Wind

This is a good introductory video about wind from: http://www.youtube.com/watch?v=uBqohRu2RRk

Air in Motion

Wind is originated from sun energy, which heats the Earth unevenly, creating warm spots and cool spots.  Two examples of this are: sea breezes and land breezes.

Sea Breezes 

This happens when inland areas heat up on a sunny afternoon.  This warms the air and causes it to rise.  The cooler air comes in from the ocean and takes its place and a wind is born.  This effect can also occur near big lakes, where the wind is called a lake breeze.

Land Breezes

These come at night, when the inland temperature drops so much that the ocean is now warmer than the land.  This simply reverses the effect of the sea breezes.

Global Patterns

Forces similar to the ones discussed produce global wind patterns and affect the climate.  The Coriolis effect is an offshoot of the Earth's rotation and makes moving air masses curve.  Trade winds are winds converging on the Equator coming from the northeast in the Northern Hemisphere and the southeast in the Southern Hemisphere.
Farther from the Equator, the surface winds try to blow toward the Poles, but because of the Coriolis effect, they bend the opposite direction creating westerlies.  This concept explains why so many weather evens in the United States come from the west.
At latitudes high than 60 degrees, cold surface winds try to blow toward the Equator, but they are also bent by the Coriolis effect.  These winds produce polar easterlies.

http://science.nationalgeographic.com/science/earth/earths-atmosphere/wind/

Wind Power

Much to our surprise, air is actually a fluid like every other but its particles are in gas form instead of liquid.  When air moves quickly, in the form of win, the particles are moving quickly.  Motion means kinetic energy which can be captured.  This is just like the energy caught by the turbine in a hydroelectric dam.  In a wind-electric turbine, the turbine blades are designed to catch the kinetic energy in wind.  When the turbine blades capture the wind energy and start moving, they spin a shaft that leads from the hub of the rotor to a generator   This generator turns the rotational energy into electricity   It is all about transferring energy from one medium to another.  

The process of wind power starts with the sun.  When the sun heats up a piece of land, the air around that land absorbs some of that heat.  The hot air begins to rise quickly because the volume of hot air is lighter than the cooler air.  When the lighter hot air suddenly rises, cooler air flows to fill the gap.  The rushing air in to fill the gap is wind.

http://www.howstuffworks.com/environmental/green-science/wind-power.htm

Here is another video that can aid in the classroom discussion on wind farming from: http://www.youtube.com/watch?v=NfOZjsOaqSQ

References

Layton, J. (n.d.).  How stuff works: How wind power works. Retrieved April 29, 2013 from http://www.howstuffworks.com/environmental/green-science/wind-power.htm

National Geographic. (n.d.).  Wind, wind information, facts, news, photos.  Retrieved April 29, 2013, from http://science.nationalgeographic.com/science/earth/earths-atmosphere/wind/

Rainbows

How Rainbows Work 

Light Bends

Refraction is the "bending" of light.  This is what is happening to light when rainbows are formed.  Light bends or changes direction when it goes from one medium to another because light travels at different speeds in different mediums.  

In order to picture this process, imagine pushing a shopping cart through a parking lot.  The pavement is a medium that it is traveling through. Now, imagine you go off the pavement and onto the grass and the cart with simply slow down.  The medium has changed.  The amount of force you place on the cart depends on the medium in which it is travelling through.  The grass medium has more resistence so it takes more energy to move the cart.  

But if you push the cart onto the grass at an angle, something else will happen.  If the right wheel hits the grass first then that wheel will slow down while the left wheel is till on the pavement.  Since the left wheel is briefly moving faster than the right wheel, the shopping cart will naturally turn to the right as it moves onto the grass. (See visual).  

This is what happens to a beam of light when it enters a glass prism. A simplified explanation is that one side of the light wave slows down before the other, so as the light moves from the air to the glass, the beam turns.  

Not only is the light bent, but the white light is also separated into different colors.  Different colors of light have different frequencies.  These frequencies cause them to travel at different speeds as they move through matter.  

The slower the light is travelling, the sharer it will bend.  This is because when the light moves slowly, the speed difference is more severe.  Dispersion is when the glass bends the light twice  like in a prism, and you can see the separated colors more easily. 

