace with one another as good neighbors, to work for the equal rights of men and women and of nations large and small, and to promote better standards of life.

2. Try making your own criss-cross puzzle from the underlined words in the excerpt above.

3. Relate the word ‘equal’ to the definition learned in math.

4. Research to find the member nations of the United Nations and write them down. Once they are written, put them in alphabetical order; count the syllables in the names; find them in an atlas and make note of their geographic location (which continent has the most members? the least members?); make tally marks representing each country and practice counting by 5’s and 10’s. Which nations were charter members? Which countries were added later? Find out more about each country by breaking your class into groups.

5. Unscramble the names of these member countries:

DESWEN, LAPNOD, GARTENANI, SUITARALA, DIANI, GEPTY, TRAGE TRABINI, NADACA, HACNI, TENUDI TASSET

Now put these letters, from the countries above, in sequential order to form two words telling what the United Nations is working toward:

CROWLEAPED

6. Here are two realistic situations. Ask your children how they would solve these predicaments in order to make peace. Is there another way to achieve a win-win outcome?

A. Barbara, Cindy, and Judy have always been best friends. Lately, though, Cindy and Judy have been excluding Barbara from their playtime fun. Consequently, Barbara has decided to turn the rest of the class against them. Which way would achieve peace? Brainstorm other ideas!

a. Talk to the three girls privately to determine why Barbara is being ignored.

b. Punish all three girls by not allowing them to play.

c. Start a class discussion about what it means to be a friend.

B. William and Jose were close pals because they liked doing the same things, going to the same places, and going out with the same friends. When it was time for their first school dance, however, they both wanted to ask the same girl. Having found out that Jose had asked Maria first, William wouldn’t talk to Jose at all. Which way would achieve peace? Brainstorm other ideas!

a. Suggest that neither boy take Maria to the dance.

b. Suggest that William, Jose, and Maria all go together as friends.

c. Suggest that William tell Jose how he feels and see what Jose says.

I hope these ideas are useful and inspire your own creativity.

And remember…Reading is FUNdamental!

In part one of this article, you read about representing and adding numbers using base ten blocks. Once these two skills are mastered, it is time to move onto many a child’s nightmare: subtraction. Subtraction, as you may have heard, is essentially addition in reverse. It can be an arduous task on paper, but it can be quite easy with base ten blocks.

Recall that there are four different base ten blocks: cubes (ones), rods (tens), flats (hundreds), and blocks (thousands). Groups of ten base ten blocks can be regrouped or traded for equivalent amounts of other base ten blocks; for instance, ten cubes can be traded for one rod because both are worth ten. For subtraction, it is useful to know how to trade down rods, flats, and blocks. Trading down means converting larger place value blocks into smaller place value blocks. For instance, one flat can be traded for ten rods since they are both worth 100.

Before describing the subtraction procedure, let’s go over some vocabulary . . .

Minuend - The amount from which you are subtracting.

Subtrahend - The amount that you are subtracting.

Difference - The answer.

In the equation, 234 - 187 = 47, the minuend is 234, the subtrahend is 187, and the difference is 47. Most people don’t bother with the terms minuend and subtrahend, but they are useful in describing the subtraction procedure using base ten blocks.

To begin, represent the minuend with base ten blocks. Try to keep the blocks in order from largest to smallest as this will help to transfer knowledge and skills to paper and pencil methods later on. Remove from the minuend piles, enough blocks to represent the subtrahend. If there aren’t enough blocks available, trade some of the larger place value blocks until there are enough smaller place value blocks to remove. The resulting piles after the subtrahend is removed represents the difference.

In the example, begin by representing 234 with 2 flats, 3 rods, and 4 cubes. The goal is to remove 187 or 1 flat, 8 rods, and 7 cubes from these piles. Removing one flat is simple enough, but 8 rods and 7 cubes are difficult to remove if there are only 3 rods and 4 cubes! To solve this problem, trade in one flat for 10 rods, and one rod for 10 cubes. The result would be 1 flat, 12 rods, and 14 cubes. Removing the subtrahend - 1 flat, 8 rods, and 7 cubes - at this point would leave no flats, 4 rods, and 7 cubes. The difference is whatever is left after removing the subtrahend, so the difference is 47.

