Author: Maddie Van Beek

Most of the time, people don’t associate video game players or “gamers” with sports, but do you think that your time spent playing video games might improve your reaction time? Having a good reaction time is definitely a part of being a good athlete! For example, a baseball player must react quickly in order to hit a fastball!



Can you react quickly enough to hit a 90mph fastball?
https://www.exploratorium.edu/baseball/reactiontime.html


How can you test this theory out? Before we get experimenting, let’s learn a little more about reaction time.


In simple terms, a reaction is when you detect something, process it, and respond.

​Basically, reaction time is how it takes one to respond and make a decision to a stimulus.

​A stimulus is any change inside or outside the body. In response to any stimulus, the following happens:



Sensory neurons detect the stimulus ----> Sensory neurons send the message to other neurons, which go to your brain and spinal cord ----> Brain interprets the message ----> Message received by motor neurons ----> Motor neurons tell muscles how to respond



Now that you know a little science behind reaction time, let’s get testing!


YOU WILL NEED:
* Meter stick
* “Gamers” to test
* “Non-gamers” to test
* Table or countertop

Here’s what to do!
1. Test yourself. Sit down at a table or counter with your arm resting on the surface. Your hand should be just off the edge of the counter.

2. Have a friend hold the meter stick so the end that says 0 is right in between your thumb and forefinger. View the image above for reference.

3. Have your friend drop the stick. Pinch the stick as quickly as you can. Record the number that your thumb/forefinger is closest to. The lower the number, the better your reaction time. Do this two more times and record your reactions.

4. Add all three reactions together and then divide by 3 to get your average reaction. For example, if you got 8 cm, 4 cm, and 7 cm, you would add them together first. 8 cm + 4 cm + 7 cm = 19 cm Then you divide the sum by three to get your average. Round to the nearest tenth of a centimeter. 19 cm / 3 = 6.33 cm

5. Once you’ve tested yourself, find your subjects! You should have an equal number of gamers and non-gamers. Shoot for ten total subjects or more. The more subjects you have, the more accurate your results will be.
6. Repeat steps 1-4 for each subject.
7. Analyze your results. Does it appear that gamers have quicker reaction times than non-gamers?
8. Find the average reaction time for each group. Do this by adding together the average reactions of each non-gamer and then dividing by the number of non-gamers. Do the same for the gamers. Compare averages.


Alternatively or in addition, you could try out this computer-run reaction test: http://www.humanbenchmark.com/tests/reactiontime


If you decide to use the computer test, make sure you have good internet connection and use the same computer and mouse for each subject.


Extension: Test other subject groups that might have differences in reaction time. Example: Contact sports players vs. Runners


For other experiments that test the brain, check out:

http://www.discoveryexpresskids.com/blog/mind-games-how-optical-illusions-can-fool-your-brain
http://www.discoveryexpresskids.com/blog/are-you-right-side-dominant-or-left-side-dominant-find-out
http://www.discoveryexpresskids.com/blog/how-does-smell-affect-your-taste
http://www.discoveryexpresskids.com/blog/remember-this-test-your-memory


If you’re looking for activities that get you active, check out:

http://www.discoveryexpresskids.com/blog/running-for-your-heart
http://www.discoveryexpresskids.com/blog/how-physically-fit-are-you
http://www.discoveryexpresskids.com/blog/why-is-heart-health-so-important


References
http://www.sciencebuddies.org/science-fair-projects/project_ideas/Sports_p009.shtml#summary
http://www.scientificamerican.com/article/bring-science-home-reaction-time/
http://slideplayer.com/slide/4497621/

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

Today we are going to experiment with GRAVITY! Last week we learned about this mysterious force and tested a few different ways we could defy gravity. If you missed it, check it out here: http://www.discoveryexpresskids.com/blog/defying-gravity

Today, we are going to learn about AIR RESISTANCE.


As you know from last week, gravity is the force that pulls all objects towards the core of the Earth. It’s what causes anything that is dropped to fall to the floor, and it’s what keeps you and me from flying off the Earth as it spins on its axis at incredible rates! Every single object is pulled towards the Earth with the same amount of gravity. So in theory, every object should fall at the same speed, right? Let’s test it out.


Grab a rock and a piece of paper. First, drop the rock. Next, drop the paper. Did they both fall at the same pace? Why do you think the paper fell slower than the rock? Next, crumple the paper into a ball and drop it once again. What happened? You should have noticed that the crumpled paper falls faster than a flat piece of paper. What’s going on?


AIR RESISTANCE! The reason that some objects fall slower than others is that they encounter different amounts of air resistance. The amount of air resistance depends largely on the surface area of the object. If the surface area is larger, the air resistance is stronger. That’s why a flat piece of paper falls slower... it has a much larger surface area than a rock. When you crumpled the paper, you reduced the surface area, so it fell faster.


Every object that falls accelerates at approximately 10m/s/s, but at a certain point, that acceleration levels off. That point is called terminal velocity. Terminal velocity is the point at which air resistance balances out the force of gravity. When an object reaches terminal velocity, it quits accelerating and continues to fall at a steady speed.

