The Ultimate Bubble Solution

Bubbles may very well be the world’s first toy. From sea foam, to hand soap, to those bubbles you blow in your milk, it seems bubbles are part of our daily life. Soap bubbles way be the most fun off all bubbles and they are an inexpensive and limitless way to explore our bubbly world.

For years bubbleologists have perfected the solution for the longest-lasting and most durable bubbles. Perhaps the person who has studied the science of bubbles the most, is  Keith Michael Johnson. And he recently shared his unlikely TOP-SECRET formula for the best bubble solution…

You will need:

• Water – many bubble enthusiasts are convinced that distilled water makes the best bubbles
• Liquid dish soap. Dawn dish soap has always been a favorite
• SurgiLube (available at medical supply stores) or K-Y Jelly (available at pharmacies)
• A clean plastic bottle to hold your bubble solution

What to do:

Simply pour all three ingredients into the bottle in the following ratio:

• 12 parts water
• 1 part dish soap
• 1/2 part SurgiLube

For example you would start with 12 ounces of water, add 1 ounce of liquid dish soap, and 1/2 ounce of SurgiLube. You can increase the amounts equally to make more.

1. Shake the ingredients up well (don’t worry, the bubbles  from shaking will go away)
2. For best results, allow the bubble solution to sit overnight. Then you’re ready to go!

How do bubbles work?

Every soap bubble is made of a film that has 3 layers: Soap, then Water, then Soap. Because of the way that soap molecules are arranged, and the way they attract and repel from each other and the water, the soap creates bonds that give the water additional strength, and allow them them to last much longer. Bubbles will always be round when they are floating because the elastic nature of the soap bubbles allows air pressure to push equally on the entire surface of the bubble forming a sphere.

Bubble fun:

• You do not need bubble wands from the store to make bubbles. Simply dipping your hand in bubble solution and making a circle with your fingers makes a great bubble wand. Straws, plastic strawberry containers, fly swatters, and aquarium nets make great bubble wands.
• To make foamy bubbles, use a rubber band to secure a piece on cotton cloth over the end of a small section of plastic pipe. Soak the cloth in the bubble solution and blow from the other end.
• Pour a small amount of bubble solution onto a clean counter top and spread it out. Use a straw to blow a dome-bubble on the counter top. Keep blowing into the bubble to make it bigger and bigger. With some practice, you can get a bubble dome as big as a dinner plate!

Oreo Cookie Moon Phases

I’ve always been a fan of science activities that you can eat. One of my favorites that I have been using for years is the Oreo Cookie Moon Phases activity. It’s almost as if Oreo cookies were made for this lesson, and it’s a great way to see how well students can match a moon phase name with a moon phase appearance.

You will need:

• An Oreo cookie for each student
• A piece of paper with a moon phase written on it for each student (I omit “Full moon” – that’s just too easy)
• A popsicle stick or other tool for scraping the frosting

What to do:

1. Fold up each piece of paper with the moon phases written on it and hand one to each student as they enter the room – tell them not to open it yet. I will often have them store it in their shoe. They think that’s funny, and they won’t lose it.
2. Demonstrate the proper way to slowly twist an Oreo to maximize the amount of frosting on one side when you separate the halves. (practice yourself, it can be tricky)
3. Give each student a cookie and have them twist the halves open. Hopefully most will the frosting will be on one side or the other. They can always transfer frosting if needed.
4. Have the student retrieve their moon phases while you hand out the craft sticks.
5. Recreate the given phase in frosting!

I will usually tour the room and once they show me that they’ve got the phase right, they can eat the moon! Of course be aware of food allergies and such. If you try this out, let me know how it goes!

Science On The Set of Little Fockers

Daisy Tahan and Colin Baiocchi in Little Fockers

One of the best parts of sharing experiments on this website is hearing back from people that get to try them out. I was happy to recently find out that the young actors that appear in the movie, The Little Fockers were fans of sciencebob.com. Even famous child actors have to go to school every day, so film and TV productions set up a special room or trailer that gets used as the classroom while the filming is going on. A teacher is on the movie set every day to teach lessons in between filming scenes. While this film is targeted for adults, we were happy that some great science lessons were going on behind the scenes with the young actors. The lessons were led an amazing teacher named Maura who enjoys exploring hands on science and bringing learning to life. Maura was kind enough to contact me and send us some behind-the scenes photos from the set of the movie.

