This article will give you some fun ideas of how to explore the sense of smell in science experiments with kids.
While many of us may try to imagine from time to time what it would be like to not have our sense of sight or hearing, we often don't think about how we would function in a world without our sense of smell. Smells tell us a lot about the world such as what foods are safe to eat or if our house is on fire. Smell enhances our enjoyment of food and the world around us.
A large part of the manufacturing industry in the world is based on adding or improving scent. Scents are added to soaps and detergents and many products are sold to eliminate smells from our homes and bodies.
Scent also plays a large role in memory. How many of us have gotten a whiff of one scent and were immediately transported in our minds back to our kindergarten classroom or a day at summer camp?
When we smell something, molecules from the air are brought up into the sinus cavity. At the top of the sinus cavity is a small area called the olfactory epithelium. Many neurons come together at the olfactory epithelium to form the olfactory bulb. The olfactory bulb is able to recognize specific scents. Humans have about 20 million neurons here. Animals that rely on scent for their survival have a more developed olfactory bulb. The acute sense of smell of dogs and other animals help them know if a predator is in the vicinity. Salmon use smell to help them return to the river where they were born. Have you ever seen the movie Jaws? Sharks can smell the blood of injured prey to find their next meal.
The following experiments will demonstrate how important our sense of smell is.
HOW SCENT PROTECTS US FROM UNSAFE FOOD.
This experiment will help you see why smell is important for human survival. Smells help us determine if a food is safe to eat.
Gather four clean jars. Pour a quarter cup of milk in this jar and date it. The next day do the same thing in the second jar. Date that one too. Do this the next day and the next. Leave the jars covered, at room temperature and exposed to some light. On the fourth day get a willing friend to help you. Have your friend close her eyes and give her each of the jars to smell. Have her rank the jars in order of how badly they smell. The old milk will smell bad and she will be repelled by it. The older it is the worse it will smell. This shows how your sense will protect you from consuming foods that can hurt you.
HOW SCENT ENHANCES OUR ENJOYMENT OF FOOD
This experiment will help you how closely linked the senses of smell and taste are.
Peel and cut up a potato and an apple into equal sized cubes. Have a friend pinch his nose and give him one of the cubes. Have him guess which one it is. Now have him do it when her nose isn't closed.
It is difficult to distinguish which food is being eaten. Our sense of smell and taste are closely linked. This experiment proves this.
HOW ACUTE IS YOUR SENSE OF SMELL?
Another interesting experiment involves identifying individual smells. While we may not have as acute a sense of smell as some animals, this experiment will determine which of your friends has a more acute sense of smell and also show you which smells are more identifiable than others.
Gather ten different common household materials with different scents. Some ideas might include coffee grounds, toothpaste, vanilla extract, vinegar, ketchup, peanut butter, tuna fish, an orange slice, and mouthwash. Place these items in individual small containers, cups or spoons. Have your friend sit with his eyes closed and bring the objects to him one by one and hold them by his nose. Have your friend
try to guess what it is he is smelling. Make a chart recording what he smelled and if he was able to identify it. Using the same items, do this with other friends. Which of your friends has the most acute sense of smell? Were some materials more frequently harder to identify than others?
HOW DOES SCENT PLAY A ROLE IN MEMORY?
Certain scents remind us of certain times. Signals sent from the olfactory bulb are also analyzed by a portion of our brains called the limbic system which is where emotions and memories are processed. Here is an experiment that can determine how scent can conjure up memories.
Place several peppermint lifesavers or similar candy in a plastic bag. Lightly crush the candies with a hammer. Ask a friend close her eyes and sniff inside the bag. Do not let her see the bag before allowing her to sniff it. Ask her if the smell reminds her of any particular holiday or time of year. Because peppermint candy canes are often associated with Christmas and December she may find that the scent inside the bag reminds her of this. Have many different people try this experiment. Record what your
friends say the scent reminds them of.
The sense of smell is important because it provides us with a measure of safety from consuming spoiled foods, lets us know if we are in a dangerous situation, it allows us to enjoy our food more fully and can even help us to remember things.