For beginners, it would be wise to start with subtraction that does not require trading. For example 1954 - 1831 would require no trading because there are enough blocks in the minuend to remove the subtrahend. For more advanced students, questions that include zeros can present a bit of a challenge. For example, 4000 - 3657 would require several trading steps all starting with four blocks. .math-drills.com has several thousand free math worksheets including subtraction questions with no regrouping (trading). One of the nice features of this website is that answer keys are provided, so students can get feedback on their results.

With enough experience, students learn subtraction on a conceptual level and are better equipped to apply it to pencil and paper methods later on. Students who only learn the paper and pencil method don’t always develop a conceptual understanding of subtraction and are less able to identify errors in their work.

Base ten blocks are not limited to just addition and subtraction of whole numbers. In part III of this series, several other uses of base ten blocks will be explored.

Securing enough funding for the Dallas schools is a problem experienced by many school districts in the United States. Most funding has become program specific, with government controlling its use and generally benefiting only a portion of the Dallas schools students. State funding has been scarce, requiring Dallas schools to rely upon local property and school taxes to cover the general needs of the schools. Additionally, federal government oversight creates a lot more administrative requirements. This means that many of the precious dollars the Dallas schools receive through government funding must be spent on administrative costs, rather than directly to benefit the students.

Recently, the Texas legislature passed new legislation for tax and school finance reform. Many are touting the law as especially good for Dallas schools. The law includes tax cuts to businesses, property tax cuts, strong taxpayer protections, and school funding and accountability improvements.

Here is how the new legislation affects the Dallas schools.

School Property Tax Control. Previously, the Dallas schools, along with other schools in Texas, could raise the school property tax rate by six cents per $100 of property every year &ndash without voter approval. With the new legislation, any raise of the school property tax rate of more than four cents must have local voter approval. Additionally, the maximum school property tax was $1.50 per $100 of property. The new legislation will lower that maximum to $1.00 per $100 of property over the next two years.

More Accountability and Transparency. The new legislation not only requires even more bureaucracy for the Dallas schools, but they are required to make it available on the Internet. The Dallas schools will now be required to place detailed local school spending information on a web site for anyone to review. This new level of heavy oversight gives ammunition to anyone who wishes to get their name in the paper through official complaint to the legislators or even bogus court action. Some question whether this might lead to more costs to the Dallas schools to defend needed expenditures that benefit Dallas schools students, either directly or indirectly.

Teacher Compensation. On the upside, the new legislation includes a $2,000 teacher pay raise, sorely needed by Dallas schools teachers. A $250 million state teacher performance pay plan is also included in the law, of which Dallas schools will receive its portion. The performance plan is to encourage teaching innovation and excellence.

Overall, the new legislation puts $1.7 billion dollars of new money into schools across the state, dramatically increasing the state’s share of public school funding. Though this new legislation does take a burden off the Dallas schools property taxpayers by providing more state funding for general school expenditures, it does decrease the local dollars that do not carry the heavy price tag of red tape administration, as well as lowering the Dallas schools ability to raise funds locally.

With declining enrollment and building space for tens of thousands more students than they have enrolled, the Baltimore schools announced last December their restructuring plans to close several elementary, middle and high schools with others becoming combined K-8 schools.

The Baltimore schools held a series of community meetings, where they released a list of possible options they were considering. The options included schools to close, some to renovate, and where to build new ones. The options also were listed at their web site, where parents and community voted on which options they thought were best.

All options would close several Baltimore schools middle schools with consistently low test scores and high rates of violence. Some of these targeted schools are on the state’s “persistently dangerous” schools list, while others are being watched closely for inclusion to the list. The troubled Thurgood Marshall High School, site of a shooting in the 2004-2005 school year, also is included in all options. A new building will replace the current middle school, located at the same site, and be a K-8 school.

The Baltimore schools are dealing with deteriorating buildings, declining enrollment, and state demands that they operate the school system more efficiently. The Baltimore schools’ chief executive officer Bonnie S. Copeland stated that community committees, which used public input gathered earlier last fall, developed the options.

Copeland believed that much of the community shared her vision to expand the K-8 schools, which have been outperforming the traditional middle schools. Many parents, as well as community activist groups, were outraged and vehemently opposed several proposed options and school closings.

Many do not wish to see K-8 schools, unhappy with older children who set bad examples being mixed in with younger children. They believe the low test scores of several middle schools is more complex than just integrating the students with the elementary schools. Additionally, some high-performing schools could be closed, due to building conditions and capacity.

