Saving Humpty Dumpty Again

It was time for Humpty Dumpty with the Kindergartners again.  It is a bit rushed this year.  Our school has grown so large over the past two years that in the time that I have been working with the school we have grown from 4 classes to 7.  Getting to all the classes is a challenge, but we managed it this year.

This year in our 30-35 minute sessions we discuss what an engineer is.  Again, from the first session with the kindergartners, they know I don't drive a train, and that I don't injuneer (help people who are injured), but some are still struggling a bit with the idea of designing, but most are getting the idea that engineers are people who design things.  Today, I told them they were to be engineers that designed a safety device to protect Humpty Dumpty from cracking after he falls off the wall.  We talked about a couple of safety devices that they were familiar with:  safety belts and airbags.  I then had them think about what kind of safety devices they would want if they jumped off a wall.  The ideas included a mattress, a pillow, a parachute, and a slide.  I told them to keep these things in mind as they built their designs.

This year our design kit included:

• a small paper cup
• two cotton balls
• a sheet of paper
• a paper clip
• 6 inches of tape
• 2 3 inch pieces of straw
• a popsicle stick
• and a 4 inch square piece of paper towel.

I am always amazed at the kinds of designs the kids come up with.  We had one with a paper parachute, and another with a kind of roll bar out of straws and the popsicle stick.  We had a couple of groups that tried the mattress idea, however, they learned that the mattress idea doesn't work too well.   Humpty Dumpty rarely lands on the mattress and usually cracks up.

Here we see the typical design which is the egg in the cup surrounded by paper towel, cotton balls and paper.  If they pad all sides this design usually works pretty well.   Often, the group forgets to cover the side or top and we end up with a cracked egg.  But that is okay, the lesson they take away?  Engineers are not always successful with their first design, and often have to redesign and retest.  They can also use their ideas and combine them with successful ideas they see and make a new design.

The most successful design this year?   A cup padded on the bottom with cotton balls, the sides padded with paper towel and cotton balls, and a roll bar over the top made from straws and popsicle sticks.  One of the most innovative designs?  It was a cup heavily weighted and padded on the bottom but open on the top, with only a rubber band holding the egg in.  The weighted cup always landed with the cup underneath and the egg right side up.  It was an unexpected solution!

The Spark: A Radio Interview

Just last week, Martha Woodruff from WMRA and the host of The Spark aired an interview that we had in October.  I was thrilled with the results.  I just had my first call this morning asking for some of my activities for a school near Norfolk.  Thank you Martha!

If you are interested, here is the link to the interview:  

Robot Expert's "EaSiEE as Pi" Project

If you find this and are interested in the activities that I do, just email me.  I would be happy to help.

What keeps me coming back

As I sit here nursing my second cold of the year wondering if all the colds and flus are worth it ( yes, elementary schools are germy places) I just received a note in my email written to me by a student's mom.  Here is the text:

My son loved the class on making thermometers and wrote in his journal,

"It was awesome! It was very, very, very epic!" 

 This is what keeps me coming back to the school each week despite all the germs!  I figure if I can just reach a few students and get them excited about science and engineering then this program is a success.

Thermometers for Fourth Grade

Last week we made thermometers in fourth grade.  One of the standards is to understand that temperature is the measure of thermal or heat energy in the atmosphere.  The students are required to use a thermometer to compare air temperatures over a given time period.   So, to help them better understand thermometers and the idea of force, we have them build a thermometer.  There are lots of directions on the web, but I started with the Teach Engineering site.  The activity is directed toward fifth graders, and is mainly about making a scale and comparing their own scale to a celsius or fahrenheit thermometer.  However, we concentrate just on making the thermometer itself and getting the students to explain to me exactly how it works.  Here is a great photo of a working thermometer and an enthusiastic student, excited to see the apparatus working.

You start with a plastic soda or gatorade bottle.  If you use the gatorade bottle, you need to drill a hole in the cap to insert the straw.  For the soda bottle, just use the bottle as is without the cap.  CAUTION:  water bottles will not work!  We found out the hard way that water bottles will not work.  The manufacturers have taken so much plastic out of the water bottles that they are very thin walled.  The walls are not strong enough to resist the pressure changes and they will not work.

You will also need a mixture of rubbing alcohol (1 to 1 ratio), a straw, and clay.  I also have a bucket of ice on hand, containers for iced water and very warm water, say 110 degrees or so.

Here is copy of the sheet that I use:

EaSiEE as Pi^TM

Engineering and Science in Elementary Education

Thermometers

1. Place the straw in the bottle with the alcohol/water mixture but do not let it touch the bottom.

2. Use clay to seal the neck of the bottle by making a snake out of the clay, wrapping it around the straw and putting it on the opening of the bottle.  DO NOT shove the clay in the bottle, but just seal the top and around the straw.

