Author: Maddie Van Beek

You might think coffee tastes disgusting, but the majority of the adults in your life probably drink coffee in the morning! A big reason that people drink coffee in the morning is because of the benefits of caffeine. Caffeine is a substance in coffee (as well as some other beverages and food items) that is classified as a stimulant. This causes people to WAKE UP! when they drink their morning cup of coffee. If no one in your life drinks coffee, I’m sure you or a friend has had a caffeinated beverage such as Mountain Dew or Pepsi. Did you know that even chocolate has a small amount of caffeine? It’s true!
​
Our experiment today has less to do with coffee and more to do with the effects of caffeine on the body. In our activity, you will create an experiment to see the difference in effects between caffeinated and decaffeinated coffee on a variety of test subjects. Before we start that, let’s learn a little more about caffeine and what a stimulant does. ​

What is caffeine?
Caffeine is classified as a legal stimulant that appears in many beverages and foods that we consume. Check out the links below for information about how caffeine affects those who consume it.

http://kidshealth.org/teen/drug_alcohol/drugs/caffeine.html
http://science.howstuffworks.com/caffeine1.htm
 
What is a stimulant?
A stimulant is “a substance that raises levels of physiological or nervous activity in the body.” This means that stimulants make you more alert and energized, but also raises your heart rate and blood pressure.
 
How is coffee decaffeinated?
Decaf coffee doesn’t come from different “special” coffee beans. Normal coffee beans go through a decaffeination process in which steam or water is added that causes the bean to swell. This swelling allows for caffeine to be extracted. Read more in the link below.

http://coffeeandhealth.org/all-about-coffee/decaffeination/
 
Some people even say that caffeine can increase athletic performance! According to several sources such as
Runner's World, having caffeine before a workout can reduce an athlete's perceived exertion. Basically, you don't feel as tired. If you do take caffeine before working out, just make sure to also stay hydrated! 

Taking Pulse:
1. Find your artery on your wrist, right below your thumb.
2. Place two fingers of one hand over the other artery, as pictured above. (Do NOT use your thumb, as it has its own pulse. 
3. Count the beats for 10 seconds, then multiply by 6 to get the beats per minute. 

Now you can get started on your experiment! 

1. Gather 10 test subjects. A higher number is always better to get more accurate results, so if you can get more participants, go ahead! When you ask your subjects to participate, make sure you tell them to refrain from eating or drinking for two hours before the test. Why do you think this would matter?
2. Write your test subjects’ names on small slips of paper. Fold the slips and put them in a bag.
3. Draw out five names. These five will receive regular coffee.
4. Draw out the last five names. These five will receive decaf coffee. They are receiving a placebo. This means that they think they are receiving the regular treatment, which is normal caffeinated coffee, but they are really receiving decaffeinated coffee. Make sure you do not tell your participants whether they are receiving regular or decaf!
5. Write your test subjects’ names on the coffee cups.
6. Brew a pot of decaf coffee and pour it into the cups of the last five names you drew.
7. Brew a pot of regular coffee and pour it into the cups of the first five names you drew.
8. Now it’s time for testing!
9. Before you test your subject’s pulse, ask them about their normal caffeine consumption. Take notes on their response. Take your subject’s pulse before you give them any coffee. Write down the result.
10. Give your subject the coffee. Take their pulse 5, 10, and 15 minutes after drinking the coffee.
11. Move on to the next subject and repeat steps 9 and 10 until you are finished with all 10 participants.
12. Graph the pulse for each participant. The X-axis should be time and the Y-axis should be pulse.
13. Analyze your results. Trace your graphs for caffeinated coffee participants in green. Trace your graphs for decaffeinated coffee participants in red. Do the green graphs look different than the red ones? What does this tell you about caffeine’s effect on the body?
14. Look at the graphs again and trace the regular caffeine consumers in blue. Do these graphs look different from those who are not regular caffeine consumers? Did caffeine affect non-users more so than regular users?
15. How else could you test caffeine? Example: Have runners who regularly use caffeine run a mile without caffeine and record their time, pulse, and perceived exertion. The next day, repeat the process with the same subjects after they drink a cup of coffee. Does the coffee make a difference?

Schorzman, J., 2005. A small cup of coffee. 
https://upload.wikimedia.org/wikipedia/commons/thumb/4/45/A_small_cup_of_coffee.JPG/800px-A_small_cup_of_coffee.JPG File used in accordance with the 
Creative Commons Attribution 2.0 Generic License. Image was not changed. 

Jynto, 2011. Caffeine (1) 3D ball. 
https://upload.wikimedia.org/wikipedia/commons/thumb/0/05/Caffeine_%281%29_3D_ball.png/800px-Caffeine_%281%29_3D_ball.png File in the Public Domain. 

Haggstrom, M., 2012. 
https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Health_effects_of_caffeine.svg/800px-Health_effects_of_caffeine.svg.png File in the Public Domain. 

Pulse photo and running photo provided by Maddie Van Beek. 

Author: Maddie Van Beek

The name “meat tenderizer” seems pretty self-explanatory, but have you ever wondered how meat tenderizer works? Doesn’t the tenderness of the meat just depend on the quality or how long it’s cooked? Obviously a filet mignon is more tender than a sirloin, right? It’s not quite that simple. You can use meat tenderizer to make tougher cuts of meat softer, and this is actually a chemical process!

You CAN tenderize meat through force, using a tool that looks something like this: ​

Click HERE for more information about enzymes!

Are enzymes only used in meat tenderizer? Of course not! 

PREDICT: How do you think enzymes work in YOUR body? 

Check this video out to find out more about what enzymes do for YOU! 

​Whats the difference between using an enzymatic meat tenderizer and marinating meat in vinegar, tomato or lemon juice? 

They both break down bonds in the meat, but enzymatic meat tenderizers use enzymes to break down the connective tissue in meats while acidic substances use acid to break down that same tissue. 

PREDICT: Which meat tenderizer will be most effective? 

