W. Lincoln Hawkins

19 02 2010
For Black History Month, we would like to recognize an African-American who invented technology still used today.  W. Lincoln Hawkins was a chemist who would help make telephones universally possible with science. Here’s his story.

Hawkins worked as a chemist for AT&T’s Bell Laboratories, part of the telephone company. At the time, telephone cables on telephone poles were made of a plastic that didn’t work very well.  Because of the coating on the wires, the wires wouldn’t last in different weather, like extreme heat or cold.

Telephone cables.

In 1956, Hawkins created a new kind of plastic that wouldn’t be destroyed easily.  The telephone company could now put up telephone lines where they wanted without worrying about animals or weather. Although this technology has advanced since then, this polymer is still used for other kinds of cables.

Like telephone cords made of polymer that W. Lincoln Hawkins created, we can find polymer in many parts of our everyday life. In this experiment from Carnegie Mellon University, you can create a polymer.

Gumdrop Polymer

Supplies:

Package of flavored gelatin powder like Jello (cannot be sugar-free)
Bowl or cup
Small, shallow dish, less than 2 inches wide
Water
Eyedropper
Plastic fork
Paper plate

Instructions:

1. Place the gelatin in the small dish, less than an inch deep.

2. Pour your water into a bowl or cup. Take your eyedropper and extract some water from the bowl or cup.

3. Drop the water in the center of the gelatin.

4. After the first drop is absorbed, drop another one in the same place. Keep doing this for 6-8 more drops.

5. Take your fork and scoop under the drops in the gelatin. Lift the lump out of the gelatin and place it on your plate. You just made a gumdrop, which is a natural polymer! (Remember, as yummy as it looks, this polymer gumdrop is like most parts of experiments and cannot be eaten.)

For more fun with polymers, click here to see how we experiment with polymers at the Museum, or here to see how someone else experiments with them. Information and history on W. Lincoln Hawkins courtesy of the Lemelson-MIT Program.





Everyday Science at C-Day Camp!

16 02 2010

On Monday at the Museum we had a C-Day Camp. We did a bunch of activities like writing secret messages, growing Lima bean plants and creating Shrinky Dink charms.

As part of the day, we made polymer slime. A polymer is made up of long chains of molecules, and in this experiment the polymer is glue.  When Borax is added to the glue it turns it into slime. To find out how to make this slime yourself, click here!

After we made our slime, we discovered how the inside of a diaper works. Seems icky, but it’s scientific! The special polymer inside of a diaper can absorb eight times its weight, allowing nothing to leak. Cool, huh? Check out a C-Day video of it here.

Because we know how well this polymer works, we poured two cups of water into the diaper and trusted it enough to put it over our heads. Then we cut open the diaper and actually felt the polymer.

Before the day ended, we made Shrinky Dinks. Shrinky Dinks are also made of a polymer.  When you put them in heat they shrink and harden as their long strands of molecules are forced closer together.

First we colored the Shrinky Dinks with permanent markers.

Then we heated them up in the oven until they shrank and became hard.

After the Shrinky Dinks cooled, we could put them on to string and make necklaces or bracelets with the charms.

These activities can all be done at home, so be sure and try one!

 





Darwin and DNA

12 02 2010
Today is Charles Darwin’s birthday.  Darwin was born in 1809 and discovered that living things adapt to their environment in a process called natural selection. Natural selection can take a long time, but eventually these plants and animals evolve and keep certain traits so they can survive longer in their environment.

DNA is contained in the cells of every living thing, and it’s the code that makes every living thing unique. When plants and animals evolve, they do so through changes in this special code. It’s amazing that Charles Darwin was able to develop his theory of natural selection without even knowing about DNA and how it works!

In this activity from the New York Hall of Science you can extract the DNA of a strawberry.

Supplies:

1 large glass
1 small glass
measuring spoons
9 tbsp water
1/4 plus 1/8 tsp salt
1 coffee filter
2 tsp dishwashing liquid
rubbing alcohol, at least 70%
1 sealable sandwich baggie
1 wooden coffee stirrer or toothpick
1 strawberry with the top taken off

Instructions:

The extraction buffer.