You now have a homemade thermometer.  Test it and see if it works.

1. Cup your hands around the bottom of the bottle and see if the water/alcohol in the straw rises.  What is the approximate temperature of your body?  What is approximate room temperature?  What is the difference between the two?

If your thermometer doesn’t work, what could be wrong?  What are the three parts of the design.  What do you think you need to fix?

1. Put the bottom of the bottle in warm water, what happens?  What happens if you put it in ice water.  Keep observing the bottle, does something interesting happen in the alcohol/water mixture?

1. Why does the water/alcohol in the straw go up and down with temperature?

4.  Did you see bubbles in the water/alcohol mixture when you put it in the ice water?  Where did the bubbles come from?  Can you explain the phenomena?

Here are some students, getting the straw to the right height, and one of our wonderful volunteers looking on.

Here is a good photo of a thermometer working.  I color the water and alcohol mixture so that it is easier to see.  It is not easy to find clear straws.  Usually, you have to purchase them at a restaurant supply store.  But be careful, I did purchase some that were clear, the only ones they had, but they were brittle, so we had to go with the light colored straws.  The white ones that you can find are usually a bit opaque and not great for this application.  You can see the clay at the top of the bottle around the straw.  Also, this time, I could only find the straws with the flexible section.  You can cut them off, but it often makes them too short for the bottles.  Instead, have them place the flexible piece down inside the bottle. If you place it at the top, it often results in an air leak and a non-working thermometer.

The key to this device is the seal.  If the seal is not airtight, then the thermometer does not work.  You can see that the water/alcohol will rise just by heating with the hands.  If the water/alcohol does not rise in fairly short order, then there is a leak at the top.  Caution the students though, that if they squeeze the bottle, the mixture will shoot out the top!  

What is happening?  The system is sealed, when working properly.  As you heat the alcohol/water mixture, the mixture expands, but it cannot expand into the air in the bottle because there is nowhere for the air to go, so the only place the water/alcohol mixture can go is up the straw!  With a little coaching and some leading questions, the students are able to figure this out on their own.  

This is a fun activity, and all of them enjoy it.  There is always a bit of excitement when they work!

Creativity and Brainstorming for 2nd Grade

I started this school year visiting second grade.  The teachers selected the creativity exercise to start their year of activities.  In this activity, we start by discussing what an engineer is.  There will be a few students who discuss someone who drives the train, but many of the classes understood that an engineer is someone who designs and/or builds things.  We talk about all the different things that engineers have designed.  I ask the students to look around and name some things they think that engineers have designed.  Sometimes I get the idea that engineers only design things with engines, but then they begin to understand that pretty much everything around them has been touched by an engineer in some manner including their desks, the air conditioning system, the bus or car they rode to school in, the pencils they use, etc.  We talk about things that engineers do not design or build and they realize that it will be things in nature such as trees, animals, and humans.  Of course, I do not bring in genetic engineering, that is a discussion for later!

We then discuss how different designs come about.  Often there are water bottles sitting at the desks, so I will pick up two different designs and ask the students to talk about what is the same and different about the bottles.  The bottles all hold water, but the tops, the color, the size, and the shape can all be different.  I ask them why.  Eventually, we get to the idea that different engineers have different ideas about how to design the bottles for different needs.  I then ask them where the ideas come from, anad they will answer their brains.  This discussion leads into the creativity exercise.

This exercise encourages the kids to work as a team to come up with as many solutions to a challenge as they possible can.  I link this exercise to the discussion about the creativity of engineers and their designs.  The children are divided into teams of three or four.  The most challenging portion of this exercise is to work as a team.  Often one member will dominate the team, the idea is to get them all to contribute to the effort.

Introduction

Each team will be given a challenge box.  The challenge can come in many forms:

a.     A large, upside down cup taped to one corner of the box that contains a marble and a metal ball.  At the opposite corner is a cup, also taped to the box.  The challenge is to move the marble and metal ball from the large cup to the small cup without touching them.  

b.     A barrier is set in the middle of a challenge box.  The challenge is to move a marble and a metal ball over the barrier to the other side without touching the balls.

c.     A barrier is set in the middle of the challenge box, but on the other side is a cup which is taped down.  The challenge is to move a marble and a metal ball over the barrier into the cup without touching them with their hands.

This year, as you will be able to see from the photographs, I used option a.  Each year I put together the boxes from whatever I can find in my stash.  But these things can include:

Materials

·      2 or 3 index cards.