YOU WILL NEED:

• One large steak
• Knife
• McCormick (or other brand) Meat Tenderizer
• Meat Tenderizing tool
• Baking soda
• Vinegar
• Yogurt
• Six small tupperware containers
• Masking tape
• Pen

HERE’S WHAT TO DO: 

1. Make sure you have an adult to help you cut the steak.
2. Wash your hands and prepare a clean cooking space. Place the steak on a clean surface. 
3. Cut the steak into six equal pieces. 
4. Place each piece into a separate container. 
5. Sprinkle a teaspoon of baking soda onto the first piece. Rub the baking soda into the meat. Label the container using the masking tape and a pen and place in the refrigerator. Make sure you label each container right away so you can keep the pieces of meat straight. 
6. Sprinkle meat tenderizer onto the second piece of meat, label the container, and place in the refrigerator. 
7. Cover the third piece of meat in yogurt, label, and refrigerate. 
8. Douse the fourth piece of meat in vinegar, label, and refrigerate. 
9. Tenderize the fifth piece of meat by hitting it with the meat tenderizer tool for two minutes, label, and refrigerate. 
10. Do not do anything to the sixth piece of meat. Label the container and place in the refrigerator. 
11. Leave all pieces of meat in the refrigerator for 24 hours. 
12. Remember to clean up and wash your hands!!! It’s very important to wash your hands after handling raw meat. 
13. Make your prediction! Which piece of meat will be the tenderest? 
14. After 24 hours, have an adult help you cook the meat. Make sure each piece of meat is cooked in the same way for the same amount of time. 
15. In order to keep the pieces organized after cooking, you could use separate plates and label each with the masking tape and pen.
16. After each piece is done, it’s time to sample! 
17. Grab a few friends to help you sample the meat and have them each rate the pieces from toughest to tenderest. 
18. Create a visual representation to report your findings. 

EXTENSION:

Have you ever heard that Coca-Cola can dissolve a steak? Try it out and see if it works! Start by making predictions: How long will it take? Why is the Coca-Cola able to break down a whole steak? Is the Coca-Cola breaking the steak down through acid or enzymes? 

Check the steak and record your observations every 8 hours for the first 24 hours and then every 24 hours after that. What changes is the steak going through? Did the steak ever fully dissolve? How long did it take? 


References:

http://www.slideshare.net/mixhiela/enzymes-activity-in-tenderizing-meat

http://homecooking.about.com/od/specificdishe1/a/marinadescience.htm

http://www.slideshare.net/mzsanders/how-enzymes-work

http://www.cookingscienceguy.com/pages/wp-content/uploads/2012/07/The-Many-Lives-and-Uses-of-Baking-Soda.pdf

https://en.wikipedia.org/wiki/Enzyme

Image and video credits, in order of appearance:

dumbledad, 2008. Flatten pork steaks-01. Uploaded from Wikimedia Commons on 9/18/2016.
https://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Flatten_pork_steaks-01.jpg/1024px-Flatten_pork_steaks-01.jpg File used in accordance with the Creative Commons Attribution 2.0 Generic license. No changes were made. 

Shafee, T., 2015. Hexokinase induced fit. Uploaded from Wikimedia Commons on 9/18/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/Hexokinase_induced_fit.svg/800px-Hexokinase_induced_fit.svg.png File used in accordance with the Creative Commons Attribution-Share Alike 4.0 International license. No changes were made. 

Ricochet Science, 2015. How Enzymes Work. Uploaded from YouTube on 9/18/2016. 
https://youtu.be/UVeoXYJlBtI

Author: Maddie Van Beek

Energy: What you get when you eat a whole bag of Skittles and six Mountain Dews? Not exactly. What IS energy? Let's find out! 

Ok, so what are the two main types of energy? Put them into your own words!

• Potential

• Kinetic

So remember, energy is never actually LOST--it is just transferred or converted into other TYPES of energy. To go a little further into what potential and kinetic energy actually are, let’s watch this video! It may be an old cartoon, but the reality of energy has not changed! ​

Examples of potential and kinetic energy: 

Dropping a ball (or anything, really!)

Stretching a rubber band or shooting an arrow: The farther I stretch the rubber band, the more potential energy it has. When I let go of the rubber band, the potential energy immediately transfers into kinetic energy. This concept is very similar to archery. The stretched bow is full of potential energy; when the string is released, the bow's potential energy transfers into the arrow's kinetic energy. 

A roller coaster: As the roller coaster car climbs upwards, it is gaining potential energy. At the top of the peak, potential energy is at its height. As soon as the car drops downwards, all that gained potential energy is converted to kinetic energy. Kinetic energy is at an all-time high at the very bottom of the drop, and then it begins to convert back to potential energy. Kinetic energy increases at the same rate that potential energy decreases. They are INVERSES of one another.

Still confused? Think again of a roller coaster. If the roller coaster starts at the top with 100 Joules (Joules are the units used to measure both kinetic and potential energy) of potential energy, the point at the end of drop would have 100 Joules of kinetic energy, because that’s when the roller coaster would be at its fastest. A moment later, when the roller coaster starts going up again, that kinetic energy goes down, and what increases? That’s right, potential energy. 

Take a moment to think of a few more examples. When have you seen potential energy? When have you seen kinetic energy? 

Let’s demonstrate this! 

YOU WILL NEED:

• Basketball
• Tennis ball
• Tape measure or yard stick

Hypothesize: Does the height from which a ball is dropped affect how high a ball will bounce? 

Here's what to do!

1. Use the tape measure or yard stick to measure three feet up from the ground. 
2. Lift the basketball to the three foot mark. 
3. Drop the ball and pay attention to how it bounced. Record the height. Do this three times and find the average height.
4. Now, measure five feet up from the ground. Repeat steps 1-3. 
5. Did the height from which the ball was dropped affect the height that the ball bounced? Explain. 

Now, we will do the same with a tennis ball.

Hypothesize: Does the size of the ball affect how high it will bounce? 

Repeat steps 1-5 with the tennis ball. 

Did you get the same results? Explain.

Let's try something new! First, hold the basketball. Next, hold the tennis ball in place directly on top of the basketball. Drop both balls at the same exact time and watch what happens! 

You should have seen the basketball hit the ground and the tennis ball hit the basketball, which then sends the tennis ball flying! When does the tennis ball bounce higher--on its own, or when it hits the basketball? Record your observations. 

Why did the basketball cause the tennis ball to come bouncing back up? Would this work the same way if you dropped the balls in the opposite order? If you’re not sure, try it out and see what happens!

Based on your previous observations, which ball has more kinetic energy, the tennis ball or the basketball? Why do you think this is? 


Force

When you dropped the tennis ball and the basketball, you saw two forces at work. First, both the tennis ball and the basketball had a force acting upon them--gravity. Second, when the basketball hit the ground, the energy from the impact was transferred to the tennis ball, creating contact force. 

What is force, you ask? Force is the push or pull of an object that happens when an interaction between two objects occur. Picture two vehicles crashing into each head on at the same speed. If one vehicle is a semi-truck and one is a Mini Cooper, which vehicle will have more force enacted upon it? Well, think of the tennis ball as the Mini Cooper and the basketball as the semi-truck. That’s just a start on understanding force and Newton’s Laws, but that's enough for now! 