Now, if you are like me, you aren't very familiar with the concept of making rainbows through prisms.  Most of us, as well as most of our students, will think of rainbows in the sky.  They will relate rain with rainbows. So, let's look at how rain causes rainbows

Making a Rainbow

An individual raindrop effects light in a similar way that the glass prism did.  When white sunlight hits a collection of raindrops at a low angle, you can see the different colors of the rainbow: red, orange, yellow, green, blue, indigo, and violet.  To keep it simple the diagrams only show red and violet, the end colors of the spectrum.  

Each single raindrop disperses white sunlight into its component colors.  So why do we see a wide band of colors? Because we only see one color from each raindrop.  For example, when raindrop A disperses light, only the red light exits at the correct angle to travel to the observer's eye.  The other colored beams exit at a lower angle, so the observer doesn't see them.  The surrounding drops will be hit by sunlight in the same way, so they will all bounce red light onto the observer.  

However, raindrop B is lower in the sky, so violet light exits to the observer, not red.  The surrounding drops also turn the light violet.  The raindrops between A and B all bounce different colors of light, so the observer sees the whole color spectrum.  

If we stood above the rain, we would see the rainbow as a full circle because the light would bounce back from all around you, but we see the arc of the rainbow that is visible above the horizon.

A View from Above

Sometimes, we see a double rainbow which is a sharp rainbow with a fainter rainbow on top of it.  This happens because the light is reflected twice instead of once.  If you look carefully, you will notice that the colors in the second rainbow are in reverse order. 

A Double Rainbow: Can you see the reverse order?

Rainbows in the Elementary Classroom

Now, I think we can all agree that the idea of rainbows is very abstract.  This is a hard concept to explain to students, especially elementary students.  I don't think that we should go as in depth as the article did, but it is good to know the information yourself to feel comfortable with the concept.  There are many things that you can do with rainbows to show students that it is simply the bending of light.  

Below is a good introductory video that can be shown to students before a lesson on rainbows.  

http://www.youtube.com/watch?v=K0S3RlHTPSI

• A good chance for students to see a rainbow is to simply take them in the sunlight and allow them to hold a CD with the back of it toward the light.  The reflection will make a rainbow appear.

Rainbow in a Box

This activity also involves using a CD.  It is important that students understand that the CD seperates white light into all the colors that make up the rainbow.  When light waves reflect off the CD, they overlap and interfere with each other.  Sometimes the waves ad together to make a rainbow. 

Materials:

1. CD
2. Box
3. Flashlight

Directions:

• Shine a flashlight on an old CD in the bottom of a box turned on it's side.
• Turn off the lights, and move the flashlight across the CD to make the rainbows dance. 

Cross-Curricular Themes

The neat thing about rainbows is that they can be implemented into many different subject areas.   By following the link below, you can find many of these activities.  There is rainbow addition,  eat the rainbow (a health lesson), and rainbow symmetry.  Rainbows can also easily be implemented into art, reading, and music. 

Click Here for More Rainbow Activities

References:

Harris, T. (2002). How rainbows work. HowStuffWorks.com. <http://science.howstuffworks.com/nature/climate-weather/storms/rainbow2.htm>. 12 April 2013.

J Ross. (2012, June 6). Rainbows day 5: What makes a rainbow. Retrieved from http://mylearningboys.blogspot.com/2012/06/rainbows-day-5.html

Tornados

Toward Twister Forcasting

In 2011, tornadoes killed more than 550 people.  Technology has made many natural disasters (such as hurricanes) more able to be predicted in order to keep people safe.  However, this is not the cas with tornadoes.  Though is improving and now, tornado activity can be predicted up to a month in advance.  This improvement has been possible because of patterns in short-term climate trends.  Studies have shown that tornadoes are growing more frequent because of long-term climate warming.  Tornadoes involve winds of up to 300 miles per hour.  The U.S. Midwest is the twister capital of the world.  Tornadoes seem to be becoming more frequently as climate warms, but the connection is an uncertainty.  Typically, a tornado watch gives only a few hours notice when dangerous conditions begin.  This gives people only a few minutes to get out of the way.  Studies identify two parameters that closely associate with monthly tornado activity: rain associated with strong updrafts; and helicity, which measures the tendency of winds to spin those updrafts. Studies wanted to predict the tornado activity of the individual months from 1979 to 2010 from an index based on each month's average wind and rain parameters.  This was successful in predicting about a month in advance.  This success, especially in June, is the first showing of predictability of monthly tornado activity.  (The Earth Institute at Columbia University 2012).