1. Make an extraction buffer by mixing together the dishwashing liquid,
water and salt in the small glass.

To be able to see the DNA of the
strawberry you have to use an
extraction buffer to break open the cells. The buffer includes soap and salt. The soap breaks apart fat layers of the cell membrane. The salt makes the contents of the cell to come out through  a process called osmosis. The contents inside the cell with a lower salt concentration rush out of the cell to a higher salt concentration.

2. Place your strawberry in your bag and squeeze all the air out of the bag and close it properly.

3. Squash the strawberry in the bag. Then open the bag and add 3 teaspoons of the buffer. Close the bag, squeezing the air out again.  Keep squashing the strawberry and the buffer.

The strawberry and buffer squashed.

4. Strain the mixture into the large glass by using the coffee filter. Wrap the filter closed and gently squeeze the contents against the side of the glass to get the liquid into the glass. Make sure the coffee filter doesn’t rip.  The filter helps separate the cellulose and bigger components of your contents from the DNA in the liquid.

5. Tilt your glass to increase the surface area and  very slowly add the rubbing alcohol. Slowly rock the glass back and forth as you are doing this. Pour until there is a layer 1/2 inch deep on the top of the water.

Pour the alcohol slowly so the DNA can properly be extracted.

6. Let the glass sit for a minute. You should see three layers. One is reddish and contains water with proteins, the middle layer is whitish, and the upper layer is clear (the rubbing alcohol has the lowest density so it goes to the top).

Your mixture should look like this after you pour in the alcohol.

7. Look for the white cobwebs or clumps in your glass resembling mucus, they should be in the middle layer.  This is your strawberry DNA! Take your coffee stirrer or toothpick and stick it into the glass. Twirl the stick until DNA attaches to it.

Strawberry DNA!

For more cool experiments like this, check out the New York Hall of Science’s website here.





Dry Ice Experiment #3: Floating ghost bubbles

22 10 2009

Some ghosts like playing with bubbles just as much as kids do! In this experiment, watch as your normal soap bubbles seem to float midair!

ghost bubbles

What you’ll need:

-Empty fish tank or other clear tub container

-Dry ice, which can be found at Central Market or the HEB on Congress and Oltorf

-Tongs, a thick hand towel, or oven mitts to pick up the dry ice (Warning!: Dry ice is so cold it will burn your bare skin, so make sure you don’t use your hands to pick it up!)

-Bubble mix and bubble wand

What to do:

 Fill your container an inch deep with warm or hot water. Use your tongs, thick hand towel, or oven mitts to drop a few pieces of dry ice in the container. The dry ice will start to sizzle and smoke as it transforms from a carbon dioxide solid into a carbion dioxide gas.

As you patiently wait for the fog to die down, you can blow some experimental bubbles and watch them bounce on top of the fog!

ghostbubbles

When the fog dies down and the container looks mostly empty, blow some bubbles in the container. Watch as the bubbles mysteriously float midair instead of immediately sinking to the bottom…as if a ghost was holding it up! Invent a story about what kind ghost haunts your fish tank!

even more ghost bubbles

So why does this happen?

Even as the smoke dies down, there’s still an invisble layer of carbon dioxide gas. Carbon dioxide is heavier and more dense than air, which means its particles are more condensed (tightly packed together) compared to air’s. The bubbles full of air float on top of the gas because it has a lower density than the carbon dioxide.

Let’s use water as another example. Just like the bubbles on top of the carbon dioxide gas, a beach ball full of air floats on water because the stuff that makes up air is more spread out than the stuff that makes up water—giving it a lower density than water.  An anchor, however, sinks because the stuff that makes up an anchor is more packed together than the stuff that makes up water, giving it a higher density than water.

This is the last experiment in a three-part series featuring dry ice. You can find out more information about dry ice and also check out the first two experiments here and here!





What’s inside the mystery box?

19 10 2009

Be a super science sleuth this Halloween and let’s see if you and your fellow scientist friends can figure out each other’s experiments—without looking! For this game, you brave scientists will put your hand inside some covered boxes and try to guess what’s inside using your sense of touch.

questionmark

Grab a friend, sibling or parent to be your partner. Both of you will secretly gather supplies, such as a bowl of jello or a teddy bear. You can pretend these things are old lab experiments gone wrong or supplies for a new creepy project! Then you will cover each object with a cardboard box. Cut a hole in the box big enough for your partner to stick an arm inside.

