The “Big Ideas”
Quantum physics and relativity brought a set of “big ideas” to the description of nature. To say that these ideas violate common sense is to say that they are inconsistent with what seems natural based on ordinary experience.
Here are a dozen big ideas that animate the presentation in this book.
- Quantization
- Nature is granular, or lumpy, both in the bits of matter than make up the world and also in changes that occur.
- Probability
- Probability rules events in the small-scale world.
- Speed limit
- The speed of light sets a speed limit in nature.
- E = mc2
- Mass and energy are united into a single concept, so that mass can be changed to energy and energy to mass.
- Wave-particle duality
- Matter can exhibit both wave and particle properties.
- Uncertainty principle
- There is a fundamental limit in nature in the precision to which certain measurements can be made.
- Annihilation and creation
- All interactions involve annihilation and creation of particles.
- Spin
- Even “point particles” (those with no apparent physical extension) can spin, and spin is a quantized property.
- Exclusion principle
- Particles called fermions obey an exclusion principle: No two identical ones can occupy the same state of motion at the same time.
- Bose-Einstein condensation
- Particles called bosons can cluster (and even “like” to cluster) in the same state of motion.
- Conservation
- Certain quantities remain constant during all processes of change. Other quantities (“partially conserved quantities”) remain constant during particular kinds of change.
- Superposition
- A particle or system of particles can exist in two or more states of motion at the same time.