phi

n. the 21st letter of the Greek alphabet.

n. the twenty-first letter of the Greek alphabet, represented as Φ or φ.

“The professor used the symbol phi to represent a specific angle in the diagram.”

“In classical Greek studies, the letter phi is often transliterated as 'ph' to distinguish it from the simpler 'p' sound.”

n. a special number in math (about 1.618) that people often find beautiful in art and nature.

n. an irrational mathematical constant, approximately 1.618, representing the golden ratio.

“Architects sometimes use phi to create buildings that look perfectly balanced.”

“The Fibonacci sequence is closely related to phi, as the ratio between successive numbers approaches this value as the sequence progresses.”

Technical

n. a trick for your eyes where flashing lights look like they are moving.

n. the optical illusion of perceiving continuous motion between separate objects viewed rapidly in succession.

“The phi phenomenon is why a series of flashing neon lights looks like a moving arrow.”

“Psychologists study the phi phenomenon to understand how the human brain synthesizes discrete visual inputs into a coherent sense of movement.”

Technical