Nonfiction Main Idea Practice

Being a clown isn't all fun and games. Rodeo clowns expose themselves to great danger every time they perform. When cowboys dismount or bulls buck them off, rodeo clowns jump in front of the bulls and motion wildly to get their attention. In this way rodeo clowns provide an alternate target, and in doing so protect the rider. Of course, this is a very dangerous thing to do. So you see, sometimes clowning around can be serious business.

• Rodeo clowns distract bulls.

• Rodeo clowns protect cowboys by putting themselves in danger to distract the bulls.

• It's fun to be a rodeo clown.

Sometime in December of 1891, Dr. James Naismith was teaching gym at the YMCA College in Springfield, Massachusetts. It was raining, and Dr. Naismith was trying to keep his students active. He wanted them playing a vigorous game that would keep them moving. He rejected a few ideas that were too rough. Then Naismith had his breakthrough. He wrote out the rules for a game with peach baskets fixed to ten-foot elevated tracks. Naismith's students played against one another, passing the ball around and shooting it into the peach baskets. Dribbling wasn't a part of the original game. Also it took a while to realize that the game would run more smoothly if the bottoms of the baskets were removed. But this game grew to be one of the most popular sports in America today.

• While teaching gym at the YMCA, James Naismith invented the game of basketball.

• Dr. James Naismith was a gym teacher.

• Initially, dribbling was not part of basketball.

• In the first stages of its creation, baskets still had the bottoms attached.

In the summer of 1939, a few months before World War II started, Albert Einstein and a group of Hungarian scientists wrote to President Franklin D. Roosevelt. In this letter they warned Roosevelt that the Nazi’s were conducting atomic research and that the consequences would be dire if the Nazis were to win the race to build an atom bomb. They recommended that U.S. become involved in uranium research. As a result of this letter, the U.S. joined the atomic race and poured billions of dollars into the development of weaponry. The U.S. won the race and became the first country to build an atomic bomb. The bomb was then used in Japan, killing hundreds of thousands of civilians. In 1954, a year before his death, Einstein would refer to the moment that he signed the letter to President Roosevelt as the greatest mistake of his life.

• Albert Einstein lived to regret recommending that the US develop atomic bombs.

• President Franklin D. Roosevelt order the creation of the atomic bomb.

• The war was ended when the US bombed Japan.

• Albert Einstein invented the atomic bomb.

It's hard to imagine what things were like before there was money, but such a time did exist. During these times people exchanged goods using the barter system. The word barter means to trade. People using the barter system traded things instead of buying and selling them. So if you were a rice farmer, you would trade your rice with many people to get all the things that you wanted or needed. Unfortunately, the people from whom you needed things might not want your rice. Isn't it nice to just go to the store and buy candy instead of having to trade rice for it?

• Sometimes, the things you needed were not available to barter.

• The bartering system was used to exchange goods, but it had many shortcomings.

• Rice farmers traded rice for other necessities.

• The bartering system was in place before money existed.

For most of human history, people thought that the Earth was the center of the universe. Nicolaus Copernicus changed how people understood the universe when he theorized that it was heliocentric, or sun-centered. Interestingly, Copernicus had most of this theory worked out some time before 1514, and his work was fully articulated by 1532, yet publication of this text was not completed until 1543 as he lay dying. Some scholars believe that Copernicus delayed publishing this work because it contradicted the Catholic Church’s view that the Earth was at the center of the universe. Copernicus’s may have been smart in doing so because the Church did not formally accept his view of the universe until 1822, almost 300 years later.

• Copernicus' theories were ahead of his time.

• The church finally accepted Copernicus' view of the universe in 1822.

• Copernicus discovered that the Earth revolved around the sun, but was too afraid to talk about it.

• Copernicus changed how people understood the universe.