Daisy Tahan plays Samantha Focker in the film. She’s been acting since she was just 4 years old. In this picture she is trying out our experiment titled “The Fizz Inflator” which allows you to inflate a balloon using only the power of chemistry. As you can see it was quite a success for Daisy.  To try out the experiment yourself, just click HERE.

Daisy also experiment with non-newtonian fluids when she created oobleck using corn starch and water. In the right combination, these two ingredients make very unique goo that can act like both a solid and a liquid. (If Daisy’s hands look a little blue in any scenes of the movie, now you will know why.) If you want to try making a little gooey oobleck yourself, it’s easy. You can find all the instructions HERE.

Daisy and fellow actor Colin Baiocchi, who plays Henry Focker in the movie, confirm what famous scientist Archimedes observed hundreds of years ago regarding the displacement of water when an object is placed in it. The graduated cylinder with the green water allowed them to measure how much the water was raised when different objects were placed in it.

Maura reports the two actors also got to try out our film canister rockets. We’re happy that our experiments were able to provide some fun and learning on a backlot in Hollywood as much as they are in classrooms and living rooms around the world. Thanks again, Maura!

We’d love to see YOUR pictures of our experiments in action. We may post them right here on our blog. You can email them to comment@sciencebob.com. Happy exploring!

Medical Myths from Dr. Oz Explained

Was Everything Your Mother Told You Wrong?

The Dr. Oz Show recently took on the topic of whether or not the common guidance that your mother gave you was actually wrapped in myth. You can check out the segment HERE. I was happy to get the call to try to add some visual demonstrations to bring home the concepts of these myths. The segment was a lot of fun, and everyone a the show is amazing. Despite all the big demos, there was some interesting medical science discussed. I spoke with some audience members after the show that had a lot of questions about the myths. While I’m obviously am not a doctor, I thought I’d share my explanation of some of the science behind these interesting myths from the show:

MYTH #1 Eating Too Much Sugar Will Make You Hyper
It seems to be a common idea that when children eat a lot of sugar they quickly become active and energetic. The demonstration with the celery and the gummy bear shows just how much energy can be released from foods. It also showed that, without a doubt, sugary foods pack quite a punch when it comes to releasing energy. Here is where the myth comes in: simply eating sugar does not make you hyperactive. It just gives you a source of energy to tap into. You could eat a candy bar and use that energy to run around the block, but it will not MAKE you want to run around the block. If you decided to read a book, the energy from the candy bar would be stored as fat. As Dr. Oz  pointed out, kids tend to eat a lot of sugary snacks in environments that would get them excited and give them reason to run around and be active such as a birthday party, Halloween, or just having a friend over after school.

MYTH #2 Breathing in Helium Will Kill Brain Cells
This was a fun demo. The audience was laughing so much from Dr. Ozs’ Barry White voice, I’m not sure they heard all his explanation. In case you missed it, here’s a recap: At some point in our lives, we are all likely to breathe in a balloon full of helium and enjoy the comical Daffy Duck voice that follows. When I was growing up, I was told that this was a bad idea and that brain cells were being destroyed. The good news is, breathing helium does not kill brain cells. The bad news is that breathing helium can, in fact, kill you — but not because of the helium, rather because the lack of oxygen when you inhale the helium. As you breathe in a balloon full of helium, you are not breathing in any oxygen, which your cells need -  usually we get this from the air we breathe. The lack of oxygen that comes from breathing in helium can cause fainting or even asphyxiation and death. This is especially likely if you were to breathe several balloons full of helium without getting enough oxygen in between. The bottom line; avoid breathing any gas that is not already in the air around you.

But why does your voice change with helium? Helium makes your voice sound higher pitched because helium is six times lighter than air and sound travels through helium faster than it does through air. The result is that the low sounds of your voice get “suppressed”  by the less dense helium and you hear the high tones of your voice. Our sulfur hexafluoride demo had the opposite effect; because it is more dense than air, it drowns out the higher sounds sounds and emphasizes the lower pitch (really timbre) of our voice. On a sulfur hexafluoride side-note, there is a great guy that I get my liquid nitrogen from that NEVER smiles, I mean, never. That all changed when I visited him with the tank of sulfur hexafluoride, took a breath of it from a balloon, and did my best evil laugh…we got a smile from him.