In real life, you see air resistance at work when someone uses a parachute. Using a parachute drastically decreases your terminal velocity by increasing air resistance, allowing you to float safely to the ground. Check out this link for more details on how parachutes work:
http://www.explainthatstuff.com/how-parachutes-work.html


Your job today is to create a parachute that will allow an egg to float safely to the ground without breaking.

YOU WILL NEED:
* Eggs
* Tape
* Plastic
* Cellophane
* Tissue paper
* Paper
* Cardboard
* Scissors


Here’s what to do!
1. Design your parachute. Use your imagination! You can use whatever materials you want to design a parachute that you think will help keep your egg safe. Think back to the information you’ve learned. Larger surface area = more air resistance.
2. Once you’ve designed your parachute, start building!
3. Cut four strings of equal length and tape one end to each corner of your parachute.
4. Tape the other end of the four strings to your egg. Make sure to tape them securely so they stick to the egg!
5. Time for testing! Hold your parachute as high above your head as possible, then let it drop.
6. Check your egg! Did it survive? If not, back to the drawing board. Continue redesigning until you have a parachute that transports your egg safely to the ground.


Extension: Create other parachutes of different sizes (make sure to keep all other design aspects the same). Does the size affect how well the parachutes work? Time each parachute to see which one floats the ground fastest/slowest.


Extension: Design other parachutes of the same size but with different materials. Which materials work best? Why do you think this is?


References
​http://www.physicsclassroom.com/class/newtlaws/Lesson-3/Free-Fall-and-Air-Resistance http://www.science-sparks.com/2011/09/08/gravity-and-air-resistance/

Author: Maddie Van Beek

Gravity! We can't escape it. You've experienced gravity whenever you've dropped something, tripped and fell to the ground, or just stood in one place while the Earth spins at an incredible rate, yet you don't fly off! How does this work? The force of gravity pulls you, and everything else, towards the core of the Earth. Without it, we would just float off into space!

Does gravity only exist on Earth? Nope! Gravity is actually “the force of attraction between any two masses,” so it doesn’t just exist on Earth, and gravity doesn’t just exist between the Earth and other objects. Anything with mass has a gravitational pull. Mass stays the same wherever you go, but gravity is what gives you weight. The more mass an object has, the stronger the gravitational pull, the higher the weight. In the object below, you can see that the astronaut’s mass stays at 120kg whether he’s on Earth or the moon, but his weight changes due to the differences in gravitational pull.

Sir Isaac Newton was the scientist who first defined gravity. His Theory of Universal Gravitation stated that gravity is a force that acts on all objects, and has to do with both mass and distance. Gravitational pull is higher with larger masses and lower with smaller masses. If the two objects are closer, the gravitational pull is stronger. If the two objects are further away, the gravitational pull is weaker.


The law of gravitational force looks like this:


(G * m1 * m2) / d^2


G = Gravitational constant
m1 = First object
m2 = Second object
d = Distance between the centers of gravity of m1 and m2


Check out more about gravity here: http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question30.html


Here’s a great video explanation of what gravity is and what it does:

Can we ever defy the force of gravity? Think of a time when you should have fallen but didn't. Think of a roller coaster. People spin upside down without falling out. How is this possible? Can you think of any other examples?
​
Now that you know what gravity is and does, let’s try a few activities that demonstrate gravity and ways that we can defy it!

Magic paper clips
One way that we can defy gravity is through magnetism. In this experiment, you will see how objects that normally should fall the ground defy the laws of gravity.


YOU WILL NEED:
* Two rulers
* Three strong magnets
* Three paper clips
* Scissors
* String
* Tape
* Two glasses


Here’s a video preview of what you will be doing:

Here’s what to do!
1. Pick a paper clip up. What happens when you drop it? It falls to the floor.
2. Cut three pieces of string. Each should be the same length, about 6 inches.
3. Tie a piece of string to each paper clip.
4. Tie the other end of each string to a ruler. Make sure they are evenly spaced apart. What happens when you pick the ruler up? The paper clips should dangle below. If you tilt the ruler, what do the paper clips do? Notice that they all continue to point directly at the ground, no matter which way you tilt the ruler.
5. Tape three magnets to your second ruler. They should be equally spaced out and should align with the paper clips on your first ruler. For example, if you tied your paper clips at 2inches, 6inches, and 10inches on the first ruler, that’s where you should tape your magnets on the second ruler.
6. Set a glass (at least 7 inches tall) on each side of the first ruler.
7. Place the ruler with the magnets across the glasses with the magnets facing down.
8. Lift each paper clip towards the magnet. What happens? You should see all three paper clips floating in mid-air! Why is this happening? The magnets are attracting the metal paper clips, causing them to defy gravity!
9. Lift the ruler with the magnets. What happens to the paper clips? Without the magnetism pulling on them, they comply with the laws of gravity and crash back to the ground.


