duality

• 表示事物具有双重性或由两个对立部分组成的状态或性质。在物理学中指物质的波粒二象性；在几何学中（射影几何）指点与平面的互换对应关系。

A noun referring to the state or quality of being twofold, often involving a classification into two opposed parts or subclasses; in physics, it describes the wave-particle nature of matter and electromagnetic radiation; in geometry, it denotes the interchangeability of points and planes in projective geometry.

1. Twofold natureB2formal

   The state or quality of being made up of two distinct, often opposing, parts or subclasses.

   二元性

   • The duality of good and evil is a common theme in literature.
   • There is a fundamental duality in her character between ambition and compassion.
   • The concept explores the duality of mind and body.

   同义词dichotomydualismpolarity

2. Wave-particle dualityC1formalscientific

   A principle in quantum physics stating that matter and electromagnetic radiation exhibit both wave-like and particle-like properties depending on the experimental context.

   波粒二象性

   • Wave-particle duality is a cornerstone of quantum mechanics.
   • The experiment demonstrated the duality of light as both a wave and a particle.
   • Understanding duality is essential for studying subatomic particles.

   同义词complementarity

3. Geometric dualityC2formalscientific

   In projective geometry, the principle that points and planes can be interchanged in theorems, preserving their truth.

   几何对偶

   • The duality principle allows a theorem about points to be transformed into one about planes.
   • Geometric duality simplifies many complex proofs in projective geometry.
   • Students often find the concept of duality challenging at first.

   同义词reciprocity