Myth #3 Bundle-Up in Cold Weather or You’ll Catch a Cold
Well this makes sense, after all they must call it a “cold” for some reason. The producers of Dr. Oz had seen talented science educator Steve Spangler make smoke rings during his appearance on Ellen and they really liked the visual. Since you catch a cold from bacteria and viruses, and NOT a cold environment, we used the smoke ring vortex generator as a way to visualize the germs that were spread out during a cough. It ultimately demonstrated that despite whether you are bundled up or not, germs that cause a cold and flu can still get to you – so wash your hands regularly with a moisturizing foam soap soap.

Myth #4 – Hydrogen Peroxide is a Good Way to Disinfect a Cut?
Before we started this demo, Dr. Oz  asked how many people in the audience have used hydrogen peroxide to clean a cut. We were both surprised to see that almost the entire audience raised their hands. Perhaps we should not be surprised, after all, it says right on the bottle that it can be used to disinfect a cut. Hydrogen peroxide works as a disinfectant by releasing oxygen when it comes in contact with an enzyme in the body called catalase. That is why putting hydrogen peroxide on an open cut will create bubbles — the bubbles  are actually filled with oxygen and in some cases that oxygen-rich environment can kill bacteria. The downside is that it can also harm healthy cells surrounding the cut. Some evidence also points to the fact that the reaction happens to fast in a cut to make much of a difference.  For that reason, hydrogen peroxide is not a good choice for disinfecting most cuts although it is used in other applications for disinfecting. The larger demonstration with the flasks showed a very fast release of oxygen from a 30% hydrogen peroxide solution (store-bought hydrogen peroxide is 3%.) During rehearsal, the flask shot foam so high into the air and it hit the lights above, and we were hoping you would do that during the show.  It turns out the bottle of hydrogen peroxide that was used during the show was slightly older and less powerful than the bottle used during rehearsal, but it was still just as messy nonetheless.

Hopefully that explains the myths a bit more. I hope you enjoyed the segment and that it made some medical and not so medical science fun to watch.

Purple Brew: An Acid-Base Indicator

Next time kids say they don’t like vegetables, try out an experiment that will bring out the fun side of our leafy friends. Mom and Kiddo of  the blog What Did We Do All Day? shows us how to play with color in this demonstration that uses an acid, a base, and a vegetable. She suggests keeping some of the solution in the fridge for a rainy day and allowing kids to experiment on their own.

You will need:

• purple or red cabbage
• small and large glass jars
• baking soda
• water
• vinegar
• measuring cup
• 1/4 teaspoon

What to do?

1. Chop up a cabbage and simmer on the stove for 20 minutes to make a cool purple liquid (kids, please let a grown-up do this)
2. After the purple brew has cooled, collect some small and large jars. Place about 1/4 tsp baking soda and 1/4 tsp water in one jar, a small amount of vinegar in another and about 1/4 cup purple brew in a third.
3. Put some of the brew in a measuring cup and pour 1/4 tsp of the brew in each of the first small jars. What happens when you mix the purple brew with the different solutions?
4. In the jar filled with a 1/4 cup of purple brew,  pour about 1/4 cup vinegar. What happens?
5. Next, add 1/4 tsp baking soda to the same solution. What is your observation?

How does it work?

Red cabbage contains a chemical called flavin and flavin has the ability to change color based on the pH level of certain liquids. Nuetral solutions, (like water) are purple. Acid solutions, like the vinegar, turn will turn flavin red. Basic solutions, like the baking soda water, become blue.

You can check out Mom and Kiddo’s full post of this experiment HERE. Let us know what your results are when you make your own purple brew. What would happen if you tried different vegetables? What would happen if you used cream of tartar, lemon juice, salt, lemonade, or other materials from your kitchen pantry? Can you make your own litmus paper and test the pH of the solution?

Eggshell Geode Crystals

 Print This Post

This project comes to us from Melissa Howard who is a Mom, Blogger, and photographer. This project nicely demonstrates how real-life geodes are formed in igneous and sedimentary rock. It also demonstrates super-saturated solutions and shows a nice variety of crystal shapes and formations.