Many parents and activists believe it would be cheaper to renovate existing schools, rather than build new ones. David Lever, executive director of Maryland’s Public School Construction Program, backs this belief.

In March 2006, the Baltimore schools reacted to public pressure and released a substantially revised plan, stating that they took to heart the public’s concerns. The changes did little to appease the opponents of the plan, leaving the Baltimore schools caught between the state demanding a school closings plan and the parents and community activists.

After 85 public meetings on the topic and more than 10,000 participants, the Baltimore schools board voted at the end of March to close 16 Baltimore schools over the next two years. They also approved a 10-year, $2.7 billion plan to build 27 new Baltimore schools, moving thousands of children from middle schools to pre kindergarten through eighth grade.

Now, I am all for special education for children with disabilities. I attended school at a time when such children were either put into “special” schools or thrown in with the general student population to sink or swim on their own. It was a terrible inequity. It finally was addressed in the 1970s with a law designed to correct such discrimination by giving these children the civil right to an equal opportunity to learn. The law covered children from birth to age 22, guaranteeing them the right to a free and “appropriate” public education. It is the ambiguous word “appropriate” written into the law that is creating a crisis for the California schools, according to Nanette Asimov, staff writer for the San Francisco Chronicle.

The article cited a situation of one California schools child with a disability. The assigned public middle school offered special college prep classes, daily help from a special education expert, a laptop computer, extra time for tests, the opportunity to temporarily leave class if the child’s had an anxiety attack, and a special advocate to smooth over any problems with teachers.

The parents hired a special consultant instead, who found alternative schooling opportunities &ndash all were private schools and all were out-of-state. They settled on a boarding school in Maine, outside the main city, that had one-tenth of the enrollment of the California schools. The one thing this school did not offer was a special education program. The mother said that smaller classrooms and a smaller campus were more important than a special education program. Since the possibility of anxiety attacks was mentioned in the article, no one can truly judge the merit of this situation except the child’s physician and/or psychologist.

After the child was placed into the private school, the parents then hired an attorney, who specializes in special education cases, to file papers with the court demanding the California schools pay four years of tuition and family travel costs between California and Maine. Tuition was $30,000 annually. The California schools met the demands.

This is only one such case in the California schools, which may or may not have been justified. The problem is that it is not the only case. In 2005, there were 3,763 California schools children with disabilities that were the focus of formal complaints &ndash the vast majority of which came from parents. This is triple the number of only ten years ago, and the numbers are growing.

With a cost of almost $40,000 to go to a court hearing and the possibility of an expensive judgment, the California schools attempt to settle cases before they get that far. In 2005, ten percent of the California schools’ cases went to a full hearing &ndash 386 in all. The remaining 90 percent were resolved through confidential settlements. With 700,000 special needs students currently in the California schools and already paying hundreds of thousands of dollars each year for private placements, the school system is headed for a financial crisis.

In 2004, the California schools received $4.1 billion for special education from the government and local sources. It was still not enough to pay these extra settlement costs, and the California schools had to take $1.6 billion from the regular class budget. Twenty-eight percent of the special education expenditures that year came from the regular education budget.

California schools educators complain that parents who are able to afford an attorney are assured more opportunities for their children than those who cannot afford to do so, creating an inequity between the haves and have-nots. Additionally, special education teachers see benefits to special programs, such as horseback riding therapy, but acknowledge that such parent demands are not education related. California schools parents and educators are at odds.

Parents are making tuition payment demands of the California schools for such programs as private day schools, boarding schools, summer camps, horseback riding therapy, and aqua therapy. Additionally, the California schools are expected to pay for computers, airfare, car rental, hotel stays, meals, new clothing and tailoring for the children, cell phone calls, stamps, gas and tolls, and future round-trip visits from time of enrollment until the children graduate from high school.

In all, the California schools are paying billions of dollars each year for private placements and auxiliary costs. It is creating an inequity for children the civil rights law was passed to protect and a financial crisis for the California schools.

I have to admit that I wanted every opportunity possible for my child to live a happy and normal adult life. I had a special needs child and spent many hours sitting in principals’ offices and at the school board demanding that his needs be met. I was thankful that he received access to the available offerings within the public school system.

