Chapter 1: The Challenge of the Riddle

In these times of the Coronavirus pandemic, I feel grateful to be working from home, with my family safe and sound. While schools and businesses remain closed, I find the perfect opportunity to reflect on the intriguing Pi Day riddle.

Many may recall this classic puzzle from their middle school math lessons:

A man travels one mile South, then one mile East, and finally one mile North, returning to his original starting point. Where is he?

This riddle gained renewed fame as the one Elon Musk often presents during job interviews to evaluate candidates' analytical skills.

As a child, I learned that there was only one location on Earth where this scenario could occur: the North Pole. (This assumes the North Pole is frozen over, as it typically is, though future learners might envision the man in a boat.)

However, there's another solution worth considering: Picture the man starting just over a mile North of the South Pole—precisely at (1 + 1/(2π)) miles.

He first walks one mile South, placing him at 1/(2π) miles North of the South Pole. Then, as he moves one mile East, he traces a circular path around the South Pole, where the circumference equals one mile (C = 2πr, r = 1/(2π), C = 1). Finally, walking one mile North leads him back to his initial position.

This means there are infinitely many starting points along that circle, all positioned 1/(2π) miles North of the South Pole.

Next, could there be other potential answers? Consider starting at (1 + 1/(4π)) miles.

After walking a mile South, he would be at 1/(4π) miles North of the South Pole. In this case, when he walks a mile East, he encircles the South Pole twice, since the circumference of this circle is 1/2 mile (C = 2πr, r = 1/(4π), C = 1/2). Once again, walking a mile North brings him back to where he began. Thus, we discover another infinite set of points around that circle, situated 1/(4π) miles North of the South Pole.

This pattern continues, with the man starting from points that allow him to circle the South Pole three times, four times, and so on. Therefore, he can start at (1 + 1/(N*2π)) miles North of the South Pole, where N represents any positive integer.

In essence, there exists an infinite number of starting points along infinitely many concentric circles around the South Pole, as long as the distance from the South Pole adheres to this formula.

As N approaches infinity, the starting point nears one mile North, and the radius (and thus the circumference) of the circle becomes negligible. The man walks South a mile, then meanders in increasingly smaller circles just inches from the South Pole, before heading North again. While this may seem impractical and somewhat whimsical, it remains theoretically valid!

Are there any other intriguing answers to this riddle? I invite you to share additional Pi Day riddles, thoughts, or reflections. Wishing you all a wonderful Pi Day!

Chapter 2: Engaging with the Riddle

Explore the fascinating Pi Day Puzzle, where viewers are challenged to solve for each letter while delving into the mathematics behind the riddle.

Witness the incredible hand calculation that took place during Pi Day 2024, showcasing the power of mathematics and its real-world applications.