YOU WILL NEED:

• clean eggshells
• water
• a variety of soluble solids: table salt, rock salt, sugar, baking soda, Epsom salts, sea salt, borax, or cream of tartar
• small heat proof containers (coffee cups work well)
• spoons
• food coloring
• egg cartons and wax paper or mini-muffin tins

WHAT TO DO:

1. Crack the eggs for this project as close to the narrow end as possible. This preserves more egg to use as a container for the solution.
2. Clean the eggshells using hot water. The hot water cooks the lining and allows you to pull the skin (egg membrane) out of the inside of the egg using your fingers. Make sure to remove all the egg membrane, if any membrane stays inside the shell it is possible that your eggshell will grow mold and your crystals will turn black.
3. Use an egg carton lined with waxed paper or mini-muffin tins to hold the eggs upright.
4. Use a saucepan to heat the water to boiling. .
5. Pour half a cup to a cup of water into your heatproof container. If you poured half a cup of water into the container, add about a ¼ cup of solid to the water. Stir it until it dissolves. Likewise if you used a cup of water, add about ½ a cup of solid to the water. You wanted to add about half again the volume of the water as a solid to the mixture. When the initial amount of solid is dissolved continue adding small amounts of the solid until the water is super-saturated. Super-saturated simply means the water has absorbed all it is able to absorb and any solid you add will not dissolve.
6. Add food coloring.
7. Carefully pour your solution into the eggshell, filling it as full as possible without over-flowing it or causing it to tip.

Find a safe place to put your shells while the water evaporates. Crystals will form inside the eggshells as the water evaporates.

HOW DOES IT WORK?
Dissolving the crystals in hot water created what is called a “super-saturated solution.” This basically means that the salts took advantage of the energy of the hot water to help them dissolve until there was no more space between molecules in the solution. As the solution cooled, the water lost its energy and the crystals are forced from the solution to become a solid again. Since this happens slowly along with the evaporation, the crystals have time to grow larger than they were when the experiment started. Natural geodes in rock are form in much the same way as mineralized water seeps into air pockets in rock. This is also how rock candy crystals are formed.

You can visit Melissa’s great blog and see more pictures HERE.

Lemon Chemistry: An Acid-Base Experiment

Kari Wilcher runs a great blog. She was looking to teach her pre-school children about the Scientific Method while trying out some kitchen chemistry at the same time. Her plan was to show a dramatic acid-base reaction using lemons, baking soda, and a little dish soap. She writes:

“I firmly believe that children are never too young to be exposed to the scientific method and should follow it. I have found that the scientific method is very easy for them to understand, and follow, when presented to them in a simple way. I like to use a rebus (picture) to help my non-readers understand the directions. I also use these “big” words: data, hypothesis, prediction, and observation. We, including Momma, wear goggles (from the dollar store) and a lab coat (a.k.a. dad’s white button up shirt) because we are real scientists doing real science experiments…and it just makes us cool.”

You will need:

• Fresh Lemons
• A knife
• A small measuring cup & measuring spoon
• Baking Soda
• Liquid dish soap
• A clear cup for the reaction

What to do:

1. Roll the lemons on the counter like dough. This releases the juice inside the lemon.
2. Cut the lemon in half (adults only, please) and carefully squeeze out the juice into a small measuring cup. Note how much juice was created from each lemon and put the juice aside.
3. Into the empty glass place 1 Tablespoon of baking soda.
4. Add 1 teaspoon of liquid dish soap to the baking soda. Stir these up a bit.
5. Pour the lemon juice into the cup and stir. Now watch the lemon suds erupt!

How does it work?
This is a classic example of an acid-base reaction. This is often done with vinegar and baking soda, but we liked Kari’s “lemon twist.” The baking soda (a base) and the lemon juice (an acid) combine to release Carbon Dioxide gas. The liquid soap turns the bubbles into a foam that often erupts right out of the glass.

Try it out and let us know how it goes!

You can check out Kari’s full blog post of this experiment including the worksheets she created HERE.

Do Birds Care What Color Their Food Is?

Would you want to drink green milk, how about orange mashed potatoes? The color of foods might affect just how much you want to eat them, but what about the birds in your neighborhood, would they care what color their food is? This sounds like an experiment in the making…. you coul even try this out for a science fair project, or just to learn something new while making your locals birds happy.

