Scientific Method
"Scientific Method of Madness"
This rap songs teaches all the steps of the scientific method, in addition to some history of the method. We cover Galileo Galilei and his cannonball experiment, and you’ll witness Galileo pay the price for questioning the Church. We hypothesize that you’ll be an expert on the scientific method by the end of this song. Now, we just need to prove it and report our results.
Intro
"This is Galileo Galilei, a.k.a. Double-G. Mama mia!"
Live from the Tower of Pisa,
Grab a piece of pizza, the 17th century feature
Is Galileo Galilei, a scientist
Who questioned everything the church had to say.
Like, "Well, how’s about gravity,
Do you think a heavy object will fall rapidly?"
Naturally, Galileo wanted proof,
He used experiments to obtain the truth.
"So if I drop these cannonballs at the same time,
They’ll fall at the same time. Arrivederci!"
And now he’s holding two cannonballs,
Dropped from the top, and both of them should plan to fall
At the same moment, though one was heavier.
BOOM! Proof gravity’s constant;
Get ready for a revolution, but the Church wouldn’t listen,
And later he was locked up by the Inquisition.
That’s what could happen when you make a commitment,
The scientific method to the madness, what is it?
The scientific method
Starts out when you ask a question.
The hypothesis is the second step,
Then you test it.
That’s what an experiment is, of course.
Analyzing the results is the fourth.
Have we reached a conclusion?
Do we need more support?
That’s the fifth step, yep,
We’ve been waiting.
The sixth step: take our results,
Communicate them.
But shall we dig further?
Ask good questions to be a good observer.
In this case, it was weight: does it influence
The rate that an object falls? Well, we can prove it ("How?"),
By forming a hypothesis,
An educated guess, or what our thought process is.
If gravity is constant,
Then everything will fall at the same rate — Accomplished.
A controlled experiment was conducted,
With only one factor that we adjusted — Bust it.
It was the weight of the cannonball,
That was the variable that we can control.
Another type is a double-blind test,
Even the researchers don’t know which is which.
A control group of people is given a placebo,
And that’s a fake pill they take to see what we know.
Flocab Spits Facts:
Cola Experiment
A Hammer and a Feather
Science Speaks
Check out the complete Scientific Method lesson plan.
Galileo Galilei lived in the Italian city of Pisa in the early 17th century. He is best remembered for his observations with the newly invented telescope. In 1610 he discovered the moons of Jupiter; he shared the ideas of another scientist named Copernicus, who taught that the Earth was in orbit around the sun. In those days people believed that the Earth was the center of the universe, but when he saw moons circling the planet Jupiter, Galileo knew that Copernicus was right. The only problem was that the Catholic Church disagreed. Galileo would later be arrested and imprisoned by the Inquisition for his teachings.
Galileo was a keen observer of everything around him. He was also one of the first scientists to use experiments to test a hypothesis. One of his most famous experiments challenged a common belief about gravity.
People believed that the heavier an object is, the faster it fell to Earth. This made perfect sense to everyone except Galileo. So after many observations of falling and rolling objects, he began to ask questions: Does the weight of an object really influence how fast it falls? What if you tie two objects together - will the heavier one pull the other down faster? Or will the lighter object slow down the heavier one?
Everyone told Galileo that these were foolish questions, of course heavier objects fell faster. But Galileo didn't believe that popular opinion was proof. He wanted experimental proof. He took his questions and wrote a hypothesis that he could test: If gravity is a constant force, any two objects of similar size will fall at the same rate, regardless of their respective weights.
To prove his hypothesis, Galileo came up with an ingenious experiment. The city of Pisa was famous, and still is, for one very special, crooked building - the Leaning Tower of Pisa. Galileo proposed to drop a pair of cannonballs from the top of the tower. One ball was twice as heavy as the other. If his hypothesis was correct, both cannonballs would hit the ground at the same time. If weight did influence the speed of falling objects, the heavier one would hit first.
When he dropped the two cannonballs, they always hit the ground together. It didn't matter if he had two heavy cannonballs, two light ones, or one of each. Considering the results of his experiment, Galileo concluded that gravity is a constant: Weight does not change the speed at which objects fall.
People were surprised when they read what Galileo had proven. Some people, like those behind the oppressive Inquisition, felt threatened by his findings, and especially by his support of Copernicus's idea that the Earth revolved around the sun, so they arrested him. But Galileo certainly left his mark. In the future, scientists would frequently use experiments such as he had designed to prove or disprove their ideas. We call this method the scientific method.
The scientific method is a way of thinking and solving problems. It's a series of steps that scientists use to answer questions or investigate problems. Most importantly, it demands evidence before an answer is accepted. There are generally six steps that are followed in the scientific method. Sometimes steps must be repeated; sometimes there are no good answers. Sometimes proving you were wrong is just as important as proving you were right. The six steps are creating a question, a hypothesis, a test, an analysis, a conclusion, and communicating the results.
