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  • After many adventures in Wonderland,

  • Alice has once again found herself in the court

  • of the temperamental Queen of Hearts.

  • She's about to pass through the garden undetected,

  • when she overhears the king and queen arguing.

  • It's quite simple,” says the queen. “64 is the same as 65, and that's that.”

  • Without thinking, Alice interjects. “Nonsense,” she says.

  • If 64 were the same as 65, then it would be 65 and not 64 at all.”

  • What? How dare you!” the queen huffs.

  • “I'll prove it right now, and then it's off with your head!”

  • Before she can protest,

  • Alice is dragged toward a field with two chessboard patterns

  • an 8 by 8 square and a 5 by 13 rectangle.

  • As the queen claps her hands, four odd-looking soldiers approach

  • and lie down next to each other, covering the first chessboard.

  • Alice sees that two of them are trapezoids with non-diagonal sides measuring 5x5x3,

  • while the other two are long triangles with non-diagonal sides measuring 8x3.

  • See, this is 64.”

  • The queen claps her hands again.

  • The card soldiers get up, rearrange themselves,

  • and lie down atop the second chessboard.

  • And that is 65."

  • Alice gasps. She's certain the soldiers didn't change size or shape

  • moving from one board to the other.

  • But it's a mathematical certainty that the queen must be cheating somehow.

  • Can Alice wrap her head around what's wrongbefore she loses it?

  • Pause the video to figure it out yourself. Answer in 3.

  • Answer in 2

  • Answer in 1

  • Just as things aren't looking too good for Alice, she remembers her geometry,

  • and looks again at the trapezoid and triangle soldier

  • lying next to each other.

  • They look like they cover exactly half of the rectangle,

  • their edges forming one long line running from corner to corner.

  • If that's true, then the slopes of their diagonal sides

  • should be the same.

  • But when she calculates these slopes

  • using the tried and true formula "rise over run,"

  • a most curious thing happens.

  • The trapezoid soldier's diagonal side goes up 2 and over 5,

  • giving it a slope of two fifths, or 0.4.

  • The triangle soldier's diagonal, however, goes up 3 and over 8,

  • making its slope three eights, or 0.375.

  • They're not the same at all!

  • Before the queen's guards can stop her,

  • Alice drinks a bit of her shrinking potion to go in for a closer look.

  • Sure enough, there's a miniscule gap between the triangles and trapezoids,

  • forming a parallelogram that stretches the entire length of the board

  • and accounts for the missing square.

  • There's something even more curious about these numbers:

  • they're all part of the Fibonacci series,

  • where each number is the sum of the two preceding ones.

  • Fibonacci numbers have two properties that factor in here:

  • first, squaring a Fibonacci number gives you a value

  • that's one more or one less

  • than the product of the Fibonacci numbers on either side of it.

  • In other words, 8 squared is one less than 5 times 13,

  • while 5 squared is one more than 3 times 8.

  • And second, the ratio between successive Fibonacci numbers is quite similar.

  • So similar, in fact, that it eventually converges on the golden ratio.

  • That's what allows devious royals to construct slopes

  • that look deceptively similar.

  • In fact, the Queen of Hearts could cobble together an analogous conundrum

  • out of any four consecutive Fibonacci numbers.

  • The higher they go, the more it seems like the impossible is true.

  • But in the words of Lewis Carrollauthor of Alice in Wonderland

  • and an accomplished mathematician who studied this very puzzle

  • one can't believe impossible things.

After many adventures in Wonderland,

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