How to make an air vortex cannon
Making an Air Cannon is super easy and you probably have everything you need at home or in the garage right now. Learn how it’s done. Read more
Exploding Eggs
Some people color eggs for Easter, I think it’s more fun to fill them with hydrogen gas and see what happens when you bring a flame nearby.
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Rip a pop-can in half with your hands
Ripping a pop can in half with your bare hands is not all that hard if you know a bit of chemistry and a little about how soda cans are fabricated. The key, is the plastic liner that coats the inside of the can. In order to protect the aluminum can from the carbonic acid in sodas, can manufacturers coat the inside of a can with a plastic liner. The liner also protects the inside of beer cans as well.
Fun with Instant Snow
Superabsorbant polymers are amazing things. They trap liquids in diapers and can even simulate snow. Read more
Where’s the Bacteria?
We have just passed through the 2011 peak flu season according to Google flu trends as well as the Center for Disease Control. This reminded me that washing your hands is one of the simplest things anyone can do to stop the spread of disease. It’s also one of those things that most people don’t do as often as they should. I thought it would be interesting to test some common surfaces around an office for bacteria. Even better would be to test some spots at abc13 – the host of our Imagine It segments. What do you think would have the highest bacterial count – the toilet seat or the microwave start button?
The Earthquake Platform
A new exhibit at Imagination Station, the earthquake platform. As part of engineering week I challenge local meteorologist Jay Berschback to build a stable tower on the Earthquake platform exhibit. Using only foam noodles and some cross-bracing he must construct a stable tower at least 5 stories tall. Find out if he can meet the challenge. Read more
What makes safety glass, Safe?
Learn about the various kinds of glass that material scientists use to create a safe automobile environment. Read more
There’s Iron in My Cereal?
Many iron fortified cereals contain tiny iron fillings. I’m talking about plain old elemental iron, the kind you would find in a nail, train or car, in your breakfast cereal. It turns out that this form of iron is ideal for a cereal additive.
The reason is that iron ions (iron that would more easily combine with other molecules in the cereal) increase the spoilage rate of the food. Using iron in its pure metal form gives the cereal a longer shelf-life. Of course, not all cereals use elemental iron, some use iron in the form of ferrous sulfate (FeSO).
For those that use elemental iron, after ingestion, the hydrochloric acid and other chemicals in your stomach react with the iron to form FeCl, a compound easily absorbed through the intestines. Generally however, much of the iron remains untouched and is excreted.
The most important roles of iron in the body are in oxygen transport and electron transfer in respiration. Iron binds oxygen in the blood, allowing an adequate supply of oxygen to be carried throughout the body from the lungs. Iron is also involved in immune reactions of the body. If the body does not receive an adequate supply of iron, red blood cells in the body are not as effective at transporting oxygen.
Check out how much iron is inside various cereals (and other foods) at the Nutrition Data website.
Do this at home
If you want to try this experiment at home or in your classroom you will need a few things.
- Various cereals that are iron fortified
- A large ziplock bag
- Some water
- A very strong magnet
The critical item you need for this experiment is a very strong magnet. A regular refrigerator magnet will not be strong enough to pull the iron out of the cereal and water mixture. Check out the following sites for magnets strong enough for this experiment.
Once you have your magnet your are all set. Grab a cup or two of cereal and place it in a bowl. Crush the cereal into as fine a powder as you can. Take this fine powder and add two or three cups of water inside a ziplock bag. Allow the cereal and water to soak for 20 minutes or so and then bring the magnet near the bottom of the bag. Since the iron is heavier than the cereal/water mixture you will have more success gathering iron near the bottom of the bag. Move your magnet around for a few minutes and then carefully slide it to the top of the bag. You should see a small black spot of iron that you can move around with the magnet.
How to break glass
Breaking glass is easy unless it’s tempered glass that can take quite a beating before breaking. Read more
Tri-zonal Space Warper
For today’s Imagine It segment, I thought it would be fun to talk about how your brain processes the information that your eyes send it. The Trizonal Space Warper is a pretty cool tool to explore this because it illustrates how the neurons in your brain can become fatigued when you send them a continuous input.
When you look at something, your brain has to process all sorts of information coming from your eyes such as color, contrast, depth and motion. Lets take a specific example such as motion. When you look at something such as a waterfall, there are nerve cells in your brain that fire off a signal that represents, “downward motion.” There are also some cells (a small number) that might randomly fire off the wrong signal – “upward motion.” Your brain receives both signals and does a sort of strength comparison. It determines that it is receiving more “motion down” signals and so we perceive the water as moving “down.”
Keep in mind that your brain is a big chemical machine. All these nerve cells generate their electrical signals from a chemical reaction. If you keep asking them to send the same signal for a long time, they will run out of their local supply of chemicals. They become tired or fatigued and this is the interesting part. If you keep watching the waterfall for say 30 seconds then look at the trees nearby an interesting thing happens. The nerve cells for downward motion are firing slow – we have tired them out by staring. There are still a few cells that might fire off randomly an upward motion signal. These may out number the downward signal for a few seconds. The end result is your brain “sees” the trees as moving slowly upward even though they are not really moving!
Animated version of the Tri-zonal Space Warper. Click for a much larger and rotating version.
Animated version of the Tri-zonal Space Warper. Click for a much larger and rotating version.
In the early 19th century psychologists experimented with spinning spirals and the effects they had on apparent motion. In 1977, Jerry Andrus, a well known magician, improved on the simple spiral with what he called the Tri-Zonal Warper. His improvement stacks three spirals with alternating expanding and contracting zones. These multiple zones create a much stronger motion aftereffect than a single spiral.
To the right is an animated version of Jerry’s Tri-Zonal Warper. Click on the small image to open up a much larger and moving image. To experience the effect the best, stare at the center of the rotating spiral for at least 20 seconds then look at something that is not moving.
Now that you know what the effect looks like you are ready to conduct a real experiment. When this motion aftereffect was first noticed (first mention comes from the ancient Greeks) it was not understood if the effect originated in the retina of the eye or in the brain. You can do a simple experiment to find out. Fire up the spinning spiral image, but this time cover your right eye. Stare for 30 seconds with your left eye, then quickly cover your left eye. We are trying to see if the effect will transfer from one eye to the other. If you see the effect after swapping eyes, then the origin has to occur not in the retina but further along the visual processing system.
As with all good experiments, don’t limit yourself to just collecting data from one person – like yourself. Give this a try with your friends and family and see what happens. Let us know in the comments below what you find.