In the Classroom

Tornado in a Bottle

This is a fun and easy way to model tornadoes to students.  The easy ingredients and steps make it very realistic for elementary science teachers.  

All you need is: water, a container, and dish soap!

Here is a link to the full and more detailed directions: http://www.inlieuofpreschool.com/tornado-in-a-bottle-easiest-diy-science-lesson-ever/

References

The Earth Institute at Columbia University (2012, January 20). Toward twister forecasting: Scientists make progress in assessing tornado seasons. ScienceDaily. Retrieved March 15, 2013, from http://www.sciencedaily.com­/releases/2012/01/120119134019.htm

Water Cycle

Introduction

Water is a necessity for life.  It is the only form of matter that can be a solid, liquid, and a gas at Earthly temperatures.  It is important for students to understand how the water cycle works.  The water cycle is typically taught in 5th grade science.  However, it is important that teachers keep in mind the big idea when it comes to teacher science, specifically water.  According to Malonne I. Davies and C. Matt Seimears, "water is a common topic for study and investigation in chemistry, physics, and biology, as well as the Earth, atmospheric, and space sciences" (2008).  Not only is water studied in many science fields, but it is also easily connected across different subject areas.  An example of this is social studies.  Bodies of water adn waterways have an important role in history especially during exploration, trade, and colonization.  Despite that the water cycle is taught in science class, it is important that the teacher draws on activities and questions from other disciplines in order to increase student understand and critical-thinking skills. Along with this discussion, the article by Davies and Seimears includes two lesson sets with the water cycle that include multidisciplinary connections. (Davies & Seimears 2008).  

The Water Cycle

The water cycle is made up of three parts: evaporation, condensation, and precipitation.  Some sources, like the diagram above, also counts the collection of water as an additional step.  Through these steps, water is transported from the land and oceans to the atmosphere and then back to the land and oceans. The water cycle is driven by the sun.  It is the sun's heating of the water that causes evaporation.  During evaporation  the water changes from liquid water to water vapor.  Once in the atmosphere, the water is cooled and becomes a cloud.  The clouds lead to precipitation.  During precipitation, the water falls back to earth in the form of rain, snow, or ice. After falling back to land, most of the water re-enters the water cycle.  The water that does not evaporate flows into the streams, rivers, lakes, or underground aquifers. 

This article also has a side note on the fact that the water cycle can change.  This change occurs due to glacier retreating.  This occurs when glaciers melt faster than their ice can be replaced.  Glacier retreating limits the amount of fresh water on earth.  Today, glacier retreating is occurring at it's fastest rate yet.  

Saturn's Moon Has Water Cycle Too!

New evidence shows that Saturn's moon has lakes and a "water" cycle like the one that occurs on earth.  However, the lakes on Titan (the name of Saturn's moon) are not filled with water.  Instead, they probably consist of liquid methane.  This is the cause of Titan's super-chilled climate.  The lakes on Titan have been seen to be as big as 40 miles in diameter. The river-like channels that they found on Titan indicated to researchers that there was liquid methane falling as rain.  However, not all the lakes had these channels sprouting from them.  This suggested that there had to be some sort of aquifer that held the liquid methane just below the surface.  This shows that if you would dig a giant hole on the surface of Titan, then it would fill with water.  The article compares this suggestion to the Crater Lake in Oregon.  

Researchers are amazed at the similarities that Titan has with Earth.  If we were to go to Titan and stand at the shores of one  of the lakes, it would look similar to what we are used to seeing.  The water would be clear so you can see the pebbles at the bottom of the lake.  Earth and Titan are the only two places in the solar system where water is present at the surface.  As we discussed with the water cycle, water is necessary for life, so can there be life on Titan? Scientists say no because the temperatures are too cold to sustain any living organism.  Temperatures on Titan are about -179 degrees Celsius (-290 degrees Fahrenheit.  (Lovett 2007).

