Sunday, February 1, 2015

Weird, But True

At our library the Weird, but True series by National Geographic is extremely popular and we wanted to capitalize on that with a STEM program.  We went through all six volumes looking for any fact we could realistically test.  We ended up finding eleven different facts that would work.  We started the program with three group activities before letting the kids loose to test the others.

Group activity: It is impossible to hum while holding your nose.

Why can’t you hum while holding your nose?
Sound is made by air flowing over your vocal chords.  When you plug both your lips and nose, air cannot flow over the chords.  Also, humming resonates in your nasal passages.  When you hold your nose, there may be some sound, but no true humming.

Group activity: Ripe bananas glow blue under a black light.
We took bananas in various stages of ripeness and held them under a black light.  

Why do bananas glow blue under UV light?
As bananas ripen, chlorophyll breaks down producing fluorescing products, which get concentrated in the bananas peel.  As the ripening continues to progress, the blue glow decreases.

Group activity: Apples float but pears sink.
We held up each one and asked the kids if they thought it would sink or float.  We then placed it in the water to see what would happen.  We also asked the kids why they thought the apple floated more than the pear.

Why do apples float but pears sink?
Apples are less dense than water. Air pockets in between the cells of an apple allow for enough air to be captured inside the apple to create an overall density less than that of water. Apples continue to absorb air after being picked.   Pears have a higher water content making it more dense than the water around it. They can no longer absorb air once picked, so the amount of air decreases as the pear ripens.

Individual activity: The length of your arms stretched out is about equal to your height. 
Along one wall we placed wide blue painters tape on which we marked inches from 0-6 feet.  The kids stood against the wall to see how tall they were.  This was recorded on a data sheet.  They then spread their arms and recorded the length outstretched.  At the end, we discussed the results and how most people were close, but not exact.

Individual activity: The length of your foot is about equal to the distance from your elbow to your wrist. 

We gave the kids rulers and had them measure their foot and then the distance from their elbow to wrist.  These measurements were recorded on a data sheet and then discussed at the end of the program.  Some kids didn't want to remove their shoes, so their measurements were off.

Individual activity: Scents smell better through your right nostril than your left.
We placed drops of lemon, orange and peppermint essential oils onto separate cotton balls and placed them into empty baby food jars.  The kids were supposed to try sniffing them using each nostril.  Most forgot and use both.  At the end of the program we talked about the science behind the difference.

Why do scents smell better through right nostril than left?
When you sense a smell, the odour chemicals float into your nose, and land on the olfactory epithelium in each nostril. They stimulate the olfactory epithelium, which then sends electrical signals into the brain. If you look at the electrical wiring, you'll see that the electrical impulses from the left nostril go to the left side of your brain, while those from the right nostril go to the right brain.
Now this is a slightly "fuzzy" statement to make, but overall, your left brain tends to deal with language and words, while your right brain tends to deal with emotions. The scientists thought that this might influence how your brain processes identical odours that are presented to each of your nostrils.

They were correct. The scientists found that each side of your brain did process the information from each nostril differently. When odours came in through the right nostril, the volunteers thought that they were smelling something more pleasant than when the same odour came through the left nostril. That fits in with the right brain being involved in emotional processing.

But what does the left brain being involved in language do to odours? Well, the scientists checked for that by asking the volunteers to give a name to the smells that they were smelling. Sure enough, when the smells came in through the left nostril, the volunteers were more accurate in using their linguistic skills to give the correct name to the odour that they were exposed to.

So your brain tells you that odours are more pleasant if you sniff them through the right nostril, and your brain can name odours more accurately when you sniff through the left nostril.

Individual activity: Three back-to-back strikes in bowling is called a turkey.
We set up our bowling set and the kids had three chances to see if they could get three back-to-back strikes.

Individual activity: The world’s largest toilet-paper pyramid was made up of 23,821 rolls.
We put out around 50 rolls of toilet paper for the kids to build with.

Individual activity: An architect built a bridge out of cardboard tubes.
We gave the kids cardboard tubes and masking tape and had them try to create a bridge. 

Individual activity: There’s an artist who creates tiny portraits on his fingers.
We purchased rubber gloves from Target and cut the fingers off.  Each child got a finger to decorate with permanent markers.

Individual activity: No piece of square paper can be folded more than 7 times in half.
My questions upon reading this were: Does thickness of paper matter?  Does size of the sheet of paper matter?  We provided the kids with three different thicknesses (construction, printer, origami) and three different size (4 inch, 6 inch, 8 inch) squares.  The kids each picked one square and folded it as many times as they could.  Some had trouble folding the paper.  They just folded it and didn't fold it exactly in half.  We did have one say they folded a piece of origami paper 8 times, but overall most couldn't get more than seven.  

Attendance: 25, 12
Evaluation: This was an awesome program!  Originally we had decided not to do the bridge building activity, but the kids finished all the other activities so quickly we needed to add it as extra filler.  Overall, the bowling, bridge building and toilet paper building were hits and many didn't want to take time away from that to get measured.  The banana experiment was a flop as it was VERY hard to see the blue glow.  It was so faint and the kids wearing white added extra glow to the room making it even hard to see!  The pear floated a little, but not as much as the apple.  Maybe a riper pear would have sank more. 

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