Until next time--May the force be with you! 

References:
​
https://en.wikipedia.org/wiki/Forms_of_energy

http://www.sciencekids.co.nz/experiments/bouncingballs.html

http://www.physicsclassroom.com/class/newtlaws/Lesson-2/The-Meaning-of-Force

http://www.eschooltoday.com/energy/kinds-of-energy/what-is-kinetic-energy.html

Image and Video Credits, in order of appearance:

The Science Asylum, 2013. What is Energy REALLY?! Uploaded from YouTube on 9/4/2016. https://youtu.be/jCrOtF7T4HE

cassiw2, 2009. The story of potential and kinetic energy. Uploaded from YouTube on 9/4/2016. https://youtu.be/7K4V0NvUxRg

​Bartz & Maggs, 2007. Bouncing ball strobe edit. Uploaded from Wikimedia Commons on 9/4/2016. 
https://upload.wikimedia.org/wikipedia/commons/thumb/3/3c/Bouncing_ball_strobe_edit.jpg/1024px-Bouncing_ball_strobe_edit.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made. 

Psalter, 1324. Longbowmen. Uploaded from Wikimedia Commons on 9/4/2016.
https://upload.wikimedia.org/wikipedia/commons/a/a7/Longbowmen.jpg File released into the Public Domain. 

BrandonR, 2005. Wooden roller coaster txgi. 
https://upload.wikimedia.org/wikipedia/commons/3/30/Wooden_roller_coaster_txgi.jpg
​Uploaded from Wikimedia Commons on 9/4/2016. File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license. No changes were made. 

Utchay Endre, 2008. May the force be with you. https://youtu.be/vSJNeXrCbE4 Uploaded from YouTube on 9/4/2016. 

Author: Maddie Van Beek

The past couple of weeks, you may have been watching the Olympics! It's pretty amazing to see some of the best athletes in the world compete! Of course, not all of us are at that level. So why is fitness important? Think about it. Sure, you have to be fit to do well in sports, but not everyone cares about sports, and that's okay! What’s the incentive to stay fit?

Facts about fitness:

• People who exercise frequently have healthier hearts. 
• Healthier hearts are less likely to have heart disease or strokes. 
• Exercising causes your body to release endorphins, which then make you feel better! Some runners describe this as a “runner’s high.” All I know is that whenever I’m having a bad day and I exercise, I am in a better mood afterwards! 

More reasons to exercise:

• Strengthens your muscles
• Improves mental health
• Strengthens heart muscles
• Counteracts unwanted weight gain
• Reduces some health risks, such as diabetes and depression
• Increases endurance and energy

​
There are many ways to determine fitness, such as VO2 max (oxygen used while exercising at capacity), flexibility, body fat percentage, etc. But today, we are going to focus on heart rate. 

Vo2 max testing:

Figuring out your resting heart rate and your heart recovery rate after activity is just one way to determine physical fitness, but it is a great start to making healthy goals for yourself. Heart recovery rate is “the time it takes for the heart to return to its normal resting beat” (NOVATeachers). While healthy hearts generally return to their resting rates rather quickly, unhealthy hearts can take much longer. 

Normal resting heart rates:

• Infants: 100-160 beats per minute
• Children 1-10 years old: 70-120 beats per minute
• Over 10: 60-100 beats per minute

How can you improve your heart health? ​

Sometimes the easiest way to improve is to make some simple goals. Here are seven ways to help keep your heart healthy.

Make a goal for the Life’s Simple 7s! Analyze how you are doing for each one now, and make a measurable goal for improvement in at least four categories. 

Now that you know a little bit about heart health and why it’s important, let’s test our resting heart rate! (Use the data sheet below to record your results)

Data sheet:

YOU WILL NEED

• Data sheet
• Partner
• Clock or stopwatch

Use this video to help you find your pulse if you have trouble:

YOU WILL DO

1. Place two fingers on the inside of your wrist to find your pulse. If you have a difficult time locating your pulse, place two fingers on your neck, just below your jaw. Whether you choose to use your wrist or your neck, continue to use the same spot for the rest of the activity, for sake of consistency.  
2. Have your partner watch the clock for 15 seconds. In those 15 seconds, you should count how many beats you feel. Record your results.
3. Repeat step 2 two more times. 
4. Average the three results, and then multiply by 4 to calculate your average resting heart rate in beats/minute. 

Next, you are going to figure out your heart recovery rate.


Predict: How long do you think it will take your heart to return to its resting rate? 


YOU WILL DO

1. Do 50 jumping jacks. 
2. Find your pulse in the same spot that you used earlier.
3. Have your partner watch the clock for 15 seconds while you count your beats.
4. Record in your data sheet in the column titled, “Pulse Rate (Beats per 15 seconds).”
5. Continue to take your pulse every minute for 7 minutes and record results in your data sheet.
6. Multiply each result by 4 to find your beats per minute for each minute recorded. Record in table titled, “Pulse Rate per Minute (Beats Per 15 Seconds x 4).”

Now, you are going to graph your heart recovery rate: 

1. Open Microsoft Excel, or other spreadsheet program, on a computer
2. Create two columns: one for time (in minutes), the other for Change in heartrate over your resting rate (in Beats per Minute).  Your spreadsheet will look something like this:

3. Enter minutes 1-7 in the left column, and the change in your heart rate for each minute in the right column, like the example below (your numbers may vary).

4. Use the spreadsheet to create a graph of your heart rate as a function of time.  If you are using Excel, just select all the data and the column headings, go to the “Insert” tab, and select the scatter plot option, with lines and markers.  Use the example below for guidance:

The graph you created should look something like this:

Extension: Push yourself!

1. Run one mile as fast as you can (if you don’t have access to a track, set a certain distance, such as around the block).
2. Find your heart recovery rate. 
3. Repeat weekly to see how you improve your time AND your heart recovery rate!

OR

1. Do as many pushups as you can.
2. Find your heart recovery rate.
3. Repeat weekly to see how you increase your number AND decrease your heart recovery rate!

Are there certain activities that you recover from quicker? Try out different exercises and compare recovery rates. 



Why does heart recovery rate even matter? How could having a slower recovery time affect you? 



