When you hold a stretched Slinky vertically and let go of the top, why does the bottom of the Slinky stay hanging motionless in mid-air until the collapsing coils reach it?
Physics
Post a problemIs it really impossible to fold a piece of paper in half more than about 7 or 8 times, and what determines the true limit?
Why does thunder from a single lightning stroke sound like an extended rumble rather than one sharp bang?
What causes the brief green (sometimes blue) flash sometimes seen at the upper edge of the sun just as it sets or rises over a clear horizon?
For a coin or plate spinning and wobbling flat on a table, why is the wobble (precession) frequency exactly twice the spin frequency in the small-angle limit?
What determines the propagation speed of a wave of toppling dominoes, and why does it approach a roughly constant value regardless of how hard the first domino was pushed?
Why do bubbles in champagne form in orderly rising chains from specific spots on the glass, and what determines the bubbling rate?
Why do snow crystals always grow with six-fold symmetry, and why is no two snowflakes exactly alike?
Why does a cold squash ball barely bounce, while the same ball bounces energetically once warmed up by play?
Given a single strand of curly hair's intrinsic curvature, what determines the diameter of the curls it forms under its own weight?
Why does a drying layer of mud or paint crack into a network of roughly polygonal (often near-hexagonal) plates?
Why is the popular 'teardrop' cartoon shape of a falling raindrop physically wrong, and what shape do real raindrops actually take?
Can a singer's voice alone, without amplification, really shatter a wine glass purely by resonance, as claimed in a famous old commercial?
Why does everyone naturally switch from walking to running at close to the same critical speed relative to their leg length?
Why do wet mammals from mice to bears shake themselves dry at a frequency that scales in a simple, predictable way with their body size?
Why does holding a seashell to your ear seem to produce a 'roaring ocean' sound, even far from the sea?
How does a pop-pop boat, which only pulses water in and out of a rear nozzle with no net average flow, manage to move forward continuously?
Why does a thin, fast vertical jet of water shoot upward after the air cavity created by a falling ball or drop collapses beneath the surface?
Why, when a container of mixed different-sized granular particles (like nuts or cereal) is shaken, do the largest particles reliably rise to the top rather than settling based on density?
What is the physical mechanism that produces ball lightning — the luminous, floating, sometimes room-sized spheres of light occasionally reported during thunderstorms — and can it be reliably reproduced in the lab?