Now take turns putting an arm inside each other’s boxes and feel around with your hands and figures. As you feel around, jot down what you feel on a sheet of paper. You can fold a piece of construction paper to make a scientific journal like I did!

scientistjournal_001resized

Is it wet? Is it rough? Is it squishy? Is it round? Using your deductive reasoning skills, can you correctly guess what’s inside?

Scientists have to be very detailed about their observations, so try to be as descriptive as you can. What do the mystery objects remind you of—does it feel like brains inside one box? Maybe eye balls inside another? Draw a picture to go along with each box.

jello

scientist's journal entry

When both of you reveal your mystery objects, see how close your guesses were!

Happy guessing!





Dry Ice Experiment #2: Mix a bubbling potion

15 10 2009

 Using household items and a little bit of dry ice, you can make a bubbling potion!

dry ice soap bubbles

Fill a tall glass or cylinder with warm water. Mix in food coloring to give your potion some color. Next add a little dish soap—the more soap, the more bubbles.

Break off a piece of dry ice with a hammer or chisel. Dry ice can be found in most commercial grocery stores, including the HEB on Oltorf and Congress or Central Market. Remember, dry ice will burn your skin so don’t touch it with your bare hands! Using tongs, a thick hand towel, or an oven mitt, pick up a small chunk or two of dry ice and place it in your container.

Watch as the liquid immediately bubbles up and over!

Usually dry ice dissolves into a smoke-like carbon dioxide gas when placed in warm water, but the soap trapped the carbon dioxide in bubbles.

You can pretend to be a mad scientist or sorceror this Halloween. Make this potion and tell others what it does. Does your potion make people invisible? Does it make a candy tree grow? I think mine makes your skin turn green!

This is the second experiment in a three-part series using dry ice. Click here to see the first one and learn about what makes dry ice different from regular ice!





Make a terrifying T-shirt

13 10 2009

Audrey, the Museum Programs Coordinator, just showed me a cool way to transform a regular T-shirt into a TERRIFYING T-shirt with just Sharpies and rubbing alcohol.

Terrifying T-shirt!

What you need:

-A T-shirt to decorate (colors show up best on light-colored shirts)

-Sharpies of various color

-Rubbing alcohol

-Pipette, eye dropper, or spoon to distribute the rubbing alcohol

-Cardboard that can fit inside your T-shirt

bloody knife wound

Put the cardboard inside the shirt so the colors don’t bleed through the fabric. Then begin drawing designs on your shirt. Use the pipette or other tool to drop small amounts of rubbing alcohol on the desgins. The rubbing alcohol makes the ink spread out in a circle. Sometimes the inks in one color separate, like the yellow coming out of the green ink in the picture below.

tentacle and scar

Once you’re done dripping the alcohol, let the shirt dry for 10-15 minutes before popping it in the dryer so the design sets. You can then add more embellishments on your designs afterward. Audrew made a creepy eyeball, a monster tentacle, and bloody scar out of her designs! 

creepy eyeball

Why does the ink do that?

Permanent marker ink is soluble in rubbing alcohol. Soluble is how you describe a substance if it dissolves in a liquid. For instance, salt dissolves in water so salt is soluble in water. Permanent marker ink, however, is not soluble in water. That’s why if you put water on your T-shirt drawings, the ink wouldn’t spread out like it does with rubbing alcohol.

Experiment with different colors and observe what happens with some colors, but not others. For instance, the color green is made up of yellow and blue. The rubbing alcohol brought out the yellow from the green. Does this work with other colors too?





Dry Ice Experiment #1: Concoct a witch’s brew!

12 10 2009

Double, double, toil and trouble….

With some dry ice and punch, you can make your own smoking witch’s cauldron full of tasty brew.

witch's cauldron

This is the first experiment in a three-part series using dry ice. Dry ice experiments are great for Halloween or anytime you feel like being a mad scientist!

What you need:

-Ingredients for your favorite kind of punch or Kool-aid mix

-Two punch bowls so that one can fit inside the other (try using a Halloween cauldron for the outside container to make it look more like a witch’s brew!)

