Science is a way of organizing what we already know and learning more by experiments.

Scientists use the scientific method to learn about the world.

• biology is the study of living things
• zoology is the study of animals
• botany is the study of plants
• chemistry is the study of the elements (like carbon) and their compounds (like carbon dioxide)
• biochemistry - if you combine biology and chemistry, you get biochemistry - the chemistry of living things
• geology is the study of rocks and the earth
• astronomy is the study of stars, planets, moons, and everything in space
• meteorology is the study of the weather
• physics is the study of energy - light, sound, heat, electricity, and motion
• anthropology is the study of humans

The different kinds of scientists are named for what they study. Biologists study biology. Zoologists study animals. So there are botanists, chemists, geologists, astronomers, and many more!

Science is all about getting answers to questions -

• Why?
• When?
• Where?
• What?
• Who?

Scientists are curious - they want to know the answers. Then they want to share what they learn.

What kind of scientist do you think you might like to be? Think about what interests you - is it volcanoes? Then maybe you’d like to be a volcanologist, a special kind of geologist. Is it grasshoppers and wasps? Then entomology is for you - that’s the study of insects. There’s more than a whole world of science, since you might even study things far beyond our earth, and be an astronomer.

Science may seem like it’s a strange thing — complicated, even a mystery. But really, science is all about finding out about nature and how things work, the reasons behind every-day things. So it’s more about questions and answers than anything. How? Where? Why?

It’s about making strange, mysterious, and complicated things become things we understand. There’s still lots more that we don’t understand about our world and the whole universe, but that’s where scientists come in. They are always asking questions and then finding the answers. So science isn’t really strange at all! It’s just curious people finding out about everything!

Have you ever heard of an "epidemic", perhaps as in a "flu epidemic", or "polio epidemic"? "Epidemiology" is a branch of medicine that deals with the study of "epidemic" diseases. "Epidemics" usually affect a lot of people at one time or in one place. So "epidemiology" can include studying groups of people who have been exposed to something in the environment (like pesticides, or ozone) to see if they have been affected by this exposure.

The world of science is one of constant experimentation. But what does that word, experimentation, actually mean? Experimentation is the act or process of trying out a new procedure, idea, or activity. The scientists at the National Institute of Environmental Health Sciences do a lot of "experimenting" to determine how things in our environment affect our bodies. Their experiments help us determine what role environmental exposures and/or our unique genetic structures play with regard to human health. Armed with such knowledge, they may be able to discover some way to prevent that from happening.

Key concepts

• Chemistry
• Molecules
• Physics
• Chemical solutions

Introduction

Bubbles can be fun to play with outdoors, but does it seem like they just don't last very long? With a little chemistry on your side you can mix up a solution that lets you make some amazingly huge and durable bubbles—ones that like to linger! Experiment with the shape and size of bubbles as you design your own wands, make a colorful bubble snake and try to grow giant bubbles.

Background

A bubble is a thin film of soapy water filled with air. The soapy film is composed of three layers: one layer of water molecules sandwiched between two layers of soap molecules. Millions of these molecules will stick together to form the spherical shape of a bubble. Now you just need to make this ultrastrong bubble solution and start playing!

Materials

• Water
• Dish soap (Original blue Dawn works best.)
• Glycerin (Pure glycerin is different from soap and can be purchased at many pharmacies in the cosmetics section or where cooking supplies are sold.)
• Sugar
• Container with a lid, such as a plastic food storage container
• One-cup measuring cup
• Measuring spoons (teaspoon and tablespoon)
• Two or more pipe cleaners
• Scissors (optional)
• Cotton string (optional)
• Cotton yarn (optional)
• Two dowel rods or sticks (optional)

Preparation

• This activity is best done outside.

Procedure

• Mix one cup of water with two tablespoons of dish soap, one tablespoon of glycerin and one teaspoon of sugar. What role do you think these different ingredients play in making a strong, long-lasting bubble?
• Stir the mixture thoroughly and store for at least an hour in a covered container. When you're ready to use the solution, gently swirl the container in case the ingredients have separated.
• Now it's time to design your own bubble wand! Be creative! Bend a pipe cleaner into a closed shape so that the two ends meet with at least an inch to spare on each end.
• Use a second (or a second and third twisted together) to serve as a handle; twist the ends of your shaped pipe cleaner to the end of your handle pipe cleaner(s). Now you have your basic bubble wand!
• Dip the wand in the container holding the bubble solution for a few seconds and then lift it out and blow on it. What do the bubbles look like coming off of the wand? How long do they last? Are they more difficult to break than bubbles you blow from a store-bought jar?
• Extra: How big can you go? Experiment by making a giant bubble wand: Use cotton yarn to make two braids, one that measures 18 inches long and another that measures 36 inches. Tape one end of the long braid to the end of one dowel and tape the other end to the other dowel. Tape the shorter braid in the same way to the same ends of the dowels. Both braids should form a loop with the shorter braid at the top and the longer braid at the bottom. Dip the wand into the bubble mix and let the yarn soak in plenty of solution. Lift the wand and slowly move it around to create huge bubbles! How long do your big bubbles last?

