May 2002 AGGMAN Geology

By Bill Langer

Author’s Note: For the past few years this column has taken on issues of concern to the aggregate industry and has described how geology relates to those issues. While most folks who read this column probably have some knowledge of geology, it is a science with a history worth sharing.

One summer’s evening, when my daughter Kimberly was a tyke, she and I raced around the backyard catching fireflies. We put them in a mayonnaise jar with holes in the top. At bedtime, Kimberly took the jar of fireflies with her.
Later that evening, I checked in on my daughter. She was still awake, and excitedly greeted me, “Daddy, I know why fireflies light up! It’s because they are mad.” When I asked why she thought that, she shook the jar and responded, “See. When I shake the jar, they get mad and light up!”
What Kimberly had just done was use the Scientific Method to devise a theory. 1) She made an observation—that fireflies light up when the jar is shaken; 2) She made a tentative hypothesis to explain the observation—that fireflies light up when they get mad; 3) She made a prediction and tested it against the hypothesis—she predicted that the fireflies would light up when she shook the jar and tested the prediction by shaking the jar; and 4) She subjected the theory to review—she described her hypothesis, the experiment and the results to me.
For centuries, people based their beliefs on their interpretations of what they saw going on in the world without testing their observations or conclusions. It took a long while to determine how to effectively investigate the world. One way was to talk about it. For example, the Greek philosopher Aristotle (384-322 BCE) stated that females had fewer teeth than males. He then provided long arguments as to why this is the way things ought to be. Even though Aristotle may have failed to follow the scientific method, he and other Greek philosophers of the time are commonly credited with developing the process of critical thinking, which ultimately evolved into the scientific method.
The application of the scientific method is not reserved for scientists. The method can be applied to many problem-solving situations in the aggregate industry including planning, operational, environmental and reclamation issues. Let’s create an imaginary situation—a quarry blast propelled a piece of rock outside of the intended blast area (flyrock).
1) Make an observation—the flyrock.
2) Make tentative hypotheses—In a cause-and-effect relationship such as this, the effect is the observation (the flyrock).The tentative hypotheses (it is best to propose a number of hypotheses) are possible causes or explanations for the ob-
servation. Your hypotheses reflect your experience with similar situations (educated propositions) as well as the work of others. For this imaginary situation, your hypotheses include engineering issues such as improper drilling, improper explosives, improper burden or improper delay timing and geologic issues such as weaknesses in the rock face, the existence of cavities in the bedrock or a highly irregular bedrock surface.
3) Test the hypotheses—In some situations it may not be practical to test your hypotheses by experimentation. Instead, you can subject your hypotheses to deductive reasoning. Your reasoning might include how the current situation is different from others. For this imaginary situation, you have not had any previous flyrock problems in that quarry. You have been successfully using the same drilling crew, the same blasting crew and the same explosives. Therefore, engineering issues are unlikely, but should not yet be ruled out. The difference is that you started a new level in the quarry. You do know that the area you previously quarried contained fractured but non-cavernous limestones, but prior to the blast you had not seen many exposures of the bedrock at the new quarry level.
As you test your hypotheses, it is acceptable to collect more data. Discussions with the driller revealed that small cavities were encountered during drilling. A site visit to the new blast face confirmed that observation. It was further determined that the amount of explosives used was based on the weight of the truck when entering the operation (before filling the shot holes) and when leaving the operation (after filling the shot holes). Exactly how much explosive went into each hole was not recorded. In this imaginary situation, the most likely hypothesis, which becomes a theory, is that cavities were inadvertently filled with excessive blasting agent, and because the blast holes were filled at a fast rate using a bulk loader, the application of excessive explosives was not noticed. The excess explosives generated too much blast, thus resulting in the flyrock occurrence.
4) Subject the theory to review. In this imaginary situation, the most likely theory, as well as the critical thinking process that helped you create the theory, was discussed with other experienced personnel. They agreed with your theory. Procedures for the subsequent blast were revised, and no flyrock occurred.
Theories cannot be absolutely proven—that is why they are theories rather than facts. And theories evolve and improve over time. For example, I recently asked Kimberly—who is now an educated adult—why fireflies light up. She replied that fireflies light up for many different reasons, especially sexual communication. She said that fireflies have been observed using their luminescence for illumination during landing and walking on the ground, and many species flash when threatened, captured or confined, probably to warn other fireflies or to intimidate predators. And then, as though she could read my mind, she said, “No, fireflies don’t get mad.”

William H. Langer is a geologist with the Mineral Resources Team of the U.S. Geological Survey.