In my view, however, it is not a question of right or wrong, justified expenditure or not. It is a question of the legislators going back and specifically defining the word “appropriate”. Until then, the California schools are borrowing from Peter to pay Paul, which means less opportunities all the way around.

At the Biotechnology Industry Organization (BIO) convention earlier this month in Chicago, former President Bill Clinton sent a message to those in attendance: the biotechnology industry has a job to do.

In his speech, the former President discussed the importance that biotechnology has in food security and health issues in the developing world. He said the first obligation of society is to feed people and that biotechnology can help individuals feed more people while addressing environmental concerns. He also stressed the need for interdependence in the world today as well as the unsolved problems that biotechnology is uniquely suited to face.

Clinton also discussed the need to efficiently manage agricultural production. He mentioned several key aspects of environmental health that agricultural biotechnology can address, including climate change and top soil erosion.

“All of these applications of biotechnology have the potential to lift people out of poverty,” he said.

The former President also asserted that scientific evidence should rule any debate over issues such as genetically modified foods. He said that in America, we “should be driven by science, evidence, and argument, not by assertion and fear.”

Former President Clinton called upon the biotechnology industry to work to reduce the spread of a variety of diseases, including infectious diseases, guard against pandemics, create genetically engineered foods that will feed more of the world’s hungry, tap into sources of renewable energy, and confront global warming head on.

“When we empower individuals to feed and care for their families,” he said. “It is a good thing.”

As President, Bill Clinton supported the development of biotechnology and its practical applications in American life, as well as the development of genetic engineering and agriculture, and since he left office in 2001, President Clinton has dedicated almost all of his time to support causes, from raising funds for Hurricane Katrina victims in the United States to helping individuals with AIDS receive the drugs they need. He has seen first hand the needs that biotechnology can address around the world and the good that genetically modified foods can bring to developing nations in feeding the poor.

I agree with what former President Clinton said in his speech. Modern biotechnology holds such an importance in the world today and these continued developments should not be driven by the fearful beliefs that those opposed to biotechnology and genetically modified foods continuously try to impose upon the general public.

The world needs to support biotechnology, genetically modified foods, and the innovative developments the technology can bring in order to ensure a better future and life for all.

Residents of the Dominican Republic, especially the impoverished ones, have long viewed the United States and especially New York City as a land of limitless wealth. All you have to do is live there for a few years, and you too will be wealthy.

This erroneous vision was fostered in the 1980s with the crack epidemic centered in Washington Heights, an area located north of New York City and predominantly populated by Dominican immigrants. Thousands of dollars in cash were sent back to the families, who still lived in the Dominican Republic.

Though the days of easy money have passed, the Dominican poor still believe that, if only family member can reach the U.S. and remain for a few years, he or she could bring the entire family remaining in the Dominican Republic out of poverty. Thus, the Dominican Republic is the largest exporter of immigrants to the New York City schools. Dominican immigrants now comprise ten percent of the 1.1 million students in the New York City schools.

These young New York City schools immigrants face particularly difficult problems as they attempt to acclimate into American society. They face the pressures to integrate at school, while facing the pressures to remain the same at home. Parents too face challenges with the New York City schools.

The first problem is culture shock. In the Dominican Republic, children always must defer to their elders and hold their tongues, having no way to express their own feelings or opinions. In contrast, children quickly learn in the New York City schools that American children are vital members of society, like any adult. They realize that adults care what they think. They become more outspoken both at school and at home, finding the social freedoms compelling and liberating.

Parents feel themselves losing control of their children, who are shedding their cultural restrictions. They view New York City schools children as arrogant and flamboyant, with no respect for their elders. Such contrasting expectations between children and parents cause stress at home. Of course, many parents blame the New York City schools for their children adopting these attributes, where they did not wish to send their children anyway.

The Dominican immigrant home environment is not always conducive to learning. For impoverished families in the Dominican Republic, education is not a priority, as it is with the wealthy families there. Though early schooling is free for children, it is seen as a costly endeavor for families just trying to make ends meet. Clothing for school, meals, school supplies, books, and transportation are luxuries for such families. According to the World Bank, 13 percent of children ages 7-14 work outside the home, rather than attend school. According to Unicef, 16 percent of children ages 10-17 are illiterate. Usually, one or both parents have little or no education, due to less long-term educational exposure for children of poorer families. Is it any wonder they may resent the mandatory law for their children to attend the New York City schools?

