What If?: Serious Scientific Answers to Absurd Hypothetical Questions: Summary & Key Insights

The most iconic question I’ve ever received was about baseball—beloved, understandable, and familiar to almost anyone. The twist was cosmic: what would happen if you pitched a baseball at nine-tenths the speed of light? The short answer is simple—it would destroy everything. The long answer shows just how astonishingly violent physics can be when pushed outside everyday limits.

At those speeds, even a small baseball’s mass-energy equivalence becomes staggering. The air molecules in its path wouldn’t have time to move away; they’d immediately fuse into an expanding plasma of superheated particles, forming a miniature nuclear explosion. The batter, the stadium, and a chunk of the surrounding city would vaporize within microseconds. The physics here rests on Einstein’s relativity: as the baseball’s velocity approaches light speed, its kinetic energy skyrockets exponentially. The energy released from such a pitch would rival a large atomic bomb.

Of course, no human-made object could ever accelerate or survive at that speed. The point of this problem isn’t the violence—it’s perspective. Relativity’s equations show us how matter, motion, and energy interrelate on a level that words can hardly capture. Thinking through the absurd teaches us humility. The everyday kinetic energy in a moving car suddenly becomes something awe-inspiring when we contextualize it within the grand puzzle of physical law.

Imagine a swimming pool containing every element from the periodic table, neatly arranged by density. It’s the ultimate chemistry demonstration—also a perfect disaster. Hydrogen and helium would evaporate instantly, sodium would explode in water, and chlorine gas would suffocate everything nearby. This thought experiment, like many in the book, reveals scientific reality’s capacity for both beauty and chaos.

Each element’s behavior tells a story about chemical reactivity and atomic structure. What might look like a stable pool would, in truth, be a cauldron of violent reactions—fire, radiation, and corrosion in every direction. Within seconds, the pool would essentially become a superheated toxic blend, generating clouds of noxious gas.

This scenario helps us glimpse chemistry not as static but as dynamic—matter constantly struggling toward equilibrium. The exercise also mirrors human curiosity: when we try to mix incompatible things (hydrogen and oxygen, for instance), we unleash nature’s pent-up energy. The rules are strict but elegant, and they reward precise thinking with magnificent explosions.