Skip to main content

The Nature of Science – Lesson 3 experiments

In the Nature of Science lessons, we are looking at how the subject of marine science started, and how it works.  In Lesson 1 we looked at the observations made by the ancient sea captains and looked closer at the ocean currents they charted.  Observations are the first step in the scientific process. 

 

Step two would be to explain them.  In Lesson 2 we saw how the early scientists explained observations with mathematics and logic.  All good, but not completely scientific.  The reason… they did not TEST their reasons.  It was just understood that if it were logical, then it was so.  In some cases, they were right (Copernicus and the sun centered solar system) but in others – as well see in this lesson – they were not.  In Lesson 2 we asked you to observe the rising of the moon for 5 nights and notice the difference in time each night.  Did you notice that?  Then we asked that you come up with a logical explanation as to why this is happening.  Not so easy to do that.  It is easy to believe your idea is wrong, but it may not be.  The next step in science would be to test your idea. 

 

In Lesson 3 we are going to make that next step – testing our ideas.  These ideas are called hypotheses – or an educated guess as to why the observation you have made (rising of the moon, the pattern of the ocean currents) is so.  This step would seem to be a “no brainer” but it honestly did not happen right away.  The first to try this concept was an English scientist by the name of William Gilbert.  Gilbert was interested in magnetism and there were published articles on the topic suggesting that placing a magnetic lodestone on your head would cure headaches and rubbing a magnet with garlic would remove its magnetic properties.  You would think that these would be easy to test – but they did not.  Logic suggested it was so, so it was so.  Gilbert easily disproved these by simply doing a series of tests to see – and the test did not hold up.  Gilbert published many of his experiments, as they would be called, in a book entitled De Magnete

Galileo
Image: Ohio State University

There was a young Italian by the name Galileo Galilei who read this book and fell in love with the idea of experimental testing.  Galileo was interested in many things, including Copernicus’ idea of a sun centered solar system, and he designed experiments to test many hypotheses.  His designs were pretty simple.  He looked at hypotheses and set up what he called an HONEST test.  There were certainly people who wanted their results to come out they way logic had said they would, so they would be wrong – and this could be done.  But it was very important to “not cheat”.  It is important today! 

 

The second part was to repeat these experiments – over and over – to see if the results came out the same each time.  This is good science.  It was important that each repeated experiment was as HONEST as the first. 

 

The third part was to publish the design so that others could also do the experiments – the HONEST way – and see if their results matched his.  The concept of peer review was born. 

Modern science involves well designed, honest, tests that are repeated many times.
Photo: Washington High School Marine Science Academy

Galileo conducted many experiments over his life.  One of his more famous ones looked at the logic statement that a larger rock would hit the earth faster than a smaller one.  Makes sense, larger rocks are heavier.  But was it true?  Again, you would have thought they would have tested this from the first time it was mentioned, but Galileo wanted to put it to the test.  He was then teaching at the University of Pisa in Italy and decided to drop two rocks, a large and small one, from the top of the Leaning Tower.  In reality it was not Galileo, but another professor who believed the logic state was true, who beat him to it.  This professor climbed the tower and… you guessed it… dropped the two rocks.  What do you think happened?  Yep… they hit at the same time.  Frustrated probably, the professor repeated the experiment several times and each time the large and small rocks hit at the same time – Galileo was right – a logical explanation was shown to be wrong – and the science method was born. 

 

ACTIVITY

 

There are a couple of activities we can do with this lesson. 

 

#1 – We can repeat Galileo’s experiment with the rocks, if you have a second-floor balcony where you can drop two rocks to the ground without breaking flowerpots or cracking a sidewalk.  If you have such a set up, and mom and dad are cool with it, give it a whorl.  We already know what will happen but learning the process is still fun.  Repeat it several times.  Maybe you have something besides a rock you want to try.  The key here is that MUST be the same thing.  Here is a fun one that astronaut Alan Shepard tried while standing on the moon.  He dropped a hammer and feather from the same distance (shoulder height) to see which would hit first.  Which do you think it would have been?  Do you think the results would have been the same as Galileo’s rock experiment?  This one you can do because he did it standing on the ground – not from the second floor of your house.  Try this one in your yard. 

 

#2 – This activity is designed to understand the importance of repeating an experiment.  Let’s go with the logic that the number of blue M&Ms in a bag of M&Ms is low.  We would expect this.  Blue is not a popular color with this candy.  Let’s say that the number of blue M&Ms will always be less than 5% of the candies in the bag. 

There… a logical statement.  Since it is logical, then it is true right?

Let’s test it…

Purchase several bags of M&Ms one for each person involved in the experiment.  Since we are dealing with COVID – facetime each other and see what everyone gets. 

Open yours and count how many total candies in the bag.  Now count how many are blue.  Determine the percentage – (# of blue candies / # of candies) x 100.  What did you get?  What did you get the second time?  What did your friends get?  Can you now make a statement as to whether blues ALWAYS make up less than 5% of the candies in the bag?  Do you think doing more samples would lead you closer to the truth? 

Now eat them 😊    

 

#3 – Here’s one for the younger kids

Place a cup of water on the counter, another in the refrigerator, and a third in the freezer.  What do THEY think will happen?  Leave over night and see what happens. 

Now try it with coke – do you think the same thing will happen? 

Do an EXPERIMENT and let’s see 😊