May 2002 Carved in Stone Fireflies, Flyrock and the Scientific Method				Fireflies, Flyrock and the Scientific Method By Bill Langer Author’s Note: For the past few years this column has taken on issues of concern to the aggregate industry and has described how geology relates to those issues. While most folks who read this column probably have some knowledge of geology, it is a science with a history worth sharing. One summer’s evening, when my daughter Kimberly was a tyke, she and I raced around the backyard catching fireflies. We put them in a mayonnaise jar with holes in the top. At bedtime, Kimberly took the jar of fireflies with her. Later that evening, I checked in on my daughter. She was still awake, and excitedly greeted me, “Daddy, I know why fireflies light up! It’s because they are mad.” When I asked why she thought that, she shook the jar and responded, “See. When I shake the jar, they get mad and light up!” What Kimberly had just done was use the Scientific Method to devise a theory. 1) She made an observation—that fireflies light up when the jar is shaken; 2) She made a tentative hypothesis to explain the observation—that fireflies light up when they get mad; 3) She made a prediction and tested it against the hypothesis—she predicted that the fireflies would light up when she shook the jar and tested the prediction by shaking the jar; and 4) She subjected the theory to review—she described her hypothesis, the experiment and the results to me. For centuries, people based their beliefs on their interpretations of what they saw going on in the world without testing their observations or conclusions. It took a long while to determine how to effectively investigate the world. One way was to talk about it. For example, the Greek philosopher Aristotle (384-322 BCE) stated that females had fewer teeth than males. He then provided long arguments as to why this is the way things ought to be. Even though Aristotle may have failed to follow the scientific method, he and other Greek philosophers of the time are commonly credited with developing the process of critical thinking, which ultimately evolved into the scientific method. The application of the scientific method is not reserved for scientists. The method can be applied to many problem-solving situations in the aggregate industry including planning, operational, environmental and reclamation issues. Let’s create an imaginary situation—a quarry blast propelled a piece of rock outside of the intended blast area (flyrock). 1) Make an observation—the flyrock. 2) Make tentative hypotheses—In a cause-and-effect relationship such as this, the effect is the observation (the flyrock).The tentative hypotheses (it is best to propose a number of hypotheses) are possible causes or explanations for the ob- servation. Your hypotheses reflect your experience with similar situations (educated propositions) as well as the work of others. For this imaginary situation, your hypotheses include engineering issues such as improper drilling, improper explosives, improper burden or improper delay timing and geologic issues such as weaknesses in the rock face, the existence of cavities in the bedrock or a highly irregular bedrock surface. 3) Test the hypotheses—In some situations it may not be practical to test your hypotheses by experimentation. Instead, you can subject your hypotheses to deductive reasoning. Your reasoning might include how the current situation is different from others. For this imaginary situation, you have not had any previous flyrock problems in that quarry. You have been successfully using the same drilling crew, the same blasting crew and the same explosives. Therefore, engineering issues are unlikely, but should not yet be ruled out. The difference is that you started a new level in the quarry. You do know that the area you previously quarried contained fractured but non-cavernous limestones, but prior to the blast you had not seen many exposures of the bedrock at the new quarry level. As you test your hypotheses, it is acceptable to collect more data. Discussions with the driller revealed that small cavities were encountered during drilling. A site visit to the new blast face confirmed that observation. It was further determined that the amount of explosives used was based on the weight of the truck when entering the operation (before filling the shot holes) and when leaving the operation (after filling the shot holes). Exactly how much explosive went into each hole was not recorded. In this imaginary situation, the most likely hypothesis, which becomes a theory, is that cavities were inadvertently filled with excessive blasting agent, and because the blast holes were filled at a fast rate using a bulk loader, the application of excessive explosives was not noticed. The excess explosives generated too much blast, thus resulting in the flyrock occurrence. 4) Subject the theory to review. In this imaginary situation, the most likely theory, as well as the critical thinking process that helped you create the theory, was discussed with other experienced personnel. They agreed with your theory. Procedures for the subsequent blast were revised, and no flyrock occurred. Theories cannot be absolutely proven—that is why they are theories rather than facts. And theories evolve and improve over time. For example, I recently asked Kimberly—who is now an educated adult—why fireflies light up. She replied that fireflies light up for many different reasons, especially sexual communication. She said that fireflies have been observed using their luminescence for illumination during landing and walking on the ground, and many species flash when threatened, captured or confined, probably to warn other fireflies or to intimidate predators. And then, as though she could read my mind, she said, “No, fireflies don’t get mad.” William H. Langer is a geologist with the Mineral Resources Team of the U.S. Geological Survey.