References
https://en.wikipedia.org/wiki/Aerobic_exercise

http://www.pbs.org/wgbh/nova/education/activities/3414_marathon.html

http://www.heart.org/HEARTORG/GettingHealthy/GettingHealthy_UCM_001078_SubHomePage.jsp#

http://www.heart.org/HEARTORG/GettingHealthy/HealthierKids/LifesSimple7forKids/Keep-your-heart-healthy-with-Lifes-Simple-7-for-Kids_UCM_466541_Article.jsp

Images and videos, in order of appearance: 

Memorial Hermann, 2013. VO2 max test: What to expect. Uploaded from Youtube on 8/21/2016.  https://youtu.be/fn3Yr-LS_l0

Nova, 2007. Marathon challenge. Uploaded from pbs.org on 8/21/2016. No changes were made. 

eHow, 2009. Hospital basics: How to check your heart rate. Uploaded from Youtube.com on 8/21/2016. https://youtu.be/Wda4MeCSYyE

Excel images and instructions created by Dr. Erin Nyren-Erickson.

Author: Maddie Van Beek


What do you think of when you hear the word reaction?


Explosions? 


A rash? 


A response based on a previous situation or event? 


None of these thoughts are wrong, but today, we are talking about acid-base reactions. Check out the link below to define exactly what an acid-base reaction is.

FOLLOW UP QUESTIONS

1. What is an acid-base reaction? 
2. Why do acids and bases react and what happens when acids and bases react with one another? 
3. What compound is created from an acid-base reaction? 
4. Use a Venn Diagram to compare and contrast acids and bases. 

Learn more about Acid-Base reactions in this Crash Course video by Hank Green! 

Let’s check out our own acid-base reaction!

Make sure you do this experiment in the kitchen (or other easily cleanable area) or outside, if weather permits. 



YOU WILL NEED:

• Baking soda
• Vinegar
• Ziplock bag
• One square of paper towel
• Measuring spoons
• Measuring cups

Predict: What do you think will happen when you mix baking soda and vinegar in a sealed plastic bag? 



YOU WILL DO

1. Double check that your Ziplock bag has no holes. To test this out, fill it up with water and zip it up. If you see a leak, get a new bag. 
2. Create a “time-release” packet of baking soda. 
   1. Place your paper towel on a flat surface. 
   2. Measure 1.5 Tablespoons of baking soda and dump it in the center of the paper towel. 
   3. Fold the paper towel into a small square so that the baking soda is enclosed and will not leak out the sides. 
3. Measure 1/2 cup vinegar and 1/4 cup warm water, then pour both into the plastic bag. 
4. Now, you will need to move quickly! You may need a partner to help you out. You will need to hold your Ziplock bag open and place the time-release packet into the bag. The tricky part is that you need to zip the bag shut immediately after inserting the time-release packet. If you have a partner, have them put the packet in so you can focus on zipping the bag shut.  
5. Shake the bag up for a few seconds and then place it in the sink (or on the ground, if you’re outside). 
6. Record your observations!

What exactly happened and why?


EXPLANATION
Baking soda is a base and vinegar is an acid. When the two mixed together, there was an acid-base reaction! When the reaction occurred, it created carbon dioxide, which is a gas. The gas is what created those bubbles that blew up your Ziplock bag. 


Now that you have seen an acid-base reaction first-hand, you are going to try another one. This one will take a little longer to occur, so you won’t be able to watch the whole process.


YOU WILL NEED

• Two eggs
• Vinegar
• Two glasses
• Saran wrap
• A soup spoon

YOU WILL DO

1. Place one egg carefully inside each glass.
2. Pour enough vinegar to cover both of the eggs. You should see bubbles form on the eggs’ shells. Why?
3. Cover both glasses with saran wrap and put them in the refrigerator.  
4. Wait 24 hours.

Predict: What might the vinegar do to your eggs?

1. Use a soup spoon to CAREFULLY scoop the eggs out of the glass. What do they look like so far?
2. Dump the vinegar into the sink and then place the eggs back into the glasses.
3. Fill the glasses with enough fresh vinegar to cover the eggs, and place them back in the fridge for 24 more hours. 
4. Once again, use a soup spoon to carefully remove the eggs from the glasses. 
5. What do the eggs look like now?!

WHAT HAPPENED?
The eggshell is made up of calcium carbonate, which is a base. Referring to the experiment you already did with baking soda and vinegar, what do you think happened when you put the eggs into vinegar? Why? How was this experiment similar or different from the one above? 



Extension: Learn about Osmosis! 

Now that you have two shell-less eggs, let’s try a new experiment with them as an introduction to osmosis.

FIRST: What is osmosis?

A hypertonic solution has a higher concentration of solute outside the cell, therefore less water, than in the cell, while a hypotonic solution has a lower concentration of solute outside the cell than in the cell. 


An isotonic solution is “at peace.” It has an equal amount of solute outside the cell than inside the cell.


What is solute and what is a solution? 

An example of a solution is sugar water. The solute (substance to be dissolved) is the sugar and the solvent (the substance doing the dissolving) is the water. 
​

What does this all mean? 

Basically, a cell within a hypertonic solution will shrink, as the movement of water goes from the cell to the solution. A cell within a hypotonic solution will swell, as the movement of water goes from the solution to the cell. A cell within an isotonic solution will stay the same, as the water moves in and out of the cell equally. 


Check this science rap to help you remember these osmosis terms and learn more about where osmosis occurs in real life! ​

Let's start our activity!
Goal: See what happens when you put an egg in a hypertonic solution versus a hypotonic solution. 

YOU WILL NEED

• Two glasses
• Two naked (shell-less) eggs
• Corn syrup
• Water
• Soup spoon

CHECK FOR UNDERSTANDING

• Is the corn syrup hypotonic or hypertonic?
• Is water hypotonic or hypertonic?

Predict: How will your two eggs differ after hours? 


Here's what to do! 

1. Place each egg in a clear glass.
2. Fill one glass with enough water to cover the egg.
3. Fill the second glass with enough corn syrup to cover the egg. 
4. Place both glasses in the refrigerator for 24 hours. 
5. Take both glasses out and record your observations. 

What do your eggs look like? How do they differ? Why did this happen?


What do you think would happen if you now placed the eggs in opposite solutions? Try it out! 

1. Put the corn syrup egg in a glass of water and the water egg in a glass of corn syrup. 
2. Place in the refrigerator. What do they look like after 24 hours? 
3. Record your final results. 

