How Hard Can You Hit a Golf Ball? (at 100,000 FPS) - Smarter Every Day 216

Episode Overview

• The episode explores the physical limits of a golf ball by asking the question: "How hard can you hit a golf ball?"
• It features a collaboration between Destin from Smarter Every Day and engineer Mark Rober to design and build devices capable of achieving supersonic speeds.
• Experiments are conducted using a rocket-powered golf club and a high-powered vacuum cannon to test the impact forces on both golf balls and golf clubs.
• High-speed cameras are used to capture the deformation, rebound, and catastrophic failure of golf equipment in extreme slow motion, revealing the underlying physics.

Key Concepts

• Elastic vs. Plastic Deformation: The core scientific concept explaining how materials behave under force. Elastic deformation is temporary (the object returns to its original shape), while plastic deformation is permanent. The experiments push golf balls and clubs past their elastic limit into plastic deformation and ultimately to failure.
• Vacuum Cannon Physics: The principle of using a pressure differential to accelerate a projectile. By creating a vacuum in a barrel and then suddenly introducing high-pressure air, the cannon can launch a golf ball at speeds over 500 mph, far exceeding what is possible with a human swing.
• Material Science & Failure Analysis: The video analyzes how different types of golf balls (modern solid-core vs. old rubber-band-wound) react to extreme impacts. It demonstrates how the internal structure dictates how the ball stores and releases energy, and how it ultimately fails.
• High-Speed Videography: The use of Phantom high-speed cameras (at up to 110,000 frames per second) is crucial for visualizing and analyzing the incredibly fast collisions, allowing the hosts to observe phenomena like shockwaves, material failure propagation, and energy transfer that are invisible to the naked eye.
• Engineering Iteration: The process of testing, failing, and improving designs is shown throughout the episode. From failed golf swings to the successful rocket club and the even more powerful vacuum cannon, the collaboration demonstrates an iterative approach to solving a complex engineering challenge.

Quotes

• At 02:40 - "that thing is past those trees!" - Mark Rober's exclamation of shock after the rocket-powered golf club successfully launches the golf ball an incredible distance, demonstrating the immense power of their creation.
• At 06:36 - "Are you kidding me?" - Mark Rober's reaction of disbelief upon seeing the slow-motion footage of a golf ball significantly deforming against a solid anvil without breaking.
• At 10:10 - "It's like a little mouth. It's like 'rawr'." - Mark Rober describing the appearance of the slit in the golf ball as it deforms against the anvil in slow motion, just before it ruptures.

Takeaways

• To study extreme physical limits, sometimes you must reverse the experiment. Instead of trying to swing a club at extreme speeds, they achieved higher and more controlled impact velocities by firing the golf ball from a cannon at a stationary target.
• Modern materials are engineered for specific performance within an expected range. A modern golf ball is designed to be highly elastic to maximize energy return, but an old, wound golf ball explodes spectacularly because its internal rubber bands store energy differently and fail catastrophically when pushed beyond their limits.
• The transfer of momentum in high-speed collisions can produce counter-intuitive and destructive results. Firing a lightweight golf ball at 500 mph was sufficient to completely shatter a metal driver head, demonstrating that extreme velocity can overcome a significant difference in mass.