The Clip Beneath the Paper
Chapter 1A Moving Dot
Rebbi supervised a magnet demonstration at the classroom table.
Yanky and Meir could use the large classroom magnet only as Rebbi directed. Small metal pieces stayed in the teacher's tray except during the checked demonstration.
Rebbi placed a paper clip beneath a thin sheet of paper. The sheet had a black dot above it.
He moved the magnet over the paper without touching the dot.
The paper bumped upward slightly.
"The ink is being pulled," Yanky said.
Chapter 2A Certain Explanation
Yanky had seen the bump right below the dot. His explanation seemed obvious.
Meir asked whether the clip underneath could be causing it.
"But look where it moved," Yanky said.
Rebbi lifted the paper. The clip was beneath the marked spot.
"You have two things at the same place," he said. "How could we check which one matters?"
Yanky looked at the black dot, then the clip.
He had not tested either by itself.
Chapter 3Just the Mark
Rebbi put the clip back in his tray.
With the teacher guiding the magnet, Yanky tried over the paper again.
The dot did not rise toward it.
He tried the same movement a second time as directed. Nothing happened.
"The mark alone doesn't do what I said," he admitted.
Meir did not laugh at him.
"Try the clip without the mark."
Rebbi supplied a plain paper sheet and placed the clip beneath it himself.
Chapter 4An Unmarked Bump
The magnet moved above the plain sheet.
A small bump followed it even though no dot had been drawn there.
Rebbi carefully showed how the clip beneath was attracted and lifted against the paper.
The boys kept their hands where he directed. Nobody put a clip near a mouth, device, or pocket.
Yanky compared the plain sheet with the marked one.
The ink had helped him notice the place. It had not made the pull happen.
Chapter 5What to Tell the Class
Rebbi asked the boys to describe what they had checked.
Yanky began with his first claim, then corrected it.
"I thought the ink was being pulled because the bump was under the dot. Without the clip, the mark didn't move. With the clip under plain paper, the bump still appeared."
Meir held up the two sheets while Rebbi retained the metal pieces and magnet.
Their classmates could see that one paper was marked and the other was not.
The explanation now matched both checks.
Chapter 6The Dot Stays Behind
At cleanup, Rebbi collected and counted the clips before putting the materials away.
Yanky kept only the approved paper sheets for his notebook.
He drew the hidden clip in a small diagram beneath the first dot and labeled it.
Meir pointed to the original marked sheet.
"That dot looked important."
"It was important to where I looked," Yanky said. "Not to what pulled."
He left space beside the diagram for the plain-sheet check. One picture would not tell the whole demonstration anymore.
