Inside and Outside Twister

Can you be inside-out and outside-in at the same time? No? What if you can?

It's called a Möbius Strip, and we're going to make one today. It's surprisingly easy and fun.

My Möbius Strip after I cut along the middle.

Usually, a Möbius Strip is made with thinner strips of paper (1 in width). But I made this with thicker width because I wanted to cut it along the middle and make a longer one.

List of Materials:

• Paper
• Scissors
• Tape

I folded a piece of paper in half, then again in half, to make 4 quarter width thick strips.

I'll only be using two strips.

I overlapped the 2 strips and taped along the width, front and back.

Then I twisted the strip and taped the other ends, both front and back.

Began cutting along the middle, all the way around the Möbius Strip.

Half way done cutting along the Möbius Strip.

Now, I have a Möbius Strip twice as long.

And if I decide to cut along the middle of this strip, it will keep its shape. It'll just be twice as long as this one.

Interesting Facts:

• Möbius Strip was invented by a German Mathematician, August Möbius who was interested in Topology.
• Topology is a study of geometrical shapes that won't change when it is bent or stretched.

Did you know?

When I first saw this twisted strip, I thought, hmm.... Interesting. Yum..., brain candy. I could imagine all kinds of possibilities. But I didn't know what kind of practical use a shape like this would have. But you know what I've learned recently? That Möbius strips have been used as fan belts in cars and conveyor belts in factory set ups. 

Imagine that!

Elephant's Toothpaste

I haven't done many Chemistry experiments in class, because there isn't enough time to clean up the mess before the next class comes in, etc. But I always wanted to try this one (even though there are many variations of this on youtube and elsewhere) because any kind of foaming, explosive reactions I've done before were based on vinegar and baking soda (any this one is based on hydrogen peroxide). And it's always really fun to get your hands dirty.

This is what we're doing today. 

This was the extent of the mess I had to clean up from this experiment, which is less than I expected.

List of supplies:

• Empty plastic bottle
• Baking tray (bigger the better)
• 4 fluid oz of hydrogen peroxide (3% concentration is the one I used. I bought it from a nearby pharmacy)
• Dish washing liquid
• Dry yeast
• Hot water
• Funnel
• A small bowl to mix yeast and hot water
• A measuring spoon set (1 tsp & 1 Tbsp)
• A spoon to stir the yeast and hot water mixture

Measure 4oz of 3% concentration of hydrogen peroxide.

Pour hydrogen peroxide into the empty water bottle along with a couple of drops of food coloring and a couple of drops of dishwashing liquid.

Mix a 1 tsp of yeast with 2 Tbsp of hot water.

Using a funnel, add the yeast and water mixture to the hydrogen peroxide in the bottle.

Too bad I didn't do this experiment a couple of days ago. It has a nice heart shaping going. It's probably more impressive in person than in picture.

Big bubbles on the left outer edges of the foam mixture (bubbles from earlier reactions).

Big bubbles on the left outer edges of the foam mixture (bubbles from earlier reactions).

Smaller bubbles in the closer vicinity of the plastic bottle (bubbles from the later reactions).

SO..., why does this happen? Think about what happens in the bottle.

Science notes:

Well, if hydrogen peroxide is left alone long enough, it'll break down to water and oxygen on its own. BUT, by adding yeast into hydrogen peroxide, we're speeding up the break down process.

1. The hydrogen peroxide locks on to the yeast.
2. The yeast breaks down into oxygen and water.
3. The oxygen released by the yeast mixed with dishwashing liquid creates the bubbles and produces the foam.
4. And this one, you can't tell from looking at the pictures, but when I touched the water bottle, it was warm.
5. Hydrogen peroxide + yeast is an exothermic reaction (heat-producing), and that's why the water bottle was warm to touch.

I liked this experiment a lot because it was simple and even though there was a mess, it was easy to clean up after I was done.

I'd like to do this in class varying the concentration of yeast and water mixture. I'd like the students to figure out the relationship between the yeast concentration and the amount of foam (which probably is hard to measure) or the amount of heat the experiment released (which probably is also hard to measure). Also, I can play around with different concentrations of hydrogen peroxide. Anything over 6% concentration is not recommended online.

Again, for a Chemistry project, this was fun, easy to clean up, and it offered a lot of opportunities to mix it up.

Have fun & have a great day!

NOTE: If you have really little kids around you, please make sure they don't consume the foam.