Anti-gravity water
In this experiment, you’ll see another way that we can defy gravity!


YOU WILL NEED:
* Glass
* Water
* Piece of cardboard


Here’s what to do!
1. Pour water into the glass all the way to the top. Make sure it’s right up to the rim.
2. Cut a square of cardboard big enough to cover the mouth of the glass.
3. Carefully place the cardboard over the mouth of the glass. Make sure there are no space for air or air bubbles in the glass!
4. Carry the glass to the sink with your hand over the cardboard. Flip the glass upside-down.
5. Remove your hand from the cardboard. What happens? The cardboard stays in place, keeping the water from falling out! Defying gravity!
6. Why does this happen? The air pressure outside the glass is greater than the pressure of the water inside the glass, so the cardboard stays in place.




References
http://coolcosmos.ipac.caltech.edu/ask/300-What-is-gravity-
http://www.turtlediary.com/kids-science-experiments/defying-gravity-experiment.html
http://buggyandbuddy.com/gravity/
http://science.howstuffworks.com/environmental/earth/geophysics/question2321.htm

Author: Maddie Van Beek

Did you know baking involves science? It’s true! You use many of the same skills when you bake that you also use when you conduct a science experiment. You have to measure, pay attention to detail, and carefully follow directions. Altering your recipe could lead to an undesirable result!


Today, you’re going to test the differences between baking soda and baking powder.


Baking soda is... sodium bicarbonate (or NaHCO3 as a chemist would write). Simply put, it’s a base that reacts immediately with anything acidic. Can you think of a few examples of something that contains an acid?

Do you remember any baking soda activities? We’ve seen baking soda react in many different experiments, such as when we made exploding glow-in-the-dark art (www.discoveryexpress.com/blog/exploding-glow-in-the-dark-art) or created New Year’s foam eruptions (www.discoveryexpress.com/blog/happy-new-year)!


Just as a reminder (and a fun break), let’s try it out again!


YOU WILL NEED
* Baking soda
* Deep pan
* Vinegar


Here’s what to do!
1. Measure out 1/2 cup of baking soda and dump it into the center of your pan.
2. Measure 1/2 cup of vinegar and pour it over the baking soda.
3. What happens?! Fizzy bubbles! You should have seen the baking soda and vinegar react and suddenly produce white fizz. That fizz is a bunch of tiny bubbles of carbon dioxide gas. Why does that happen? Baking soda is base, and vinegar is an acid. When the two mix, they create a chemical reaction!


Now, what do you think will happen when you mix baking powder with vinegar? Test it out! Follow steps 1-3, except substitute baking powder for baking soda. Reflect on your results. Did baking powder react the same way baking soda did? Why do you think this happened?


Baking powder is... baking soda PLUS other ingredients. So is baking powder still a base? Sort of. It contains the base sodium bicarbonate, but it also contains acids. When the baking powder is dry, the base and acid do not mix. Think of our experiments when we’ve used Alka-seltzer®; it’s very similar in the sense that the base and acid stay separate when dry, but react when mixed in water. When you mix baking powder into wet ingredients it begins to react, but ONLY when it reaches the right temperature.

Takeaway: Both baking soda and baking powder create chemical reactions in recipes, but baking powder has a prolonged reaction while baking soda has an immediate reaction.


Lastly, think about what baking soda and baking powder actually DO when they react in your recipes. When carbon dioxide gas is released, how might that affect the dough?

Yes... it RISES!


Now that you understand the ways that baking powder and baking soda react, let’s test them out in a real life situation... baking sweets! You are going to follow the exact same recipe twice, but one recipe will have baking soda, and one recipe will have baking powder.


Predict: What differences will your two desserts have? Will changing the baking powder to baking soda even matter? Why do you think this?


The Bake Off

YOU WILL NEED
* Whatever your recipe of choice calls for


Here’s what to do!

1. Pick your cake recipe (it needs to be from scratch, not using a mix)! You can choose any cake recipe you want, just make sure that the ingredient list calls for baking powder. I’ve included a recipe below, but feel free to pick a different one!

2. After you’re done preparing the first dessert (with baking powder), repeat the same recipe but use baking soda instead.

3. Put both desserts in the oven. Make sure you know which one is which!

4. After the baking time is complete, remove your desserts from the oven. How do they look? Are there any visible differences between the two?

5. After the desserts cool off, cut a piece of each and pick them up. Do they feel different? What are the textures of each like? Does one feel heavier? Fluffier?
​
6. Time for a taste test! Did the change of ingredients affect taste?


Chocolate Coffee Cake Recipe: allrecipes.com/recipe/8014/simple-n-delicious-chocolate-cake/


Extension: If you want to try this the other way around, find a cookie recipe to test out! Cookies usually use baking soda. What do you think would happen if you used baking powder instead?




References
www.ehow.com/about_6470369_baking-baking-powder-reaction-vinegar.html
m.phys.org/news/2014-05-differences-soda-powder.html