 

Teaching the Water Cycle

http://www.youtube.com/watch?NR=1&v=YPJYPo2qhOM&feature=endscreen

Above is a Bill Nye the Science Guy video on the water cycle.  I suggest using this as a learning tool for students because Bill Nye does a good job of making science fun and interesting for students.  He also includes a lot of experiments in his videos that could be implemented in the classroom.  Personally, my favorite is the cloud in a jar experiment that is performed.  I think that this could be implemented into a classroom and I think it is a good way to help students visualize an abstract concept. Because of my interest in this experiment, I went online to try and find specific steps and I was successful! So, here is a link to a pdf file of the experiment along with journal prompts and safety cautions.

http://www.lauracandler.com/filecabinet/science/CloudinaJarDemo.pdf

I also came across another creative way to demonstrate the water cycle.  I have seen this done before, but I especially like how the teacher wrote the cycle on the bag so that students could see what was happening to the water when it "disappeared" from the bag.  I like this idea because it is an ongoing experiment that doesn't take a lot of time, it is mainly just observations.  

http://primaryreadingparty.blogspot.com/2012/04/science.html

References

Davies, M.I., & Seimears, C. (2008).  Water: A topic for all sciences.  Science Activities, 45(3), 27-36.

Lovett, R.A. (2007).  Saturn moon has lakes, "water" cycle like earth's, scientists say.  National Geographic News.  Retrieved (March 1, 2013) from http://news.nationalgeographic.com/news/2007/01/070105-saturn-titan.html

Rutledge, K., et al (2013). Water cycle. National Geographic Society. Retrieved (March 1, 2012) from http://education.nationalgeographic.com/education/encyclopedia/water-cycle/?ar_a=1

Floods

What is flooding?

     Flooding is a serious concern for many people around the world.  All parts of the U.S. experience the same after effects of a flood, but what causes the flood varies depending on location.  Floods occur when a normally dry area experiences heavy rain. According to PBS, floods can be described very simply.  If we are discussing floods in our classroom, hopefully, we have previously done lessons on the water cycle.  If students understand the water cycle, then floods are simply defined as when that cycle gets backed up, the water is not evaporating into the atmosphere fast enough.  According to PBS, the following are some ways that this cycle can become unbalance:

• heavy, intense rainfall
• run-off from a deep snow cover
• over-saturated soil, when the ground can't hold anymore water.
• frozen soil
• high river, stream or reservoir levels caused by unusually large amounts of rain
• ice jams in rivers
• urbanization, or lots of buildings and parking lots

     There are also two different types of floods: the regular river flood and the flash flood.  I will go over these two different types of floods in more detail in the following paragraphs.  But first, as a future teacher I can't help but thing of this topic in the context of teaching this within a weather unit.  I would take these two different types of floods and have the students compare and contrast them.  Which do you think that we experience in Iowa? What is the difference between Iowa floods and the floods that occur along the coastlines?  These are the types of discussions that we would have based on the information they learn about different types of floods.

River Flood

     River flooding is, for the most part, fairly easy to predict.  However, it causes a lot of damage to property.  Scientists, and even residents, can tell when they are going to be flooded because they can see the river rising every day as it continues to snow or rain.  This gives authorities enough time to warn and evacuate the people living in the danger zones of the flooding area.  

     Winter weather can also cause river flooding.  Flooding in the winter time is caused by ice jams in the river.  Large chunks of ice floating in the river can get piled up.  This pile up of ice can stop the water flow in the river.  PBS explains this winter flooding by relating it to driving on an interterstate when you come upon a construction area and the multiple laned road becomes a one way.  The traffic begins to get backed up, just like the water does when ice chunks block it's flow.  

      Here are some pictures from the flooding that occurred in the Midwest United States in 2011.

Many roads were closed due to water flowing over them.

Notice how high the water is in relation to the white house in the top left-hand corner.

Many fish and other animals from the river suffered and were exposed as the water levels started to decrease.

Notice the sandbags that were air lifted to different levy breaks along the Missouri River.  In the background, baseball fans gather in Omaha for the 2011 College World Series. 

http://www.ibtimes.com/flooding-midwest-latest-photos-disaster-707337

     I would be sure to include pictures and articles from the flooding in the Midwest of the United States, because some students may be able to make personal connections to this concept of flooding.  Many people volunteered to help move sandbags in hopes to protect property. Now, let's compare what we know as flooding to what the coastal states experience. 