Hoop Gliders

I came across these hoop gliders several years ago, but I revisited them with my children when we were participating in the Tech Challenge 2016, Taking Flight. And just like the Birds of PLAY, we made these gliders to prototype (we thought using the gliders in the shape of birds would be fun at the competition) and understand the mechanics of flight.

Before you start, throw a plain straw. Does it fly well? Not really. It’s because the straw doesn’t have wings. It has nothing to generate lift. But when you add hoops, they act as wings, generating lift. And depending on where you put the hoops, your hoop glider will generate more lift or less. You experiment with sizes and locations of the hoops and decide what works best for your hoop glider. 

 This is what we're making today. 

These are quite simple to make, and they are incredibly fun to throw and watch them fly. This is a great project you can do with your children/students inexpensively. I hope you try this project and have a lot of fun.

List of Supplies:

·                     Straws (different lengths and diameters)

·                     Paper strips (copy paper, construction paper, cardstock, etc., whatever you have handy)

·                     Scissors

·                     Adhesive tape

Cut the paper in 1/2" or 3/4" strips. You can experiment with other widths, but these are the widths that seemed to work best. I also have three different sizes of straws. For my convenience, I made my hoop gliders with the wider, pearl drink straws. But I had students make hoop gliders with regular straws, and they did well with the smaller diameters, too. So, it really doesn't matter too much. Again, if you have different sizes available, experiment.

These paper strips are 3/4" wide. I like this width for no other reason than that it's the width of scotch tape. So, that's the width I use, but I've seen other project instructions online with 1/2" width instructions. Tape the ends of the strips together and make circles. You can experiment with lengths, but I tend to use 3", 6", 9" and 12" strips. I don't know why. I think it's the proportions that matter, not the actual lengths.

You can put as many or as few hoops as you want. But the minimum number is 2.

Have fun with where you put the hoops. Go crazy and fail spectacularly!

As you see, the left hoop gliders hoops are not aligned. The hoop in the back is attached in the middle, but the hoop in the front is attached to the right handside. Play with where you attach the hoops - in the middle, left side, right side, etc.

Just want to show you the different sizes of the hoops I attached. Again, the goal of these projects is to have fun.

I made 4 hoop gliders this morning. but when I conducted this project in class, some students have made as many as 10+ gliders. So, make a lot and have fun.

How to throw a hoop glider. Gently throw it forward.

 

This one flew pretty straight and far.

This one flew the farthest, almost toward the fence & the rose bushes.

This one was interesting to look at slow-mo, because the largest loop would swing back and forth between left and right. But it didn't fly far.

This one was all over the place, but interesting to watch.

It's a perfect day to fly gliders! Have fun!

Squeeze Bottle Rockets

This is a variation on Strawkets I saw at RAFT, and I wanted to see if these would fly as well as the original Strawkets experiment I did with students a while back.

Four 6th grader classes conducted this experiment recently, and the results were conclusive - lung power wins! There's no comparison between lung power and squeeze bottle power. Unfortunately, I didn't take pictures in class, so I took these pictures separately.

This is what we're building today.

List of Supplies:

• Straws, 2 kinds, one skinnier than the other (they should be able to slide easily inside of one another but not too loose)
• Facial tissue
• Index cards
• Adhesive tape
• Scissors
• Squeeze bottle
• A piece of soft foam to cover the bottle opening

All the materials are easy to find except for the squeeze bottle. I think you can find these at Target or Walmart in the travel container section.

The black piece on top of the squeeze bottle is a squishy foam with a hole in the middle for the straw. If you don't have anything like this, you can just tape over the opening, insert the straw, and tape around the straw to make sure that no air is escaping (except through the straw).

Try flying your straw rockets with the inner straw pushed all the way in & pulled out to the bendy neck of the skinnier straw. Experiment and find out which way works better.

Take a piece of tissue, twist and fold into an oval shape, and push it into one end of the straw to make it the front end of rocket. Cut pieces of an index card (try to have fun with different shapes and sizes) and attach them at the end of your rocket as tails.

These are some of the shapes I experimented with today, but in class, students are VERY creative with sizes (huge to tiny) and shapes (let your creativity explode). Have fun with them.

This is one of those experiments where I have the students yell, "Fail Spectacularly!"

So, go forth and fail spectacularly by experimenting with crazy shapes and sizes.

And always, I hope you have a lot of fun.