Amazing Kids! Magazine

How Science makes Everyday Items Work

By Sean Traynor, Editorial Adviser and Contributing Writer

 

Science happens every day in things you probably don’t even notice: crumbs sticking to saran wrap, hair clinging to a balloon, and soap cleaning your hands.  Just by opening your eyes you can see science in so many everyday items. Let’s explore just a few.

Kitchen Science

Let’s say you have to boil some water for pasta. You notice a few things happening as the water starts to boil.  Steam comes off of the water and you can see water droplets clinging onto the sides of the bowl and onto the top of the lid. This is called condensation. The water (matter) is changing from a liquid to a gas. As the gas cools, it turns back into water.  Try putting an ice cube in the boiling water. You can now see a solid change back into a liquid.

To get a little more complicated, you can make your own lava lamp type liquid by mixing oil and water. Then pour in some glycerin (found in your local pharmacy or convenience store) to see three densities (level of how crowded the material is or mass per unit of volume.) These liquids move to different levels in the glass or bowl because of their densities. You can further explore differences in densities by adding things to the mixture such as a cork, coin, or ice cube and watch where they move to. The denser the material, the lower in the bowl the item will go.

Bathroom Science

Have you ever wondered how a mirror works?  A mirror is nothing more than a sheet of glass attached to a thin layer of metallic backing. Surprisingly, these modern-day mirrors haven’t been around very long. The first mirrors appeared around 600 B.C.  as polished obsidian (naturally occurring volcanic glass.) One thousand years ago mirrors were polished discs of plain metal that were very expensive.  They moved from volcanic glass to better mirrors made of copper, bronze, silver, gold, and lead. Because of this, most people did not own mirrors. They would use a pond or other reflective surfaces to see themselves. Full length mirrors did not come about until about 400 years ago. The modern mirror is made by silvering, or spraying a thin layer of silver or aluminum onto the back of a sheet of glass. The law of reflection says that when a ray of light hits a surface, it bounces in a certain way. Mirrors, however, don’t scatter light in this way. Light reflects on a mirror without disturbing the incoming image. This is called specular reflection. Mirrors switch front and back like a rubber stamp. It may look backward, but it looks the same as if you looked at it from behind. The mirror image is a “print” of you, not a reflection of you. Interesting right?

Have you ever wanted the person reflected in the mirror to have a whiter smile?  How do teeth whiteners work? First, let’s look at what makes our teeth look dull.  Your teeth are made up of an inner dentin layer and a hard outer enamel layer which protects your teeth. When you eat food (chocolate, Cheetos, etc.) or colored drinks such as sodas, a film layer of these substances gradually forms on top of the enamel layer. As this sits on your teeth over years, it gets into the enamel. The enamel is made up of porous hydroxyapatite crystals. Tooth whiteners use bleaching chemicals to get down into the tooth enamel and set off a chemical reaction (oxidation) that breaks apart the staining components. Most tooth whiteners use either carbamide peroxide or hydrogen peroxide. You can get this process done in your dentist office or at home using teeth whitening products found in your local store.

Other Everyday Science Examples

One thing we use every day are zippers. They are in our jeans, coats, sleeping bags, and even in our lunch boxes. Have you ever thought about how zippers work? In less than 100 years zippers have become the main fastener for thousands of items. Modern machines must be used to manufacture zippers because of the accuracy required to make them work properly. Two simple tools are used: the wedge and the hook. A wedge is an object with a slanted surface. When pushed forward, it moves what it is pushed into either to the left or the right. You might recognize this as a door stop. When pushed under the door, it applies an upward force on the bottom of the door. The other tool used is a hook. A hook is a curved piece of material that is used to grab onto another piece of material. A zipper track is made up of dozens of teeth that combine a hook and a hollow. Every hook is latched into a hollow on the opposite side. The latching mechanism, called the slide, is just a collection of wedges that push the hook into the hollow. While the slide pushes the sides to making a connection when it is pulled up, when it is pulled down, the wedge pushes against the slanted edges of the hooks, pivoting each tooth off of the tooth below it. This detaches it from the track.

Many kids need glasses, or corrective lenses, to see clearly. Have you ever wondered why that is necessary and how glasses work? First, let’s explore how the eye itself works. On the back of your eye is a layer of cells called the retina, which reacts to light and sends that information to the brain. The brain translates that information into an image. Since your eye is a sphere, the retina surface is curved. In order for you to see something clearly, the image must be shrunk down in size to fit onto the retina, the scattered light must focus at the surface of the retina and the image must be curved to match the curve of the retina. This is accomplished by a lens between the retina and the pupil and a transparent covering called the cornea. They work together to focus the image onto the retina. Sometimes the eye doesn’t focus right because the surface of the cornea may not be smooth, the lens may not be able to change its curve to properly match the image, the cornea may not be shaped properly causing blurred vision, or other things. Most vision problems are caused because the eye does not focus the image onto the retina. Corrective lenses (or glasses) are prescribed to adjust the focal point onto the retina or to compensate for other problems. Like a prism, lenses cause light to pass through and be bent toward the thickest part of the prism. This spreads the light away from the center of the lens and moves the focal point forward. Placing the correct type and power of lens in front of the eye will adjust the focal point to make up for the eye’s inability to focus the image on the retina.

Don’t take things for granted. There is so much science we can learn by everyday items in our lives. Ask questions and open your mind. You’ll be surprised with what you can notice and apply to other things in your life!