Though cultural differences present a major obstacle, language is the biggest difficulty for these immigrant children in the New York City schools. According to Robert Mercedes, Principal of Middle School 390 in the Bronx and President of the Association of Dominican-American Supervisors and Administrators, Dominican children arrive at the New York City schools lacking the basic native-language skills of the Dominican Republic. This makes transitioning them into the English language even more difficult.

They feel like outsiders in the New York City schools. They are in a language and cultural isolation. They are generally dumped into bilingual classes at low-income schools, and feel more of a burden to the New York City schools than an equal to the other students. The victim mentality takes over for many of these youth, who separate themselves into close-knit ethnic groups. They are especially vulnerable to street gang recruitment, which pervades the areas around the ghetto-like atmosphere of some of the New York City schools they attend.

On one side, the New York City schools are a haven of new opportunities for the Dominican children and their parents. Yet, these same opportunities can be the downfall of the immigrant family values and the children, as well. It is a dual-edged sword, afflicted with stressful difficulties and insurmountable obstacles for many.

With energy issues becoming a daily subject in the news, wind energy is gaining notoriety. Here is an overview of wind farms and their potential.

An Overview of Wind Farms

A wind farm is simply a collection of wind turbines in a location used to produce electricity. Wind farms can be found in the United States, but are far more prevalent in Europe. China is also beginning to invest large amounts of resources in wind farms as its energy needs grow.

The fundamentals of electricity production through wind farms are pretty simple. Highly efficient wind turbines are placed in locations where they will receive the maximum amount of wind energy. These turbines can be traditional horizontal windmills or vertical eggbeater windmills.

Regardless, the wind turns the blades as it passes, which turns a generator within the turbine. The turning motion converts the wind energy into electricity when the generator cranks, which is then sent into a utility company power grid or stored in batteries. This process is similar to hydropower with wind being used instead of water.

The stereotypical wind farm is an exercise in topography. The goal is to find locations where wind exists as frequently as possible. Put in practical terms, ideal spots are in areas where ground variation occurs as wind is produced when different surface areas heat up at different rates. As each surface heats up, the air rises and cooler air rushes in to replace it. Thus, we have wind. Given this situation, ideal locations for wind farms are often along shorelines or in valleys funneling winds from the shore.

Many people are under the impression that wind farms are located only in areas of land where winds are howling through valleys and over hills. While this is certainly true, the current trend is to build wind farms off the shorelines of countries.

The advantage of offshore wind farms has to do with the frequency and generation of winds. Shorelines represent fertile wind generation areas. On top of this, the open space of the ocean allows winds generated from remote locations to move towards shorelines. If you have ever spent time going sailing, you have an understanding of how strong these winds can be. On top of all of this, placing wind farms in the ocean avoids the cost of buying pricey space on land.

Wind farms are up and functioning in most first world countries. The bigger issue is getting them to produce enough energy at as low a price as possible to make them a viable energy production platform.

There are many people who love fiction, but can’t read. Maybe you’re one of them. Some people can’t read for a physical reason &ndash because they’re blind or have bad eyesight, for example &ndash while some find reading difficult or strenuous on a mental level, such as dyslexic people and children. If any of these descriptions fit you, then maybe you should try audio books.

Audio books are voice recordings of people reading books &ndash they used to be called ‘books on tape’, but now they mostly come on CD or even over the Internet as mp3 files. They are a surprisingly versatile medium, allowing for everything from straight readings to radio drama-style productions of the books with actors and sound effects. Some are read by the author, which can be an interesting experience, especially for books of poetry, while others are read by celebrities.

The best thing about audio books is that it’s much less effort to listen than it is to read. You can do other things while you have the audio book on, much like listening to music, such as driving or household chores. Audio books on long car journeys can be relaxing both for you and for children as well, as there are few things children love as much as hearing stories.

However, one word of warning. You should avoid any audio books you might find on the web that have been automatically produced by computer. The standard of computerised reading is not yet up to scratch for most purposes, and that’s certainly the case for audio books &ndash it’s like hearing a robot trying to tell a story. The tone of voice is all wrong, the stresses go in the wrong place, and there’s no sense of drama. It’s difficult to even listen to for a long time, never mind enjoy. Until technology leaps forward (it’ll probably take a few decades), stick to human-read audio books.