·      String, yarn, pipe cleaners, etc.

·      Blocks of various sizes.

·      Legos or tinker toys for building supports for a track.

·      Magnets

·      Straws

·      A square of aluminum foil

·      Paper clips

·      Washers

·      Any other items that you think could be useful

      Here are some photographs from the six sessions we ran last week.

• In the photograph below, you can see some of the materials we included in the box, which were wooden blocks, index cards, rubber bands, a paper clip, a pipe cleaner, a sheet torn from a magazine, a chopstick, unit cubes, and a straw.  You can see the clear cup where the marble and metal ball are placed.

The photo below shows a group of boys working well together as a team.

The series of photos below show various teams with some of their solutions.  These girls are using a straw to move the metal ball.

This child is making a container out of legos.

These girls are trying to make a solution using paper.

This group is using half of an egg an a rubber band to scoop the balls off the top of the cup.

Here the girls have made some device out of string.

Here is the clever use of a rubber band to pick up a marble.

Here the students are working on a more elaborate device.

What is interesting about this exercise is the how some groups just really seem to click and work madly to come up with a number of interesting solutions, and how other groups struggle to come up with just a few.  In general, the groups are randomly selected by counting off, so we don't group the students in a thoughtful way.  I have some groups who are lucky to come up with 4 or 5 solutions in 15 minutes, and others that come up with 17 or more.  The idea is not that the winner comes up with the most designs, but that the students should try and think creatively and this gives them a safe way to try it.

In general, the students like this activity.  Their enthusiasm is always the thing that keeps me coming back.  I was asked if I could come back and run this activity again the next day, and if I would come back the following week.  I just hope what I am leaving them with is a more positive outlook on science and engineering, and hopefully sparking an interest that will continue with them throughout school.

Reach for the Sky

Today the 5th graders built skyscrapers.  I found this fun activity in the teachengineering.org website, in an activity called Newpaper Skyscrapers.  It is accompanied by class material, but I found that material a bit lacking, but it does have great links to other web sites.  One link I used was "Building it Big" on the PBS site.  It is a great help for learning more about skyscrapers and a good overview of some of the ideas behind the building of them.  On this site they talk about geometry, loading and have photographs of some of the most famous skyscrapers.  There is also a great site called skyscraperpage.com which has some great illustrations of big buildings all over the world and their height.  The PBS special did not have the Burj Khalifa in it, since the program predated its construction, so I got most of my information about the world's tallest building from its web site and from the skyscraper page.  The Burj Khalifa, by the way, is more than 2 times the height of the Empire State Building.

First, I gave a short overview of the history of skyscrapers, and a brief introduction on how they stand and how they withstand wind loads.  The major types that I covered, as shown in the teachengineering page were stone towers (B.C. onward), Gothic Cathedrals (1200's to 1600's) especially noting Notre Dame Cathedral and the flying buttresses (which of course was thought to be a hilarious term by the fifth graders and elicited giggles every time I used the term buttress), the Home Insurance Building (1880's), the Empire State Building (1930's), the Sears Building (1970'), and the Burj Khalifa (2011).  Each had a concept to get across.  The towers illustrated stout stone walls bigger at the bottom than at the top.  With Notre Dame I discussed the flying buttresses which held up the walls from the outside so they would not be pushed out from the weight of the ceiling.  I showed the idea of the reinforced supporting core for the Empire State Building, which is also a three dimensional grid of steel beams.  With the Sears Building I showed them the hollow tubes that surround the perimeter to provide support, and finally with the Burj Khalifa we discussed the reinforced center support supplemented by the idea of buttressing.

Next, I gave them 4 sheets of newsprint and 12 inches of tape and let them work on building their skyscrapers.  They were to build a skyscraper that could stand on its own without being taped to the table, and then withstand a wind load: a big breath blown on the tower from an arm's length away.

It is fascinating to watch how the students work together, or not, and how their minds think.  I worked with 5 classes today.  In the first three classes, not one group used the cone.  In the fourth class, several groups used a cone, but that may be because my son saw one of my designs that I quickly made just to test out the exercise.  My design used succeedingly smaller cones to attain height and stability.  However, I only obtained 28 inches of height in my quick design.  Another interesting thing to note was that the students tended to put the smaller tube inside the larger tube and then taped it to the larger outer tube.  None of the students stacked cylinders so that they were supported by the one below rather than just the tape.

The most successful designs used flying buttresses that the students made of rolled up paper and attached to a paper base.  The flying buttress designs reached heights of 32" and 50".

The most successful design of the day was a tripod design which attained a height of 50 1/2 inches.  This design had the most stability of any of the designs.  It used three rolled up cylinders which fit in the base of another cylinder to achieve its height, a very elegant design by the students!

