The Scientific Method in Action

Step 1: Ask a question 

When you drop a hammer and a feather, will they fall to earth at the same time?

Step 2: Gather information

Do an experiment to see what the effect of gravity is when you drop a hammer and a feather at the same time. 

Results: The hammer and piece of paper did not fall to the ground at the same time. 

Step 3: Form a hypothesis

The hammer and piece of paper did not fall to the ground at the same time, but why? Does gravity pull objects to earth faster that have more mass? This was a popular hypothesis in 1589 when Galileo was a professor at the University of Pisa in Italy.  

Step 4: Test the hypothesis.

Galileo tested the popular hypothesis that gravity pulls objects to earth faster that have more mass. He had formulated a different hypothesis: Objects with different masses will fall to earth at the same rate of speed. To test this, he dropped weights with different masses off the top of the leaning tower of Pisa. To everyone’s disbelief, the weights hit the earth at the same time. 

The results of Galielo’s experiment show that in our experiment with the hammer and feather, the hammer does not fall faster than the feather because of its mass.

Step 5: Draw a Conclusion

However, the heavy hammer did fall faster than the lighter feather. So, what conclusion can we draw? The correct conclusion to draw is not one about gravity and weight. It is one about the force of air resistance that is pushing against the feather and slowing it down. If you dropped the hammer and feather (or other objects that are different sizes, shapes, and weights) in a vacuum where there is no air, they would fall at the same rate of speed. This hypothesis was tested when David Scott, an astronaut on Apollo 15, dropped a hammer and a feather on the moon. They dropped at the same rate of speed since the moon’s atmosphere is like a vacuum and has no air resistance. 

Step 6: Share the results

Galileo shared the results of his experiment and helped us understand that objects with different masses will fall to earth at the same rate of speed, and that if objects fall at different rates of speed, it is due to air resistance. Standing on the moon, astronaut David Scott helped us see that the objects that fall at different rates of speed on earth will fall at the same rate of speed in a vacuum where there is no air resistance.