You will need:

• Several bird feeders that are the same size and type
• Light colored birdseed appropriate for the birds in your neighborhood
• Several colors of food coloring

QUESTION -  What color of birdseed, if any, will birds prefer the most?

RESEARCH: Ornithologists (scientists that study birds) are rather certain that most birds can see in color. One reason they think this is because birds themselves are very colorful.  In many species, male birds tend to be more colorful than females. This is likely because the males use their coloring to attract a mate,  while female birds tend to have less coloring to provide camouflage as they protect their eggs in the nest.  Before beginning a large experiment with lots of bird seed, you may want to put out a few small handfuls of different colored birdseed (see instructions for coloring birdseed below) to see how the birds near you react to different colored seed.  You may also want to refer to books and talk to an ornithologist to get their opinion about how birds see the word.

MAKE A HYPOTHESIS: Use the information that you’ve gained from your research and make a hypothesis based on your question. An example might be “Birds will eat more green birdseed than other colors.”

EXPERIMENT:  This is the fun part. You should get several bird feeders that are all the same size and type. Purchase a bird seed that is very light in color for this experiment.  To color the bird seed, pour it into a bowl and then add food coloring that you can purchase from the store. Mix it up well with a spoon and continue to add color until all the seed is colored.  You should sample at least a few colors and have one feeder with seed that has not been colored -  this is called the control and it will give you something to compare your results to. Now just hang them up outside in the same location, and wait for your feathered friends to show up. This works best in an area that birds are used to feeding from a feeder – it can take birds over a week to find new feeders.

COLLECT DATA:  Observe your bird feeder whenever possible, and keep track of how much seed is in each bird feeder each day. A ruler is helpful for this. You might also want to take pictures of the feeders and keep track of which kind of birds visit each feeder.  Over time, you should be able to see if one color of seed gets eaten more than others.

MAKE A CONCLUSION: Once your experiment is done, you will be able to go back to your hypothesis and see if it is correct. Remember,it’s not bad if your hypothesis was wrong. The main thing is that you’ve learned something from your experiment, and hopefully you had some fun doing it.

If you try this, let me know how it goes!

If you need inexpensive bird feeders, you can get some on-line HERE.

Oobleck – The Corn Starch And Water Experiment

 Print This Post

This may just be the easiest, messiest, and most fun science activity I know. It is a classic, and I have gotten several requests recently to post directions. You should know that if you try this activity and  you are not smiling and messy with corn starch goo at the end, then you are definitely doing something wrong. Also keep in mind that this is not just about fun, there is some pretty amazing science going on here.

You will need:

• Cornstarch (a 16 oz. box is good for every 2-3 participants – but more is always better)
• Water
• Food coloring (we always say it’s optional, but it does make it more fun – don’t use too much or you could end up with colored hands…and clothes…and curtains)
• A large bowl
• A camera – you’re probably going to want to take pictures.

Everyone should roll up their sleeves and prepare for some gooey fun.

1. This is easy. Pour the cornstarch into the bowl. Don’t rush to add water – take time to feel the cornstarch. Cornstarch does not feel like any other powder. It has a texture that can be compared to that of whipped cream. The grains of cornstarch are so small that they will fill into grooves of your fingerprints and make the prints stand out.
2. After you’ve taken-in the feel of the powder, it is time to add water. (You should add the food coloring to your water before adding it to the powder.) There are no exact formulas regarding how much water to add, but it will end up being about 1/2 cup (120 ml) of water per cup (235 ml) of cornstarch. The secret is to add the water slowly and mix as you add it. Don’t be shy here – dig in with your hands and really mix it up. This is usually when you notice that this is not your average liquid. Add enough water so that the mixture slowly flows on its own when mixed. The best test is to reach in and grab a handful of the mixture and see if you can roll it into a ball between your hands – if you stop rolling it and it “melts” between your fingers – success!

We’ll get the the science soon, for now just dig in and explore. Notice that the goo does not splash (or even move) if you hit it quickly. Squeeze it hard and see what happens. How long can you get the strands of goo to drip? What happens if you let the goo sit on the table for a minute and then try to pick it up? How does it feel? Hows does it move? Try bouncing a ball on the surface of the cornstarch. You get the idea – explore!

