Invention Facts

Inventions: The Scientific Method [in-'ven(t)-shən-z-thē-sī-ən-'ti-fik-me-thəd]

Ideas or things created using the scientific method.

Scientists use a method or process for testing ideas and theories. Inventors use the scientific method to figure out how to make their inventions work.

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Take a moment and look around. Do you see any inventions? Inventions are everywhere you look! Your computer, your clothes, your notebook, your furniture - inventions are all around you. An object may have been invented a long time ago, or it may be an improvement based on other inventions, but every manmade object you see was originally an invention of some kind.

How do inventions come about? It all starts with the Scientific Method.

The Scientific Method

Science is all about being curious and asking questions. The scientific method always begins by observing and wondering why and how. If you have ever seen something going on and wondered why or how it happened, you have started down the road to discovery. Why do leaves on trees turn colors and fall to the ground when winter comes? How does a spider move around its web without getting stuck like its victims? Why is my dog barking at night? When you see something and ask yourself, "I wonder why that is happening?" or "How could I fix that?" you've taken the first step in the scientific method.

When you think about a question, maybe you will guess at some possible answers, and think of ways to find out if your ideas are correct. Just by wondering, guessing, and trying something out, you are acting as a scientist and using what scientists call the scientific method.

Suppose you come into your room and notice the lamp isn't working. You might ask yourself: Why won't the light turn on? Could the electric power have gone out? Could the light bulb be burned out? Could there be something wrong with the cord or the wall outlet? Maybe you predict that the power is out, so you first check to see if other lights in the house are working. If they all turn on, you decide that's not the answer. Then maybe you decide to change the light bulb and see what happens. You're using the scientific method!

No matter what the question, you can use the scientific method to guide you toward an answer. The scientific method is simply a problem-solving method, an organized way of investigating questions, making observations, coming up with a possible idea (or hypothesis), testing out your idea, and looking at the results to decide if you have answered the question. When you approach a problem that way, you're thinking like a scientist.

Let's look at each step of the scientific method:

  • The Question. What do you hope to find out or discover? What problem do you want to solve? Your question needs to be something you can observe or measure and usually starts with words such as what, when, where, how, or why.
  • Do research. Use what you already know, make observations, and learn from other people, books, or the internet. Gather information and find out as much as you can about your subject.
  • Make a hypothesis. A hypothesis is an "educated" guess, your prediction of a possible answer to your question. What do you think is going to happen?
  • Experiment. Test your hypothesis in a step-by-step procedure and see what happens. Test only one variable at a time while keeping other conditions the same. For example, if you are testing whether listening to music helps you with your homework, do the same kind of homework in the same place and at the same time, while you experiment with music. Repeat your experiment several times to make sure your results are consistent.
  • Collect and analyze data. Write down what happened during your experiment in a notebook with measurements and descriptions. Look carefully at your data and see what kinds of patterns you find.
  • Conclusion. Explain the meaning of your results. Do the results of your experiments support your hypothesis or disprove it? Can you answer your beginning question?

Any time that you ask a question, propose an answer, do some experiments to see if your answer is correct, and write down what you learn, you have done just what a scientist might do in a laboratory or out in the field when doing research. Learn more about the scientific method.

It's important to realize that the scientific method doesn't always go in a straight line of six steps. You might need to repeat several of the steps before finding an answer. Often, you'll need to do more than one or two experiments. If your hypothesis turns out to be wrong, you'll want to go back to the earlier steps, do some more research, and come up with a different hypothesis. If you weren't able to collect enough data, you may need to make changes to the experiment procedure. Many times, the scientific method involves backing up and repeating steps.

Remember: A final step in the scientific method is to report what you've learned! Share your findings with your teachers, friends, and family. That way, everyone can learn from your investigation.

The Scientific Method in Action

Suppose you observe that the raspberries in your garden are not growing very well this year. You wonder: why are the raspberries so small? After talking to other gardeners, you make a hypothesis that the plants aren't getting enough water. You make sure that all the plants are getting the same amount of sunlight, but you increase the water for half of the raspberry plants. Every day you measure the size of the berries in both groups. At the end of your experiment, you find that the berries on the plants that got the most water are bigger. Your hypothesis is supported; your raspberries were not growing well because they needed more water. That's the scientific method in action!

In a famous example, scientist Alexander Fleming was studying a kind of bacteria that makes people sick. He was growing the bacteria in lab dishes. He observed that mold was also growing in one of the dishes. In that dish, there was a clear area around the mold where no bacteria was growing. He made a hypothesis that something in the mold had killed the bacteria. To test it, he grew the mold separately and then added the mold to a collection of harmful bacteria. The bacteria died. He repeated his experiment many times and got the same results. It turned out that this mold was penicillin, and these experiments led to the development of antibiotic medicines, which have saved millions of lives.

Inventors and the Design Process

The scientific method is used every day by scientists, ordinary people, and even kids to solve problems and figure out answers. It is also the foundation of all new inventions!

An invention is something new that a person creates that hasn't been made before. (An innovation refers to an existing product or process that adds value and usefulness.) An invention usually solves a problem, meets a need, or improves how something is done, and makes life easier or better in some way. Inventions can be things (like a cell phone) or processes (like a new way of producing energy.) The key to inventing is identifying a need and devising an original solution.

Imagine how different our lives would be without inventions such as computers, refrigerators, electricity, cars, cameras, and medicine. The very first human inventions, such as stone tools and wooden spears, were made from nearby materials and were intended to help people survive. In modern times, inventors use all kinds of materials and aim to make people's lives easier or more efficient.

