This is the rest of the story. Click here for the beginning
To Dan’s surprise, he not only got to work on time, he actually arrived with a few minutes to spare. For once the rush-hour tangle had worked in his favour. As he was pulling into his parking space the radio was talking about a major crash which had blocked the motorway, but in doing so it had reduced the traffic making it onto the roads Dan had to use.
He used the extra time to grab a bottle of water and a cereal bar from the vending machine, and had barely enough time to eat the bar before he was straight into his first tutorial of the day.
It had been a rush… but he’d made it! No chewing out for being late today. No dirty looks from whoever had covered for him. And no guilt for the rest of the day that he’d let others down. His nose tingled, payback for not taking his medication, but that was a small price to pay.
* * *
The first tutorial was one of his favourites, covering conservation of momentum. While the first half hour was all equations and explanations, it was the second part of the lesson he really loved.
To his class’s surprise he gestured them up and out of their seats, then led them off to the high ceilinged gymnasium where the demonstration had been prepared. It was simple enough. A heavy bowling ball hanging on a seven metre cable, with a raised stage erected on one side.
Dan made certain his class were all in a safe position well back from the experiment, and ensured they understood they must not cross the safety line for any reason.
He slipped on some safety glasses, took hold of the bowling ball, climbed onto the raised area, and let the bowling ball go. It swung heavily down, arced up the far side of the swing until it stopped and reversed its trajectory.
In the meantime Dan had picked up the dummy he’d prepared for this part of the demonstration. It was simply a shirt and trousers stuffed with straw with a melon in place of the head. And as the bowling ball swung back towards the platform, Dan carefully moved the melon head of the dummy into the bowling ball’s path.
He grinned at the shouts of dismay from the students as the dummy’s head was pulped. He made sure to give them all a good look at it as the bowling ball once more swung away, then he dropped the dummy and moved into position to catch the bowling ball as it returned and reached the apex of its second swing back toward him. Once it reached him and he had it safely in his hands he spoke again.
“So, we covered the laws governing the swing of a pendulum earlier,” he said. “Now it’s time for proof of just how accurate they are. Kids, don’t try this at home!”
He stood so he would be directly in line with the swing of the bowling ball, drew it up so it was underneath his nose and pressing lightly against his lips, then let it go.
There were several cries of dismay from the students, but he simply stood there smiling. He’d done this more than enough times before. He didn’t even flinch these days. He watched as the bowling ball completed its swing away from him and started to move back in his direction.
He could hear whispering amongst the students, knew some of them wouldn’t believe he’d leave his head where it was. Even those who’d truly understood and believed the equations they’d seen in class would struggle to accept that they applied in this demonstration. That was what made it so powerful.
Dan just stood there, the bowling ball gaining speed on the downswing toward him. It passed the midpoint, carrying the most speed and energy it would gain, then started to swing up towards his face.
He carefully checked to make sure he hadn’t accidentally moved, ensuring several markers still lined up exactly. If any of them wasn’t precisely matching its counterpart he would have stepped back, knowing he was in danger. But all of them were perfectly aligned.
As it always did, the bowling ball seemed to suddenly be screaming towards his face, a massive amount of momentum ready to pulverise his head, but at the last moment it slowed and stopped, just brushing his nose and his lips. Then it started to drop away, starting its swing again.
The reaction from the class was thunderous. When he glanced at them at least two of his students looked ready to pass out. Most wore huge but nervous grins.
“You see?” he called out. “The pendulum will never swing further up than its starting point. That’s true for the second swing as well!”
He stepped back and forth, shuffled around without any apparent purpose. In fact he was lining up the markers again. As soon as he was happy they were all precisely aligned he held still. Once more the pendulum swung towards him, stopped with the slightest of kisses then arced away again.
“This is why you should all choose to study physics,” he called out. “Biology is messy, unpredictable. Even chemistry can be. But physics… physics is beautiful. Physics is clean. Physics is consistent!”
He watched as the bowling ball once again started to return, swinging down so the rope was pointing straight downwards, the point where the bowling ball carried the maximum amount of energy. Then it continued to swing upwards, towards his face. He checked his marks once more. He was safe.
The bowling ball once again seemed to accelerate up towards his face, but he was relaxed. He knew he was safe.
That was the moment that disaster struck. A wayward grain of dust or pollen sneaked its way up his nose at absolutely the worst possible moment. If he’d taken his allergy medicine that morning he would probably have been fine. But he’d been in too much of a rush.
Biology took over. He sneezed powerfully, which forced his head forward. The only positive was that it also made his eyes close. The sneeze had changed the position of his head. He was no longer lined up with his marks, no longer in a safe position. Before the recoil from the sneeze could shove his head back again the bowling ball struck him with massive force.
That was the end. For Dan, at least. It certainly wasn’t for the traumatised students, nor for the faculty staff who had to undergo dozens of gruelling interviews about safety procedures. And not for the poor bowling ball, which somehow ended up taking much of the blame even though Dan would have pointed out it was simply obeying the pure laws of physics.
No, Dan would have defended the bowling ball to the end. Physics was clean. The problem had been biology. Where physics was pure, biology was messy. And as those who’d had to clean up the gym knew, in this case it had been incredibly messy!