-Dry ice (Both Central Market stores and the HEB on Congress and Oltorf carry dry ice)

-A hammer or other tool to break the dry ice into smaller chunks

-Tongs, oven mitts, or thick hand towel to touch the dry ice—the chemicals in dry ice can burn your skin so never use your bare hands to handle it!

What to do:

1. Put the smaller bowl in the bigger bowl. Mix your punch in the inner bowl. You can snap some some non-toxic glowsticks and drop them into the punch to make it look more eerie!

2. Break the dry ice into chunks so they fit in the outer bowl and around the inner bowl. Make sure you pick up the pieces using the tongs, oven mitts, or thick hand towel, not your hands!

making the smoke

3. Pour warm water on the dry ice. Continue to pour warm water if the smoke slows down. Hot water will make more smoke come out, but the ice will disappear faster.

4. As your cauldron smokes, serve your magical concoction to people!

ooh, witch's brew

Dry ice is different from regular ice because it is made from frozen carbon dioxide. (Carbon dioxide is the air we breathe out!) When regular ice breaks down, it melts from a solid to a liquid. Dry ice doesn’t turn into a puddle when it breaks down because it goes through sublimation. Sublimation is the process of a  solid changing into a gas. That means the dry ice transformed directly into carbon dioxide gas, creating the smoke effect.





Eggs-perimenting with air pressure

6 10 2009

Air is a lot stronger than you think! With enough air pressure, you can squeeze an egg in a bottle. Whoa!

All you need is a bowl of hot water, a bowl of ice cold water, a hard-boiled egg, and a glass bottle. This experiment works best with a milk bottle or any glass bottle that has a wide neck and an opening a little bit smaller than the tip of the egg. We used a Promised Land milk bottle for this experiment.

Watch the experiment in action:

So how is that possible?

When you put the bottle in the bowl of hot water, the air inside the bottle is heated. Hot air expands, which means the air molecules (tiny particles that make up air) spread out, increasing air pressure.

Next, when you put the bottle in the bowl of cold water, the molecules come closer together because cold air contracts. This causes air pressure to start decreasing. As air pressure decreases, the greater air pressure outside the bottle pushes the egg into the bottle.





Engineering Saturday: Wind-powered Cars!

5 10 2009

Kids combined the sails of a boat to wheels to make wind-powered cars! With the help of UT engineering students, they experimented with different shapes and sizes of sails to see what made their car go the straightest, or the fastest, or the farthest.

decorating the car

A dad helps his daughter give her car some style by decorating with stickers.

cars racing

On your mark, get set, go! Young engineers race their cars in front of the fans.

future engineer

Another young engineer points to some mechanical gears as he tells Steven, a Gallery Educator, he wants to grow up and build lots of stuff.

mother daughter team

A mother and daughter team up to build their car!

Are you interested in making a wind-powered car too? The UT engineering students gave us the instructions on how to make one. Click here to download them! They also included some handy things to consider when building your car.

Did you know if you design a car with a low center of gravity, the car is less likely to tip over? For a low center of gravity, make sure you’re car isn’t too tall and that the heaviest parts of the car are close to the ground.

Test run some different sails to see what will make your car go the fastest and farthest!

Check out the Museum’s Flickr as well for more photos from Engineering Saturday. Also check out the Engineering Saturday page on the Museum web site to see upcoming events.





Amazing Brain, Amazing Scientist

11 09 2009

gouldLiz Gould is one of the many scientists studying the way our brains and minds work. She is a famous scientist who pursued her observations and experiments even though other people doubted her. Her groundbreaking research has inspired other brain researchers, and has even become its own scientific field!

One day, Gould was in her lab counting the neurons (brain cells) in an adult brain. She kept counting more neurons than there should have been. This didn’t make sense because most scientists believed the brain stops making new cells in adulthood. She kept experimenting and continued to get the same result. Too many cells! Through her experiments, she was able to show that the adult brain does grow new cells! This conclusion changed the whole field of brain research.

Liz Gould now works at Princeton University, where she studies the brains of marmosets (small monkeys). Even here she has made changes from the way scientists traditionally work with animals. Instead of keeping the marmosets in cramped cages, they live in a large habitat where they can play and live more naturally. Gould discovered that when animals are kept in cages, their brains don’t grow new cells. But when they live in a natural environment, they do!

marmosetIt’s important to keep an open mind when exploring the world. Asking questions and experimenting can lead to new discoveries that change the way we look at everything. Maybe you’ll find something no one has ever discovered before!