One problem that the U.S. faced when rebelling against the British was currency. While under British control, colonists mainly used British paper money and foreign coins. But after forming a new nation, the Americans needed their own currency. They created Continental currency. Congress issued over 240 million Continental Dollars during the Revolution. Unfortunately, these dollars soon dropped in value. This gave rise to the popular expression, "not worth a Continental." By the end of 1778, Continentals were worth 1/5th of their face value. By 1780, they were worth 1/40th. In the 1790s, the U.S. bought back Continentals for 1% of their printed value. One reason for this decline was economic warfare. During the war the British hired artists to counterfeit Continental Dollars. Then they funneled large amounts of these counterfeit notes into the American economy. The value of the Continental Dollar crashed. When people complain about today's inflation rates, I tell them about Continentals.

• Continental dollars were worth 1/5th of their face value.

• After dropping in value, the Continental Dollar was brought back for 1% their printed value.

• The Continental Dollar failed due to economic warfare.

• America's first currency, the Continental Dollar, quickly dropped in value after it's initial release.

What's that humming sound? Could it be the hummingbird, the only bird capable of backward flight? Hummingbirds have many unique flight habits that distinguish them from other birds. Most birds flap their wings up and down to fly, but the hummingbird moves its wings forward and backward very rapidly in a figure eight pattern. This allows the hummingbird to hover in position. They can also fly upside down and move about very rapidly. Other birds have to push off with their feet to begin flying and work their ways up to their top speeds. The hummingbird can both start flying at maximum speed and stop flying instantaneously. Once you've seen a hummingbird in flight, it's unlikely that you'll mistake them for another bird.

• Hummingbird wings make a soft sound when they fly.

• Hummingbirds can fly upside down.

• Hummingbirds can stop flying in an instant.

• The hummingbird flies in unique and an unusual way.

Marie Curie not only the first woman to have won a Nobel Prize, she is also the only person to win a Nobel Prize in two different sciences. Most notably, however, Marie Curie discovered radiation. She was also the first person to use radiation to treat tumors. Curie experimented extensively with radioactivity during her scientific career. Unfortunately the damaging effects of radiation were not known then. Her exposure to radiation most likely was the cause of her blindness and early death. Still today her scientific papers are considered too dangerous to handle without protective equipment. These documents are stored in lead-lined boxes. Even her cookbook is radioactive. She must have made some really hot food in her lifetime.

• Marie Curie is the only person to win a Nobel Prize in two different sciences.

• Marie Curie was exposed to radiation, causing her blindness and early death.

• Marie Curie discovered radiation.

• Marie Curie did amazing work with radiation that caused her health problems later in life.

You might think that all automobile fuels are the same, but they aren't. Automobiles can run on one of three types of fuel: gasoline, diesel, and biodiesel. All these fuels are burned inside of the engine, which creates the heat and energy that is used to power the car. But there are important differences between these fuels. Gasoline and diesel are more common than biodiesel. But each burns differently. Diesel fuel is heavier and less flammable than gasoline, so it has to be compressed before it will burn. Gasoline may be lighter than diesel, but both fuels are made from crude oil. On the other hand, biodiesel fuel is made from vegetables. Both biodiesel and diesel fuels must be burned in diesel engines, which only use diesel fuel. If gasoline is pumped into a diesel engine, it will have to be pumped out. These fuels may look pretty similar at the gas station, but remember that there are important differences between them or it may cost you.

• Gasoline, diesel, and biodiesel are all fuels, but differ in how they are made and used.

• Diesel fuel is the heaviest and least flammable fuel.

• Gasoline and diesel are more similar than biodiesel.

• Biodiesel is made from vegetables, making it more sustainable than the other types of fuels.

Wolverines are medium sized mammals. They weigh no more than 50 lbs. Yet they have earned their reputation for ferocity by killing prey many times their size. But why do they get in so many fights? The reason why wolverines have so many conflicts with other animals (including wolves, cougars, and even bears) is probably because of the wolverine's preferred hunting style. Rather than chasing down or tricking its prey like most hunters, the wolverine prefers to take its meals directly from other hunters. So while a polar bear or a lone wolf might be enjoying a hard earned carcass, a hungry wolverine may try to take his lunch. As you might imagine, this style of hunting get the wolverine in plenty of fights.

• Wolverines can kill prey many times their size.

• The wolverine is a very tough hunter and often takes food away from other animals.

• Wolverines are a medium-sized mammal, only weighing about 50 lbs.

• The wolverine gets into lots of fights with other animals.