30 minutes later…

So now goo is everywhere and you’re thinking you should probably start cleaning. Actual clean up of the goo is a snap. A bucket of warm water will quickly get it off your hands. It will brush off of clothes when it dries, and it is easily cleaned off surfaces with a wet rag. Important: Make sure you do not dump the goo down the drain – it can get caught in the drain trap and take the joy out of your day of science. Dump it in the trash, or even mix it into soil in the garden.

Cornstarch grains under the microscope

Now for the science…
Our cornstarch goo (sometimes referred to as “oobleck” from the Dr. Suess book) is what scientists call a “Non-Newtonian” liquid. Basically, Sir Issac Newton stated individual liquids flow at consistent, predictable rates. As you likely discovered, cornstarch goo does NOT follow those rules – it can act almost like a solid, and them flow like a liquid. Technically speaking, the goo is a SUSPENSION, meaning that the grains of starch are not dissolved, they are just suspended and spread out in the water. If you let the goo sit for an while, the cornstarch would settle to the bottom of the bowl.

So why does this concoction act the way it does? Most of it has to do with pressure. The size, shape, and makeup of the cornstarch grains causes the cornstarch to “lock-up” and hold its shape when pressure is applied to it. People have filled small pools with oobleck and they are able to walk across the surface of it (as long as they move quickly.) As soon as they stop walking, they begin to sink.

I hope you get to try this out. Let us know how your day with non-newtonian liquids went. Comment here, or, even better, send us pictures to comment@sciencebob.com . Have fun exploring!

-Science Bob

Growing Bacteria For Science Fairs

 Print This Post

Testing for bacteria (germs) can be a great idea for a science fair experiment since there are so many possibilities for science questions, and because carrying out the experiment is pretty easy using widely available bacteria growing kits. Besides, who doesn’t like checking out bacteria and fungus?

All good science experiments start with a question – this is what you want to find out by experimenting. Here are a few example questions to get you started using the scientific method for growing bacteria:

• Is a dogs mouth cleaner than a humans mouth?
• Who has the cleanest mouth in the class?
• Do antibacterial soaps really kill bacteria?
• Which door handle in the school has the most bacteria?
• Does toothpaste kill bacteria in your mouth?
• Do dark socks create more bacteria in a shoe than white socks.
• Do hand sanitizers work to kill bacteria?
• What location in the school contains the most bacteria?
• Is there more bacteria in tap water, bottled spring water, rain water, or pond water?

Step 1 – Ask A Question: Let’s imaging that you want to answer the question, “Which door handle in the school has the most germs?”

Step 2 – Research: You can’t just jump in and start experimenting. It’s important to do a little research. Ask the school nurse which door handle he or she thinks the most germs (bacteria) are. Observe and chart which door handles get the most use, survey friends and family to get opinions and write down the results. All this information will help you narrow down which door handles are the most likely to contain germs – and which ones you should choose to use in your experiment.

Step 3 – Make a Hypothesis: This is when you make a prediction based on your research. This is not an “I think…” prediction, it is a statement that will either be proven true or false based on experimenting. An example would be, “The handle to the nurse’s room contains the most bacteria.”

Step 4 – Experiment: This particular science experiment requires a simple bacteria testing kit. You would choose several door handles that you think might contain the most bacteria. These door handles are considered the Independent Variable in your experiment because each handle is independent and you control which ones are chosen. In a typical kit you would touch a separate cotton swab to each door handle, and then touch it to the bacteria growing Petri dish so that you would have one dish for each handle. Take good notes that would include when you collected each sample and where you collected the sample, and be sure to label everything well in any experiment.

Step 5- Collect Data: In this experiment, bacteria will start to grow in the Petri dish over the next few days, and you may be surprised by just how much gross bacteria is lurking in your school. Take good notes each day and determine which dish has the most bacteria growing in it.

Step 6 – Make Your Conclusion: This is when you decide if your hypothesis is correct. If your hypothesis was, “The handle to the nurse’s room contains the most bacteria,” your experiment will show if your hypothesis was right. It is not bad at all if your hypothesis is incorrect, what is important is that you answered your question from step 1. Now pat yourself on the back for your fine scientific discovery using the Scientific Method.

CLICK HERE for information about Bacteria Growing Kits.

Next Page »