 

 

Neurons are very small and difficult to see. Scientists stain them with color so that they are easier to view under a microscope. Their slides are beautiful little works of art that become research. In this activity you can pretend you are a neuroscientist, preparing neurons for experimentation!

 

You will need some white construction paper, food coloring, white crayon, and a shallow tray (or a spray bottle).

neurons 001

Fill the tray with water and mix in the food coloring of your choice until the water is a uniform color.  You can also mix the water and food coloring in a spray bottle.

neurons 002

Use the white crayon to draw a “neuron” on the paper. The drawing will be very hard to see at this point.

neurons 005

Lay the paper on the surface of the colored water (or spray the paper using the spray bottle) until the white paper turns the color of the water.

neurons 007

The stain will reveal your white crayon drawing. Now you can more easily study the “neurons”!

neurons 009





Invisible Ink

3 08 2009

invisink

Materials:

· Baking Soda

· Paper

· Water

· Light Bulb (for your heat source)

· Paintbrush or cotton swab

· Measuring Cup

· Purple grape juice

Instructions:

Here are two ways to experiment with your baking soda based Invisible Ink:

1) Mix equal parts water and baking soda.

2) Use a cotton swab or paintbrush to draw a picture or write a message on your paper using the baking soda solution.

3) Allow your invisible ink to dry.

4) One way to reveal your message or drawing is to hold your paper near the heat source, the light bulb. The baking soda will react with your heat source and turn brown, revealing your “invisible” drawing. Be careful when holding your paper up to the light bulb. Paper is flammable!

5) The second way to reveal your image is to paint over your invisible drawing with purple grape juice. The baking soda and grape juice with have an acid-based reaction and the invisible message will appear.





Create A Balloon Brain

20 07 2009

Austin Children’s Museum’s Engineer It! campers created Balloon Brains yesterday. Our brains are protected by our very sturdy skulls. The campers’ challenge was to make a hard shell to protect their balloons, just the way our skulls protect our brains!

3729306799_9a61f8b60e3730106610_dcf8e180a03730106836_374af6d436

Materials:

· Water Balloons

· Soft and protective materials (cotton, fabric, egg cartons, bubble wrap, plastic)

· Tape

Instructions:

Cover your balloon with your protective materials. You can use anything you like, but be sure you can still see part of you balloon. Don’t cover it completely.

Next, test your design! Start by tossing your Balloon Brain softly, then add a little more force each time.

Watch our Engineer It! campers test their designs:

This movie requires Adobe Flash for playback.





Budding Paleontologists

16 06 2009

A Paleontologist is a scientist who studies the fossils of animals, plants, and other organisms from prehistoric times.  Do you know how Paleontologists find dinosaur fossils?

dino_blog2 copy

They have to carefully remove the fossils that are buried deep in the ground.  Many times this requires very delicate tools, like a brush. The Paleontologist brushes the dirt away from the fossil, until it is free from the ground. You can create your own archaeological dig at home!

dino_blog copy

Materials:

-Toy dinosaurs or any other “fossil” you would like to use

-Paint Brush

Directions:

1) Bury the artifacts just below some sand or dirt.

2) Carefully brush the dirt away from the artifact, just like a Paleontologist.





Create a Soda Geyser

15 06 2009

Have you ever seen your soda do this?

This movie requires Adobe Flash for playback.

Adding Mentos to a bottle of soda creates quite a reaction! Why does it create a soda explosion? When the Mentos hits the surface of the soda, the compressed carbon dioxide forms bubbles on the surface of the Mentos. It is released into the air and pushes the soda out with it. You can try this at home with the help of an adult.

Materials:

Roll of Mentos (candy mints)

2-liter bottle of soda (diet soda is less sticky when it is time to clean up)

Directions:

This activity is best done in an open outdoor space.

1) Open the bottle of soda and set it on even ground. Be sure it will not tip over.

2) Drop the roll of Mentos into the bottle. The trick is to drop all the mentos in at once. You can roll a piece of paper into a tube. (The paper tube should be just big enough to hold the loose mentos.)

3) Position the paper tube over the bottle, release the Mentos, and step back quickly!

4) Watch your Soda Geyser go!