Asking a question comes first. This question is usually based on something we observe but can't easily explain.
Forming a hypothesis is the second step. A hypothesis is a possible explanation for what we have observed. We may look at what other scientists have found or suggested in forming this hypothesis.
Testing the hypothesis follows. We do this by conducting controlled experiments.
Analyzing the results is the fourth step. Here, we think carefully about the results collected from our tests.
Drawing conclusions is the fifth step. Do the results we collected support our hypothesis or not? Is the hypothesis valid or not? Do we need to do more testing?
Finally, the results are communicated. We tell others what we've learned so that they can repeat our test and check our work.
Asking good questions is at the center of the scientific method, and good questions are based on being a good observer. Galileo was a good observer because he noticed what others did not.
A hypothesis, again, is an educated guess. It's written in way that allows us to test whether it is true or not, a form called if-then. In Galileo's experiment, his hypothesis said that if gravity is a constant force, then two cannonballs of different weights will still fall at the same rate.
Scientists test a hypothesis by conducting a controlled experiment. In a controlled experiment, the scientist studies just one single factor. He or she tests this one factor by using what is called a control. In a control, a pair of tests is carried out, and only one factor is changed between them. This factor, which we control, is called the variable. The only thing different between the two tests is the variable. In Galileo's case, the two cannonballs were the same. The only variable factor was the weight.
Scientists have found that it's always best to have a control group. Why? Let's say you are measuring whether drinking soda makes people smarter. You get a bunch of kids who don't drink soda, and give them a test. Then you have them drink lots of soda for a few weeks and have them take a similar test. You notice that their scores have gone up. Wow, did you just prove that soda makes you smarter? Not exactly. It could be that those kids had been studying on their own, or learning stuff in school that helped them on the test. A better experiment has a control group. In this case, it would be a second group of kids from the same place whom you test but who don't drink the soda. If their scores don't go up, then you've just figured out that soda is the real cause.
An even better type of experiment is known as a double-blind test. In this case, neither the scientists nor the subjects know if they are in the control group or not. Let's say scientists are testing a new medicine. First they find a hundred people who suffer from a certain illness. Each is told that they are receiving a new drug. They are all given identical pills to take once a day for a set number of days. Half of the subjects receive the real medicine, while the other half receives a fake pill called a placebo. A placebo is like a sugar pill: There is no medicine in it at all. The test is double-blind because neither group knows if they received the real medicine or the placebo. The group that was given the placebo is the control group.
Scientists analyze results when they are done to see if a test proved or disproved their hypothesis. If the cure rate is the same in both groups, then the medicine obviously didn't work. If only those who took the real medicine improved, then their hypothesis has been proven. In Galileo's case, he compared the results for cannonballs of different weights and those of similar weights. In this way, he had a control to his experiment as well. In drawing conclusions, scientists can only decide if the experiment proved or disproved their hypothesis. If their conclusions are valid, other scientists should be able to replicate or repeat their tests and receive the same conclusions. Scientists publish their conclusions and describe their tests so that other scientists may repeat their tests. Until others have repeated a test and received the same or similar results, we do not accept a scientist's conclusions as definite. If many tests have reached similar conclusions, scientists will begin to accept a hypothesis as a proven theory.
Try a taste test experiment with your classmates.
Question: Is there really a difference between name-brand cola drinks (like Coke and Pepsi) and less expensive store brands?
Hypothesis: If people can tell the difference between a name-brand cola and a store-brand cola, then they should be able to identify each in unlabeled taste tests. Experiment: Pour the soda into different cups without letting the subject see which soda is in each cup. Have the subject drink the soda, rate it on a scale of 1 to 10, and guess which cola it is. Repeat this with many different people. Then write up and analyze your results.
Question: Is there really a difference between name-brand cola drinks (like Coke and Pepsi) and less expensive store brands?
Hypothesis: If people can tell the difference between a name-brand cola and a store-brand cola, then they should be able to identify each in unlabeled taste tests. Experiment: Pour the soda into different cups without letting the subject see which soda is in each cup. Have the subject drink the soda, rate it on a scale of 1 to 10, and guess which cola it is. Repeat this with many different people. Then write up and analyze your results.
According to Galileo, if it weren't for air pushing on it, a feather would fall as fast as a hammer. Well, the astronauts on Apollo 15 got a chance to put Galileo's theory to the test in 1971. They brought a hammer and a falcon feather to the moon. One astronaut held both objects and then dropped them at the same time. Just as Galileo had predicted, they fell at the same speed and hit the moon at the same time. You can view clips of this experiment online.
"You cannot teach a man anything; you can only help him discover it in himself."
- Galileo Galilei
"They laughed at Galileo. They laughed at Newton. But they also laughed at Bozo the Clown."
- Carl Sagan
- Galileo Galilei
"They laughed at Galileo. They laughed at Newton. But they also laughed at Bozo the Clown."
- Carl Sagan
Click here for the complete lesson plan.
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