Physics 101 by James Rumpel

Dr. Wesley Randolph looked up from his notes and surveyed the lecture hall. He was used to seeing a large number of empty seats at his Physics 101 lectures but today’s attendance was especially sparse. He examined the faces of the few students who had decided that coming to class was a worthy endeavor. A few showed the normal expressions of boredom and confusion. The rest of the class, however, displayed an emotion that Dr. Randolph rarely saw during a class period that did not include a major exam. Those students were afraid.

“I’d like to commend you all for ignoring the perceived threat and coming to class today,” he announced.

“I have to pass this class,” yelled someone from the back row. That announcement was met with a few nervous chuckles.

The professor sighed and flipped over his sheet of notes. “I am going to forgo my scheduled lecture on circular and rotational motion and spend some time talking about the elephant in the room.” He was not surprised to see a couple of the students look around for said pachyderm, though given the situation the action was somewhat understandable.

“I want to assure all of you that you are in no danger,” he continued. “I have conferred with the authorities and the university administration and convinced them that there is nothing to fear. They totally accepted my explanation of why we are all safe. If there were any actual threat, we would not be holding classes.

“Yes, there indeed was a . . . unique radiation spill near the university. It is also true that the radiation has contaminated five acres of undeveloped marshland and that it has the effect of causing infected creatures to grow to approximately one hundred times their original size.”

“I would say that’s something to be afraid of,” said a coed sitting in the front row. “Giant animals roaming the campus sounds pretty dangerous to me.”

“But that’s just it,” answered Randolph. “There won’t be any giant animals wandering around. It’s physically impossible for them to do so.”

“What do you mean?” asked a young man wearing a backward baseball cap.

Randolph moved to the whiteboard. “Mathematics . . . physics says it’s impossible for giant creatures to function. It’s really quite simple. Suppose there was a normal-sized dog exposed to the radiation. Let’s say it was two feet tall and weighed fifty pounds.” He wrote those numbers and continued to jot down others as he spoke. “The radiation would cause it to grow to a height of two hundred feet; one hundred times normal. The dog would also become one hundred times wider and one hundred times longer. All three of those dimensions are critical to determining the weight of the enlarged dog. Therefore, its weight would not be multiplied by a hundred but by one hundred to the third power. That’s one million times the original. The giant dog would weigh fifty million pounds.”

“Oh, so not only is it a giant dog it’s super heavy,” said a young man. “Doesn’t that make it even more dangerous?”

“Not at all,” answered Randolph. “You see, the dog’s ability to support its weight is directly related to the thickness of the bones in its legs. If we looked at a cross-section of one of leg, that area is what determines how much weight it can bear.” The professor drew a small circle on the board before continuing. He pointed to the length and width of the circle. “Area is a two-dimensional measure. That means the dog’s leg bones would only be one hundred to the second power or ten thousand times stronger than before.”

A few of the students nodded their heads. They seemed to understand what the professor was getting at. The fellow in the ballcap was not one of them.

“I don’t get it. What are you saying?”

Randolph took a deep breath before continuing. He pointed to numbers on the board. “If the dog weighs a million times what it originally weighed but its legs are only ten thousand times as strong there is no way they could support the additional weight. Any giant dogs or cats or squirrels created by the radiation would be unable to move. Dare I say, the poor creatures would be crippled by their own weight.”

“Oh,” said the coed, a huge smile on her face. “So, any giant animals created by the radiation would be harmless.”

“Or, at the very least,” added Randolph, “confined to their original location and unable to cause any damage on campus. As I said, we are all perfectly safe.”

“What about elephants and dinosaurs?” called a voice from the back of the room. “They’re huge and they can still walk around.”

Professor Randolph gave his famous scoff and eye-roll. “But those creatures had millions of years of evolution to develop the leg strength necessary for their weight; the animals in the meadow don’t.”

He waited to see if there were any other questions and then glanced at the large clock on the wall behind the students. “You know, we still have time to discuss the first section of chapter five.” He ignored the sound of desks shifting while he searched through his lecture notes. When he looked back up the classroom was almost empty. Two students remained at their desks; laptops open. The rest of the class had either already left or were quickly making their way toward the door.

“Ok, I get it,” shouted Randolph. “We’ll pick up chapter five tomorrow. Read and take notes on that chapter.”

After the students had all left, Dr. Wesley Randolph went to erase the whiteboard. He looked at the numbers he had written down and smirked. “At least they got to see a useful application of physics,” he thought. He packed his bag and headed out the back door to the faculty parking lot.

He was quite surprised when he found himself grabbed by a three-hundred-foot-long garter snake.

—

James Rumpel is a retired high school math teacher who has greatly enjoyed using his newfound additional free time to rekindle his love for science fiction and the written word.