All of the students had a great time, and wanted to stay and work on their designs longer than the allowed time.  That for me is a success, along with the fact that they did learn a few things today.

Slinky Waves

Recently, EaSiEE as Pi was in the 5th grade looking at waves.  One great way to show a wave is to use slinkies.  Everyone loves playing with slinkies and they make looking at certain types of waves visually possible.  The 5th graders had just finished studying the rock cycle, the Earth's interior, and plate tectonics.  Earlier in the year they studied sound and light.  So, I decided we would look at waves which would relate to all three of those subjects.  With the help of books and the internet I came up with four stations for the students to rotate through:

1.  Making waves with strings and ropes
2.  Making waves with a slinky
3.  Making nodes and anti nodes with a slinky on a string
4.  Earthquake impacts and characteristics

Before starting, I had to get a couple of slinkies and build some devices for the stations.  I found the slinkies at Toys R Us.  They had the metal versions and the plastic one.  I bought several of the large metal versions and one plastic slinky.  The plastic ones are not really good for demonstrating wave propagation, so make sure you get the big metal ones.  I will explain why I bought the large plastic slinky later in the description of the earthquake station.

In the first station that I listed above, we used different types of string a rope and let the students generate waves.  I used light weight string, elastic string, and a light weight rope.  The elastic string was able to generate the waves with the most nodes.  If you look carefully at the photo below, you can see the rope in the middle with some waves.  This was a popular station and one that I have seen in books and one the internet.  This experiment I looked at the book Making Waves by Bernie Zubrowski.  What we found is that it is very hard to make waves with a student at each end moving the string.  It works better if one person holds the string or rope steady and then the other makes the waves.  The idea was to try and make one wave, then two, then three, and then to make as many as you could.  The idea was for each student to try and make waves with each material so that they could find out which material allowed them to make the most waves. 

Another station that was popular was the slinky station where we had the students make a P or pressure wave with the slinky.  You have one student at each end of the slinky, and have them back up so they have the slinky stretched out quite a bit.  Then as you can see below with the student on the right.  Have them cup their hands, then strike their hand with the other hand to create the pressure wave.  When I did the demonstration for all of the students before we started, the kids all oohed and ahhhed.  I was surprised that they would be so excited seeing the wave in the slinky, but I have to admit, it is pretty cool!  I also had them produce S or shear waves on the floor.  If you have them make S waves with the slinky in the air it often gets out of hand and results in very tangled slinkies.  You can see a great visual graph of P and S waves at the Purdue University site.

One internet source which is a great help in finding fun hands-on activities is the Exploratorium Snack page.  The activity I used was "Slinky in Hand".  I set up a slinky on a fishing line that was tied between two chairs.  With the slinky you can do some interesting things with compression waves.  I used a 10 pound line, although the instructions said use a 20 pound line.  I think a good thick line is indeed needed.  The first class broke the fishing line in the first few minutes.  I then tied a thin cotton string to the chairs and used that.  However, the monofilament line is better because it has a lot less friction than the string.  From the series of photos below, you can see how the students can make pressure waves with the slinky by either moving their hands toward each other in a clapping motion, or moving them together in sync.  However, we found that moving together in sync is pretty hard, and if you get two people who work well together, they can act as if they are sawing a tree and get multiple wave forms that way.

For a couple of the experiments showing the earthquakes, you need to attach the slinky's to a small block of wood.  That setup is described on a website about Earth Science at Purdue University.  If you look at the Seismic Waves writeup, you can see how to build a couple of the devices that I used.  I show a photo below of drilling a hole into a block of wood.  I then used screws and washers to secure the last slinky link to the block of wood, and then built a little house per directions on the website.

This is a photo of the final device in action.  A student is generating a wave and shaking the building and you can see how it is leaning to the left as a result of the "earthquake".

In this earthquake station I also had the metal and plastic slinky's taped together to show how the waves propagate differently through different types of material just as a earthquake would propagate through different types of rock.  This device works quite well.  It also works well to have the kids put it on the floor and generate S or shear waves and see how the propagate differently in the metal vs. the plastic.  This was a popular station.

Overall, I think this set of experiments worked well.  I think I would do a little tweaking.  I think I would use a set of whacking balls.  You can use marbles and string, but buying a set of these balls, called Newton's cradle, would be better.  They show how an seismic P waves can propagate through the earth.  

Another  experiment I might add would be to set a slinky on a piece of sandpaper and have the students move the paper quickly about 6 inches and see reaction.  You can also join two slinky's together for a taller building.  I found this experiment in Janice Van Cleave's book Earthquakes.