References

• https://www.exploratorium.edu/cooking/eggs/activity-naked.html
• https://www.exploratorium.edu/cooking/eggs/activity-nakedexperiment.html
• http://www.exploratorium.edu/science_explorer/bubblebomb.html
• http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/acidbase.html
• http://www.microbelibrary.org/library/biology/3120-osmosis-a-cell-in-an-environment-that-is-hypotonic
• http://www.chem4kids.com/files/matter_solution.html

Image and video credits, in order of appearance:

CrashCourse, 2013. Acid-Base Reactions in Solution: Crash Course Chemistry #8. Uploaded from Youtube on 8/15/2016. ​https://www.youtube.com/watch?v=ANi709MYnWg&feature=youtu.be

Openstax, 2016. The process of osmosis over a semi-permeable membrane, the blue dots represent particles driving the osmotic gradient. Image uploaded from Wikimedia Commons on 8/15/2016. 
https://upload.wikimedia.org/wikipedia/commons/6/62/0307_Osmosis.jpg File used in accordance with the Creative Commons Attribution-Share Alike 4.0 International license. No changes were made. 

LadyofHats, 2007. Effect of different solutions on blood cells]]. Image uploaded from Wikimedia Commons on 8/15/2016. ​
https://upload.wikimedia.org/wikipedia/commons/thumb/7/76/Osmotic_pressure_on_blood_cells_diagram.svg/553px-Osmotic_pressure_on_blood_cells_diagram.svg.png File released into the Public Domain. 

Sciencemusicvideos, 2013. Osmosis! Rap science music video. Uploaded from Youtube on 8/14/2016. https://youtu.be/HqKlLm2MjkI

Author: Maddie Van Beek

​Think back to a time that you’ve stood in a pool or a lake. When you look down, do your legs look like they normally do? No! Have you ever wondered why your legs look bent, or as if they are shorter? This weird effect is called refraction! 

Refraction happens when a wave travels from one medium to a second medium in which the wave travels at a different speed (the speed of light is only constant in a vacuum). For example, when light goes from traveling through the medium of air to the medium of water, the speed of the light slows down and the wavelength shortens (the frequency of the wave—that is, the number of times the wave repeats in a given time—remains the same). The amount of refracting that occurs depends on the index of refraction. We can calculate the index of refraction (n) by dividing the speed of light in a vacuum (c) by the speed of light in that specific medium (v). That is:

Index of refraction = vacuum/specific medium

n = c / v
For example, the speed of light is 299,792,458 meters per second, but is commonly denoted as c. Let’s try calculating the refractive index for a vacuum.

Index of Refraction (n) = c (the speed of light) / c (the speed of light)

Anything divided by itself equals 1. Therefore, the refractive index for a vacuum is 1.

Below, you can see that the all other mediums have a larger refractive index than in a vacuum. This is because the speed of light in any other medium will be slower than in a vacuum. Therefore, the index of refraction will usually be over 1. Negative refractive indexes are only achieved with synthetic materials that possess uncommon refractive properties.

References:

• http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/refr.html#c3
• http://en.wikipedia.org/wiki/Refraction
• http://teachinginroom6.blogspot.com/2012/04/light-refraction-fun-independent.html
• http://science.howstuffworks.com/nature/climate-weather/storms/rainbow1.htm

Image and Video Credits in order of appearance: 

Image 1: Bcrowell, 2014. Refraction-with-soda-straw-cropped. Uploaded from Wikimedia Commons on 7/31/2016. https://en.wikipedia.org/wiki/Refraction#/media/File:Refraction-with-soda-straw-cropped.jpg File used in accordance with the Creative Commons Attribution-Share Alike 3.0 Unported license.

Image 2: JrPol, 2015. Refraction in a glass of water. Uploaded from Wikimedia Commons on 7/31/2016. https://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/R-DSC00449-WMC.jpg/800px-R-DSC00449-WMC.jpg File used in accordance with the Creative Commons Attribution-Share Alike 4.0 International license. No changes were made. 

​Home Science, 2014. Amazing water trick - Amazing science tricks using liquid. Uploaded from Youtube on 7/31/2016. https://youtu.be/G303o8pJzls

Image 3: Inaglory, 2007. An inferior mirage on the Mojave desert in spring. Uploaded from Wikimedia Commons on 7/31/2016. https://upload.wikimedia.org/wikipedia/commons/7/7c/Desertmirage.jpg File released into the Public Domain. 

Image 4: Сергей Banifacyj Морозов, 2008. Rainbow after the rain, Grodnow, Belarus. File uploaded from Wikimedia Commons on 7/31/2016.
https://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/%D0%A0%D0%B0%D0%B4%D1%83%D0%B3%D0%B0_%D0%BD%D0%B0%D0%B4_%D0%93%D1%80%D0%BE%D0%B4%D0%BD%D0%BE.jpg/1280px-%D0%A0%D0%B0%D0%B4%D1%83%D0%B3%D0%B0_%D0%BD%D0%B0%D0%B4_%D0%93%D1%80%D0%BE%D0%B4%D0%BD%D0%BE.jpg File used in accordance with the Creative Commons Attribution-Share Alike 4.0 International license. No changes were made. 

Author: Maddie Van Beek

It has been an incredibly windy day in Fargo! Wind may be annoying, but can also cause major issues! For example, wind can cause erosion of natural formations like mountains and hills as well as manmade structures such as buildings and walls. Erosion often occurs in flat areas where there are few natural wind blocks. Fargo is the perfect example of this type of landscape, as it has little trees and very few hills.


What exactly is erosion? Basically, erosion is a slow, steady destruction of something, often due to wind or water. Here’s a few examples:

http://examples.yourdictionary.com/examples-of-wind-erosion.html

​Erosion from water: 

Erosion from wind: 

In order to avoid wind erosion, some areas have wind blocks. Wind blocks could be fences, walls, or even trees that help reduce the wind’s strength.


Here’s an example of a fence with a wind screen. Although wind can still pass through the screen, it drastically reduces the wind’s power.

How do builders know what will withstand the wind? Not all structures are created equal! Engineers have to think very carefully about how they construct walls or wind blocks based on the location’s climate. Today your task is building the strongest wall possible that will withstand the wind.


Think about different walls that you’ve seen. What makes them strong?


What can you do to design a wall that will withstand the wind?


YOU WILL NEED:
* An electric fan
* Foam board (1/2 inch, 1 inch, and 1 1/2 inch thicknesses)
* Tape
* Mesh screen
* Utility knife (be careful!)
* Hot glue gun (optional)


Here’s what to do!
1. Set up a fan on a flat surface.
2. Mark a spot about 3 feet away from the fan with a piece of masking tape. This is your wall testing spot. You will test each wall you design on this same spot.
3. Test your control (the original wall with which you will compare your own design). The control is a plain piece of 1/2 inch foam board with no alterations. Set the control wall on the testing spot. Turn the fan on. Start at low, then turn it to high. What happens? You probably saw that a plain, thin foam wall was not enough to withstand the wind from the fan.
4. Test out the other thicknesses next. Does the thickness of the wall improve the strength?
5. Things to think about: Aside from thickness, what other alterations can you make to create a stronger wall? What if you create slats or cut holes in the wall? Will this make the wall more likely to withstand the wind? How can you create a wall that withstands the wind but also protects the area behind it? How could you use the mesh screen to create wind block?
6. Sketch your idea for your wall.
7. Use your materials to create a wall that you think will best withstand the wind while also protecting the area behind it.
8. Test your wall. What happens? Did it survive the low setting on the fan? Turn it up to high. Is it still standing? If so, great job! If your wall fell down, don’t worry! Just go back to the drawing board and redesign.
9. Continue to test and redesign until your wall survives the wind test.




