A Round Disk Through a Smaller Square Hole (Bending Spacetime)

Summary by Krater

The video demonstrates how folding a 2D square sheet of paper into a 3D structure allows a larger round disc to fit through a smaller square hole, and explains this phenomenon through the concepts of intrinsic and extrinsic curvature and geodesics.

From the video

Answers: How does a CD fit through a smaller square paper hole when folded?

• Kirigami paper folding mechanics
• Intrinsic and extrinsic curvature
• Geodesics in spacetime
• Gravity visualization with stretched fabric

What it concludes

• Transferring a 2D square into a 3D structure allows a larger disc to fit through a smaller square hole by moving the excess paper into a higher spatial dimension.
• Intrinsic curvature affects the geometry of a surface and can alter geometric measurements like the sum of angles in a triangle.
• Spacetime undergoes intrinsic curvature rather than bending into a higher spatial dimension, and this bent geodesic path explains phenomena like gravitational lensing.