Inventing doesn't usually happen as one great moment when an idea strikes and a product changes the world. More often, invention is a process that takes a lot of time, study, experimentation, and even some failures before an invention is successful. The Design Process is similar to the steps of the Scientific Method:

  • Identify a problem or need (Think It)
  • Research and Brainstorm (Explore It)
  • Design the invention (Sketch It)
  • Build a prototype (Create It)
  • Test the invention (Try It)
  • Refine the invention (Tweak It)
  • Communicate (Share It)

Let's take a look at some famous inventors who followed this process. 

Before the electric light bulb, people had to use candles or smoky oil lamps if they wanted to have light indoors or after dark. Thomas Edison was determined to find a way to make long-lasting electrical light a practical reality. Electric lights did exist, but they were unreliable and usually burned out in less than a minute.  In his lab, Edison and his team worked to perfect an incandescent light bulb containing a filament that would glow when heated by electricity. He tested over 6,000 different materials for the filament.  Yet he said, "I have not failed.  I've just found thousands of ways that won't work." In 2879, after years of trying, he invented a light bulb that could burn for hundreds of hours.  His invention improved the lives of people all over the world. 

Wilbur and Orville Wright were brothers who invented the first airplane. For many years before, the Wright brothers had worked with kites and gliders. They studied and read as much as much as they could about science and technology. They experimented with different wing designs, pilot controls, and propellers. When their designs failed, they went "back to the drawing board" and tried again. Most of all, they didn't give up, even when people said flight was impossible. In 1903, they made the first human flight in an aircraft that was powered by an engine and was heavier than air. That first flight only lasted 12 seconds and traveled 120 feet, but their invention eventually changed the course of modern life.

Stephanie Kwolek is the inventor of Kevlar, a material that is five times stronger than steel. In 1965, she was working as a lab chemist when she discovered a substance that was lightweight, heat-resistant, stiff, and strong. She said, "All sorts of things can happen when you're open to new ideas." It took six years of experimenting and modifying the material until it became a usable product. Today, Kevlar is used in bulletproof vests, boats, gloves, camping equipment, ropes, tires, helmets, coats, airplanes, bridges, skis, and bicycles. Kwolek's invention has saved the lives of thousands of soldiers, police officers, and firefighters.

Inventors have many different interests, but they all have a few things in common. They are curious about the world. They like to learn and explore and use their imaginations. They recognize possibilities that others may not see. And they have perseverance, which means they keep trying and don't give up when things get hard. They recognize that it takes time and work to go from idea to prototype to finished product. Learn more about famous inventors.

Accidental Inventions

Not all inventions change the course of history. Some can be practical, like the telephone, and some just make life more fun, like bubble gum. While most inventions target a specific problem and involve lots of research and many prototypes, sometimes inventions actually come about by accident or mistake, or when the inventor was investigating something else.

A man invented the microwave oven only after accidentally melting a candy bar while tinkering with vacuum tubes. The first wooden matchstick was created by accident when a chemist was trying to clean a mixture off the end of a stirring stick. When he scraped the stick on the ground to clean it, suddenly the stick burst into flames. During World War II, an engineer working on a naval ship invented the Slinky when a coiled spring accidentally fell off a shelf and continued moving. The ice cream cone was invented when an ice cream booth at a fair ran out of dishes, and a nearby waffle seller rolled up a waffle to hold his neighbor's ice cream. Other well-known foods such as chocolate chip cookies, cornflakes, and potato chips were also accidentally invented by cooks who were making something else. What they thought were failures or mistakes turned out to be popular with their customers. As Thomas Edison said, "Just because something doesn't do what you planned it to do, doesn't mean it's useless!"

Learn more about accidents that led to successful inventions.

Young Inventors

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Did you know that even kids can be inventors? Children and teens have invented things that people buy and use today. A 15-year-old invented earmuffs. An 11-year-old invented Popsicles. The trampoline was first invented by a 16-year-old. A 12-year-old invented plastic crayon holders that you can buy in local stores. A 10-year-old invented a glow-in-the-dark writing pad now used by medical and military workers. Learn more about successful kids' inventions.

More often, kids invent things for use in their own homes and families. One boy saw a problem: his cat kept trying to escape out the front door. He invented a motion-activated device that blew a burst of air near the floor whenever the cat approached the doorway. It worked! The cat stayed away from the door. Another girl, whose mom often biked to work in the rain, invented a backpack umbrella for her to use. A boy who often stumbled in the dark when he got up at night invented portable motion-sensor lights for the slippers he kept by his bed. One young inventor came up with a windshield ice-scraper that can be operated from inside a car. His dad appreciated that on cold winter mornings! Another ten-year-old whose grandfather's illness made him drop and spill things invented a no-spill cup that was easier for him to hold. Learn more about kids' ideas and their contest-winning inventions.

Future Inventors

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People from every corner of the world, of different ages and from different backgrounds, become inventors by identifying problems, pursuing ideas, and developing new solutions. Perhaps you'll be an inventor too! You might just come up with a solution to some of the problems around us today. Maybe you will find ways to make solar or wind energy more efficient, build more energy-efficient houses, or make healthy food available to more people. Maybe you'll invent a useful computer program, a device to help sick people, a new kind of space probe, or something that helps scientists save endangered animals.

You can start right now to become an inventor. Creative thinking and problem-solving drive the inventive spirit. Play, explore, and use your imagination. Be curious. Notice problems that need solutions. Take old machines apart, if your parents say it's okay. Learn from your mistakes. Check out the Science Trek Simple Experiments page and try some investigations. Read about science and engineering.

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With imagination, knowledge, and perseverance, anyone can be an inventor!