For other windy day science activities, check out one of our other blog posts to learn about windchill AND make a wind-powered car:

http://www.discoveryexpresskids.com/blog/windy-day-science-measure-windchill-and-create-a-wind-powered-car


Although wind can be destructive, it can also be a great source of power! Learn more here from these wind energy facts:

http://www.sciencekids.co.nz/sciencefacts/energy/windenergy.html


References:

http://www.sciencebuddies.org/science-fair-projects/project_ideas/CE_p014.shtml#summary

Author: Maddie Van Beek


Last week, we learned about Newton’s First Law of Motion, or the Law of Inertia. You learned that an object in motion will stay in motion, or an object at rest will stay at rest, unless affected by an outside force. If you missed us last week, check out http://discoveryexpress.weebly.com/…/demonstrating-the-law-…. 




Newton’s Second Law tells us that the acceleration of an object--as produced by a net force--is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. 




What does that even mean?! 




It can be simplified into this equation:




F = m * a




F = force

- Force is measured in Newtons. 

m = mass

- Mass is measured in kilograms. 

a = acceleration 

- Acceleration is measured in meters per second squared. 







Before you try using this equation, here’s a great example from howstuffworks.com. 

Let’s say you are trying to calculate the acceleration for this dog sled. As you can see, the force is 100 newtons, and the mass is 50 kilograms. 




Before you plug the numbers into the equation, isolate acceleration, since that is what you are trying to find. 




F = m * a




Take the force divided by mass to get acceleration by itself. 




a = F/m




Next, plug the numbers into the equation. 




a = 100N/50kg




Now, divide! 




a = 2 m/s^2 




You’ve calculated the acceleration of the sled! 




But what if another dog that pulls with equal force is added to the team? 

Try calculating the acceleration this time! 




F = 200 N

m = 50 kg

a = ? 




a = F/m

a = 200 N/50 kg

a = 4m/s^2




What would have happened if you had doubled both the force and the mass? 




F = 200 N

m = 100 kg

a = ? 




a = F/m

a = 200 N/ 100 kg

a = 2m/s^2




You’d be right back to an acceleration of 2m/s^2.  




This example demonstrates how the acceleration is proportional to the force. 

The picture above illustrates the idea of net force. If two equal forces are opposing each other, the net force becomes zero. In this picture, you see that there are two dog sled teams pulling with a force of 200 N on either side of the sled, so the net force is zero. This means that the sled would not move. If the sled team on the right were bigger and were pulling with a force of 300 N, then the sled would move to the right. Make sense? 




You now have plenty of information to complete the practice equations and the activity below, but for further description of Newton’s Second Law of Motion, check out this helpful video from KhanAcademy: 

Now that you have seen a few demonstrations, let’s practice:




1. Erin and Andrew are playing tug of war. Erin is pulling to the right with a force of 100 N. Andrew is pulling to the left with a force of 200 N. What is the net force? What direction would they move? 

2. Grady is pulling a wagon that has a mass of 30 kilograms. Grady is pulling with a force of 300 N. What is the acceleration? 


3. Ashley is pushing a stroller that has a mass of 20 kilograms. The stroller is accelerating at 3 m/s^2. 
Use F = m * a to find the force. 


4. Deidre is pulling her puppy’s leash with a force of 50 N, but the puppy is pulling in the opposite direction with a force of 25 N. What is the net force? 

5. Josiah is pushing a shopping cart with a force of 75 N at a rate of 1 m/s^2. What is the mass of the shopping cart? 




Activity




YOU WILL NEED:

• 2 marbles of the same size, but different masses. Both should be lighter than the ball bearings. 
• 2 identical ball bearings
• Ramp (could be constructed out of poster board) 
• Tape Measure
• Scale
• Stopwatch

Here’s what to do!

1. Use the scale to determine the mass of each marble and ball bearing. Record these masses in your observation journal. 
2. Use a tape measure to create two meter-long ramps. You could use heavy poster board to make the ramp. Make sure you fold up the sides so the marble won’t roll off. 
3. Place one end of the first ramp on top of a stack of books to create an approximately 10 degree incline. 
4. Mark the first ramp at 30cm and 60cm. 
5. Place the end of the second ramp at the bottom of the incline of the first ramp. Make sure the marble will be able to roll smoothly from one ramp to the next. You could place a piece of tape to connect the two ramps and make sure it’s a smooth transition. 
6. Now that you’ve made your ramp, place one ball bearing at the base of the first ramp, right where the second ramp starts. Here is what your final set-up should look like: 

1. Place the marble with the smallest mass at the top of your ramp. What do you think will happen when it hits the ball bearing? Try it out! 
2. As you can see, the ball bearing moves when it is struck by the marble. Think back to Newton’s First Law, an object at rest stays at rest until enacted upon by an outside force. 
3. Try this again, except this time, use the stopwatch to time how long it takes the marble to travel from the top of the ramp to the ball bearing at the bottom of the ramp. 
4. Do this three times and then calculate the average time. 
5. Repeat step 8 and 9 with first the second marble and then the ball bearing. 
6. Next, repeat step 8-10, except start at the 30cm mark. 
7. Last, repeat steps 8-10, except start at the 60cm mark. 

Record your data and calculate the acceleration in this chart: 
 

To calculate acceleration, subtract the ball’s initial speed (zero) from its final speed and divide by the time it took to hit the target ball. 




Example: 

Speed:          100cm/2sec

Simplified:      50cm/sec

Acceleration:  (50cm/sec - 0cm/sec) / 2 sec

                      25cm/sec^2




Part 2

What’s happening when the first ball hits the second ball? 

So now that you’ve determined acceleration for each impact ball, let’s focus on what happens when each ball hits the target ball bearing at the bottom of the first ramp. As you have seen, the force of the accelerating ball causes the once-stationary target ball to move. 




How do you think the mass of the impact ball affects the time it takes the target ball to travel down the second 1m ramp once it is struck? 




