Wednesday

Raven stacks sheets of paper on the kitchen table, one at a time, over a single paper clip.

"One sheet, two sheets, three," she counts, lowering the magnet onto each stack. The clip jumps every time.

At six sheets, the clip wiggles but stays down. At seven, nothing. Rocket writes a six in the Field Log.

"The paper is not blocking it," he says. "The paper just makes the gap bigger."

"What do you notice about the pull as the gap grows?" Raven asks.

"It fades," Rocket says. "Close is strong, far is weak."

Nova hovers over the stack. "Now test that with two magnets, and then with tape," she says. "One change at a time."

Today you run three short tests. First, how many sheets of paper can your magnet pull a clip through?

Second, how close do two fridge magnets need to be before they snap together or push apart?

Third, how close must a charged tape strip get before a paper scrap jumps? Change one thing at a time.

The paper did not block the magnet. Paper is not iron, so the magnet ignores it. The sheets only made the gap bigger.

Electric and magnetic forces can be attractive or repulsive. Their size depends on the strength of the charges or magnets and on the distance between them.

That is why your clip stopped lifting at some number of sheets. The scrap jumped only when the tape came close.

If your two magnets pulled from one side and pushed after a flip, you saw like poles repel and unlike poles attract.

A physics text suggests the same test at home: will two refrigerator magnets still stick if you turn one over?

Careful measuring. Tomorrow you read two reference tables and meet the idea that explains forces across a gap.