Flash Flooding

     Flash floods are typically the more dangerous type.  The rainfall is so intense and happens so quickly that flash floods serve a great challenge to meteorologists. However, technology is every improving and the Doppler radars have greatly assisted meteorologists to better predict flash flooding.  

     An article by Andrea Thompson discusses how lightning is able to help meteorologists predict flash floods.  She mentions that, in the past 30 years, more people have died from flooding than from hurricanes, tornadoes, or lightning (Thompson 2008).  Intense strikes of lightning may provide a warning that a flash flood is going to occur. Flash floods occur spontaneously with intense rain fall in a short period, usually several inches in one hour (Thompson 2008).  Most of the time, flash floods occur when a storm remains in one area for a long time, or when multiple storms pass through the same area repeatedly (Thompson 2008).  When this intense rain occurs, the ground cannot absorb the rain quickly enough and that is when the flooding occurs.  The flooding is usually more severe in the cities, because they have more concrete (which doesn't absorb water as efficiently as soil).  Most of the deaths associated with flash floods occur when people are in their cars and they lose control of the vehicle.  Thompson says that many people underestimate the power of water; it only takes two feet of water to float a car (2008).  

     When using lightning to predict rainfall, the meteorologists use what is call nowcasting. Nowcasting predicts weather in a shorter time scale, than compared to forecasting which predicts weather days in advance (Thompson 2008).

     Below is a video from the flood in Mississippi that happen in 1927.  This video came from the USGS website that shares water resources for the United States. 

http://archive.org/details/mississippi_flood_1927

This video, along with the information discussed about new technology that is used to predict flash floods would make a great writing assignment or discussion prompt for the students.  The students can compare and contrast past floods to present floods.  They can also compare and contrast flash floods to river floods.

Reference List

Thompson, A. (2008).  Lightning warns of flash floods.  Live Science. 
http://www.livescience.com/7611-lightning-warns-flash-   floods.htmlutm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+Livesciencecom+%28LiveScience.com+Science+Headline+Feed%29 

N.A. The hows and whys of floods. PBS.  http://www.pbs.org/newshour/infocus/floods/science.html

Signal Corps of the Mississippi flood of 1927 (Producer).  (1936).  Mississippi river flood of 1927.  Internet   Archives. Retrieved from: http://archive.org/details/mississippi_flood_1927

Nature Has a Formula That Tells Us When It's Time to Die

I just read an article by Robert Krulwich, in which he suggested that there is a mathematical formula as to when organisms will die.  He mentions that death is related to size.  The mathematical formula suggests that if the size of the organism is known then the lifespan of that organism can be calculated. They do mention that there are some factors that do effect the formula.  Factors such as disease and organisms killing each other. 

Now that you get the gist of the article, it's time for me to share my opinion.  To be completely honest, I do not believe it. I do not believe that the span of our life can be calculated through a mathematical formula.  Does it make sense? Yes, I would agree that it makes sense that larger animals live longer than the smaller animals.  Obviously, I think we can all agree that an elephant is going to live longer than an ant.  However, my issue comes in when they start to claim that we, basically, have a limit to the number of heart beats and once we reach our limit then we die.  They do mention factors, such as illness, that effect the prediction.   If we take out all those factors, then the formula could predict when an organism will die.  This sounds absolutely crazy to me.  I believe in fate, destiny, and God's plan for us and, therefore, I cannot believe that mathematicians can put my heart beat into a calculator and tell me when my time is up.  It is probably because of the religious side of me, I do not like to think that my life is nothing but a set amount of heart beats.  

I often have a hard time grasping scientific theories and, as a teacher, I also find them hard to explain, especially to younger students.  Science is often very abstract and hard to visualize or explain.  However, it is articles like these that are important to read because they really make us think.  They force us to have an opinion and to be able to back up the opinion with more information.  Being a teacher, it is articles like these that I would like to include in my science curriculum.  This article would provide some very interesting and thought-provoking discussion in the classroom.


Krulwich, R. (2013). Nature has a formula that tells us when it's time to die. NPR. 
https://lms.bvu.edu/section/content/default.asp?WCI=pgDisplay&WCU=CRSCNT&ENTRY_ID=7AE7F8CFB2A047C3A449F9F9651ABABC