Let’s find out! 




1. Just as you did before, start with the lightest marble at the top of the ramp. This time, you are using the stopwatch to measure the time it takes the target ball to travel from its starting point to the end of the second 1m ramp. You will start the stopwatch once the target ball is struck and stop the stopwatch once it reaches the 1m mark. 


2. Repeat step 1 three times and record the average time. 


3. Repeat steps 1-2 with the second marble. 


4. Repeat steps 1-2 with the other ball bearing. 


5. Record in the table below: 

Record your observations. Did the mass of the impact ball affect the average time the target ball took to travel 1m? Why do you think this is? 

You should have found that the more mass the impact ball had, the faster the target ball rolled 1 meter. This explains Newton’s Second Law: Larger mass means larger force, which then means larger acceleration. This demonstrates how the variables of mass, acceleration, and force are proportional with one another. 




Extension: 

Now that you have the mass and the acceleration of the impact balls from part one, you can calculate the force with which they hit the target ball bearing. Remember, the force is found by multiplying the mass and the acceleration. 

References

http://science.howstuffworks.com/innovation/scientific-experiments/newton-law-of-motion3.htm

http://www.physicsclassroom.com/class/newtlaws/Lesson-3/Newton-s-Second-Law

http://swift.sonoma.edu/education/newton/newton_2/html/Newton2.html

http://www.physicsclassroom.com/class/1DKin/Lesson-1/Acceleration

Author: Maddie Van Beek

We all know that trees and plants make our world prettier and provide us with fruits and vegetables. But did you know that we actually NEED plants to live? Through the process of photosynthesis, plants take in the carbon dioxide that we give off and convert it to the oxygen that we desperately need to survive! How does this whole process work? 




This diagram explains the basic components of photosynthesis: 

Plants not only need carbon dioxide, but also use water and sunlight to complete the photosynthesis process. 




Check out our blog on xylem to understand how water gets from the ground to the leaves of a plant:

Photosynthesis reaction equation:

This catchy song will help you remember the basics of photosynthesis!

Follow-up questions: 

• What happens during photosynthesis? 
• How is chlorophyll involved in photosynthesis? 
• What do xylem do? 

Try defining this important vocabulary in your own words: 

• Chloroplasts
• Chlorophyll
• Photosynthesis
• Xylem

You now know everything you need to complete our basic photosynthesis experiment, but if you want to learn EVEN MORE, watch the video below!




This video explains the complexities of photosynthesis! You’ll know more than you ever wanted to know about how photosynthesis works. 

Activity



YOU WILL NEED:

• Spinach leaves
• Hole punch
• Tweezers
• 10cc syringe (no needle)
• Water
• Baking Soda
• Soap

Here’s what to do!



If you like visual instruction, watch this video to see how to complete the experiment: 

1. First, you need to create your bicarbonate solution. Do this by combining 1/8 teaspoon of baking soda with 1 and 1/4 cups of water. Stir the baking soda in until it is completely dissolved. 
2. Next, use the hole punch to punch holes in your spinach leaves until you have about 20 spinach leaf discs. 
3. Remove the plunger from the syringe, and place the spinach discs into the syringe. 
4. Use the tweezers to push the discs down as far as they can go. Be careful not to crush or damage them. 
5. Once you have all the leaf discs in the syringe, replace the plunger. 
6. Put the tip of the syringe in the bicarbonate solution and pull back the plunger to suck up 10ccs of the solution. The baking soda solution is a source of bicarbonate ions, which is one source of carbon dioxide for photosynthesis.  
7. Cover the end of the syringe with your finger, and then pull the plunger upwards as far as it can go to pull the air out of the leaf discs. Alternate pulling the plunger out and pushing it down (remember to keep the end covered with your finger the whole time to create a vacuum). Pushing the plunger down is forcing the bicarbonate into the leaf discs and pulling it up will remove any air from spaces in the leaves.
8. Continue to do this until you see the leaf discs start to sink. Once all your leaf discs have sunk, squirt out the baking soda solution into a sink, making sure not to allow the leaf disks to plug the syringe.
9. If you have trouble getting your leaf discs to sink, you can add a small drop of soap to the bicarbonate solution and try again. The soap makes the leaf less hydrophobic and will help it more easily absorb the solution.  
10. Next, add more baking soda solution. You should suck up about 10 ccs, as you did in step 6.  Swirl your syringe around to make sure the leaf discs aren’t stuck to the sides or to each other. 
11. Place your syringe upright in a well-lit area. Either artificial or natural light will work. 
12. Wait to see how long it takes for the leaf discs to float. Record the time when the first disc rose to the surface. Wait until at least 5 leaf discs have risen back to the surface. Record the time it took for 5 leaf discs to float. If you are patient enough, record the time that it takes for all your leaf discs to float. What’s the point of this? You just watched photosynthesis occur!  The oxygen created inside the leaves by photosynthesis is making the leaves float again.  
13. Practice making graphs! Create a line graph to show how long it took for the discs to float. I would put time along the x-axis and number of leaf discs along the y-axis. You could do this by hand, or you could use Excel to create it electronically. If you need help using Excel, refer to our blog on heart health for instructions. 

Follow-up questions:

1. Would this experiment have worked with normal tap water? Why or why not?
2. What was happening when the leaf discs sunk?
3. Why did the leaf discs float at the end? 
4. Create a diagram to show the steps of your experiment and how it relates to photosynthesis. 

If you had fun learning about photosynthesis, you might also like our blog on plant transpiration.



References:

• <iframe width="560" height="315" src="https://www.youtube.com/embed/XV9FOWleErA" frameborder="0" allowfullscreen></iframe>
• https://blog.udemy.com/photosynthesis-experiment/

Author: Maddie Van Beek


I’m guessing that at this point, all of you have heard of the dreaded ebola virus. Just in the past few months, US citizens have been more concerned than ever about this horrific disease. In this blog, you will learn a little bit about the background of the ebola virus, as well as how diseases spread. 

Ebola’s History and Mortality Rate

• First identified in 1976 in Congo near Ebola river. 
• Then: 90% mortality 
• Now: 50% mortality 

How did ebola evolve to affect humans?

2014 Ebola Outbreak: Largest in HISTORY

• Ebola is now spreading in West Africa and concentrated in Guinea, Sierra Leone, and Liberia. 
• The number of cases that have occurred during this outbreak have been more than the combined number of cases occurring previous to 2014 combined. 

# of ebola cases 1976-2013 < # of ebola cases in 2014

How does ebola spread? 