Observations and results

Adding glycerin and sugar to the solution helps the bubbles last longer. The water in bubbles evaporates quickly, which makes them more fragile. Adding glycerin and sugar slows evaporation, which makes bubbles last longer.

Did you notice that no matter what your wand looks like, a bubble will always take on the shape of a sphere? The sphere shape minimizes the surface area of the bubble, which makes it the easiest shape to form using the least amount of energy.

Cleanup

After you are finished making bubbles, pour the unused solution down the drain.

Make your own illusion, and then see how many people are fooled by it.

All you need for this is a piece of paper, a black marker, and a ruler.

Look at the second illusion - (Which is longest?) You are going to draw your own version of this.

On the paper, draw two straight lines that are just the same length. Use the ruler to make sure that the lines are the same length. Put them a couple of inches apart.

Now add short lines at the top and bottom of the lines, like the letter V - for the long line on the right, make it look like arrows pointing up and down. For the other line, make the points of the V's start at each end of the long line. Check what you have drawn against the example, to make sure your V's are pointed the right way.

Now take a look at what you have drawn. Even though you know the two long lines are the same length, one line looks shorter than the other. That’s the illusion.

Now for the experiment. Let’s see how many people can see that both lines are the same. When you show it to someone, ask them, “Which line is longer?”

Keep track of how many say -

• the line on the left is longer
• the line on the right is longer
• both lines are the same length

How many boys get it right? How many girls get it right? Are girls better than boys at this? Do more older kids get it right, or are younger kids better at this?

If you show it to both kids and adults, who is better at seeing that it is an illusion?

After people guess which line is longer, you can let them use a ruler to prove to themselves that the lines are the same length.

A good scientist learns about the world by using the scientific method. The scientific
method tests a hypothesis, which is an educated guess based on what information we already have.

All fields of science use the scientific method as a framework to make observations, gather data, and draw conclusions.

Here is a list of the steps of the scientific method:

• Gather information
• Form a hypothesis
• Test with an experiment
• Write down results
• Analyze results
• State conclusions
• Report results

You can use the scientific method yourself!

An optical illusion is something that plays tricks on your vision. Optical illusions teach us how our eyes and brain work together to see. You live in a three-dimensional world, so your brain gets clues about depth, shading, lighting, and position to help you interpret what you see. But when you look at a two-dimensional image, your brain can be fooled because it doesn't get the same clues. Take a look at the optical illusions below. Can you figure them out?

Is the pencil on the right bigger than the pencil on the left? Or are they the same size?

How many fish do you see?

Is this a picture of a vase? Or two faces looking at each other? Do you see both?

Did You Know?

Color blindness doesn't mean that you see in black and white. It means that you have trouble telling the difference between certain colors.

Scientists all over the world use the metric system. There’s a very good reason for this—it’s so everyone is doing the measuring the same way, all over the world. Most other countries already use the metric system for measuring everything.

Another good reason to use metric is that you don’t have so much to remember—no 12 inches in a foot or 5,280 feet in a mile. It’s all decimal! The larger or smaller units go up or down by 10, 100, or 1,000.

Meter is for length. A meter is a little longer than a yard. For long distances, there is the kilometer (a thousand meters). For small things, there is the centimeter (100 centimeters in a meter).

Liter is for volume. A liter is a little larger than a quart. There are a thousand milliliters in a liter.

Gram is for weight. A gram is a little more than the weight of a paper clip. For heavier things, there is the kilogram (a thousand grams).

Temperatures are in degrees Celsius (also called centigrade). Water freezes at 0 degrees Celsius and boils at 100 degrees Celsius. That’s easy!

Have you seen some funny spelling in books or webpages from other countries?

• caesium
• colour
• litre
• oesophagus

It may be wrong here, but right in another country—even though it’s all English!

In America, we spell some words our way. In England, Scotland, and Wales, they spell it the British way. And in countries like Canada, they spell some words the British way and other words more like the American way. Confused? Check out the table below to see some of the differences.