As you saw in the video, ebola spreads first from animal to human and then from human to human. Fruit bats, monkeys, gorillas and other primates become infected with ebola and become carriers. People may become infected with ebola by eating uncooked infected meat or coming in contact with infected animals. Once people are infected, they can infect other people by coming in contact with each other’s bodily fluids. 

How is ebola contracted?

Ebola in the US

Although ebola has stayed out of the US in the past, it has recently made its way in, starting with a Texas man who was diagnosed on September 30th, 2014 and passed away on October 8th. The man had traveled from Liberia to Texas, so he was infected in Liberia before coming to the US. Since then, three others have been reported to have ebola. Two of these people who have contracted ebola have been health care workers from the Dallas, Texas, hospital where the first ebola patient was treated, and the third was a New York City doctor who had traveled to Guinea. Both Dallas patients have recovered and the New York City patient is currently being treated. 

Why would health care providers be the ones to get ebola? Shouldn’t they knew the best way to stay healthy?

Health care providers are at a higher risk, since they are treating those who have ebola. Although ebola can only be spread through bodily fluids, treating someone who is vomiting could lead to infiltration of the disease through touching the infected person’s bodily fluids and then touching broken skin or mucus membranes such as the eyes. Health care providers treating patients with ebola have a much higher risk than the average US citizen, since they are in direct contact with the disease. 

Do we need to worry about ebola spreading in the US?

No! The reason ebola spreads so quickly and causes so many deaths in other countries is because they do not have adequate healthcare available to them. In the US, health care providers are not concerned about ebola spreading; as stated, ebola is difficult to contract in its present form and is easily stoppable when the right procedures are followed. 

In order to help control the spread of diseases, teams of healthcare professionals work together to quarantine infected people, immunize people at risk, educate the public about prevention strategies, and treat infected people swiftly and aggressively. 

Currently, there is no safe ebola vaccine. 

Do I need to worry about getting ebola?

Although ebola is very dangerous, you most likely have no need to worry. It’s very difficult to actually get ebola, since you have to come in contact with an infected person’s bodily fluids and then get those bodily fluids in a mucus membrane such as your mouth, eyes, nose, etc. Ebola does NOT spread like a cold--you can’t get ebola from a sneeze or a cough--it’s not an airborne disease. Just like any other virus or disease, you can avoid ebola and help keep it from spreading by washing your hands, not sharing drinks, chapstick, etc., staying home if you are sick, and going to the doctor if you have symptoms. 

And remember, only ebola victims with symptoms are infectious--the disease does not spread until the infected person is already showing symptoms. 

The incubation period for ebola is 2-21 days. This means it may take 2-21 days to show symptoms of ebola. Therefore, if you come in contact with the disease, you should be on watch for about three weeks.

Quick look at ebola vs. the flu:

How do diseases spread, anyway? 
Simulation of how diseases spread: 

This activity is NOT an accurate simulation of ebola--yes, ebola spreads in a similar manner, but with adequate health care and preventative strategies, ebola can be kept from spreading in a manner similar to the simulation. This simulation is just to help you understand how unchecked infectious diseases may spread from person to person. 

YOU WILL NEED: 

Lemon juice

Clear cups

Water

Paper

Writing utensils

A light source

Red and blue food coloring

Water droppers

An iron, and a heat-proof surface to use it on

YOU WILL DO: 

1. Get a group of twenty or so students together.
2. Fill nineteen cups with water and one cup with lemon juice.
3. Hand out the cups, paper, and water droppers to each participant, and don’t announce who has the lemon juice.
4. Explain that there will be six one-minute rounds in this simulation. 
5. You may be wondering what lemon juice could have to do with infectious diseases. Lemon juice can actually be used as “invisible ink,” so the lemon juice represents the invisible infectious disease. One person has lemon juice in their cup, while others only have water. All participants should have a piece of paper with them for round one. 
6. Round 1: Give participants 60 seconds to move around the room; whenever they come in contact with each other, they should take a drop of water from the other’s cup and dot it on their piece of paper. This represents coming in contact with others’ body fluids. 
7. After the 60 seconds is up, use the iron on its hottest setting, and iron everyone’s papers. The heat from the iron will cause the lemon juice to turn brown. Those that came in contact with the lemon juice will have a brownish spot on their paper, while others will just have water spots. Those with the brown spot represent people who have been infected with the disease. Record the number of people who were infected.

Ok, so is this demonstration completely accurate? No! There was only one person spreading the disease. Let’s try something new!


8. Once again, all participants get a cup of water. This time, give one person a red dye dropper. Just like the lemon juice, the red dye represents the disease. Participants get 60 seconds to rotate around the room. The person with the red dye will put a drop of red dye in the cup of each student he or she comes in contact with. Those who receive a red drop will then also become disease carriers (equipped with red dye).  They will continue to spread the disease by putting a drop of red dye into the cup of each person they encounter. 


9. After 60 seconds, analyze how many people have pinkish-colored water--that’s how many now have the virus! 

10. Create two graphs for round 1 and round 2 to demonstrate how many people became “infected” in each round. The Y-axis should be number of people, and X-axis should be time. How do they look different? Which round had more infected people? Which round more accurately demonstrates how quickly a virus can spread? 

You should end up with something like this: 

11. This time, you are going to inoculate 20% of your group. Inoculate means to treat with a vaccine to provide immunity against a disease. Start by putting a few drops of blue food coloring into 20% of the cups. If you have twenty people, four people will get cups with blue water. Repeat step 8. 

12. You could now have some people with red water (people infected with the disease), blue water (inoculated people who did not come in contact with the disease) or purple water (inoculated people who came in contact with the disease). Because inoculated people were protected from the virus, they do not count towards the infected number of people. Before moving on to round 4, record the number of infected students. 

13. Round 4: This time, start by inoculating 40% of the class. If you have twenty people, eight should now start with blue water. Repeat step 8. Record the number of infected students. 

14. Round 5: Start by inoculating 60% of the class. Repeat step 8. Record the number of infected students. 


15. Round 6: Start by inoculating 80% of the class. Repeat step 8. Record the number of infected students. 


16. Make a bar graph for rounds 2-6 and see how inoculation affects the spread of the disease. 

You should end up with something like this:

17. Reflect on this activity. What was not realistic about this simulation? What preventative measures could people take in real life to avoid infection? 

References

• http://www.who.int/mediacentre/factsheets/fs103/en/
• http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/qa.html
• http://www.pbs.org/wgbh/nova/education/activities/3318_02_nsn.html
• http://www.seplessons.org/node/226
• http://youtu.be/qkzIGp1uYoc
• http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/index.html